JP2008101400A - Vehicle communication device - Google Patents

Abstract

When a tag ID from an RF tag cannot be received by a portable device, the position of the portable device inside and outside the vehicle is determined by determining whether or not the portable device can receive the vehicle-mounted device ID from the on-vehicle device. A vehicle communication device that can be determined is obtained.
SOLUTION: An in-vehicle device 4 for transmitting an in-vehicle device ID 7, an RF tag 2 for transmitting a tag ID 6, a portable device 5 for receiving the in-vehicle device ID 7 or the tag ID 6, and a tag ID 6 or 6 from the portable device 5 to the in-vehicle device 4. ID communication means for transmitting the vehicle-mounted device ID7. The vehicle-mounted device 4 determines the position of the portable device 5 based on the reception of the tag ID 6 or the vehicle-mounted device ID 7 transmitted from the portable device 4 by the ID communication means.
[Selection] Figure 1

Description

  The present invention relates to a vehicular communication apparatus having a function for specifying a position of a portable device such as an electronic key system, and more particularly to a passive entry technique that simply operates locking and unlocking of a vehicle door only by possessing the portable device. The present invention relates to a vehicle communication device suitable for application.

Conventionally, as a vehicle communication device for remotely controlling an in-vehicle device of an automobile, the vehicle door is automatically unlocked when a user carrying a portable device approaches the vehicle, and the vehicle door is automatically activated when the user leaves the vehicle. A vehicular communication device having a function to be locked is proposed.
However, in this type of conventional device, when the portable device is in the vehicle, the door is not automatically locked to prevent the portable device from being trapped. If the user leaves the vehicle while left unattended, the door will be left for a long time without being locked, which is a problem in terms of crime prevention.

Therefore, when the user leaves the portable device in the vehicle when leaving the vehicle, it is necessary to notify the user of the misplaced state, and the function of determining whether the portable device is inside or outside the vehicle has a function. It is requested.
Therefore, conventionally, as a technology for determining whether or not the portable device is in the vehicle (hereinafter referred to as “in-vehicle / out-of-vehicle determination technology”), a vehicle communication device using an LF charged wave with a frequency of about 120 KHz to 135 KHz has been proposed. (For example, refer to Patent Document 1).

JP 2003-221954 A

In the conventional vehicle communication device, for example, as in Patent Document 1, in the case of communication using LF charged waves, there is a problem that the device becomes expensive and the position of the portable device cannot be accurately determined. there were.
Therefore, it is conceivable to use a non-contact communication technique using a high frequency band instead of the LF charging wave to separate the reader function of the reader / writer into a portable device and an in-vehicle device. In other words, an ID transmitter (for example, an RF tag) is arranged at various locations in the vehicle, an on-vehicle device that supplies power to the RF tag is installed in the vehicle, and an RF tag that receives radio waves radiated from the on-vehicle device is provided. In addition, it is also possible to adopt a configuration for transmitting the tag ID unique to itself to the vicinity of the RF tag and determining the inside / outside of an inexpensive portable device that does not depend on the LF charging wave.

In this case, when the portable device exists in the vicinity of the RF tag and the portable device can read the tag ID, the portable device receives the ID of the RF tag and transmits it to the on-vehicle device. Can be determined in the vehicle.
However, when a portable device exists in a region where the transmission power from the vehicle-mounted device is large (hereinafter referred to as “high power region”), the portable device cannot read the unique ID of the RF tag as follows.

  That is, when a high power signal exceeding the allowable saturation power is received by the receiver circuit of the portable device in the high power range, the reception sensitivity deteriorates due to saturation of the receiver circuit, and a weak modulated wave from the desired RF tag is carried. Since the mobile phone cannot receive the signal, the mobile device that is actually in the high power range (inside the vehicle) of the in-vehicle device is misjudged as being outside the vehicle, and the position of the mobile device is still accurate. There was a problem that it could not be judged.

  The present invention has been made in order to solve the above-described problems, and in a high power range where the unique ID of the RF tag (ID transmitter) cannot be received, a pseudo signal (hereinafter, “ An object of the present invention is to obtain a vehicle communication device that can accurately determine the inside / outside of a vehicle by transmitting "pseudo ID") from the on-vehicle device as the on-vehicle device ID.

  A vehicle communication device according to the present invention is installed in a vehicle and radiates radio waves, and transmits an in-vehicle device ID held by itself, and is installed in the vehicle and responds to reception of radio waves. An ID transmitter for transmitting a unique transmitter ID, a portable device for receiving the vehicle-mounted device ID or the transmitter ID, an ID communication means for transmitting the transmitter ID or the vehicle-mounted device ID from the portable device to the vehicle-mounted device, The on-vehicle device determines the position of the portable device based on reception of the transmitter ID or the on-vehicle device ID transmitted from the portable device by the ID communication means.

  According to the present invention, in a high power range where the portable device 5 cannot receive a tag ID unique to the RF tag, the portable device is connected to the vehicle-mounted device by transmitting the vehicle-mounted device ID (a pseudo signal of the tag ID) from the vehicle-mounted device. Even when it exists in the high power range, the vehicle-mounted device ID is received, the unique ID of the RF tag is determined, the position information of the portable device is acquired, and the inside / outside of the vehicle can be accurately determined.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram schematically showing a vehicle communication apparatus according to Embodiment 1 of the present invention together with a vehicle.
In FIG. 1, a vehicle 1 has the following configuration as a vehicle communication device according to Embodiment 1 of the present invention.

The vehicle 1 is provided with an RF tag 2 and an in-vehicle device 4.
At least one RF tag 2 is installed at an arbitrary location of the vehicle 1, has a unique tag ID 6, and transmits the tag ID 6 to the surroundings by weak radio waves.
The vehicle-mounted device 4 has a vehicle-mounted device antenna (hereinafter simply referred to as “antenna”) 3 for transmission / reception, has its own vehicle-mounted device ID 7, and transmits the vehicle-mounted device ID 7 as a pseudo ID.

In a saturation power region 8 (corresponding to a high power region in which the reception circuit of the portable device 5 is saturated by a transmission wave from the on-vehicle device 4) to which the on-vehicle device ID 7 is transmitted, a reception circuit (not shown) in the portable device 5 Is saturated by the transmission wave from the vehicle-mounted device 4.
Further, here, the tag ID 6 and the vehicle-mounted device ID 7 are indicated by “ID_2” and “ID_4”, respectively.

As the RF tag 2 to be used, a tag having a frequency near 900 MHz or 2.45 GHz is suitable. However, the RF tag 2 is not limited to the above frequency as long as it has a high frequency.
The antenna 3 and the vehicle-mounted device 4 are designed according to the frequency of the RF tag 2 to be used.

The vehicle-mounted device 4 installed in the vehicle 1 supplies power to the RF tag 2 by transmitting radio waves (power supply radio waves) via the antenna 3.
The portable device 5 has an ID communication means (not shown) for transmitting the tag ID 6 or the vehicle-mounted device ID 7 to the vehicle-mounted device 4, receives the tag ID 6 from the RF tag 2, and receives the received tag ID 6 Is transmitted to the vehicle-mounted device 4.

Since the vehicle-mounted device 4 can determine which RF tag 2 the portable device 5 is near based on which RF tag 2 the portable device 5 has received the tag ID 6 from. The position of the portable device 5 can be determined based on the tag ID 6 received from the mobile phone 5.
However, as described above, in the saturated power region 8 in the vicinity of the antenna 3, the power of the transmission wave supplied from the vehicle-mounted device 4 to the RF tag 2 is large. When the transmission wave is received, it becomes saturated and the tag ID 6 from the RF tag 2 cannot be received.

  Therefore, when the portable device 5 exists in the saturated power region 8 in the vicinity of the antenna 3, in order to avoid erroneous determination of the location of the portable device 5, the modulated wave (onboard device ID7) transmitted from the onboard device 4 is avoided. Is received by the portable device 5 and based on the vehicle-mounted device ID 7, it is determined whether or not the portable device 5 exists in the saturated power region 8 near the antenna 3.

Hereinafter, the position determination process of the portable device 5 according to the first embodiment of the present invention will be described in detail with reference to the flowchart of FIG. 2 together with FIG.
FIG. 2 shows a processing procedure when the in-vehicle / outside determination of the portable device 5 is performed by transmitting the in-vehicle device ID 7 from the in-vehicle device 4 when the portable device 5 cannot receive the tag ID 6.

In FIG. 2, first, the vehicle-mounted device 4 radiates electric power supply radio waves via the antenna 3 in order to supply power to the RF tag 2 (step S201).
Subsequently, the RF tag 2 transmits a unique tag ID 6 that the RF tag 2 owns using the power supplied from the vehicle-mounted device 4 (step S202).

Next, the portable device 5 determines whether or not the tag ID 6 can be received (step S203). If it is determined that the tag ID 6 can be received (that is, YES), the ID signal (tag ID 6) received by the portable device 5 is determined. ) Is transmitted to the vehicle-mounted device 4 (step S204).
Thereby, the vehicle-mounted device 4 receives the tag ID 6 from the portable device 5 (step S205), determines that the portable device 5 exists in the vehicle (step S220), and ends the processing routine of FIG.
In step S220, the vehicle-mounted device 4 determines which RF tag 2 in the vehicle is near the position of the portable device 5.

On the other hand, if it is determined in step S203 that the tag ID 6 cannot be received (that is, NO), the portable device 5 transmits information “reception NG of tag ID 6” to the vehicle-mounted device 4 (step S206).
Thereby, the vehicle-mounted device 4 receives the information “reception NG of the tag ID 6” from the portable device 5 (step S207), and transmits the vehicle-mounted device ID 7 held by itself to the portable device 5 (step S208).

  In step S208, the transmission power when transmitting the vehicle-mounted device ID 7 from the vehicle-mounted device 4 is not saturated in the reception circuit of the portable device 5 in the space of the saturated power region 8, and the portable device 5 is connected to the vehicle-mounted device ID 7 Is set to receive.

Subsequently, the portable device 5 determines whether or not the vehicle-mounted device ID 7 can be received (step S209). If it is determined that the vehicle-mounted device ID 7 can be received (that is, YES), the processing after the above-described step S204 is performed. move on.
That is, the portable device 5 transmits the received ID signal (onboard device ID7) to the onboard device 4, the onboard device 4 receives the onboard device ID7 from the portable device 5, and the portable device 5 is in the vicinity of the antenna 3. It determines with existing in the saturated electric power area | region 8 (in-vehicle).

On the other hand, if it is determined in step S209 that the in-vehicle device ID 7 cannot be received (that is, NO), the portable device 5 transmits information “reception NG of the in-vehicle device ID 7” to the in-vehicle device 4 (step S210).
As a result, the vehicle-mounted device 4 receives the information “reception NG of the vehicle-mounted device ID 7” from the portable device 5 (step S211), the portable device 5 does not exist in the vicinity of the RF tag 2, and the antenna 3 Since it does not exist in the vicinity, it is determined that the portable device 5 exists outside the vehicle (step S230), and the processing routine of FIG. 2 ends.

  As described above, according to Embodiment 1 of the present invention, it is installed in the vehicle 1 and installed in the vehicle 1, which radiates radio waves and transmits the vehicle-mounted device ID 7 owned by itself. From the RF tag 2 (ID transmitter) that transmits its own tag ID 6 (transmitter ID) in response to reception of radio waves, the portable device 5 that receives the vehicle-mounted device ID 7 or the tag ID 6, and the portable device 5 ID communication means for transmitting tag ID 6 or OBE ID 7 to the vehicle-mounted device 4, and the vehicle-mounted device 4 is based on reception of the tag ID 6 or OBE ID 7 transmitted from the portable device 5 by the ID communication means. The position of the portable device 5 is determined.

  Thereby, even when the portable device 5 exists in the saturated power region 8 near the antenna 3 of the vehicle-mounted device 4 and the portable device 5 cannot receive the tag ID 6, the unique vehicle-mounted device possessed by the vehicle-mounted device 4. By determining whether the portable device 5 is received by transmitting ID 7 to the portable device 5, the presence position of the portable device 5 is determined, and the portable device 5 exists in the saturated power region 8 near the antenna 3. Or whether it exists outside the vehicle.

Embodiment 2. FIG.
In the first embodiment, after confirming that the tag ID 6 transmitted from the RF tag 2 could not be received by the portable device 5, the on-vehicle device ID 7 was transmitted from the on-vehicle device 4. The order of ID transmission operations may be changed and executed.
Hereinafter, the communication operation according to the second embodiment of the present invention in which the tag ID 6 is transmitted after the reception NG confirmation of the vehicle-mounted device ID 7 will be described with reference to the flowchart of FIG. 3 together with FIG.
FIG. 3 shows a processing procedure when the in-vehicle / out-of-vehicle determination of the portable device 5 is performed by changing the order of transmission of the tag ID 6 from the RF tag 2 and transmission of the on-vehicle device ID 7 from the on-vehicle device 4.

The configuration of the second embodiment of the present invention is as shown in FIG.
In FIG. 3, steps S301, S302, S305, and S306 correspond to steps S208 to S211 described above (see FIG. 2), and steps S307 to S311 and S330 correspond to steps S201 to S203, S206, S207, and Corresponding to S230, Steps S303, S304, and S320 correspond to Steps S204, S205, and S220 described above.

In FIG. 3, first, the vehicle-mounted device 4 transmits the vehicle-mounted device ID7 to the portable device 5 (step S301), and the portable device 5 determines whether or not the vehicle-mounted device ID7 can be received (step S302).
If it is determined in step S302 that the vehicle-mounted device ID7 can be received (that is, YES), the portable device 5 transmits the received ID signal (vehicle-mounted device ID7) to the vehicle-mounted device 4 (step S303).
As a result, the vehicle-mounted device 4 receives the vehicle-mounted device ID 7 from the portable device 5 (step S304), and determines that the portable device 5 exists in the vicinity (in the vehicle) of the antenna 3 of the vehicle-mounted device 4 (step S220). Then, the processing routine of FIG.

On the other hand, if it is determined in step S302 that the vehicle-mounted device ID7 cannot be received (that is, NO), the portable device 5 transmits information “received vehicle-mounted device ID7 NG” to the vehicle-mounted device 4 (step S305). The on-vehicle device 4 receives the information “reception NG of the on-vehicle device ID 7” from the portable device 5 (step S306).
In response to this, the vehicle-mounted device 4 emits a radio wave for supplying power to the RF tag 2 (step S307), and the RF tag 2 transmits a tag ID 6 (step S30).

Subsequently, the portable device 5 determines whether or not the tag ID 6 can be received (step S309). If it is determined that the tag ID 6 can be received (that is, YES), the process proceeds to step S303 described above, and the portable device 5 The received ID signal (tag ID 6) is transmitted to the vehicle-mounted device 4.
Hereinafter, the vehicle-mounted device 4 receives the tag ID 6 from the portable device 5 (step S304), determines that the portable device 5 exists in the vehicle, and the portable device 5 exists in the vicinity of any RF tag 2 in the vehicle. Is determined (step S320), and the processing routine of FIG. 3 is terminated.

On the other hand, if it is determined in step S309 that tag ID 6 cannot be received (that is, NO), portable device 5 transmits information “reception NG of tag ID 6” to vehicle-mounted device 4 (step S310). 4 receives information “reception NG of tag ID 6” from the portable device 5 (step S207).
Thereby, the vehicle-mounted device 4 determines that the portable device 5 exists outside the vehicle because the portable device 5 does not exist in the vicinity of the RF tag 2 and does not exist in the vicinity of the antenna 3 (step S330), the processing routine of FIG.

As described above, according to the second embodiment of the present invention, the vehicle-mounted device 4 transmits the vehicle-mounted device ID 7 to determine whether the portable device 5 exists in the vicinity of the antenna 3, and the vehicle-mounted device ID 7 by the portable device 5. After confirming the received NG, it is determined whether or not the portable device 5 has received the tag ID 6 transmitted by the RF tag 2 by radiating a power supply radio wave to the RF tag 2.
Thus, as described above, even when the portable device 5 is present in the saturated power region 8, it is determined whether the portable device 5 is present in the vicinity of the RF tag 2 (inside the vehicle) or outside the vehicle. The inside / outside position of the machine 5 can be determined.

Embodiment 3 FIG.
In the first and second embodiments, the transmission operation of the tag ID 6 from the RF tag 2 and the transmission operation of the on-vehicle device ID 7 from the on-vehicle device 4 are sequentially performed. These two transmission operations May be executed in parallel at substantially the same time.
Hereinafter, a third embodiment of the present invention in which the transmission operation of the tag ID 6 and the vehicle-mounted device ID 7 is executed almost simultaneously will be described with reference to the flowchart of FIG. 4 together with FIG.
FIG. 4 shows a processing procedure when the inside / outside determination of the portable device 5 is performed by simultaneously transmitting the tag ID 6 from the RF tag 2 and transmitting the on-vehicle device ID 7 from the on-vehicle device 4.

The configuration of the third embodiment of the present invention is as shown in FIG.
In FIG. 4, steps S401 to S403 correspond to steps S208, S202, and S203 described above (see FIG. 2), and steps S420 and S430 correspond to steps S220 and S230 described above.

4, first, the vehicle-mounted device 4 transmits the vehicle-mounted device ID 7 to the portable device 5 (step S401), and radiates a radio wave for power supply to the RF tag 2 (step S402).
The RF tag 2 transmits the tag ID 6 held by the RF tag 2 itself using the power supplied by the radio wave from the vehicle-mounted device 4 (step S403).
Note that the execution order of step S401 and steps S402 and S403 can be interchanged.

Subsequently, the portable device 5 determines whether or not the tag ID 6 or the vehicle-mounted device ID 7 can be received (step S404). If it is determined that the tag ID 6 or the vehicle-mounted device ID 7 can be received (that is, YES), the portable device 5 has received it. An ID signal (tag ID6 or onboard unit ID7) is transmitted to the onboard unit 4 (step S405).
Thereby, the onboard equipment 4 receives the ID signal (tag ID6 or onboard equipment ID7) transmitted from the portable device 5 (step S406), and determines that the portable device 5 exists inside the vehicle 1 ( Step S420), the processing routine of FIG.

On the other hand, if it is determined in step S404 that neither the tag ID 6 nor the vehicle-mounted device ID 7 can be received (that is, NO), the portable device 5 has not received any of the ID signals “tag ID 6 and vehicle-mounted device ID 7”. Is received to the vehicle-mounted device 4 (step S407).
Thereby, the vehicle-mounted device 4 receives the information “reception NG of the tag ID 6 and the vehicle-mounted device ID 7” transmitted from the portable device 5 (step S408), and determines that the portable device 5 exists outside the vehicle (step S408). S430), the processing routine of FIG.

  As described above, according to the third embodiment of the present invention, the transmission operation of the tag ID 6 from the RF tag 2 and the transmission operation of the on-vehicle device ID 7 from the on-vehicle device 4 are performed almost simultaneously, Based on the ID signal received by the portable device 5, whether the portable device 5 exists in the vicinity of the RF tag 2, the vicinity of the antenna 3, or outside the vehicle is more than in the case of the first and second embodiments. It can be determined in a short time.

Embodiment 4 FIG.
In the first to third embodiments, the position of the portable device 5 is determined by the vehicle-mounted device 4 based on the ID signal (tag ID 6, vehicle-mounted device ID 7) transmitted from the portable device 5. The position of itself may be determined at the stage of receiving the signal, and the position information after the determination may be transmitted from the portable device 5 to the vehicle-mounted device 4.
In Embodiment 4 of this invention, the portable device 5 determines its own position, and transmits the determination result (position information) to the vehicle-mounted device 4.

The configuration of the fourth embodiment of the present invention is as shown in FIG.
In addition, the communication operation according to the fourth embodiment of the present invention is performed by the portable device 5 instead of transmitting the ID signal received by the portable device 5 to the vehicle-mounted device 4 as it is in the above-described operation (see FIGS. 2 to 4). The only difference is that the position of the mobile device 5 is determined from the received ID signal and the position information of the portable device 5 is transmitted to the vehicle-mounted device 4. Therefore, detailed description of the operation is omitted here.

  According to the fourth embodiment of the present invention, the portable device includes the vehicle-mounted device 4 that transmits the vehicle-mounted device ID7, the RF tag 2 that transmits the tag ID6, and the portable device 5 that receives the vehicle-mounted device ID7 or the tag ID6. 5 determines the position of the portable device 5 based on the received tag ID 6 or the vehicle-mounted device ID 7, and transmits its own position information to the vehicle-mounted device 4, and the vehicle-mounted device 4 uses the position information transmitted from the portable device 5. Based on this, the position of the portable device 5 is determined.

In this case, although the ID signal determination process is performed in the portable device 5 instead of the in-vehicle device 4, the same effects as described above are obtained.
That is, even when the portable device 5 exists in the saturated power region 8 near the antenna 3 and the portable device 5 cannot receive the tag ID 6, the unique on-vehicle device ID 7 possessed by the on-vehicle device 4 is transmitted to the portable device 5. By doing so, it can be determined whether the portable device 5 exists in the saturated power region 8 near the antenna 3 or outside the vehicle, and the in-vehicle device 4 also determines the position information of the portable device 5. Can do.

Embodiment 5. FIG.
In the first to fourth embodiments, the vehicle-mounted device 4 determines the position of the portable device 5 based on the response signal (ID signal or position information) transmitted from the portable device 5. Is transmitted to the portable device 5 by radio waves of a predetermined specification when the vehicle-mounted device ID 7 is transmitted from the vehicle-mounted device 4 to the portable device 5. In order to avoid this, the transmission power may be variably set in stages.
Hereinafter, Embodiment 5 of the present invention in which the transmission power of the vehicle-mounted device ID 7 is variably set in steps will be described with reference to the flowchart of FIG. 5 together with FIG.
FIG. 5 shows a processing procedure in a case where the inside / outside determination is performed while transmitting power is reduced step by step when transmitting the vehicle-mounted device ID 7, and saturation of the receiving circuit of the portable device 5 is avoided.

The configuration of the fifth embodiment of the present invention is as shown in FIG.
In FIG. 5, steps S501 to S507, S509 to S512, S520, and S530 correspond to steps S201 to S211, S220, and S230 described above (see FIG. 2), and steps S508 and S513 are added. .

In this case, the onboard equipment 4 shall reduce transmission power in steps from an initial value (maximum transmission power) so that the receiving circuit of the portable device 5 may not be saturated at the time of transmission of the onboard equipment ID7.
In FIG. 5, first, the vehicle-mounted device 4 radiates a radio wave via the antenna 3 in order to supply power to the RF tag 2 (step S501), and the RF tag 2 uses the supplied power to generate the RF tag. 2 transmits the tag ID 6 held by itself (step S502).

Next, the portable device 5 determines whether or not the tag ID 6 can be received (step S503). If it is determined that the tag ID 6 can be received (that is, YES), the ID signal (tag) received by the portable device 5 is determined. ID6) is transmitted to the vehicle-mounted device 4 (step S504).
Thereby, the vehicle-mounted device 4 receives the tag ID 6 from the portable device 5 (step S505), determines that the portable device 5 exists in the vehicle (step S520), and ends the processing routine of FIG.

  On the other hand, if it is determined in step S503 that tag ID 6 cannot be received (that is, NO), portable device 5 transmits information “reception NG of tag ID 6” to vehicle-mounted device 4 (step S506). 4 receives information “reception NG of tag ID 6” from the portable device 5 (step S507).

Subsequently, the vehicle-mounted device 4 variably sets the transmission power from the vehicle-mounted device 4 in response to the reception signal from the portable device 5 (step S508), and transmits the vehicle-mounted device ID 7 held by itself to the portable device 5 ( Step S509).
In step S508, the transmission power is initially set to an initial value, but the initial value is a maximum transmission power (upper limit value) of the vehicle-mounted device 4 or a minimum transmission power (lower limit) at which the receiving circuit of the portable device 5 is not saturated. Value).

Subsequently, the portable device 5 determines whether or not the vehicle-mounted device ID 7 can be received (step S510). If it is determined that the vehicle-mounted device ID 7 can be received (that is, YES), the processing after the above-described step S504 is performed. move on.
That is, the portable device 5 transmits the received ID signal (onboard device ID7) to the onboard device 4, the onboard device 4 receives the onboard device ID7 from the portable device 5, and the portable device 5 is saturated near the antenna 3. It determines with existing in the electric power area | region 8 (in-vehicle).

  On the other hand, if it is determined in step S510 that the vehicle-mounted device ID7 cannot be received (that is, NO), the portable device 5 transmits information “received vehicle-mounted device ID7 NG” to the vehicle-mounted device 4 (step S511). The vehicle-mounted device 4 receives the information “reception NG of the vehicle-mounted device ID 7” from the portable device 5 (step S512).

  Subsequently, the vehicle-mounted device 4 determines whether or not the transmission power of the vehicle-mounted device ID 7 transmitted in step S509 is the minimum transmission power (limit value) of the vehicle-mounted device 4 (step S513), and the transmission power is the minimum transmission power. If not (ie, NO), the process returns to step S508, the transmission power is reduced stepwise by a predetermined amount set in advance, and steps S509 to S513 are repeatedly executed.

  On the other hand, if it is determined in step S513 that the transmission power has reached the minimum transmission power (that is, YES), the portable device 5 does not exist near the RF tag 2 and also exists near the antenna 3. Therefore, it is determined that the portable device 5 exists outside the vehicle (step S530), and the processing routine of FIG.

As described above, according to the fifth embodiment of the present invention, the vehicle-mounted device 4 variably sets the transmission power step by step when transmitting the vehicle-mounted device ID 7.
Specifically, as shown in FIG. 5, if the initial value of the transmission power is set to the maximum transmission power (upper limit value), in the case of the reception NG of the on-vehicle device ID 7 in the portable device 5, the on-vehicle device 4 Considering that the reception circuit of the portable device 5 may be saturated, the transmission power is reduced step by step.
Also, if the initial value of the transmission power is set to the minimum transmission power (lower limit value) that does not saturate, the transmission power is increased stepwise.

  Thus, by transmitting the vehicle-mounted device ID 7 (pseudo ID) while changing the transmission power of the vehicle-mounted device 4 stepwise, saturation of the receiving circuit of the portable device 5 can be reliably avoided. 5 can receive the vehicle-mounted device ID 7 (pseudo ID), and can determine whether the portable device 5 is present in the saturated power region 8 (high power region) or outside the vehicle.

Embodiment 6 FIG.
Although not mentioned in the fifth embodiment, the vehicle-mounted device 4 may add the transmission power information to the vehicle-mounted device ID7 when transmitting the transmission power of the vehicle-mounted device ID7 stepwise. Good.
Hereinafter, with reference to the flowchart of FIG. 6 together with FIG. 1, Embodiment 6 of the present invention in which transmission power information is added at the time of transmission of the vehicle-mounted device ID 7 will be described.
FIG. 6 shows a processing procedure when the position of the portable device 5 is determined in detail by adding transmission power information to the vehicle-mounted device ID 7 when changing the transmission power stepwise.

The configuration of the sixth embodiment of the present invention is as shown in FIG.
In FIG. 6, steps S601 to S608, S610 to S613, S620, and S630 correspond to steps S501 to S508, S510 to S513, S520, and S530 described above (see FIG. 5), and step S609 is described above. It is only different from step S509.

In the above-described step S509, in order to avoid the situation where the receiving circuit of the portable device 5 is saturated and the vehicle-mounted device ID7 cannot be read, the vehicle-mounted device 4 transmits only the vehicle-mounted device ID7 by changing the transmission power stepwise. However, in step S609 in FIG. 6, when transmission is performed while changing the transmission power stepwise, the transmission power information is added to the vehicle-mounted device ID 7 for transmission.
The sixth embodiment of the present invention can be applied to the first to fourth embodiments as in the fifth embodiment, but here it is applied to the communication operation of the first embodiment (FIG. 2). Shows the case.

The communication operation of FIG. 6 is different from that of FIG. 5 only in adding transmission power information to the vehicle-mounted device ID 7 in step S609, and thus detailed description thereof is omitted.
By the same steps S601 to S607 as described above, when the tag ID 6 is received NG, the vehicle-mounted device 4 variably sets the transmission power of the vehicle-mounted device 4 in step S608 and then sets the vehicle-mounted device ID 7 to which the transmission power information is added to the portable device 5. (Step S609).

Thereby, in step S605, the onboard equipment 4 can specify the transmission power of the onboard equipment 4 at the time of reception of the onboard equipment ID7 by the portable equipment 5, and the position of the portable equipment 5 from the reception area corresponding to the transmission power. Can be determined in detail.
Further, when the portable device 5 has a position determination function as in the above-described fourth embodiment, the portable device 5 is portable based on the tag ID 6 (transmitter ID) or the vehicle-mounted device ID 7 and the transmission power information. The position of the machine 5 itself can be specified, and the position information can be transmitted to the vehicle-mounted device 4.

  As described above, according to the sixth embodiment of the present invention, the vehicle-mounted device 4 adds transmission power information to the vehicle-mounted device ID 7 when the transmission power of the vehicle-mounted device ID 7 (pseudo ID) is variably set stepwise. Since the transmission power at the time when the saturation of the receiving circuit of the portable device 5 is avoided can be specified by transmitting the information, the position of the portable device 5 can be determined in detail.

Embodiment 7 FIG.
In the fifth embodiment, the transmission power is variably set at the time of transmission of the vehicle-mounted device ID 7 from the vehicle-mounted device 4, but the polarization of the antenna 3 may be variably set.
Hereinafter, Embodiment 7 of the present invention in which the polarization is variably set at the time of transmission of the vehicle-mounted device ID 7 will be described with reference to the flowchart of FIG. 7 together with FIG.
FIG. 7 shows a processing procedure when the inside / outside determination is performed while transmitting the vehicle-mounted device ID 7 while changing the polarization of the antenna 3 to avoid saturation of the receiving circuit of the portable device 5.

The configuration of the seventh embodiment of the present invention is as shown in FIG.
In FIG. 7, steps S701 to S707, S709 to S712, S720, and S730 correspond to steps S501 to S507, S509 to S512, S520, and S530 described above (see FIG. 5), and steps S708 and S713 are performed. Only the steps S508 and S513 are different.

In this case, the vehicle-mounted device 4 allows the portable device 5 to receive the vehicle-mounted device ID 7 by changing the polarization of the antenna 3 stepwise when transmitting the vehicle-mounted device ID 7.
7, first, the vehicle-mounted device 4 radiates radio waves via the antenna 3 in order to supply power to the RF tag 2 (step S701), and the RF tag 2 uses the supplied power to generate the RF tag. 2 transmits the tag ID 6 held by itself (step S702).

Next, the portable device 5 determines whether or not the tag ID 6 can be received (step S703). If it is determined that the tag ID 6 can be received (that is, YES), the ID signal (tag) received by the portable device 5 is determined. ID6) is transmitted to the vehicle-mounted device 4 (step S704).
Thereby, the vehicle-mounted device 4 receives the tag ID 6 from the portable device 5 (step S705), determines that the portable device 5 exists in the vehicle (step S720), and ends the processing routine of FIG.

  On the other hand, if it is determined in step S703 that the tag ID 6 cannot be received (that is, NO), the portable device 5 transmits information “reception NG of the tag ID 6” to the vehicle-mounted device 4 (step S706). 4 receives information “reception NG of tag ID 6” from the portable device 5 (step S707).

Subsequently, the vehicle-mounted device 4 switches the polarization of the antenna 3 step by step by a predetermined amount from the polarization (initial value) in step S701 in response to the received signal from the portable device 5 (step S708). The in-vehicle device ID 7 is transmitted to the portable device 5 (step S709).
As the antenna 3, a linearly polarized antenna, a circularly polarized antenna, or the like is used so that the polarization can be switched. In this case, the polarization is not limited to one that can be switched by one and the same antenna, and it is sufficient that at least two polarizations can be realized even by a plurality of antennas.

Hereinafter, the portable device 5 determines whether or not the vehicle-mounted device ID7 can be received (step S710). If it is determined that the vehicle-mounted device ID7 can be received (that is, YES), the portable device 5 proceeds to the processing after the above-described step S704. .
That is, the portable device 5 transmits the received ID signal (onboard device ID7) to the onboard device 4, the onboard device 4 receives the onboard device ID7 from the portable device 5, and the portable device 5 is saturated near the antenna 3. It determines with existing in the electric power area | region 8 (in-vehicle).

  On the other hand, if it is determined in step S710 that the in-vehicle device ID7 cannot be received (that is, NO), the portable device 5 transmits the information “reception NG of the in-vehicle device ID7” to the in-vehicle device 4 (step S711). The vehicle-mounted device 4 receives the information “reception NG of the vehicle-mounted device ID 7” from the portable device 5 (step S712).

  In response to this, the vehicle-mounted device 4 determines whether or not the antenna 3 has a switchable polarization other than the polarization transmitted in step S709 (step S713), and has the switchable polarization. If it is determined (that is, YES), the process returns to step S708, the polarization is changed stepwise by a predetermined amount set in advance, and steps S709 to S713 are repeatedly executed.

  On the other hand, if it is determined in step S713 that the transmission with the polarization that can be realized by the antenna 3 is completed and the switchable polarization is not held (that is, NO), the vehicle-mounted device 4 is the portable device 5. Since the vehicle-mounted device ID 7 cannot be received, it is determined that the portable device 5 does not exist near the antenna 3 (exists outside the vehicle) (step S730), and the processing routine of FIG.

  As described above, according to the seventh embodiment of the present invention, since the vehicle-mounted device 4 transmits the vehicle-mounted device ID7 while changing the polarization of the antenna 3, can the mobile device 5 receive the vehicle-mounted device ID7? Based on whether or not, it can be determined whether the position of the portable device 5 is inside or outside the vehicle.

Embodiment 8 FIG.
Although not mentioned in the seventh embodiment, the vehicle-mounted device 4 may transmit the polarization information added to the vehicle-mounted device ID 7 when the polarization of the antenna 3 is changed stepwise. .
Hereinafter, with reference to the flowchart of FIG. 8 together with FIG. 1, an eighth embodiment of the present invention in which polarization information is added during transmission of the vehicle-mounted device ID 7 will be described.
FIG. 8 shows a processing procedure for determining the position of the portable device 5 in detail by adding polarization information to the vehicle-mounted device ID 7 when changing the polarization of the antenna 3.

The configuration of the eighth embodiment of the present invention is as shown in FIG.
In FIG. 8, steps S801 to S808, S810 to S813, S820, and S830 correspond to steps S701 to S708, S710 to S713, S720, and S730 described above (see FIG. 7), and step S809 is described above. Only the step is different from step S709.

In step S709 described above, the onboard unit 4 changes the polarization of the antenna 3 stepwise in order to avoid the saturation of the receiving circuit of the portable device 5 and the inability to read the onboard unit ID7. However, in step S809 in FIG. 8, the onboard unit ID 7 to which the polarization information is added is transmitted when the polarization of the antenna 3 is changed in stages.
The eighth embodiment of the present invention can be applied to the first to fourth embodiments similarly to the seventh embodiment, but here it is applied to the communication operation of the first embodiment (FIG. 2). Shows the case.

The communication operation of FIG. 8 is different from FIG. 7 only in that polarization information is added to the vehicle-mounted device ID 7 in step S809, and thus detailed description thereof is omitted.
By the same steps S801 to S807 as described above, when the tag ID 6 is received NG, the vehicle-mounted device 4 variably sets the polarization of the antenna 3 in step S808, and then adds the vehicle-mounted device ID 7 to which the polarization information is added to the portable device 5. Transmit (step S809).

Thereby, in step S805, the vehicle-mounted device 4 can identify the polarization of the antenna 3 when the portable device 5 receives the vehicle-mounted device ID7, and from the change in the radiation region from the antenna 3 caused by the change in the polarization. The position of the portable device 5 can be known in detail.
Further, when the portable device 5 has a position determination function as in the above-described fourth embodiment, the portable device 5 is portable based on the tag ID 6 (transmitter ID) or the vehicle-mounted device ID 7 and the polarization information. The position of the machine 5 itself can be specified, and the position information can be transmitted to the vehicle-mounted device 4.

  As described above, according to the eighth embodiment of the present invention, the vehicle-mounted device 4 variably sets the polarization of the antenna 3 step by step when transmitting the vehicle-mounted device ID7 (pseudo ID), By adding the polarization information and transmitting, when the saturation of the receiving circuit of the portable device 5 is avoided, the polarization of the antenna 3 when the portable device 5 receives the vehicle-mounted device ID 7 is specified and the polarization is changed. Therefore, the position of the portable device 5 can be determined in detail.

It is a block diagram which shows the communication apparatus for vehicles by Embodiment 1-8 of this invention. It is a flowchart which shows the operation | movement by Embodiment 1 of this invention. It is a flowchart which shows the operation | movement by Embodiment 2 of this invention. It is a flowchart which shows the operation | movement by Embodiment 3 of this invention. It is a flowchart which shows the operation | movement by Embodiment 5 of this invention. It is a flowchart which shows the operation | movement by Embodiment 6 of this invention. It is a flowchart which shows the operation | movement by Embodiment 7 of this invention. It is a flowchart which shows the operation | movement by Embodiment 8 of this invention.

Explanation of symbols

  1 vehicle, 2 RF tag, 3 antenna, 4 vehicle-mounted device, 5 portable device, 6 tag ID, 7 vehicle-mounted device ID, 8 saturation power region.

Claims (9)

An in-vehicle device that is installed in a vehicle, radiates radio waves, and transmits an in-vehicle device ID possessed by itself;
An ID transmitter installed in the vehicle and transmitting its own transmitter ID in response to reception of the radio wave;
A portable device that receives the vehicle-mounted device ID or the transmitter ID;
ID communication means for transmitting the transmitter ID or the in-vehicle device ID from the portable device to the in-vehicle device,
The on-vehicle device determines the position of the portable device based on reception of the transmitter ID or the on-vehicle device ID transmitted from the portable device by the ID communication means. An in-vehicle device that is installed in a vehicle, radiates radio waves, and transmits an in-vehicle device ID possessed by itself;
An ID transmitter installed in the vehicle and transmitting its own transmitter ID in response to reception of the radio wave;
A portable device that receives the vehicle-mounted device ID or the transmitter ID,
The portable device determines the position of the portable device based on the received transmitter ID or the vehicle-mounted device ID, and transmits its own position information to the vehicle-mounted device.
The vehicle-mounted communication device, wherein the vehicle-mounted device determines a position of the portable device based on the position information transmitted from the portable device.   The on-vehicle device transmits the on-vehicle device ID to the portable device by changing transmission power in a stepwise manner from an initial value when the on-vehicle device ID is not received by the portable device. Or the communication apparatus for vehicles of Claim 2.   The vehicle-mounted communication device according to claim 3, wherein the vehicle-mounted device adds transmission power information when the transmission power is changed stepwise to the vehicle-mounted device ID and transmits the information to the portable device. . The initial value of the transmission power is set to an upper limit value,
The vehicle-mounted communication device according to claim 3, wherein the vehicle-mounted device reduces the transmission power in a stepwise manner. The initial value of the transmission power is set to a lower limit value,
The vehicle-mounted communication device according to claim 3 or 4, wherein the on-vehicle device increases the transmission power in a stepwise manner.   The vehicle-mounted device transmits the vehicle-mounted device ID to the portable device by stepwise changing the polarization of an antenna provided in the vehicle-mounted device when the vehicle-mounted device ID is not received by the portable device. The vehicle communication device according to claim 1 or 2, wherein the vehicle communication device is characterized in that:   The vehicle-mounted device according to claim 7, wherein the vehicle-mounted device adds polarization information when the polarization of the antenna is changed in a stepwise manner to the vehicle-mounted device ID and transmits the information to the portable device. Communication device.   The vehicle communication device according to claim 7 or 8, wherein the antenna is a linearly polarized antenna or a circularly polarized antenna.

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