JP2006064528A - Sensor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor system which is insensitive to effect of the surface condition of a body and the environmental condition of an installation site in detecting the presence of a body within a target detection area. <P>SOLUTION: A transmitter 3 for transmitting a compressional wave to the target detection area and a receiver 5 for receiving the compressional wave transmitted by the transmitter 3 and converting it into a receiving signal are positioned on the opposite sides across the detection area. A detection section detects the presence of a body C which intercepts the compressional wave from the transmitter 3 to the receiver 5 through a change in the receiving signal from the receiver 5. The receiver 5 comprises a plurality of receiving elements 7 each of which receives the compressional wave and outputs the receiving signal. The detection section recognizes a direction the receiver 5 receives the compressional wave through a time difference between respective receiving signals of receiving elements 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sensor device that transmits a coarse / fine wave to a target detection region and detects the presence of an object in the detection region using the coarse / fine wave.

Conventionally, as a sensor device of this type, a transmitter for transmitting a close-packed wave and a receiver for receiving a close-packed wave are provided adjacent to each other, and the close-packed wave transmitted from the transmitter is within the detection region. A so-called reflection type is known that determines that an object is present in the detection area when it is reflected by an object existing in the area and returns to the receiver. Here, the range of the detection region is delimited by the distance at which the dense wave can reciprocate from the sensor device, and this distance is the time range during which the receiver receives the dense wave after the transmitter sends the dense wave. Set by If this sensor device is used, for example, as shown in FIG. 18, it is possible to install the sensor device A at the entrance D of the room and detect a person entering and exiting the room (see, for example, Patent Document 1).
Japanese Patent Laying-Open No. 2004-180262 (page 10, FIG. 12)

  However, in the reflection-type sensor device A as described above, the dense wave is reflected by the object C in order to detect the presence of the object C, and therefore the surface state of the object C and the environment of the installation location. Depending on the conditions, the intensity of the reflected wave received by the receiver may be insufficient, or a dense wave from an unnecessary direction may be received. Even if the object C exists in the detection area, it can be detected. May be misreported, or may be misreported if the object C exists in the detection area even though the object C does not exist in the detection area.

  The present invention has been made in view of the above reasons, and in detecting the presence of an object in a target detection region, a sensor device that is not easily affected by the state of the surface of the object and the environmental conditions of the installation location. The purpose is to provide.

  According to the first aspect of the present invention, a transmitter that transmits a close-packed wave to a target detection region, a drive unit that drives the transmitter, and a transmitter that is disposed across the detection region with respect to the transmitter A receiver that receives the received signal from the receiver and receives the received signal from the receiver, and receives the received signal from the receiver. A detection unit that detects the presence of an object that blocks the dense wave from the transmitter to the receiver in the detection region, and each of the receivers receives the coarse wave and outputs a received signal. The receiving device is arranged, and the detection unit identifies the direction in which the receiver has received the dense wave by the time difference between the received signals of each receiving device.

  According to this configuration, since the presence of an object that blocks the dense wave from the transmitter to the receiver is detected, there is an advantage that it is not affected by the state of the surface of the object. In addition, since the detection unit identifies the direction in which the receiver has received the dense wave, even if the receiver receives a dense wave due to wraparound when an object exists in the detection area, It is possible to distinguish between the coarse / fine wave directly received from the transmitter and the coarse / fine wave caused by wraparound, and as a result, the presence of an object in the detection region can be detected.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the receiver receives a close-packed wave from the direction of the transmitter, the detection unit receives received signals from all the receiving elements. Delay means for delaying the received signal from each receiving element by a delay time set so as to match the timing, adding means for adding the received signals delayed by the delay means, and adding by the adding means And determining means for determining that an object is present in the detection area when the amplitude of the received signal falls below a predetermined threshold value.

  According to this configuration, the receiver detects the presence of an object by a change in the intensity of the dense wave received from the direction of the transmitter, and the receiver is from a different direction from the transmitter. There will be no false alarms when receiving signals from external noise or multiple reflections.

  According to a third aspect of the present invention, in the first aspect of the invention, the detection unit includes an intensity distribution detecting unit that detects an intensity distribution of the dense waves in each direction in the detection area from the output of the receiver, and a detection area. A storage means for storing the intensity distribution detected by the intensity distribution detection means during a period in which no object is present, and within the detection region when the intensity distribution detected by the intensity distribution detection means changes from the intensity distribution stored in the storage means And determining means for determining that an object is present.

  According to this configuration, since the presence of an object can be detected over a spatial range in which the intensity distribution of the density wave is detected by the intensity distribution detection means, the detection area can be set relatively wide.

  Invention of Claim 4 is a sensor apparatus which detects the object which moves in the said detection area | region in any invention of Claim 1 thru | or 3, Comprising: A plurality of said receivers are arranged in one direction, The detection unit includes direction detection means for detecting the direction of movement of the object in the one direction according to the order in which the amplitude of the received signal changes between the receivers.

  According to this configuration, since it is possible to detect the direction of movement of the object moving in the detection area, it is possible to distinguish between entering and leaving the room installed at the entrance of the room.

  A fifth aspect of the present invention is the sensor device according to any one of the first to fourth aspects of the present invention, wherein the sensor device detects an object moving in the detection region, and a plurality of the receivers are provided in a height direction of the object. The detection unit includes a height detection unit configured to detect the height of the object based on the number of receivers in which the amplitude of the reception signal is changed.

  According to this configuration, it is possible to detect the height of the object moving in the detection region, and thus it is possible to distinguish whether the object is a person or a small animal instead of a person.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, when the detection unit determines that an object is present in the detection region, the change in the amplitude of the received signal increases. It has a size judging means for judging that an object existing in the detection area is large.

  According to this configuration, it is possible to determine the size of the object existing in the detection region, and thus it is possible to distinguish whether the object is a person or a small animal instead of a person.

  According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the driving unit is a transmission element that is a sound source of a transmitter so as to generate a continuous dense wave in the transmitter. Are continuously driven.

  According to this configuration, the presence of an object in the detection area can be constantly monitored.

  According to an eighth aspect of the present invention, in the invention according to any one of the first to sixth aspects, the driving unit intermittently transmits a transmitting element that is a sound source of the transmitter so that the dense wave is intermittently transmitted. And a timing control unit that determines the timing at which the received signal is valid after the transmitter transmits a coarse / fine wave.

  According to this configuration, the received signal becomes valid at the timing determined by the timing control unit, and is received only during the period in which the receiver receives the coarse / fine wave transmitted from the transmitter. Since the signal can be validated, it is possible to prevent the detection unit from malfunctioning upon receiving a received signal due to external noise or multiple reflections.

  According to a ninth aspect of the present invention, in the eighth aspect of the present invention, the driving section causes a single pulse current to flow through the transmission element so as to generate a single dense wave in the transmitter.

  According to this configuration, since side lobes can be prevented from occurring in the dense wave transmitted from the transmitter, by transmitting the dense wave from the transmitter to the receiver, external noise and It is possible to prevent the detection unit from malfunctioning when receiving a received signal due to multiple reflection or the like.

  According to a tenth aspect of the present invention, in the eighth or ninth aspect of the invention, the driving unit drives the transmission element at a constant time interval so that the transmitter generates a dense wave at a constant time interval. It is characterized by that.

  According to this configuration, since the timing for validating the received signal can be set at a constant time interval, the timing for validating the received signal can be determined without synchronizing the transmitter and the receiver. Can do.

  According to an eleventh aspect of the present invention, in the invention according to any one of the eighth to tenth aspects, the transmitter does not have a resonance frequency in the frequency of the coarse / fine wave transmitted, and the receiver is the transmitter. This is characterized in that the frequency of the dense wave transmitted from the wave does not have a resonance frequency.

  According to this configuration, it is prevented that the reverberation component is included in the dense wave transmitted from the transmitter, and it is prevented that the reverberant component remains after receiving the dense wave in the receiver. The time difference between the received signals of each receiving element does not spread in the time axis direction due to the reverberant component, and the direction in which the receiver receives the dense wave can be accurately identified in the detector.

  Since the present invention detects the presence of an object that blocks a dense wave from a transmitter to a receiver, there is an advantage that it is not affected by the state of the surface of the object. In addition, since the detection unit identifies the direction in which the receiver has received the dense wave, even if the receiver receives a dense wave due to wraparound when an object exists in the detection area, It is possible to distinguish between the coarse / fine wave directly received from the transmitter and the coarse / fine wave caused by wraparound, and as a result, the presence of an object in the detection region can be detected.

(Embodiment 1)
In this embodiment, as shown in FIG. 2, a sensor device A that detects an object C passing through the detection region using a part of the passage B as a detection region will be described. As shown in FIG. 1, the sensor device A of the present embodiment is installed with a detection area sandwiched between a transmission means 1 for transmitting a dense wave to a detection area (in the air) and the transmission means 1. And a wave receiving means 2 for receiving the close-packed wave from the wave transmitting means 1. The wave transmitting means 1 and the wave receiving means 2 are arranged so that the dense waves from the wave transmitting means 1 to the wave receiving means 2 are blocked when the object C passes through the detection area through the path B. Installed on both sides.

  As shown in FIG. 3, the wave transmitting means 1 drives a wave transmitter 3 that converts a wave signal, which is an electric signal, into a dense wave, and the wave transmitter 3 so that the coarse wave is intermittently transmitted. The receiving unit 2 includes a driving unit 4, and the wave receiving unit 2 receives the coarse / fine wave and converts the coarse / fine wave into a wave reception signal that is an electric signal, and the wave reception signal from the wave receiver 5. And a detection unit 6 that detects the object C passing through the detection region by a change in the amplitude of the received signal. Here, the receivers 5 are arranged at equal intervals in the longitudinal direction of the passage B so that the direction in which the object C moves in the detection area can be specified. In order to explain the configuration for detecting the above, first, a single receiver 5 will be explained.

  In the present embodiment, the detector 6 identifies the direction in which the receiver 5 has received the dense wave. Specifically, a receiver 5 is configured by arranging a plurality of receiving elements 7 each receiving a close-packed wave and outputting a received signal, and the detector 6 receives each of the receiving elements 7. The direction in which the receiver 5 receives the dense wave is identified by the time difference between the signals. If a plurality of wave receiving elements 7 are arranged, for example, when receiving a dense wave from an azimuth inclined by an angle θ ° with respect to a direction orthogonal to the surface on which the wave receiving elements 7 are arranged in the wave receiver 5, The time difference between the received signals of the adjacent receiving elements 7 (with the interval d) is (the interval d of the receiving elements 7) × (sin θ) ÷ (sound velocity) (see FIG. 4). The receiver 5 of the present embodiment has five in the vertical direction (vertical direction) and five in the horizontal direction (horizontal direction) on one surface orthogonal to the direction connecting the receiver 5 and the transmitter 3. A total of ten receiving elements 7 are arranged at equal intervals.

  By the way, the detection unit 6 of the present embodiment detects the presence or absence of the object C in the detection region using only the received signal corresponding to the dense wave received by the receiver 5 from the direction of the transmitter 3. 3, the amplifier 11 that amplifies the received signal from the receiver 5, the AD converter 12 that A / D converts the received signal amplified by the amplifier 11, and the digital signal by the AD converter 12 It has a frame memory 13 that stores the received signal that has been converted into a signal, and an arithmetic unit 8 that determines the presence or absence of the object C within the detection area using the received signal stored in the frame memory 13. Here, when only processing of the phase difference or amplitude of the received signal is performed, the AD converter 12 may be used instead of the AD converter 12, but the AD converter 12 is employed in this embodiment. . Here, the amplification factor of the amplifier 11 is set to 40 dB to 60 dB, and the S / N ratio is about 60 dB. A 16-bit AD converter 12 is used, and the sampling frequency is 1 MHz. A series of processing of amplifying the received signal, A / D converting it, and storing it in the frame memory 13 is performed for each receiving element 7. The frame memory 13 has a storage area divided for each receiving element 7 so that the amplitude of the received signal can be stored for each sampling period (here, 1 μs) of the AD converter 12.

  The computing unit 8 serves as a delay unit that delays the received signal from each receiving element 7 in order to identify the received signal corresponding to the dense wave received by the receiver 5 from the direction of the transmitter 3. And a function as an adding means for adding received signals delayed by the delay means. Here, the computing unit 8 receives each reception unit as a delay unit for a delay time set so that the timings of all received signals coincide when the receiver 5 receives a dense wave from the direction of the transmitter 3. In a state where the wave signal is delayed, the received signal is read from the frame memory 13 for each of the receiving elements 7, so that the received signal corresponding to the dense wave received by the receiver 5 from the direction of the transmitter 3. Can be taken out as the output of the adding means.

  That is, even when a time difference as shown in FIG. 5 (a) occurs between the received signals of the receiving elements 7 when the receiver 5 receives a dense wave from the direction of the transmitter 3, By delaying each received signal, the timings of all received signals can be matched as shown in FIG. Then, by adding all the received signals after the delay as shown in FIG. 5C, a received signal corresponding to the dense wave received by the receiver 5 from the direction of the transmitter 3 is obtained. Can do it. Here, if the delay time is set as described above, the received signal corresponding to the dense wave received by the receiver 5 from an oblique direction can be used as the output of the adding means. As long as it is within the range in which the dense wave from 3 can be received, it may be installed to be inclined with respect to the transmitter 3 without facing the transmitter 3.

  Further, the computing unit 8 has a function as a determination unit that determines the presence / absence of the object C in the detection region from a change in the amplitude of the added reception signal. In the determination unit, the amplitude of the reception signal after the addition is determined. And the predetermined threshold value are compared to determine the presence or absence of the object C. The determination means determines that the object C exists in the detection area when the amplitude of the received signal after the addition falls below the threshold value.

  By the way, in this embodiment, the calculator 8 of the detection part 6 is connected to the drive part 4 of the wave transmission means 1 as shown in FIG. 3, and according to the timing with which the wave transmitter 3 transmits a rough wave. It has a function as a timing control unit that determines a period during which the received signal is valid (hereinafter referred to as a “received period”). If the distance between the transmitter 3 and the receiver 5 is constant, the time required for the dense wave transmitted from the transmitter 3 to reach the receiver 5 (hereinafter referred to as “transmitting time”). ) Is constant, the timing control unit is set to start the reception period after the transmission time has elapsed since the driving unit 4 drives the transmitter 3. By having the function as the timing control unit in this way, the received signal can be made effective only during the period in which the receiver 5 receives the coarse / fine wave transmitted from the transmitter 3. It is possible to prevent the detection unit 6 from malfunctioning by receiving a received signal due to noise, multiple reflection, or the like. However, in this embodiment, the drive unit 4 drives the transmitter 3 at a constant time interval, and the reception period is also at a constant time interval. What is necessary is just to synchronize a timing once every time it forwards.

  Further, the AD converter 12 may be provided with a function as a timing control unit so that the AD converter 12 can convert the received signal into a digital signal only during the reception period. When the number of receiving elements 7 is 10 as in the embodiment, a frame memory 13 of (30 ms) × (1 MHz) × (16 bits) × (10) = (600 kbytes) is required.

  On the other hand, in the present embodiment, by adopting the transmitter 3 and the receiver 5 that do not have a resonance frequency as the frequency of the transmitted / received coarse / fine wave, the coarse / fine wave transmitted from the transmitter 3 is used. In the case where both the reverberation component in the signal and the reverberation component in the received signal output from the receiver 5 are relatively small, and the dense wave from the transmitter 3 to the receiver 5 is blocked by the object C. The amplitude of the received signal is changed regardless of the reverberation component.

  As a specific configuration, the transmitter 3 employs a thermal excitation type as shown in FIG. This transmitter 3 includes a substrate 14 made of single crystal silicon or the like, a thermal insulating layer 15 made of nanocrystalline silicon or the like provided on the substrate 14, and a thermal insulating layer as a transmitting element that is a sound source of the transmitter. 15 and a metal thin film 16 made of aluminum or the like formed on the substrate 15. In FIG. 6, a pair of current-carrying electrodes 17 are provided on the left and right ends of the metal thin film 16 formed on both sides of the heat insulating layer 15. The metal thin film 16 generates heat when energized through the energizing electrode 17, and the heat insulating layer 15 prevents the heat from the metal thin film 16 from escaping to the substrate 14 side.

  Here, when the drive unit 4 applies an AC voltage between the energizing electrodes 17 and causes a drive current as a transmission signal to flow, a medium (air) in contact with the metal thin film 16 is caused by the temperature change of the metal thin film 16. It expands and contracts to generate a dense wave having the same frequency as the drive current. As described above, the transmitter 3 according to this embodiment generates a dense wave due to a temperature change of the metal thin film 16 and does not vibrate mechanically and does not have a resonance frequency. When this occurs, no reverberation component due to resonance is generated. The drive unit 4 drives the wave transmitter 3 by flowing a Gaussian wave-shaped drive current as shown in FIG. 7 through the metal thin film 16 of the wave transmitter 3. Since the frequency component of the drive current in the form of a Gaussian wave has a Gaussian distribution, it is possible to generate a dense wave having a specific frequency band by driving the transmitter 3 with such a drive current. Here, the frequency band of the coarse / fine wave is set to an ultrasonic region of 50 kHz to 70 kHz.

  Alternatively, the drive current output from the drive unit 4 may be a single pulse current, and a single coarse / fine wave may be transmitted from the transmitter 3. In this case, the coarse / fine wave transmitted by the transmitter 3 may be used. Since side lobes can be prevented from being generated, the detector 6 receives a received signal due to external noise, multiple reflections, etc., by transmitting a dense wave from the transmitter 3 to the receiver 5. It is possible to prevent malfunction.

  On the other hand, each receiving element 7 of the receiver 5 employs a capacitive microphone having no resonance frequency. As shown in FIG. 8, the wave receiving element 6 includes a substrate 19 made of single crystal silicon or the like and having a wave receiving hole 18 formed in a part thereof, and a substrate 19 that covers one opening of the wave receiving hole 18. A thin-film wave receiving body 20 that is continuously formed integrally and provided with a movable electrode (not shown), a fixed electrode holding portion 22 that faces the wave receiving body 20 via a gap 21, and a fixed electrode holding portion 22 are provided. The substrate 19 and the wave receiver 20 constitute a diaphragm structure. The wave receiving hole 18 is formed in a shape that becomes narrower toward the wave receiving body 20 side. With this configuration, when the wave receiving body 20 receives a close-packed wave, the wave receiving body 20 vibrates, and the distance between the wave receiving body 20 and the fixed electrode 23 changes. As a result, the capacitance between the movable electrode and the fixed electrode 23 changes. Then, by applying a voltage between the movable electrode and the fixed electrode 23, a voltage that changes depending on the change in the electrostatic capacity can be extracted as a received signal. The structure of the wave receiving element 7 is not limited to the diaphragm structure described above, and may be a cantilever structure in which the wave receiving body 20 is continuous with the substrate 19 at one side of the wave receiving hole 18.

  In the present embodiment, the above-described configuration prevents the reverberation component from being included in the coarse / dense wave transmitted from the transmitter 3, and the reverberation component remains after receiving the coarse / dense wave in the wave receiver 5. Therefore, the received signal of each receiving element 7 does not spread in the time axis direction due to the reverberation component, and the detection unit 6 accurately identifies the direction in which the receiver 5 receives the dense wave. can do. Specifically, in the wave receiving means 2 of the present embodiment in which 10 wave receiving elements 7 are arranged on one plane, the angle is 0 ° with respect to the direction orthogonal to the plane on which the wave receiving elements 7 are arranged. When the intensity is 0 dB, the directivity is relatively sharp so that the intensity is -3 dB at an angle of 5 °.

  FIG. 9 shows the operation of detecting the object C passing through the detection area by the sensor device A described above, with reference to a rough wave transmitted from the transmitter 3 and a received signal output from each receiver 5. This will be described below with reference to FIGS. The three receivers 5 are respectively a receiver 5x, a receiver 5y, and a receiver 5z, and in FIG. 9, FIG. 10, and FIG. 11, the dense waves transmitted from the transmitter 3 are (a ), The received signal from the receiver 5x is shown in (b), the received signal from the receiver 5y is shown in (c), and the received signal from the receiver 5z is shown in (d). Show. Here, it is assumed that the distance between the transmitter 3 and the receiver 5 is 10 m, and the transmitter 3 transmits the coarse / fine wave four times with a period of 50 ms. In this case, since the transmission time required for the coarse / fine wave transmitted from the transmitter 3 to reach the receiver 5 is about 30 ms, the timing control unit causes the transmitter 3 to transmit the coarse / fine wave. The timing is determined so that a period of 20 ms from the lapse of 30 ms after the wave is taken as the receiving period.

  First, the operation when the object C does not exist in the detection area will be described with reference to FIG. In FIG. 9, since the close-packed wave from the transmitter 3 to each of the receivers 5x to 5z is not blocked at all, the amplitude of any received signal does not change. It is determined that the object C does not exist.

  Next, the operation when the object C exists in the detection area will be described with reference to FIG. In FIG. 10, all the receivers 5x to 5x are transmitted from the transmitter 3 in a period from when the transmitter 3 transmits the second coarse / fine wave until the coarse / fine waves reach the respective receivers 5x to 5z. Since the coarse / fine wave to 5z is cut off, in the period from when the transmitter 3 transmits the second coarse / fine wave until the coarse / fine wave reaches each of the receivers 5x to 5z, the detection unit 6 Determines that the object C exists in the detection area.

  As shown in FIG. 11, when the reception signals to the respective receivers 5x to 5z are sequentially cut off, the detection unit 6 detects the orientation C in addition to the presence of the object C in the detection region. The direction in which the object C moves within the detection area can also be detected. In short, in FIG. 11, in the period from when the transmitter 3 transmits the second coarse / fine wave to when the coarse / fine wave reaches each of the receivers 5x to 5z, one reception from the transmitter 3 is received. The transmitter / receiver is interrupted during the period from when the transmitter / receiver 5x is cut off and the transmitter / receiver 3 transmits the third transmitter / receiver to the receivers 5x to 5z. 3 to the other receiver 5y is interrupted, and the subsequent transmitter 3 transmits the fourth dense wave until the coarse wave reaches each of the receivers 5x to 5z. Since the close-packed wave from the transmitter 3 to the other receiver 5z is interrupted during the period, the detector 6 detects the fourth close-packed wave after the transmitter 3 sends the second close-packed wave. In the detection region, the object C moves between the transmitter 3 and the receiver 5x between the transmitter 3 and the receiver 5y during the period until the receiver reaches the receivers 5x to 5z. Further determined that the movement between the wave transmitter 3 and wave receiver 5z.

  The configuration in which a plurality of receiving elements 7 are arranged to form a receiver 5 and the direction in which the receiver 5 receives the close-packed wave is detected by the detection unit 6 as in the present embodiment is the transmission described above. In addition to the sensor device A of the type and the reflection type sensor device A (see FIG. 12) shown as a conventional configuration, as shown in FIG. The present invention can also be applied to the sensor device A that is disposed and installed by tilting the transmitter 3 and the receiver 5 with respect to the direction connecting the transmitter 3 and the receiver 5. The close-packed wave transmitted from the transmitter 3 of the sensor device A has two types, a direct wave that directly reaches the receiver 5 and a reflected wave that is reflected by the object C and reaches the receiver 5. Thus, the detection unit 6 identifies the direct wave and the reflected wave based on the direction in which the receiver 5 receives the dense wave, and detects the presence of the object C using the direct wave and the reflected wave.

(Embodiment 2)
The sensor device A of the present embodiment moves the detection area as shown in FIG. 14 by replacing the three receivers 5x to 5y in the longitudinal direction of the passage B with respect to the sensor device A of the first embodiment. They are arranged at equal intervals in the height direction of the object C (that is, the direction orthogonal to the floor surface of the passage B). Here, the receiver 5x is disposed at the highest position, the receiver 5y is disposed below the receiver 5x, and the receiver 5z is disposed further below.

  The operation of detecting the object C passing through the detection region by the sensor device A is shown in (a) as the rough and dense wave transmitted from the transmitter 3, and as shown in (b) as the received signal from the receiver 5x. The received signal from the receiver 5y is shown in (c), and the received signal from the receiver 5z is described below with reference to FIGS. 15 and 16 shown in (d). Here, it is assumed that the distance between the transmitter 3 and the receiver 5 is 10 m, and the transmitter 3 transmits the coarse / fine wave four times with a period of 50 ms.

  In the period from when the transmitter 3 transmits the second coarse / fine wave to when the coarse / fine wave reaches each of the receivers 5x to 5z, the coarse / fine wave from the transmitter 3 to one receiver 5z. In the case of FIG. 15 in which is interrupted, the detection unit 6 is a period from when the transmitter 3 transmits the second coarse / fine wave until the coarse / fine wave reaches each of the receivers 5x to 5z. In addition, it is determined that the object C having a height that does not reach the height of the receiver 5y exists in the detection area. In short, in the present embodiment, the detection unit 6 can detect the height of the object C existing in the detection area as the height detection means, so whether the object C that has passed through the detection area is a person or a person It becomes possible to distinguish whether it is a small animal instead.

  In addition, as shown in FIG. 16, when the dense waves having small intensity reach the receivers 5 x to 5 z by the wraparound without being completely blocked by the object C as shown in FIG. The detecting unit 6 detects the presence of the object C based on a change in the received signal, and uses the magnitude of the change in the received signal as a measure of the size of the object C as a magnitude determination unit. Therefore, for example, when it is assumed that the object C existing in the detection area is a person, the detection unit 6 uses the magnitude of the amplitude of the received signal as a measure of the physique of the person existing in the detection area. Other configurations and functions are the same as those of the first embodiment.

(Embodiment 3)
In the sensor device A of the present embodiment, the drive unit 4 continuously drives the wave transmitting element (metal thin film 16) that is the sound source of the wave transmitter 3 so that the wave transmitter 3 generates a continuous dense wave. The point is different from the sensor device A of the first embodiment. In the present embodiment, the receiver 5z is omitted and the two receivers 5x and 5y receive the coarse / fine wave. In FIG. 17, the coarse / fine wave transmitted from the transmitter 3 is ( A received signal from the receiver 5x is shown in (b), and a received signal from the receiver 5y is shown in (c). Here, the distance between the transmitter 3 and the receiver 5 is 10 m.

  In this configuration, as shown in FIG. 17, since the dense wave is constantly transmitted from the transmitter 3, the presence or absence of the object C in the detection region can be constantly monitored. Furthermore, when generating continuous dense waves, a timing control unit that determines a reception period in accordance with the timing at which the transmitter 3 transmits the dense waves is unnecessary, and the detection unit 6 and the drive unit 4 Need not be connected. Other configurations and functions are the same as those of the first embodiment.

(Embodiment 4)
The sensor device A of the present embodiment detects the presence of the object C in the detection region using only the received signal corresponding to the dense wave received by the receiver 5 from the direction of the transmitter 3 as in the first embodiment. Instead of the configuration, the intensity distribution of the dense and dense waves in each direction in the detection area is detected, and the presence of the object C in the detection area is detected by the change in the intensity distribution.

  The detection unit 6 of the present embodiment includes intensity distribution detection means for detecting the intensity distribution of the dense and dense waves in each direction in the detection area from the output of the receiver 5, and the intensity distribution during a period in which the object C does not exist in the detection area. Storage means for storing the intensity distribution detected by the detection means as a basic intensity distribution, and when the intensity distribution detected by the intensity distribution detection means changes from the basic intensity distribution stored in the storage means, an object C exists in the detection region And determining means for determining that. That is, when the object C exists in the detection area, the density wave of the density wave in the detection area changes due to reflection or absorption of the density wave transmitted from the transmitter 3 by the object C. Utilizing this, the presence of the object C is detected.

  In this configuration, since the presence of the object C can be detected over a spatial range in which the intensity distribution of the dense wave is detected by the intensity distribution detecting means, the detection area can be set relatively wide. Other configurations and functions are the same as those of the first embodiment.

It is the schematic which shows the sensor apparatus of Embodiment 1 of this invention. It is explanatory drawing which shows the state which installed the sensor apparatus same as the above. It is the schematic which shows the structure of a sensor apparatus same as the above. It is explanatory drawing for demonstrating the direction in which a receiver same as the above receives a dense wave. (A) shows each received signal of each receiving element, (b) shows the delayed received signal, and (c) is an explanatory view showing the added received signal. It is sectional drawing which shows the structure of a wave transmitter same as the above. It is a wave form diagram which shows a drive current same as the above. It is sectional drawing which shows the structure of a receiving element same as the above. It is operation | movement explanatory drawing when an object does not exist in a detection area | region same as the above. It is operation | movement explanatory drawing when an object passes the detection area | region same as the above. It is operation | movement explanatory drawing when an object passes the detection area | region same as the above. It is the schematic which shows a reflection type sensor apparatus. It is the schematic which shows the sensor apparatus which inclined and installed the transmitter and the receiver. It is explanatory drawing which shows the state which installed the sensor apparatus of Embodiment 2 of this invention. It is operation | movement explanatory drawing when an object passes the detection area | region same as the above. It is operation | movement explanatory drawing when another object passes the detection area | region same as the above. It is operation | movement explanatory drawing when an object passes the detection area | region in Embodiment 3 of this invention. It is explanatory drawing which shows the state which installed the sensor apparatus of the prior art example in the entrance / exit of the room.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Transmitter 4 Drive part 5 Receiver 6 Detection part 7 Receiver element A Sensor apparatus C Object

Claims (11)

  A transmitter / receiver that transmits a coarse / fine wave to a target detection region, a drive unit that drives the transmitter, and a coarse / fine wave that is disposed from the transmitter with the detection region interposed therebetween. A receiver that receives the received signal from the receiver and changes the amplitude of the received signal in the detection region. And a detector that detects the presence of an object that blocks the rough wave from the receiver to the receiver, and the receiver includes a plurality of receiving elements that receive the rough wave and output a received signal. And the detecting unit identifies the direction in which the receiver has received the dense wave by the time difference between the received signals of the receiving elements.   The detector is configured to receive each reception for a delay time set so as to match the timings of the received signals from all the receiving elements when the receiver receives a close-packed wave from the direction of the transmitter. Delay means for delaying the received signals from the wave elements, adding means for adding the received signals delayed by the delay means, and the amplitude of the received signal added by the adding means is below a predetermined threshold value The sensor device according to claim 1, further comprising: a determination unit configured to determine that an object exists in the detection area.   The detection unit is detected by intensity distribution detection means for detecting the intensity distribution of the dense and dense waves in each direction within the detection area from the output of the receiver, and by the intensity distribution detection means during a period when no object is present in the detection area. Storage means for storing the detected intensity distribution, and determination means for determining that an object exists in the detection region when the intensity distribution detected by the intensity distribution detection means changes from the intensity distribution stored in the storage means. The sensor device according to claim 1, wherein:   A sensor device for detecting an object moving in the detection region, wherein a plurality of the receivers are arranged in one direction, and the detection unit is arranged according to the order in which the amplitude of a received signal changes between the receivers. The sensor device according to any one of claims 1 to 3, further comprising direction detection means for detecting a direction of movement of the object in one direction.   A sensor device for detecting an object moving in the detection region, wherein a plurality of the receivers are arranged in a height direction of the object, and the detection unit is a receiver of a receiver whose amplitude of a received signal is changed. 5. The sensor device according to claim 1, further comprising a height detection unit configured to detect the height of the object based on the number. 6.   When the detection unit determines that an object exists in the detection region, the detection unit includes a size determination unit that determines that the larger the change in the amplitude of the received signal is, the larger the object exists in the detection region. The sensor device according to any one of claims 1 to 5.   7. The drive unit according to claim 1, wherein the driving unit continuously drives a transmission element that is a sound source of the transmitter so as to generate a continuous dense wave in the transmitter. Item 1. The sensor device according to item 1.   The drive unit intermittently drives a transmitting element that is a sound source of the transmitter so that the dense wave is intermittently transmitted, and the received signal is effective after the transmitter transmits the dense wave. The sensor device according to claim 1, further comprising a timing control unit that determines a timing to be determined.   The sensor device according to claim 8, wherein the driving unit causes a single pulse current to flow through the transmission element so as to generate a single dense wave in the transmitter.   10. The sensor device according to claim 8, wherein the driving unit drives the transmission element at regular time intervals so as to cause the transmitter to generate a dense wave at regular time intervals.   The transmitter does not have a resonance frequency in the frequency of the coarse wave transmitted, and the receiver does not have a resonance frequency in the frequency of the coarse wave transmitted from the transmitter. The sensor device according to any one of claims 8 to 10.

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