JP2008151510A - Intrusion detection system - Google Patents

Abstract

An intrusion detection system having a high intrusion detection capability is provided.
An intrusion detection system includes a transmitter and a receiver. The transmitter 10 and the receiver 20 are installed in the room 30. The transmitter 10 transmits radio waves having directivity by the array antenna 11. The receiver 20 receives the radio wave transmitted from the transmitter 10 via the antenna 21, and when the received signal strength of the received radio wave is more than a certain value from the reference value, the intruder enters the room 30. Detect.
[Selection] Figure 1

Description

  The present invention relates to an intrusion detection system that detects an intruder entering a room.

  Conventionally, as an intruder detection device, for example, there is one described in Patent Document 1. The intruder detection apparatus described in Patent Document 1 includes a transmission unit, a reception unit, a phase detection unit, and an intrusion detection unit.

  The transmission means transmits radio waves, and the reception means receives the radio waves transmitted by the transmission means and generates a reception signal. Then, the phase detection means detects the phase of the received signal, and the intruder detection means determines whether or not the amount of change per unit time of the phase of the received signal detected by the phase detection means is within a preset range. The intruder in the detection space is detected by determining whether or not. More specifically, the intruder detection unit detects that the intruder has entered the detection space when the amount of change per unit time of the phase exceeds a preset range. The preset range is obtained from the average value and the variance with respect to the change amount of the phase per unit time when there is no intrusion. For example, about three times the standard deviation is set as the threshold value.

As described above, the intruder detection apparatus described in Patent Document 1 detects the intrusion of an intruder into the detection space using radio waves.
JP 2004-286567 A

  However, since the conventional intruder detection device detects an intruder by transmitting a non-directional radio wave, there is a problem that the intruder detection capability is low.

  Therefore, the present invention has been made to solve such a problem, and an object thereof is to provide an intrusion detection system having a high intrusion detection capability.

  According to the present invention, the intrusion detection system is an intrusion detection system that detects an intruder entering a room, and includes a transmitter and a receiver. The transmitter transmits radio waves having directivity. The receiver receives the radio wave transmitted from the transmitter, and detects the intrusion of the intruder into the room based on the received radio wave intensity of the received radio wave.

  According to the present invention, the intrusion detection system is an intrusion detection system that detects an intruder entering the room, and includes a transmitter and a receiver. The transmitter transmits radio waves having directivity. The receiver receives the radio wave transmitted from the transmitter, and detects the intrusion of the intruder into the room based on the received radio wave pattern.

  Preferably, the receiver detects the intrusion of the intruder into the room when the received radio wave intensity is a predetermined value or more away from the reference value. The reference value is an average value of the received radio wave intensity when no intruder has entered the room.

  Preferably, the transmitter transmits radio waves by switching the directivity to one directivity selected from a plurality of directivities for each arbitrary number of transmissions.

  Preferably, the receiver includes a plurality of receivers arranged at different positions in the room. Each of the plurality of receivers receives a radio wave transmitted from the transmitter via a directional antenna.

  Preferably, the receiver further detects the intrusion position of the intruder based on the received signal strength.

  Preferably, the transmitter transmits a plurality of radio waves at a plurality of different frequencies. The receiver detects an intrusion position of an intruder based on a plurality of received signal strengths of a plurality of radio waves transmitted at a plurality of frequencies.

  Preferably, the transmitter transmits radio waves in a plurality of different directions. The receiver detects an intrusion position of an intruder based on a plurality of received signal strengths of a plurality of radio waves transmitted in a plurality of directions.

  In the intrusion detection system according to the present invention, the transmitter transmits radio waves having directivity, and the receiver detects intrusion of the intruder into the room based on the received signal strength of the radio waves having directivity. The fluctuation range of the received signal strength of the radio wave having directivity is smaller than the fluctuation range of the received signal strength of the radio wave transmitted non-directionally.

  Therefore, according to the present invention, the ability to detect intruders can be improved.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic diagram showing the configuration of an intrusion detection system according to Embodiment 1 of the present invention. An intrusion detection system 100 according to Embodiment 1 of the present invention includes a transmitter 10 and a receiver 20.

  The transmitter 10 and the receiver 20 are disposed inside the room 30. The transmitter 10 has an array antenna 11. The transmitter 10 transmits and receives directional radio waves via the array antenna 11. The receiver 20 includes an antenna 21, and transmits and receives radio waves transmitted from the transmitter 10 via the antenna 21. Then, the receiver 20 detects the received radio wave intensity of the received radio wave, and detects the entry of the intruder into the room 30 by a method described later based on the detected received radio wave intensity.

  The room 30 includes a glass window 31 and a door 32. The room 30 has a size that is 4.7 m in length and 6.8 m in width. In the room 30, a desk 40, a houseplant 50, electronic white plates 60 and 70, and a television 80 are installed.

  FIG. 2 is a schematic diagram showing the configuration of the transmitter 10 shown in FIG. In addition to the array antenna 11, the transmitter 10 includes directivity switching means 12, intensity detection means 13, detection means 14, and communication means 15. Array antenna 11 includes antenna elements 111 to 117 and varactor diodes 121 to 126. The antenna elements 111 to 117 are arranged on the xy plane (predetermined plane) along the z axis in the xyz orthogonal coordinates composed of the x axis, the y axis, and the z axis.

  FIG. 3 is a plan layout view of the antenna elements 111 to 117 in the xy plane shown in FIG. The antenna elements 111 to 116 are arranged in a regular hexagon with the antenna element 117 as the center. The distance between each of the antenna elements 111 to 116 and the antenna element 117 is about λ / 4 (λ: the wavelength of radio waves transmitted and received by the array antenna 11), and the arrangement interval of the antenna elements 111 to 116 is also about λ / 4.

  Referring to FIG. 2 again, antenna elements 111 to 116 are parasitic elements, and antenna element 117 is a feed element. Varactor diodes 121 to 126 are connected between antenna elements 111 to 116 and ground node GND, respectively. Thus, the varactor diodes 121 to 126 that are variable capacitance elements are loaded on the antenna elements 111 to 116 that are parasitic elements, respectively.

  As described above, the array antenna 11 has seven antenna elements including one feeding element (antenna element 117) and six parasitic elements (antenna elements 111 to 116). It consists of a structure arranged in a square.

  The directivity switching means 12 supplies control voltage sets CVL0 to CVL6 to the varactor diodes 121 to 126, and switches the beam radiated from the array antenna 11. The varactor diodes 121 to 126 have different capacities (reactance values) depending on the control voltage sets CVL0 to CVL6.

  Each of the control voltage sets CV0 to CV6 includes six voltages V1 to V6 corresponding to the six varactor diodes 121 to 126. Accordingly, the six voltages V1 to V6 are supplied to the varactor diodes 121 to 126, respectively.

  Each of the six voltages V1 to V6 is composed of, for example, a DC voltage of −20V or 0V. Each of the varactor diodes 121 to 126 has a maximum reactance value ("hi") when receiving a -20V DC voltage, and has a minimum ("lo") reactance value when receiving 0V DC voltage.

  Each antenna element 111-116 functions as a director if the reactance value of the loaded varactor diode is maximized, and functions as a reflector if the reactance value of the loaded varactor diode is minimized.

  Therefore, each antenna element 111-116 functions as a director when a -20V DC voltage is applied to the loaded varactor diode, and when a 0V DC voltage is applied to the loaded varactor diode, Functions as a reflector.

  Therefore, the directivity switching means 12 determines the voltage patterns of the voltages V1 to V6 constituting each of the control voltage sets CV0 to CV6, and sets the control voltage sets CV0 to CV6 including the determined voltage patterns to the varactor diodes 121 to 126. To supply sequentially.

More specifically, directivity switching means 12, the reactance set _{x m} consisting of reactance _x m1 _{~x m6} in the varactor diode 121 to 126 determines the voltage V1~V6 such changes as shown in Table 1 The control voltage sets CVL0 to CVL6 are generated, and the generated control voltage sets CVL0 to CVL6 are supplied to the varactor diodes 121 to 126.

When all of the reactance values x _{m1 to} x _m6 are “hi” (m = 0), the array antenna 11 emits a beam BM0 composed of an omni pattern (omnidirectional beam pattern) having sensitivity in all directions. . When the reactance value x _m1 is “hi” and the reactance values x _{m2 to} x _m6 are “lo” (m = 1), the array antenna 11 has directivity having directivity in the direction DIR1 of 0 degrees. Beam BM1 is emitted. Note that the direction from the antenna element 117 to the antenna element 111 is a 0 degree direction (see FIG. 3).

Further, when the reactance value x _m2 is “hi” and the reactance values x _m1 , x _{m3 to} x _m6 are “lo” (m = 2), the array antenna 11 has directivity in the direction DIR2 of 60 degrees. A directional beam BM2 is emitted.

Further, when the reactance value x _m3 is “hi” and the reactance values x _m1 , x _m2 , and x _{m4 to} x _m6 are “lo” (m = 3), the array antenna 11 is in the direction DIR3 of 120 degrees. A directional beam BM3 having directivity is emitted.

Further, when the reactance value x _m4 is “hi” and the reactance values x _{m1 to} x _m3 , x _m5 , and x _m6 are “lo” (m = 4), the array antenna 11 is in the direction DIR4 of 180 degrees. A directional beam BM4 having directivity is emitted.

Further, when the reactance value x _m5 is “hi” and the reactance values x _{m1 to} x _m4 and x _m6 are “lo” (m = 5), the array antenna 11 has directivity in the direction DIR5 of 240 degrees. A directional beam BM5 is emitted.

Further, when the reactance value x _m6 is “hi” and the reactance values x _{m1 to} x _m5 are “lo” (m = 6), the array antenna 11 has directivity having directivity in the direction DIR6 of 300 degrees. The beam BM6 is emitted (see FIG. 3).

As described above, the directivity switching unit 12 changes the reactance values x _{m1 to} x _m6 of the varactor diodes 121 to 126 mounted on the antenna elements 111 to 116 which are parasitic elements, and directs the radiation from the array antenna 11. Switch the sex beam.

  Then, the directivity switching unit 12 switches the directional beam radiated from the array antenna 11 to the directional beams BM1 to BM6 by the method described above according to the switching signal EXD from the detection unit 14.

  The directivity switching means 12 sets the directional beam of the array antenna 11 to a predetermined directional beam in response to the setting signal BSET from the detection means 14.

  The intensity detecting means 13 is connected to the antenna element 117 (feeding element) of the array antenna 11 by a coaxial cable. The intensity detector 13 receives the radio wave received by the array antenna 11 from the antenna element 117, detects the received radio wave intensity RSSI of the received radio wave, and outputs it to the detector 14.

  Further, when the received signal strength RSSI is detected, the strength detecting unit 13 generates a transmission request signal RT for requesting radio wave transmission and outputs the transmission request signal RT to the communication unit 15.

  Based on the received radio wave intensity RSSI received from the intensity detection means 13, the detection means 14 detects the intrusion of the intruder into the room 30 by a method described later. The detection means 14 generates a setting signal BSET for setting the directional beam of the array antenna 11 to a predetermined directional beam or a switching signal EXD for switching the directional beam of the array antenna 11 to generate directivity. Output to the switching means 12. Further, the detection means 14 generates a transmission request signal RT and outputs it to the communication means 15.

  The communication means 15 receives the radio wave RF from the antenna element 117 (= feeding element) of the array antenna 11. Further, the communication unit 15 supplies electric power to the antenna element 117 (= feeding element) and transmits the radio wave RF in accordance with the transmission request signal RT from the intensity detection unit 13 or the detection unit 14.

  The array antenna 11 is arranged such that the direction from the transmitter 10 to the receiver 20 is 0 degree.

  FIG. 4 is a schematic diagram showing the configuration of the receiver 20 shown in FIG. The receiver 20 includes an antenna 21, intensity detection means 22, detection means 23, and communication means 24. The antenna 21 is an omnidirectional antenna. The antenna 21 receives the radio wave RF from the transmitter 10 and outputs the received radio wave RF to the intensity detection unit 22 and the communication unit 24. The antenna 21 transmits the radio wave RF from the communication unit 24.

  The intensity detector 22 receives the radio wave RF from the antenna 21 and detects the received signal intensity RSSI based on the received radio wave RF. Then, the intensity detecting means 22 outputs the detected received signal intensity RSSI to the detecting means 23. In addition, when the received signal strength RSSI is detected, the strength detecting unit 22 generates a transmission request signal RT and outputs it to the communication unit 24.

  The detecting unit 23 receives the received signal strength RSSI from the strength detecting unit 22 and detects the intrusion of the intruder into the room 30 by a method described later based on the received received signal presence RSSI.

  The communication means 24 receives the radio wave RF from the antenna 21. Further, when the communication means 24 receives the transmission request signal RT from the intensity detection means 22, the power is supplied to the antenna 21 to transmit the radio wave RF.

  A method in which the detection means 14 of the transmitter 10 and the detection means 23 of the receiver 20 detect intrusion of the intruder into the room 30 will be described. The detection means 14 and 23 calculate the average value of the received signal strength RSSI when the intruder does not enter the room 30, and holds the calculated average value as the reference value RSSI_std. Then, the detection means 14 and 23 compare the received signal strength RSSI received from the strength detection means 13 and 22 with the reference value RSSI_std, respectively, and when the received signal strength RSSI changes from the reference value RSSI_std by a certain value or more, the intruder Is detected to have entered the room 30. On the other hand, when the change from the reference value RSSI_std of the received signal strength RSSI is smaller than a certain value, the detection means 13 and 23 detect that the intruder has not entered the room 30.

  In the intrusion detection system 100, intrusion detection in the transmitter 10 and the receiver 20 when the array antenna 11 transmits and receives radio waves RF with non-directionality will be described.

  In this case, the detection means 14 of the transmitter 10 generates a setting signal BSET for setting the directivity of the array antenna 11 to omnidirectional and outputs it to the directivity switching means 12, and also generates a transmission request signal RT. And output to the communication means 15.

The directivity switching means 12 generates a control voltage set CVL0 (control voltage set for setting x _{m1 to} x _m6 = hi) in response to the setting signal BSET from the detection means 14 to generate varactor diodes 121 to 121 To 126. The varactor diodes 121 to 126 set the directivity of the array antenna 11 to be omnidirectional according to the control voltage set CVL0 from the directivity switching means 12.

  Further, the communication means 15 transmits the radio wave RF constituting the packet by supplying power to the antenna element 117 of the array antenna 11 in response to the transmission request signal RT from the detection means 14.

  As a result, the array antenna 11 transmits the radio wave RF received from the communication means 15 in a non-directional manner.

  The antenna 21 of the receiver 20 receives the radio wave RF transmitted from the transmitter 10 and outputs the received radio wave RF to the intensity detection means 22. The strength detection means 22 detects the received signal strength RSSI_RX of the radio wave RF received from the antenna 21, outputs the detected received signal strength RSSI_RX to the detection means 23, generates a transmission request signal RT, and sends it to the communication means 24. Output.

  The detector 23 receives the received signal strength RSSI_RX from the strength detector 22 and compares the received signal strength RSSI_RX with the reference value RSSI_std. Then, when the received signal strength RSSI_RX changes from the reference value RSSI_std by a certain value or more, the detection means 23 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_RX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  On the other hand, when the communication means 24 receives the transmission request signal RT from the intensity detection means 22, the communication means 24 feeds power to the antenna 21 and transmits the radio wave RF constituting the packet.

  The array antenna 11 of the transmitter 10 receives the radio wave RF transmitted from the receiver 20 in a non-directional manner, and outputs the received radio wave RF from the antenna element 117 to the intensity detecting means 13.

  When receiving the radio wave RF from the antenna element 117 of the array antenna 11, the intensity detecting unit 13 detects the received signal strength RSSI_TX of the received radio wave RF and outputs the detected received signal strength RSSI_TX to the detecting unit 14. In addition, when detecting the received signal strength RSSI_TX, the strength detecting unit 13 generates a transmission request signal RT and outputs it to the communication unit 15.

  The detecting unit 14 receives the received signal strength RSSI_TX from the strength detecting unit 13 and compares the received received signal strength RSSI_TX with the reference value RSSI_std. Then, when the received signal strength RSSI_TX is changed from the reference value RSSI_std by a certain value or more, the detecting unit 14 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_TX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  On the other hand, in response to the transmission request signal RT from the intensity detection means 13, the communication means 15 feeds the antenna element 117 of the array antenna 11 and transmits the radio wave RF constituting the packet.

  The transmitter 10 and the receiver 20 repeat the above-described operation to detect that an intruder has entered the room 30.

  FIG. 5 is a diagram illustrating an experiment result of intrusion detection when the array antenna 11 transmits and receives radio waves RF with no directivity.

  5A shows the relationship between the received signal strength at the transmitter 10 and the number of packet transmission / reception, and FIG. 5B shows the relationship between the received signal strength at the receiver 20 and the number of packet transmission / reception. Show.

  In FIGS. 5A and 5B, the vertical axis represents the received signal strength, and the horizontal axis represents the number of packet transmission / reception.

  In FIG. 5A, regions REG1 and REG3 represent a state in which an intruder has entered the room 30, and region REG2 represents a state in which the intruder has not entered the room 30. In FIG. 5B, regions REG4 and REG6 represent a state in which an intruder has entered the room 30, and region REG5 represents a state in which the intruder has not entered the room 30.

  Therefore, the detection means 14 of the transmitter 10 detects that the intruder has entered the room 30 by comparing the received signal strength RSSI_TX received from the strength detection means 13 with the reference value RSSI_std in the regions REG1 and REG3. In the region REG2, the received signal strength RSSI_TX received from the strength detecting means 13 is compared with the reference value RSSI_std to detect that no intruder has entered the room 30.

  Further, the detection means 23 of the receiver 20 detects that the intruder has entered the room 30 by comparing the received signal strength RSSI_RX received from the strength detection means 22 with the reference value RSSI_std in the regions REG4 and REG6. In the region REG5, the received signal strength RSSI_RX received from the strength detecting means 22 is compared with the reference value RSSI_std to detect that no intruder has entered the room 30.

  In the transmitter 10, the reference value RSSI_std is calculated based on the received signal strength RSSI_TX in the region REG2, and the received signal strength RSSI_TX in the regions REG1 and REG3 is significantly different from the received signal strength RSSI_TX in the region REG2. The detection means 14 can accurately detect that an intruder has entered the room 30 by the method described above.

  In the receiver 20, the reference value RSSI_std is calculated based on the received signal strength RSSI_RX in the region REG5, and the received signal strength RSSI_RX in the regions REG4 and REG6 is significantly different from the received signal strength RSSI_RX in the region REG5. The 20 detection means 23 can accurately detect that an intruder has entered the room 30 by the method described above.

  As shown in FIG. 5, when the array antenna 11 transmits and receives radio waves RF in a non-directional manner, the received signal strength RSSI_TX in the region REG2 and the received signal strength RSSI_RX in the region REG5 vary with a width of about 3 to 5 dB.

  In the intrusion detection system 100, the transmitter 10 sets the directivity of the array antenna 11 in various patterns and transmits / receives a packet to / from the receiver 20. Intrusion is detected. Hereinafter, the various patterns will be described.

(Pattern 1)
In the pattern 1, the transmitter 10 sets the directivity of the array antenna 11 to one directivity and transmits / receives a packet to / from the receiver 20. In this case, for example, the transmitter 10 transmits and receives packets by setting the directivity of the array antenna 11 in the opposite direction to the receiver 20 (= 180 degrees).

  The detection means 14 of the transmitter 10 generates a setting signal BSET for setting the directivity of the array antenna 11 in the direction of 180 degrees and outputs it to the directivity switching means 12 and also generates a transmission request signal RT. Output to the communication means 15.

The directivity switching unit 12 controls the control voltage set CVL4 (x _m4 = hi, x _{m1 to} x _m3 , x _m5 , x _m6 = lo in accordance with the setting signal BSET from the detecting unit 14. Voltage set) is generated and output to the varactor diodes 121-126. Varactor diodes 121 to 126 set the directivity of array antenna 11 in the direction of 180 degrees in accordance with control voltage set CVL4 from directivity switching means 12.

  Further, the communication unit 15 feeds the radio wave RF constituting the packet to the antenna element 117 of the array antenna 11 in response to the transmission request signal RT from the detection unit 14.

  Then, array antenna 11 transmits radio wave RF received from communication means 15 in the direction of 180 degrees.

  The antenna 21 of the receiver 20 receives the radio wave RF transmitted from the transmitter 10 and outputs the received radio wave RF to the intensity detection means 22. The strength detection means 22 detects the received signal strength RSSI_RX of the radio wave RF received from the antenna 21, outputs the detected received signal strength RSSI_RX to the detection means 23, generates a transmission request signal RT, and sends it to the communication means 24. Output.

  The detector 23 receives the received signal strength RSSI_RX from the strength detector 22 and compares the received signal strength RSSI_RX with the reference value RSSI_std. Then, when the received signal strength RSSI_RX changes from the reference value RSSI_std by a certain value or more, the detection means 23 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_RX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  On the other hand, when the communication unit 24 receives the transmission request signal RT from the intensity detection unit 22, the communication unit 24 feeds the antenna 21 and transmits the radio wave RF constituting the packet.

  The array antenna 11 of the transmitter 10 sets the directivity in the direction of 180 degrees, receives the radio wave RF transmitted from the receiver 20, and outputs the received radio wave RF from the antenna element 117 to the intensity detection means 13. .

  When receiving the radio wave RF from the antenna element 117 of the array antenna 11, the intensity detecting unit 13 detects the received signal strength RSSI_TX of the received radio wave RF and outputs the detected received signal strength RSSI_TX to the detecting unit 14. In addition, when detecting the received signal strength RSSI_TX, the strength detecting unit 13 generates a transmission request signal RT and outputs it to the communication unit 15.

  The detecting unit 14 receives the received signal strength RSSI_TX from the strength detecting unit 13 and compares the received received signal strength RSSI_TX with the reference value RSSI_std. Then, when the received signal strength RSSI_TX is changed from the reference value RSSI_std by a certain value or more, the detecting unit 14 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_TX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  On the other hand, in response to the transmission request signal RT from the intensity detection means 13, the communication means 15 feeds the antenna element 117 of the array antenna 11 and transmits the radio wave RF constituting the packet.

  The transmitter 10 and the receiver 20 repeat the above-described operation to detect that an intruder has entered the room 30.

  FIG. 6 is a diagram illustrating an intrusion detection experimental result in the pattern 1. 6A shows the relationship between the received signal strength in the transmitter 10 and the number of packet transmission / reception times, and FIG. 6B shows the relationship between the received signal strength in the receiver 20 and the number of packet transmission / reception times. Show.

  In FIGS. 6A and 6B, the vertical axis represents received signal strength, and the horizontal axis represents the number of packet transmission / reception.

  In FIG. 6A, areas REG7 and REG9 represent a state in which an intruder has entered the room 30, and area REG8 represents a state in which the intruder has not entered the room 30. In FIG. 6B, regions REG10 and REG12 represent a state in which an intruder has entered the room 30, and region REG11 represents a state in which the intruder has not entered the room 30.

  Accordingly, the detection means 14 of the transmitter 10 detects that the intruder has entered the room 30 by comparing the received signal strength RSSI_TX received from the strength detection means 13 with the reference value RSSI_std in the regions REG7 and REG9. In the region REG8, the received signal strength RSSI_TX received from the strength detecting means 13 is compared with the reference value RSSI_std to detect that no intruder has entered the room 30.

  In addition, in the regions REG10 and REG12, the detection unit 23 of the receiver 20 detects that an intruder has entered the room 30 by comparing the received signal strength RSSI_RX received from the strength detection unit 22 with the reference value RSSI_std. In the region REG11, the received signal strength RSSI_RX received from the strength detecting means 22 is compared with the reference value RSSI_std to detect that no intruder has entered the room 30.

  In the transmitter 10, the reference value RSSI_std is calculated based on the received signal strength RSSI_TX in the region REG8, and the received signal strength RSSI_TX in the regions REG7 and REG9 is significantly different from the received signal strength RSSI_TX in the region REG8. The detection means 14 can accurately detect that an intruder has entered the room 30 by the method described above.

  In the receiver 20, the reference value RSSI_std is calculated based on the received signal strength RSSI_RX in the region REG11, and the received signal strength RSSI_RX in the regions REG10 and REG12 is significantly different from the received signal strength RSSI_RX in the region REG11. The 20 detection means 23 can accurately detect that an intruder has entered the room 30 by the method described above.

  Since the fluctuation range of the received signal strength in the regions REG8 and REG11 is smaller than the fluctuation range of the received signal strength (see FIG. 5) when the array antenna 11 transmits and receives the radio wave RF with no directivity, the directivity array By transmitting and receiving the radio wave RF by the antenna 11, the intrusion detection capability of the intruder into the room 30 can be improved.

(Pattern 2)
In the pattern 2, the array antenna 11 of the transmitter 10 transmits and receives the radio wave RF by switching the directivity to two directivities for each communication. In this case, for each communication, the transmitter 10 has, for example, the directivity of the array antenna 11 such that the direction of the receiver 20 is the direction of the receiver 20 = 0 direction and the direction opposite to the receiver 20 (the direction of 180 degrees). Switch to and send and receive packets.

  The detecting means 14 of the transmitter 10 generates a setting signal BSET1 (a kind of setting signal BSET) for setting the directivity of the array antenna 11 in the direction of 0 degree, and outputs the setting signal BSET1 to the directivity switching means 12. A request signal RT is generated and output to the communication means 15.

The directivity switching unit 12 generates a control voltage set CVL1 (control voltage set for setting x _m1 = hi, x _{m2 to} x _m6 = lo) in accordance with the setting signal BSET1 from the detection unit 14. Output to the varactor diodes 121-126. The varactor diodes 121 to 126 set the directivity of the array antenna 11 in the direction of 0 degrees according to the control voltage set CVL1 from the directivity switching means 12.

  Further, the communication unit 15 feeds the radio wave RF constituting the packet to the antenna element 117 of the array antenna 11 in response to the transmission request signal RT from the detection unit 14.

  Then, array antenna 11 transmits radio wave RF received from communication means 15 in the direction of 0 degrees.

  The antenna 21 of the receiver 20 receives the radio wave RF transmitted from the transmitter 10 and outputs the received radio wave RF to the intensity detection means 22. The strength detection means 22 detects the received signal strength RSSI_RX of the radio wave RF received from the antenna 21, outputs the detected received signal strength RSSI_RX to the detection means 23, generates a transmission request signal RT, and sends it to the communication means 24. Output.

  The detector 23 receives the received signal strength RSSI_RX from the strength detector 22 and compares the received signal strength RSSI_RX with the reference value RSSI_std. Then, when the received signal strength RSSI_RX changes from the reference value RSSI_std by a certain value or more, the detection means 23 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_RX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  On the other hand, when the communication unit 24 receives the transmission request signal RT from the intensity detection unit 22, the communication unit 24 feeds the radio wave RF constituting the packet to the antenna 21 and transmits the packet.

  The array antenna 11 of the transmitter 10 receives the radio wave RF transmitted from the receiver 20 with the directivity set to the direction of 0 degree, and outputs the received radio wave RF from the antenna element 117 to the intensity detecting means 13. .

  When receiving the radio wave RF from the antenna element 117 of the array antenna 11, the intensity detecting unit 13 detects the received signal strength RSSI_TX of the received radio wave RF and outputs the detected received signal strength RSSI_TX to the detecting unit 14. In addition, when detecting the received signal strength RSSI_TX, the strength detecting unit 13 generates a transmission request signal RT and outputs it to the communication unit 15.

  The detecting unit 14 receives the received signal strength RSSI_TX from the strength detecting unit 13 and compares the received received signal strength RSSI_TX with the reference value RSSI_std. Then, when the received signal strength RSSI_TX is changed from the reference value RSSI_std by a certain value or more, the detecting unit 14 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_TX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  When the detection of the entry of the intruder into the room 30 is completed, the detection means 14 generates a setting signal BSET2 (a type of the setting signal BSET) for setting the directivity of the array antenna 11 in the direction of 180 degrees. Output to the switching means 12.

The directivity switching unit 12 controls the control voltage set CVL4 (x _m4 = hi, x _{m1 to} x _m3 , x _m5 , x _m6 = lo in accordance with the setting signal BSET2 from the detecting unit 14. Voltage set) is generated and output to the varactor diodes 121-126. Varactor diodes 121 to 126 set the directivity of array antenna 11 in the direction of 180 degrees in accordance with control voltage set CVL4 from directivity switching means 12.

  Further, the communication means 15 feeds the radio wave RF constituting the packet to the antenna element 117 of the array antenna 11 in response to the transmission request signal RT from the intensity detection means 13.

  Then, array antenna 11 transmits radio wave RF received from communication means 15 in the direction of 180 degrees.

  The antenna 21 of the receiver 20 receives the radio wave RF transmitted from the transmitter 10 and outputs the received radio wave RF to the intensity detection means 22. The strength detection means 22 detects the received signal strength RSSI_RX of the radio wave RF received from the antenna 21, outputs the detected received signal strength RSSI_RX to the detection means 23, generates a transmission request signal RT, and sends it to the communication means 24. Output.

  The detector 23 receives the received signal strength RSSI_RX from the strength detector 22 and compares the received signal strength RSSI_RX with the reference value RSSI_std. Then, when the received signal strength RSSI_RX changes from the reference value RSSI_std by a certain value or more, the detection means 23 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_RX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  On the other hand, when the communication unit 24 receives the transmission request signal RT from the intensity detection unit 22, the communication unit 24 feeds the radio wave RF constituting the packet to the antenna 21 and transmits the packet.

  The array antenna 11 of the transmitter 10 sets the directivity in the direction of 180 degrees, receives the radio wave RF transmitted from the receiver 20, and outputs the received radio wave RF from the antenna element 117 to the intensity detection means 13. .

  When receiving the radio wave RF from the antenna element 117 of the array antenna 11, the intensity detecting unit 13 detects the received signal strength RSSI_TX of the received radio wave RF and outputs the detected received signal strength RSSI_TX to the detecting unit 14. In addition, when detecting the received signal strength RSSI_TX, the strength detecting unit 13 generates a transmission request signal RT and outputs it to the communication unit 15.

  The detecting unit 14 receives the received signal strength RSSI_TX from the strength detecting unit 13 and compares the received received signal strength RSSI_TX with the reference value RSSI_std. Then, when the received signal strength RSSI_TX is changed from the reference value RSSI_std by a certain value or more, the detecting unit 14 detects that an intruder has entered the room 30 and the change in the received signal strength RSSI_TX from the reference value RSSI_std is detected. When it is smaller than a certain value, it is detected that no intruder has entered the room 30.

  FIG. 7 is a first diagram showing an intrusion detection experimental result in pattern 2. FIG. FIG. 8 is a second diagram showing the results of intrusion detection experiments in pattern 2.

  7 (a) and 8 (a) show the relationship between the received signal strength and the number of packet transmission / reception in the transmitter 10, and FIG. 7 (b) and FIG. 8 (b) show the receiver. 20 shows the relationship between the received signal strength at 20 and the number of packet transmission / receptions.

  In FIGS. 7A and 7B and FIGS. 8A and 8B, the vertical axis represents the received signal strength, and the horizontal axis represents the number of packet transmission / reception.

  In FIG. 7A, areas REG13 and REG15 represent a state in which an intruder has entered the room 30, and area REG14 represents a state in which the intruder has not entered the room 30. In FIG. 7B, areas REG16 and REG18 represent a state in which an intruder has entered the room 30, and area REG17 represents a state in which the intruder has not entered the room 30.

  In FIG. 8A, areas REG19 and REG21 represent a state in which an intruder has entered the room 30, and area REG20 represents a state in which the intruder has not entered the room 30. 8B, regions REG22 and REG24 represent a state in which an intruder has entered the room 30, and region REG23 represents a state in which the intruder has not entered the room 30.

  Accordingly, the detection means 14 of the transmitter 10 compares the received signal strength RSSI_TX received from the strength detection means 13 with the reference value RSSI_std in the regions REG13, REG15; REG19, REG21, and an intruder enters the room 30. In the regions REG14 and REG20, the received signal strength RSSI_TX received from the strength detecting means 13 is compared with the reference value RSSI_std to detect that no intruder has entered the room 30.

  Further, the detection means 23 of the receiver 20 compares the received signal strength RSSI_RX received from the strength detection means 22 with the reference value RSSI_std in the regions REG16, REG18; REG22, REG24, and an intruder enters the room 30. In the regions REG17 and REG23, the received signal strength RSSI_RX received from the strength detecting means 22 is compared with the reference value RSSI_std to detect that no intruder has entered the room 30.

  In the transmitter 10, the reference value RSSI_std is calculated based on the received signal strength RSSI_TX in the region REG14; REG20, and the received signal strength RSSI_TX in the regions REG13, REG15; REG19, REG21 Since it differs greatly, the detection means 14 of the transmitter 10 can accurately detect that an intruder has entered the room 30 by the method described above.

  In the receiver 20, the reference value RSSI_std is calculated based on the received signal strength RSSI_RX in the region REG17; REG23, and the received signal strength RSSI_RX in the regions REG16, REG18; REG22, REG24 is the received signal strength in the region REG17; REG23. Since it differs greatly from RSSI_RX, the detection means 23 of the receiver 20 can accurately detect that an intruder has entered the room 30 by the method described above.

  And the fluctuation width of the received signal strength in the regions REG14, REG17, REG20, REG23 is smaller than the fluctuation width of the received signal strength when the array antenna 11 transmits and receives the radio wave RF (see FIG. 5). By transmitting and receiving the radio wave RF with the directional array antenna 11, it is possible to improve the intrusion detection capability of the intruder into the room 30.

  Thus, even when the array antenna 11 switches the directivity to two directivity for each communication and transmits / receives the radio wave RF, the transmitter 10 and the receiver 20 prevent the intruder from entering the room 30. It can be detected accurately.

   From the experimental results shown in FIGS. 7 and 8, the transmitter 10 and the receiver 20 can detect the intrusion with high reproducibility.

  In the above description, it has been described that the directivity of the array antenna 11 is switched to the 0 degree direction and the 180 degree direction for each communication. However, the present invention is not limited to this, and the array antenna 11 is not limited thereto. The directivity of 11 is selected from two directions arbitrarily selected from 0 degree direction, 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction and 300 degree direction for each communication. It only has to be switched in the direction.

(Pattern 3)
In the pattern 3, the transmitter 10 transmits and receives the radio wave RF by switching the directivity of the array antenna 11 in six directions every 128 communications. In this case, the transmitter 10 sets, for example, the directivity of the array antenna 11 to 0 degree direction, 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction and 300 degrees every 128 communications. Switch sequentially in degrees.

  The detecting means 14 of the transmitter 10 generates a setting signal BSET for setting the directivity of the array antenna 11 in the direction of 0 degrees and outputs it to the directivity switching means 12 and also generates a transmission request signal RT. Output to the communication means 15.

Then, the directivity switching unit 12 generates a control voltage set CVL1 (control voltage set for setting x _m1 = hi, x _{m2 to} x _m6 = lo) in accordance with the setting signal BSET from the detection unit 14. Output to the varactor diodes 121-126. The varactor diodes 121 to 126 set the directivity of the array antenna 11 in the direction of 0 degrees according to the control voltage set CVL1 from the directivity switching means 12.

  Further, the communication unit 15 feeds the radio wave RF constituting the packet to the antenna element 117 of the array antenna 11 in response to the transmission request signal RT from the detection unit 14.

  Then, array antenna 11 transmits radio wave RF received from communication means 15 in the direction of 0 degrees.

  The antenna 21 of the receiver 20 receives the radio wave RF transmitted from the transmitter 10 and outputs the received radio wave RF to the intensity detection means 22. The strength detection means 22 detects the received signal strength RSSI_RX of the radio wave RF received from the antenna 21, outputs the detected received signal strength RSSI_RX to the detection means 23, generates a transmission request signal RT, and sends it to the communication means 24. Output.

  Upon receiving the reception signal strength RSSI_RX from the strength detection unit 22, the detection unit 23 detects the intrusion of the intruder into the room 30 by the above-described method based on the reception signal strength RSSI_RX and the reference value RSSI_std.

  On the other hand, when the communication unit 24 receives the transmission request signal RT from the intensity detection unit 22, the communication unit 24 feeds the radio wave RF constituting the packet to the antenna 21 and transmits the packet.

  The array antenna 11 of the transmitter 10 receives the radio wave RF transmitted from the receiver 20 with the directivity set in the direction of 0 degrees, and outputs the received radio wave RF from the antenna element 117 to the intensity detecting means 13. .

  When receiving the radio wave RF from the antenna element 117 of the array antenna 11, the intensity detecting unit 13 detects the received signal strength RSSI_TX of the received radio wave RF and outputs the detected received signal strength RSSI_TX to the detecting unit 14. In addition, when detecting the received signal strength RSSI_TX, the strength detecting unit 13 generates a transmission request signal RT and outputs it to the communication unit 15.

  When receiving the received signal strength RSSI_TX from the strength detecting unit 13, the detecting unit 14 detects the intrusion of the intruder into the room 30 by the above-described method based on the received signal strength RSSI_TX and the reference value RSSI_std.

  The transmitter 10 and the receiver 20 repeat the above operation 128 times in a state where the directivity of the array antenna 11 is set to the direction of 0 degree.

  When receiving the 128th received signal strength RSSI_TX from the strength detecting means 13, the detecting means 14 generates a switching signal EXD for switching the directivity of the array antenna 11 in the direction of 60 degrees, and directivity switching means. 12 is output.

Then, directivity switching means 12, in response to the switching signal EXD from the sensing means 14, the control voltage set _{CVL2 (x m2 = hi, x} m1, x m3 ~x m6 = control voltage set for setting the lo) And output to the varactor diodes 121-126. Varactor diodes 121 to 126 set the directivity of array antenna 11 in the direction of 60 degrees according to control voltage set CVL2 from directivity switching means 12.

  Then, the transmitter 10 and the receiver 20 repeat the above-described operation 128 times with the directivity of the array antenna 11 set to a direction of 60 degrees, and detect the intrusion of the intruder into the room 30.

  Thereafter, the transmitter 10 and the receiver 20 perform the above-described operations 128 times with the directivity of the array antenna 11 set to 120 degrees, 180 degrees, 240 degrees, and 300 degrees, respectively. Repeatedly, the intruder enters the room 30 and is detected. In this case, the detection means 14 of the transmitter 10 generates a switching signal EXD every time it receives 128 received signal strengths RSSI_TX from the strength detection means 13 and outputs it to the directivity switching means 12. In response to the switching signal EXD, the directivity of the array antenna 11 is sequentially set to a 120 degree direction, a 180 degree direction, a 240 degree direction, and a 300 degree direction.

  9 to 14 are first to sixth diagrams showing intrusion detection experimental results in the pattern 3, respectively.

  9 to 14, (a) shows the relationship between the received signal strength and the number of packet transmission / reception in the transmitter 10, and (b) shows the relationship between the received signal strength and the number of packet transmission / reception in the receiver 20. Indicates.

  9A to 14B, the vertical axis represents the received signal strength, and the horizontal axis represents the number of packet transmission / reception.

  In FIG. 9A, areas REG25 and REG27 represent a state in which an intruder has entered the room 30, and area REG26 represents a state in which the intruder has not entered the room 30. In FIG. 9B, areas REG28 and REG30 represent a state in which an intruder has entered the room 30, and area REG29 represents a state in which the intruder has not entered the room 30.

  Similarly, areas REG31, REG33, REG34, and REG36 in FIG. 10, areas REG37, REG39, REG40, and REG42 in FIG. 11, areas REG43, REG45, REG46, and REG48 in FIG. 12, areas REG49, REG51, REG52, and REG54 in FIG. 14 and the regions REG55, REG57, REG58, and REG60 in FIG. 14 represent states in which intruders have entered the room 30, the regions REG32 and REG35 in FIG. 10, the regions REG38 and REG41 in FIG. 11, and the regions REG44, FIG. REG 47, regions REG 50 and REG 53 in FIG. 13 and regions REG 56 and REG 59 in FIG. 14 represent a state in which no intruder has entered the room 30.

  Accordingly, the detection means 14 of the transmitter 10 receives the received signal strength RSSI_TX received from the strength detection means 13 in the regions REG25, REG27; REG31, REG33; REG37, REG39; EG43, REG45; REG49, REG51; REG55, REG57. In comparison with the reference value RSSI_std, it is detected that an intruder has entered the room 30, and in the regions REG26, REG32, REG38, REG44, REG50, REG56, the received signal strength RSSI_TX received from the strength detecting means 13 is used as a reference. Compared with the value RSSI_std, it is detected that no intruder has entered the room 30.

  Further, the detection means 23 of the receiver 20 includes the regions REG28, REG30; REG34, REG36; REG40, REG42; REG46, REG48; REG52, REG54; REG58, REG60, the received signal strength RSSI_RX received from the strength detection means 22. Compared with the reference value RSSI_std, it is detected that an intruder has entered the room 30, and in the regions REG29, REG35, REG41, REG47, REG53, REG59, the received signal strength RSSI_RX received from the strength detecting means 22 is used as a reference. Compared with the value RSSI_std, it is detected that no intruder has entered the room 30.

  In the transmitter 10, the reference value RSSI_std is calculated based on the received signal strength RSSI_TX in the regions REG26, REG32, REG38, REG44, REG50, REG56, and the regions REG25, REG27; REG31, REG33; REG37, REG39; EG43, REG45; Since the received signal strength RSSI_TX in REG49, REG51; REG55, REG57 is significantly different from the received signal strength RSSI_TX in the regions REG26, REG32, REG38, REG44, REG50, REG56, the detection means 14 of the transmitter 10 is based on the method described above. It is possible to accurately detect that an intruder has entered the room 30.

  In the receiver 20, the reference value RSSI_std is calculated based on the received signal strength RSSI_RX in the regions REG29, REG35, REG41, REG47, REG53, REG59, and the regions REG28, REG30; REG34, REG36; REG40, REG42; REG46, REG48; REG52, REG54; REG58, REG60, the received signal strength RSSI_RX is significantly different from the received signal strength RSSI_RX in the regions REG29, REG35, REG41, REG47, REG53, REG59. Thus, it is possible to accurately detect that the intruder has entered the room 30.

  The fluctuation range of the received signal strength in the regions REG26, REG29, REG32, REG35, REG38, REG41, REG44, REG47, REG50, REG53, REG56, REG59 is the non-directional radio wave RF transmission / reception. Since it is smaller than the fluctuation range of the received signal intensity (see FIG. 5), the ability to detect the intrusion of the intruder into the room 30 can be improved by transmitting and receiving the radio wave RF with the directional array antenna 11.

  As described above, even when the array antenna 11 sequentially switches the directivity to 6 directivities every 128 communications, the transmitter 10 and the receiver 20 are connected to the intruder room 30. Intrusion can be detected accurately.

   Further, from the experimental results shown in FIGS. 9 to 14, the transmitter 10 and the receiver 20 can detect the intrusion with high reproducibility.

(Pattern 4)
In the pattern 4, the transmitter 10 transmits and receives the radio wave RF by switching the directivity of the array antenna 11 in six directions for each communication. In this case, the transmitter 10 sets the directivity of the array antenna 11 to 0 degree direction, 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction, and 300 for each communication, for example. Switch sequentially in degrees.

  The detecting means 14 of the transmitter 10 generates a setting signal BSET for setting the directivity of the array antenna 11 in the direction of 0 degrees and outputs it to the directivity switching means 12 and also generates a transmission request signal RT. Output to the communication means 15.

Then, the directivity switching unit 12 generates a control voltage set CVL1 (control voltage set for setting x _m1 = hi, x _{m2 to} x _m6 = lo) in accordance with the setting signal BSET from the detection unit 14. Output to the varactor diodes 121-126. The varactor diodes 121 to 126 set the directivity of the array antenna 11 in the direction of 0 degrees according to the control voltage set CVL1 from the directivity switching means 12.

  Further, the communication unit 15 feeds the radio wave RF constituting the packet to the antenna element 117 of the array antenna 11 in response to the transmission request signal RT from the detection unit 14.

  Then, array antenna 11 transmits radio wave RF received from communication means 15 in the direction of 0 degrees.

  The antenna 21 of the receiver 20 receives the radio wave RF transmitted from the transmitter 10 and outputs the received radio wave RF to the intensity detection means 22. The strength detection means 22 detects the received signal strength RSSI_RX of the radio wave RF received from the antenna 21, outputs the detected received signal strength RSSI_RX to the detection means 23, generates a transmission request signal RT, and sends it to the communication means 24. Output.

  Upon receiving the reception signal strength RSSI_RX from the strength detection unit 22, the detection unit 23 detects the intrusion of the intruder into the room 30 by the above-described method based on the reception signal strength RSSI_RX and the reference value RSSI_std.

  On the other hand, when the communication unit 24 receives the transmission request signal RT from the intensity detection unit 22, the communication unit 24 feeds the radio wave RF constituting the packet to the antenna 21 and transmits the packet.

  The array antenna 11 of the transmitter 10 receives the radio wave RF transmitted from the receiver 20 with the directivity set in the direction of 0 degrees, and outputs the received radio wave RF from the antenna element 117 to the intensity detecting means 13. .

  When receiving the radio wave RF from the antenna element 117 of the array antenna 11, the intensity detecting unit 13 detects the received signal strength RSSI_TX of the received radio wave RF and outputs the detected received signal strength RSSI_TX to the detecting unit 14. In addition, when detecting the received signal strength RSSI_TX, the strength detecting unit 13 generates a transmission request signal RT and outputs it to the communication unit 15.

  When receiving the received signal strength RSSI_TX from the strength detecting unit 13, the detecting unit 14 detects the intrusion of the intruder into the room 30 by the above-described method based on the received signal strength RSSI_TX and the reference value RSSI_std.

  When the detection of the entry of the intruder into the room 30 is completed, the detection unit 14 generates a switching signal EXD for switching the directivity of the array antenna 11 in the direction of 60 degrees and outputs the switching signal EXD to the directivity switching unit 12. .

The directivity switching means 12 generates a control voltage set CVL2 (control voltage set for setting x _m2 = hi, x _m1 , x _{m3 to} x _m6 = lo) in response to the switching signal EXD from the detection means 14. And output to the varactor diodes 121 to 126. Varactor diodes 121 to 126 set the directivity of array antenna 11 in the direction of 60 degrees according to control voltage set CVL2 from directivity switching means 12.

  The transmitter 10 and the receiver 20 perform the above-described operation in a state where the directivity of the array antenna 11 is set to a direction of 60 degrees, and detects the intrusion of the intruder into the room 30.

  Thereafter, the transmitter 10 and the receiver 20 repeat the above-described operations in the state where the directivity of the array antenna 11 is set to the direction of 120 degrees, the direction of 180 degrees, the direction of 240 degrees, and the direction of 300 degrees, respectively. Detecting the entry of the intruder into the room 30. In this case, the detecting means 14 of the transmitter 10 generates a switching signal EXD every time receiving one received signal strength RSSI_TX from the strength detecting means 13 and outputs the switching signal EXD to the directivity switching means 12. In response to the switching signal EXD, the directivity of the array antenna 11 is sequentially set to a 120 degree direction, a 180 degree direction, a 240 degree direction, and a 300 degree direction.

  15 to 20 are first to sixth diagrams showing intrusion detection experimental results in the pattern 4, respectively.

  15 to 20, (a) shows the relationship between the received signal strength and the number of packet transmission / reception in the transmitter 10, and (b) shows the relationship between the received signal strength and the number of packet transmission / reception in the receiver 20. Indicates.

  15A to 20B, the vertical axis represents the received signal strength, and the horizontal axis represents the number of packet transmission / reception.

  In FIG. 15A, areas REG61 and REG63 represent a state in which an intruder has entered the room 30, and an area REG62 represents a state in which the intruder has not entered the room 30. In FIG. 15B, areas REG64 and REG66 represent a state in which an intruder has entered the room 30, and area REG65 represents a state in which the intruder has not entered the room 30.

  Similarly, areas REG67, REG69, REG70, REG72 in FIG. 16, areas REG73, REG75, REG76, REG78 in FIG. 17, areas REG79, REG81, REG82, REG84 in FIG. 18, areas REG85, REG87, REG88, REG90 in FIG. 20 and regions REG91, REG93, REG94, and REG96 in FIG. 20 represent a state in which an intruder has entered the room 30, regions REG68 and REG71 in FIG. 16, regions REG74 and REG77 in FIG. 17, regions REG80 in FIG. REG 83, regions REG 86 and REG 89 in FIG. 19 and regions REG 92 and REG 95 in FIG. 20 represent a state in which no intruder has entered the room 30.

  Therefore, the detection means 14 of the transmitter 10 receives the received signal strength RSSI_TX received from the strength detection means 13 in the regions REG61, REG63; REG67, REG69; REG73, REG75; EG79, REG81; REG85, REG87; REG91, REG93. Compared with the reference value RSSI_std, it is detected that an intruder has entered the room 30, and in the regions REG62, REG68, REG74, REG80, REG86, REG92, the received signal strength RSSI_TX received from the strength detecting means 13 is used as a reference. Compared with the value RSSI_std, it is detected that no intruder has entered the room 30.

  Further, the detection means 23 of the receiver 20 includes the regions REG64, REG66; REG70, REG72; REG76, REG78; REG82, REG84; REG88, REG90; REG94, REG96, the received signal strength RSSI_RX received from the strength detection means 22. Compared with the reference value RSSI_std, it is detected that an intruder has entered the room 30. In the regions REG65, REG71, REG77, REG83, REG89, REG95, the received signal strength RSSI_RX received from the strength detecting means 22 is used as a reference. Compared with the value RSSI_std, it is detected that no intruder has entered the room 30.

  In the transmitter 10, the reference value RSSI_std is calculated based on the received signal strength RSSI_TX in the regions REG62, REG68, REG74, REG80, REG86, REG92, and the regions REG61, REG63; REG67, REG69; REG73, REG75; REG79, REG81; Since the received signal strength RSSI_TX in REG85, REG87; REG91, REG93 is greatly different from the received signal strength RSSI_TX in the regions REG62, REG68, REG74, REG80, REG86, REG92, the detection means 14 of the transmitter 10 is based on the method described above. It is possible to accurately detect that an intruder has entered the room 30.

  In the receiver 20, the reference value RSSI_std is calculated based on the received signal strength RSSI_RX in the regions REG65, REG71, REG77, REG83, REG89, REG95, and the regions REG64, REG66; REG70, REG72; REG76, REG78; REG82, Since the received signal strength RSSI_RX in REG84; REG88, REG90; REG94, REG96 is greatly different from the received signal strength RSSI_RX in the regions REG65, REG71, REG77, REG83, REG89, REG95, the detection means 23 of the receiver 20 uses the method described above. Thus, it is possible to accurately detect that the intruder has entered the room 30.

  The fluctuation range of the received signal intensity in the regions REG62, REG65, REG68, REG71, REG74, REG77, REG80, REG83, REG86, REG89, REG92, and REG95 is the same as that when the array antenna 11 transmits and receives the radio wave RF. Since it is smaller than the fluctuation range of the received signal intensity (see FIG. 5), the ability to detect the intrusion of the intruder into the room 30 can be improved by transmitting and receiving the radio wave RF with the directional array antenna 11.

  As described above, even when the array antenna 11 transmits and receives the radio wave RF by sequentially switching the directivity to six directivities for each communication, the transmitter 10 and the receiver 20 are connected to the room 30 of the intruder. Intrusion can be detected accurately.

   Further, from the experimental results shown in FIGS. 15 to 20, the transmitter 10 and the receiver 20 can detect the intrusion with high reproducibility.

  In the pattern 3 and pattern 4 described above, the directivity of the array antenna 11 is sequentially changed to 0 degree direction, 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction, and 300 degree direction. In the present invention, the directivity of the array antenna 11 may be switched to six directivities in any order in the patterns 3 and 4.

  In the pattern 3 described above, the directivity of the array antenna 11 is switched to 6 directivities for every 128 communications, and in pattern 4, the directivity of the array antenna 11 is changed to 6 for each communication. In the present invention, the directivity of the array antenna 11 may be switched to an arbitrary number of directivities every arbitrary number of communications.

  Furthermore, in the above description, it has been described that the receiver 20 transmits and receives the radio wave RF using the omnidirectional antenna 21. However, the present invention is not limited to this, and the receiver 20 transmits the radio wave RF using the directional antenna. You may send and receive. In this case, the receiver 20 transmits / receives the radio wave RF with one directivity, and then switches the antenna directivity to the next directivity.

  Furthermore, in the above description, it has been described that the transmitter 10 and the receiver 20 detect the entry of the intruder into the room 30 by transmitting and receiving radio waves RF to each other. However, the present invention is not limited to this. 10 may perform only the transmission of the radio wave RF, and the receiver 20 may perform the reception of the radio wave RF and detect the entry of the intruder into the room 30 by the method described above.

  As described above, according to the first embodiment, the radio wave RF having directivity is transmitted by the array antenna 11, and the received signal strength RSSI of the radio wave RF having directivity is the reference value RSSI_std (= the intruder is invading). Intrusion of the intruder into the room 30 is detected when the received signal intensity is not less than a certain value. The fluctuation range of the received signal strength RSSI of the radio wave RF having directivity is smaller than the fluctuation range of the received signal strength of the radio wave RF transmitted with non-directionality.

  Therefore, according to the present invention, the ability to detect intruders can be improved.

[Embodiment 2]
FIG. 21 is a schematic diagram showing a configuration of an intrusion detection system according to the second embodiment. An intrusion detection system 100A according to the second embodiment is obtained by adding receivers 90 and 130 to the intrusion detection system 100 shown in FIG.

  The transmitter 10 and the receivers 20, 90 and 130 are arranged in the room 30. The receiver 90 includes an omnidirectional antenna 91 and transmits and receives radio waves via the antenna 91. The receiver 130 has an omnidirectional antenna 131 and transmits and receives radio waves via the antenna 131.

  Each of the receivers 90 and 130 has the same configuration as the receiver 20 shown in FIG.

  In intrusion detection system 100A, transmitter 10 transmits / receives radio wave RF by setting the directivity of array antenna 11 to a predetermined directivity, and receivers 20, 90, and 130 receive antennas 21, 91, and 131, respectively. Radio wave RF is transmitted and received via Then, the transmitter 10 and the receivers 20, 90, and 130 detect the received signal strength RSSI of the received radio wave RF to detect the entry of the intruder into the room 30.

  In this case, the transmitter 10 and the receivers 20, 90, and 130 detect the intrusion of the intruder into the room 30 using the patterns 1 to 4 described in the first embodiment.

  As described above, the intrusion detection system 100A is an intrusion detection system including the transmitter 10 and the plurality of receivers 20, 90, and 130. By providing a plurality of receivers 20, 90, and 130, it is possible to detect a change in the radio wave RF when an intruder enters the room 30 at a plurality of locations in the room 30, so that the ability of intrusion detection can be further improved. .

  In the intrusion detection system 100A, the transmitter 10 has only the function of transmitting the radio wave RF via the directional array antenna 11, and the receivers 20, 90, 130 receive the radio wave RF transmitted from the transmitter 10. You may make it have a function which detects the signal strength RSSI and detects the intrusion of the intruder into the room 30.

  Further, the receivers 20, 90, 130 may have directional antennas.

  Others are the same as in the first embodiment.

[Embodiment 3]
FIG. 22 is a schematic diagram showing the configuration of the intrusion detection system according to the third embodiment. The intrusion detection system 100B according to the third embodiment is the same as the intrusion detection system 100 except that a network 140, a camera 150, and a security department 160 are added to the intrusion detection system 100 shown in FIG.

  In the intrusion detection system 100 </ b> B, the transmitter 10, the receiver 20, and the camera 150 are arranged in the room 30, and the security department 160 is installed outside the room 30. The transmitter 10, the receiver 20, the camera 150, and the security department 160 are connected to the network 140.

  The transmitter 10 and the receiver 20 detect that the intruder has entered the room 30 by the above-described method, and if the intruder has entered the room 30, the transmitter 10 and the receiver 20 indicate that the intruder has entered the room 30. The signal INVD is transmitted to the camera 150 via the network 140.

  Upon receiving the signal INVD from the transmitter 10 or the receiver 20, the camera 150 captures an image in the room 30 and transmits the captured image to the security department 160 via the network 140.

  The security department 160 receives the video in the room 30 from the camera 150 via the network 140 and copies the received video to the CRT 161. As a result, the security guard of the security department 160 detects that the intruder has entered the room 30 and rushes to the room 30. The guard then eliminates the intruder.

  As described above, the intrusion detection system 100B according to the third embodiment has a function of detecting an intruder entering the room 30 and eliminating the intruder.

[Embodiment 4]
FIG. 23 is a schematic diagram showing a configuration of an intrusion detection system according to the fourth embodiment. The intrusion detection system 100C according to the fourth embodiment includes a transmitter 170 and a receiver 180.

  The transmitter 170 and the receiver 180 are installed in the room 30. The transmitter 170 and the receiver 180 have the array antenna 11.

  The transmitter 170 transmits / receives the radio wave RF via the array antenna 11 and detects the intrusion of the intruder into the room 30 and the intrusion position by a method described later based on the received signal strength RSSI of the received radio wave RF. .

  The receiver 180 transmits / receives the radio wave RF via the array antenna 11 and determines the intrusion and intrusion position of the intruder into the room 30 by a method described later based on the received signal strength RSSI of the received radio wave RF. Detect.

  24 is a schematic diagram showing the configuration of the transmitter 170 shown in FIG. The transmitter 170 is the same as the transmitter 10 except that the detection unit 14 of the transmitter 10 shown in FIG.

  The detection unit 14A holds in advance a plurality of received signal strengths RSSI_INVD1 to RSSI_INVD14 when an intruder enters each position of the room 30, and when receiving the received signal strength RSSI_TX from the strength detection unit 13, The received signal strength RSSI_INVD at the time of entry that matches the signal strength RSSI_TX is detected from the plurality of received signal strengths RSSI_INVD1 to RSSI_INVD14 to detect the intrusion and intrusion positions. In this case, each of the plurality of received signal strengths RSSI_INVD1 to RSSI_INVD14 is the reference value RSSI_std (average received signal strength when there is no intrusion) among the six received signal strengths received with the six directivities of the array antenna 11. Value) is the received signal strength having the largest change. Each of the plurality of received signal strengths RSSI_INVD <b> 1 to RSSI_INVD <b> 14 is a value determined from an actual measurement value of the received signal strength RSSI when an obstacle is actually placed at each position PS <b> 1 to PS <b> 14 in the room 30.

  This will be specifically described. FIG. 25 is a conceptual diagram of a table showing the correspondence between received signal strength and position at the time of entry. The strength detection means 13 detects in advance the received signal strengths RSSI_INVD1 to RSSI_INVD14 when the intruder enters the positions PS1 to PS14 of the room 30, and the detection means 14A holds the received signal strengths RSSI_INVD1 to RSSI_INVD14 in advance. . The detection unit 14A also holds in advance a table TBL1 (see FIG. 25) indicating the correspondence between the received signal strengths RSSI_INVD1 to RSSI_INVD14 and the positions PS1 to PS14.

  The detecting unit 14A receives the received signal strength RSSI_TX from the strength detecting unit 13 at regular intervals, compares the received received signal strength RSSI_TX with the received signal strengths RSSI_INVD1 to RSSI_INVD14, and receives the received signal strengths RSSI_INVD1 to RSSI_INVD1. Received signal strength RSSI_INVD (any of received signal strengths RSSI_INVD1 to RSSI_INVD14) that matches the received signal strength RSSI_TX is detected from RSSI_INVD14. For example, when an intruder enters the position PS1, the detection unit 14A detects the received signal strength RSSI_INVD1 that matches the received signal strength RSSI_TX.

  Then, the detection means 14A refers to the table TBL1, detects the position PS1 corresponding to the received signal strength RSSI_INVD1, and detects that the intruder has entered the position PS1.

  When the intruder enters the positions PS2 to PS14 of the room 30, the detection unit 14A similarly detects that the intruder has entered the positions PS2 to PS14.

  Moreover, the detection means 14A may detect the intrusion and the intrusion position of the intruder by the following method. FIG. 26 is a conceptual diagram of a table showing the correspondence between reactance sets and positions at the time of entry.

The received signal strengths RSSI_INVD1 to RSSI_INVD14 when the intruder enters the positions PS1 to PS14 in the room 30 are obtained when the reactance set of the varactor diodes 121 to 126 is set to a predetermined reactance set. Accordingly, the detection unit 14A is reactance set _{x mINVD1 ~x mINVD14} when each received signal strength RSSI_INVD1~RSSI_INVD14 is obtained with (either each _x m1 _{~x m6),} and the reactance set _{x mINVD1 ~x mINVD14} position PS1 To a table TBL2 (see FIG. 26) indicating a correspondence relationship with PS14, and reactance sets corresponding to the reactance set _xmTX when the received signal strength RSSI_TX is obtained are a plurality of reactance sets _{xmINVD1 to} x _Detect from _mINVD14 . For example, the detection means 14A detects the reactance set _{x MINVD5} from among a plurality of reactance sets _{x mINVD1 ~x mINVD14.}

Then, the detection means 14A refers to the table TBL2, detects the position _PS5 corresponding to the reactance set _xmINVD5 , and detects that the intruder has entered the position _PS5 of the room 30.

  In addition, the detection unit 14 </ b> A performs the same function as the detection unit 14. The receiver 180 shown in FIG. 23 has the same configuration as the transmitter 170 shown in FIG. 24, and detects the intrusion of the intruder into the room 30 and the intrusion position by the method described above.

  The transmitter 170 and the receiver 180 have a function of transmitting and receiving the radio wave RF. However, when the intrusion detection system 100C actually operates, the transmitter 170 performs only the operation of transmitting the radio wave RF, and the receiver 180 The radio wave RF transmitted from the transmitter 170 is received, and the operation of detecting the intrusion and the intrusion position of the intruder is performed by the method described above.

  Accordingly, the detecting means 14A of the transmitter 170 generates a setting signal BSET for setting the directivity of the array antenna 11 to a predetermined directivity and outputs it to the directivity switching means 12, and the directivity switching means 12 In response to setting signal BSET, control voltage set CVL (any one of control voltage sets CVL1 to CVL6) is output to varactor diodes 121 to 126 to set the directivity of array antenna 11 to a predetermined directivity. Then, the communication means 15 feeds the antenna element 117 of the array antenna 11 and transmits the radio wave RF via the array antenna 11. Thereby, the transmitter 170 transmits the radio wave RF with a predetermined directivity.

  Then, the receiver 180 sequentially changes the directivity of the array antenna 11 to the 0 degree direction, 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction, and 300 degree direction. The radio wave RF transmitted from 170 is received, and based on the received signal strength RSSI_RX of the received radio wave RF, the intruder enters the room 30 and the intrusion position is detected by the method described above.

  More specifically, the detecting means 14A of the receiver 180 sets the directivity of the array antenna 11 to 0 degree direction, 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction, and 300 degree direction. A switching signal EXD for sequentially switching in the direction is generated and output to the directivity switching means 12. The directivity switching means 12 sequentially applies the control voltage sets CVL1 to CVL6 to the varactor diodes 121 to 126 in accordance with the switching signal EXD. The directivity of the array antenna 11 is sequentially switched to a 0 degree direction, a 60 degree direction, a 120 degree direction, a 180 degree direction, a 240 degree direction, and a 300 degree direction.

  Then, the array antenna 11 of the receiver 180 switches the directivity to the direction of 0 degree, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees sequentially. The radio wave RF from 170 is received, and the received radio wave RF is output from the antenna element 117 to the intensity detecting means 13. The intensity detecting means 13 of the receiver 180 detects the received signal intensity RSSI_RX of the radio wave RF received from the antenna element 117 of the array antenna 11 and outputs it to the detecting means 14A.

  Then, the detection unit 14A of the receiver 180 compares the received signal strength RSSI_RX received from the strength detecting unit 13 with the plurality of received signal strengths RSSI_INVD1 to RSSI_INVD14, and receives the received signal strength RSSI_INVD that matches the received signal strength RSSI_RX. It detects from signal strength RSSI_INVD1-RSSI_INVD14. Thereafter, when detecting means 14A of receiver 180 detects received signal strength RSSI_INVD (any one of received signal strength RSSI_INVD1 to RSSI_INVD14), it refers to table TBL1 and corresponds to received signal strength RSSI_INVD (positions PS1 to PS14). ) To detect the intrusion into the room 30 and the intrusion position.

In addition, when the detection unit 14A of the receiver 180 receives the reception signal strength RSSI_RX from the strength detection unit 13, the detection unit 14A detects the reception signal strength RSSI_INVD that matches the received reception signal strength RSSI_RX from the plurality of reception signal strengths RSSI_INVD1 to RSSI_INVD14. . Then, the detection unit 14A of the receiver 180 detects a reactance set when the received signal strength RSSI_INVD (either the received signal strength RSSI_INVD1～RSSI_INVD14) was obtained (either reactance set _{x mINVD1 ~x mINVD14),} Referring to table TBL2, for detecting the position corresponding to (either reactance set _{x mINVD1 ~x mINVD14)} reactance set (position PS1~PS14 Noji or deviation). Thereby, the detection means 14A of the receiver 180 detects the intrusion of the intruder into the room 30 and the intrusion position.

  In intrusion detection system 100C, receiver 180 transmits radio wave RF with the directivity of array antenna 11 set to a predetermined directivity, and transmitter 170 sets the directivity of array antenna 11 to a direction of 0 degrees. The radio wave RF transmitted from the receiver 180 is detected while sequentially switching to the 60 degree direction, 120 degree direction, 180 degree direction, 240 degree direction and 300 degree direction. The intrusion into the room 30 and the intrusion position may be detected.

  When detecting radio waves RF transmitted and received in the room 30 to detect an intruder, fading of received radio waves becomes a problem. Therefore, the transmitter 170 and the receiver 180 detect the intrusion and the intrusion position of the intruder while suppressing fading. Suppression of fading is performed by the following two methods.

(Fading suppression method 1)
The transmitter 170 sets the directivity of the array antenna 11 to a predetermined directivity and transmits the radio wave RF at two different frequencies f1 and f2. The receiver 180 changes the directivity of the array antenna 11 while changing the directivity of the array antenna 11. The two radio waves RF transmitted at the two frequencies f1 and f2 are received, and the intrusion and the intrusion position of the intruder are detected based on the two received signal strengths RSSI_RX1 and RSSI_RX2 corresponding to the two received radio waves.

  In this case, the intensity detection means 13 of the receiver 180 includes the received signal strengths RSSI_INVD1 (f1) to RSSI_INVD14 (f1) at the frequency f1 when the intruder enters the positions PS1 to PS14, and the intruders at the positions PS1 to PS1. Received signal strengths RSSI_INVD1 (f2) to RSSI_INVD14 (f2) at the frequency f2 when entering the PS14 are detected in advance. And the detection means 14A of the receiver 180 holds reception signal strengths RSSI_INVD1 (f1) to RSSI_INVD14 (f1) and reception signal strengths RSSI_INVD1 (f2) to RSSI_INVD14 (f2) in advance.

  FIG. 27 is a conceptual diagram of another table showing the correspondence between received signal strength and position at the time of entry. FIG. 27A shows the correspondence between the received signal strength and the position when the radio wave RF transmitted at the frequency f1 enters, and FIG. 27B shows the intrusion of the radio wave RF transmitted at the frequency f2. The correspondence relationship between the received signal strength and the position at the time is shown.

  The detection means 14A of the receiver 180 holds the tables TBL3 and TBL4 in advance. The array antenna 11 of the receiver 180 receives the radio wave RF1 transmitted at the frequency f1, outputs the received radio wave RF1 to the intensity detecting means 13, receives the radio wave RF2 transmitted at the frequency f2, and receives the radio wave RF2. The radio wave RF <b> 2 is output to the intensity detection means 13.

  The intensity detector 13 of the receiver 180 detects the received signal strengths RSSI_RX (f1) and RSSI_RX (f2) of the radio waves RF1 and RF2, and the detected received signal strengths RSSI_RX (f1) and RSSI_RX (f2) are detected 14A. Output to.

  Upon receiving the received signal strength RSSI_RX (f1) from the strength detector 13, the detecting unit 14A of the receiver 180 receives the received signal strength RSSI_INVD (f1) (received signal strength RSSI_INVD1) that matches the received signal strength RSSI_RX (f1). (Any one of (f1) to RSSI_INVD14 (f1)) and referring to the table TBL3, the position PS (f1) corresponding to the received signal strength RSSI_INVD (f1) at the time of entry (any one of the positions PS1 to PS14) Is detected. Further, when the detection unit 14A of the receiver 180 receives the received signal strength RSSI_RX (f2) from the strength detection unit 13, the received signal strength RSSI_INVD (f2) (received signal at the time of intrusion that matches the received signal strength RSSI_RX (f2). Intensity RSSI_INVD1 (f2) to RSSI_INVD14 (f2)) is detected, and table PSL4 is referred to, and position PS (f2) corresponding to reception signal intensity RSSI_INVD (f2) at the time of intrusion (any of positions PS1 to PS14) ) Is detected. Then, the detection unit 14A of the receiver 180 detects the position PS (f1) = PS (f2) as the entry position of the intruder when the position PS (f1) matches the position PS (f2). On the other hand, when the position PS (f1) does not coincide with the position PS (f2), the detection unit 14A of the receiver 180 does not detect the positions PS (f1) and PS (f2) as intrusion positions of the intruder.

  FIG. 28 is a conceptual diagram of another table showing the correspondence between reactance set and position at the time of entry. 28A shows the correspondence between the reactance set and the position when the radio wave RF transmitted at the frequency f1 enters, and FIG. 28B shows the response time when the radio wave RF transmitted at the frequency f2 enters. The correspondence relationship between the reactance set and the position is shown.

Detecting means 14A of the receiver 180, reactance set _{x mINVD1 (f1) ~x mINVD14 (} f1) ( each time the respective received signal strength RSSI_INVD1 (f1) ~RSSI_INVD14 (f1) is obtained either _x m1 _{~x m6} ), And reactance sets x _mINVD1 (f2) to x _mINVD14 (f2) (each of x _m1 to x _m6 ) when the received signal strengths RSSI_INVD1 (f2) to RSSI_INVD14 (f2) are obtained, and a table TBL5 and TBL6 are held in advance. Upon receiving the received signal strength RSSI_RX (f1) from the strength detecting unit 13, the detecting unit 14A of the receiver 180 detects the reactance set x _m (f1) when the received signal strength RSSI_RX (f1) is obtained. detecting a detected reactance set _x m (f1) to the reactance set _x MINVD during penetration that match (f1) (either reactance set _{x mINVD1 (f1) ~x mINVD14 (} f1)), by referring to the table TBL5 Then, a position PS (f1) (any one of positions PS1 to PS14) corresponding to the reactance set x _mINVD (f1) at the time of intrusion is detected. Further, when the detection unit 14A of the receiver 180 receives the received signal strength RSSI_RX (f2) from the strength detection unit 13, the detection unit 14A detects the reactance set x _m (f2) when the received signal strength RSSI_RX (f2) is obtained. , detects the detected reactance set _x m (f2) to the reactance set _x MINVD during penetration that match (f2) (either reactance set _{x mINVD1 (f2) ~x mINVD14 (} f2)), see table TBL6 Then, the position PS (f2) (any one of the positions PS1 to PS14) corresponding to the reactance set x _mINVD (f2) at the time of entry is detected. Then, the detection unit 14A of the receiver 180 detects the position PS (f1) = PS (f2) as the entry position of the intruder when the position PS (f1) matches the position PS (f2). On the other hand, when the position PS (f1) does not coincide with the position PS (f2), the detection unit 14A of the receiver 180 does not detect the positions PS (f1) and PS (f2) as intrusion positions of the intruder.

  Thus, when the two positions detected based on the received signal strengths RSSI_RX (f1) and RSSI_RX (f2) of the radio waves RF1 and RF2 transmitted at the two frequencies f1 and f2 match, It is detected as the intrusion position of the intruder.

  Since two radio waves RF1 and RF2 having different frequencies transmitted from the transmitter 170 reach the receiver 180 via different propagation paths, the influence of fading can be suppressed by detecting the intrusion position of the intruder by the above-described method. .

  In the above description, the transmitter 170 has been described as setting the directivity of the array antenna 11 to a predetermined directivity and transmitting the radio wave RF at two different frequencies f1 and f2. However, in the present invention, Not limited to this, the transmitter 170 may set the directivity of the array antenna 11 to a predetermined directivity, and may transmit radio waves at three or more different frequencies. The directivity of the antenna 11 may be set to a predetermined directivity, and radio waves may be transmitted at a plurality of different frequencies. The receiver 180 receives a plurality of radio waves transmitted from the transmitter 170 while sequentially switching the directivity of the array antenna 11 to six directivities, and receives a plurality of receptions corresponding to the received plurality of radio waves. Based on the plurality of reactance sets when the signal strength or the plurality of received signal strengths are obtained, the intrusion position of the intruder is detected by the method described above.

(Fading suppression method 2)
The transmitter 170 transmits radio waves while switching the radio wave transmission direction in two directions at regular intervals, and the receiver 180 switches the directivity of the array antenna 11 to six directivities in two directions. 2 is received, and the intrusion position of the intruder is detected based on two received signal strengths corresponding to the two received radio waves.

  In this case, switching the radio wave transmission direction to two directions at regular intervals corresponds to switching the directivity of the array antenna 11 of the transmitter 170 to two directivities at regular intervals. Therefore, transmitter 170 transmits radio waves by switching the directivity of array antenna 11 to two directivities at regular intervals.

  In addition, the intensity detection means 13 of the receiver 180 includes received signal strengths RSSI_INVD1 (θ1) to RSSI_INVD14 (θ1) of radio waves transmitted in the direction θ1 when the intruder enters the positions PS1 to PS14, and the intruder The received signal strengths RSSI_INVD1 (θ2) to RSSI_INVD14 (θ2) transmitted in the direction θ2 when entering the positions PS1 to PS14 are detected in advance. And the detection means 14A of the receiver 180 holds the received signal strengths RSSI_INVD1 (θ1) to RSSI_INVD14 (θ1) and the received signal strengths RSSI_INVD1 (θ2) to RSSI_INVD14 (θ2) in advance.

  FIG. 29 is a conceptual diagram of still another table showing the correspondence between the received signal strength and the position at the time of entry. 29A shows the correspondence between the received signal intensity and the position when the radio wave RF transmitted in the direction θ1 enters, and FIG. 29B shows the intrusion of the radio wave RF transmitted in the direction θ2. The correspondence relationship between the received signal strength and the position at the time is shown.

  The detection means 14A of the receiver 180 holds the tables TBL7 and TBL8 in advance. The array antenna 11 of the receiver 180 receives the radio wave RF1 transmitted in the direction θ1, outputs the received radio wave RF1 to the intensity detecting means 13 by the antenna element 117, and receives the radio wave RF2 transmitted in the direction θ2. Then, the received radio wave RF 2 is output to the intensity detecting means 13 by the antenna element 117.

  The intensity detector 13 of the receiver 180 detects the received signal strengths RSSI_RX (θ1) and RSSI_RX (θ2) of the radio waves RF1 and RF2, and detects the detected received signal strengths RSSI_RX (θ1) and RSSI_RX (θ2) 14A. Output to.

  Upon receiving the received signal strength RSSI_RX (θ1) from the strength detector 13, the detecting unit 14A of the receiver 180 receives the received signal strength RSSI_INVD (θ1) (received signal strength RSSI_INVD1) that matches the received signal strength RSSI_RX (θ1). Any one of (θ1) to RSSI_INVD14 (θ1)) is detected and the position PS (θ1) corresponding to the received signal strength RSSI_INVD (θ1) at the time of intrusion (any one of the positions PS1 to PS14) is referred to the table TBL7 Is detected. Further, when the detection unit 14A of the receiver 180 receives the received signal strength RSSI_RX (θ2) from the strength detection unit 13, the received signal strength RSSI_INVD (θ2) (received signal at the time of intrusion that matches the received signal strength RSSI_RX (θ2). The intensity RSSI_INVD1 (θ2) to RSSI_INVD14 (θ2)) is detected, and the position TPS (θ2) corresponding to the reception signal intensity RSSI_INVD (θ2) at the time of intrusion (any of positions PS1 to PS14) is referred to the table TBL8. ) Is detected. Then, the detection unit 14A of the receiver 180 detects the position PS (θ1) = PS (θ2) as the entry position of the intruder when the position PS (θ1) matches the position PS (θ2). On the other hand, when the position PS (θ1) does not coincide with the position PS (θ2), the detection unit 14A of the receiver 180 does not detect the positions PS (θ1) and PS (θ2) as intrusion positions of the intruder.

  FIG. 30 is a conceptual diagram of still another table showing the correspondence between reactance set and position at the time of entry. 30A shows the correspondence between the reactance set and the position when the radio wave RF transmitted in the direction θ1 enters, and FIG. 30B shows the correspondence between the radio wave RF transmitted in the direction θ2. The correspondence relationship between the reactance set and the position is shown.

Detecting means 14A of the receiver 180, reactance set _{x MINVD1} when each received signal strength RSSI_INVD1 (θ1) ~RSSI_INVD14 (θ1) is obtained _{(θ1) ~x mINVD14 (θ1)} ( each one of the _x m1 _{~x m6} whether), a reactance set _{x MINVD1} when each received signal strength RSSI_INVD1 (θ2) ~RSSI_INVD14 (θ2) is obtained _{(θ2) ~x mINVD14 (θ2)} ( one of each _x m1 _{~x m6),} table TBL9 and TBL10 are held in advance. Upon receiving the received signal strength RSSI_RX (θ1) from the strength detector 13, the detecting unit 14A of the receiver 180 detects the reactance set x _m (θ1) when the received signal strength RSSI_RX (θ1) is obtained. detecting a detected reactance set _{x m} (θ1) to the reactance set _{x MINVD} during penetration that match (.theta.1) (either reactance set _{x mINVD1 (θ1) ~x mINVD14 (} θ1)), by referring to the table TBL9 The position PS (θ1) (any of the positions PS1 to PS14) corresponding to the reactance set x _mINVD (θ1) at the time of intrusion is detected. In addition, when the detection unit 14A of the receiver 180 receives the received signal strength RSSI_RX (θ2) from the strength detection unit 13, the detection unit 14A detects the reactance set x _m (θ2) when the received signal strength RSSI_RX (θ2) is obtained. detects an intrusion upon the reactance set _{x MINVD} matching the detected reactance set _{x m (θ2) (θ2)} ( either reactance set _{x mINVD1 (θ2) ~x mINVD14 (} θ2)), see table TBL10 Then, the position PS (θ2) (any of the positions PS1 to PS14) corresponding to the reactance set x _mINVD (θ2) at the time of entry is detected. Then, the detection unit 14A of the receiver 180 detects the position PS (θ1) = PS (θ2) as the entry position of the intruder when the position PS (θ1) matches the position PS (θ2). On the other hand, when the position PS (θ1) does not coincide with the position PS (θ2), the detection unit 14A of the receiver 180 does not detect the positions PS (θ1) and PS (θ2) as intrusion positions of the intruder.

  Thus, when the two positions detected based on the received signal strengths RSSI_RX (θ1) and RSSI_RX (θ2) of the radio waves RF1 and RF2 transmitted in the two directions θ1 and θ2 match, It is detected as the intrusion position of the intruder.

  Since two radio waves RF1 and RF2 transmitted in different directions from the transmitter 170 reach the receiver 180 via different propagation paths, the influence of fading can be suppressed by detecting the intrusion position of the intruder by the above-described method. .

  In the above description, it has been described that the transmitter 170 transmits the radio wave RF in the two different directions θ1 and θ2 using the array antenna 11, but in the present invention, the transmitter 170 is not limited thereto. May transmit radio waves in three or more directions different from each other using the array antenna 11, and generally, if radio waves are transmitted in a plurality of mutually different directions using the array antenna 11. Good. The receiver 180 receives a plurality of radio waves transmitted from the transmitter 170 while sequentially switching the directivity of the array antenna 11 to six directivities, and receives a plurality of receptions corresponding to the received plurality of radio waves. Based on the plurality of reactance sets when the signal strength or the plurality of received signal strengths are obtained, the intrusion position of the intruder is detected by the method described above.

  The intrusion detection system 100C according to the fourth embodiment may further include the network 140, the camera 150, and the security department 160 illustrated in FIG. In this case, the transmitter 170 and the receiver 180 are connected to the network 140. When the receiver 180 detects the intrusion of the intruder into the room 30 and the intrusion position, the receiver 180 transmits a signal INVD to the camera 150 via the network 140. Others are as described in the first and third embodiments.

  As described above, according to the present invention, the transmitter transmits a radio wave having directivity, and the receiver intrudes and / or positions of intrusion based on the received signal strength of the radio wave having directivity. Is detected. The fluctuation range of the received signal intensity of the directional radio wave is smaller than the fluctuation range of the received signal intensity of the non-directional radio wave.

  Therefore, according to the present invention, the intrusion detection capability can be improved.

  Further, according to the present invention, the transmitter transmits radio waves at different frequencies, or transmits radio waves in different directions, and the receiver has a plurality of radio waves corresponding to a plurality of radio waves having different frequencies. Intrusion and / or intrusion position based on the received signal strength of the intruder and / or intruder intrusion and / or based on the plurality of received signal strengths corresponding to the plurality of radio waves transmitted in different directions Detect intrusion location.

  Therefore, according to the present invention, it is possible to detect the intrusion of the intruder and the intrusion position while suppressing the fading of the radio wave. As a result, the intrusion detection capability can be improved.

  In the above, the reactance value of the varactor diode loaded on one of the antenna elements 111 to 116 (= parasitic element) of the array antenna 11 is set to “hi”, and the other parasitic elements are loaded. The varactor diode reactance value is set to “lo” and directional radio waves are transmitted. However, the present invention is not limited to this, and is loaded on two or three adjacent parasitic elements. The reactance value of the varactor diode may be set to “hi”, and the reactance value of the varactor diode loaded on the other parasitic element may be set to “lo” to transmit the directional radio wave. Thereby, since the beam width of the beam radiated from the array antenna 11 can be reduced, the intrusion detection sensitivity (intrusion detection capability) of the intruder can be further improved.

  In the above description, it has been described that an intruder has entered based on the received signal strength of the radio wave. However, in the present invention, the intruder is not limited to this, and the intruder is in the room 30 based on the radio wave pattern. An intrusion may be detected. When an intruder enters the room 30, the radio wave pattern in the room 30 changes, and as a result, the received signal strength of the radio waves in the receivers 20, 90, 130, and 180 changes as shown in FIGS. To do. Therefore, detecting that the intruder has entered the room 30 based on the received signal strength of the radio wave is equivalent to detecting that the intruder has entered the room 30 based on the radio wave pattern. It is.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to an intrusion detection system having a high intrusion detection capability.

It is the schematic which shows the structure of the intrusion detection system by Embodiment 1 of this invention. It is the schematic which shows the structure of the transmitter shown in FIG. FIG. 3 is a plan layout view of antenna elements in an xy plane shown in FIG. 2. It is the schematic which shows the structure of the receiver shown in FIG. It is a figure which shows the experimental result of an intrusion detection when an array antenna transmits / receives an electromagnetic wave omnidirectionally. It is a figure which shows the experimental result of the intrusion detection in the pattern 1. FIG. FIG. 10 is a first diagram showing an intrusion detection experimental result in Pattern 2. FIG. 10 is a second diagram showing an intrusion detection experiment result in Pattern 2. FIG. 10 is a first diagram showing an intrusion detection experimental result in Pattern 3. FIG. 11 is a second diagram showing an intrusion detection experiment result in Pattern 3. FIG. 10 is a third diagram showing an intrusion detection experimental result in Pattern 3. FIG. 10 is a fourth diagram showing an intrusion detection experimental result in Pattern 3. FIG. 10 is a fifth diagram showing an intrusion detection experimental result in Pattern 3. It is a 6th figure which shows the experimental result of the intrusion detection in the pattern 3. FIG. FIG. 10 is a first diagram showing an intrusion detection experimental result in pattern 4. FIG. 11 is a second diagram showing an intrusion detection experimental result in pattern 4. FIG. 10 is a third diagram showing an intrusion detection experimental result in pattern 4. FIG. 11 is a fourth diagram showing an intrusion detection experiment result in Pattern 4. FIG. 10 is a fifth diagram showing an intrusion detection experimental result in Pattern 4. It is a 6th figure which shows the experimental result of the intrusion detection in the pattern 4. FIG. It is the schematic which shows the structure of the intrusion detection system by Embodiment 2. FIG. FIG. 10 is a schematic diagram illustrating a configuration of an intrusion detection system according to a third embodiment. It is the schematic which shows the structure of the intrusion detection system by Embodiment 4. FIG. It is the schematic which shows the structure of the transmitter shown in FIG. It is a conceptual diagram of the table which shows the correspondence of the received signal strength at the time of invasion, and a position. It is a conceptual diagram of the table which shows the correspondence of the reactance set at the time of invasion, and a position. It is a conceptual diagram of the other table which shows the correspondence of the received signal strength at the time of invasion, and a position. It is a conceptual diagram of the other table which shows the correspondence of the reactance set at the time of invasion, and a position. It is a conceptual diagram of the other table which shows the correspondence of the received signal strength at the time of intrusion, and a position. It is a conceptual diagram of the other table which shows the correspondence of the reactance set at the time of invasion, and a position.

Explanation of symbols

  10, 170 transmitter, 11 array antenna, 12 directivity switching means, 13, 22 intensity detection means, 14, 14A, 23 detection means, 15, 24 communication means, 20, 90, 130, 180 receiver, 21, 91 , 131 antenna, 30 rooms, 31 windows, 32 doors, 40 desks, 50 foliage plants, 60, 70 white board, 80 television, 100, 100A, 100B, 100C intrusion detection system, 111-117 antenna element, 121-126 varactor Diode, 140 network, 150 camera, 160 security department, 161 CRT.

Claims (8)

An intrusion detection system for detecting an intruder entering a room,
A transmitter that transmits radio waves having directivity;
An intrusion detection system comprising: a receiver that receives a radio wave transmitted from the transmitter and detects an intrusion of the intruder into the room based on a received radio wave intensity of the received radio wave. An intrusion detection system for detecting an intruder entering a room,
A transmitter that transmits radio waves having directivity;
An intrusion detection system comprising: a receiver that receives radio waves transmitted from the transmitter and detects intrusion of the intruder into the room based on a pattern of the received radio waves. The receiver detects the intrusion of the intruder into the room when the received radio wave intensity is a predetermined value or more away from a reference value;
The intrusion detection system according to claim 1, wherein the reference value is an average value of the received radio wave intensity when the intruder does not enter the room.   4. The transmitter according to claim 1, wherein the transmitter transmits the radio wave by switching the directivity to one directivity selected from a plurality of directivities for each arbitrary number of transmissions. 5. Intrusion detection system. The receiver comprises a plurality of receivers arranged at different positions in the room,
The intrusion detection system according to any one of claims 1 to 4, wherein each of the plurality of receivers receives a radio wave transmitted from the transmitter via a directional antenna.   The intrusion detection system according to claim 1, wherein the receiver further detects an intrusion position of the intruder based on the received signal strength. The transmitter transmits a plurality of radio waves at a plurality of different frequencies,
The intrusion detection system according to claim 6, wherein the receiver detects an intrusion position of the intruder based on a plurality of received signal strengths of a plurality of radio waves transmitted at the plurality of frequencies. The transmitter transmits radio waves in a plurality of directions different from each other,
The intrusion detection system according to claim 7, wherein the receiver detects an intrusion position of the intruder based on a plurality of received signal strengths of a plurality of radio waves transmitted in the plurality of directions.