JP2012162202A - Tire position registration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire position registration system that simplifies the system configuration by allowing the tire position to be registered by one initiator.SOLUTION: A receiver 11 is disposed on a C-pillar. One initiator 17 is disposed on the left at the rear of a vehicle body 5. First, a weak trigger signal Str is transmitted from the initiator 17 in order to specify a left rear tire 2d. Next, when the door is in a closed state, a strong trigger signal Str is transmitted from the initiator 17 in order to start up a total of three tire communication devices 4b-4d and to measure received-signal intensities when the receiver 11 receives radio waves transmitted from the tire communication devices. Similarly, when the door opening operation is performed, the received-signal intensities of the radio waves transmitted from the tire communication devices are measured. A left front tire 2b and a right rear tire 2c are specified from the difference in magnitude between the received-signal intensity when the door is closed and the received-signal intensity when the door is opened. Finally, an unregistered tire air pressure signal is registered as a right front tire 2a from in tire air pressure signals Stp received from the tire communication devices 4a-4d during traveling.

Description

  The present invention relates to a tire pressure monitoring system that monitors the air pressure of each tire, and more particularly to a tire position registration system that registers the tire position of each tire in a vehicle body.

  In recent years, vehicles tend to be equipped with a tire pressure monitoring system that monitors the tire pressure of each tire during traveling for the purpose of ensuring the safety of the traveling vehicle. The tire pressure monitoring system attaches a tire communication device to each tire and wirelessly transmits a tire pressure signal detected by the tire communication device to the vehicle body. The vehicle body monitors the tire air pressure based on the tire air pressure signal received from the tire communicator, and notifies the driver of a low pressure alarm when confirming that a low pressure tire is present.

  In this type of tire pressure monitoring system, when the vehicle body receives a tire pressure signal, it is necessary to recognize from which position the tire is transmitted. Therefore, a direct method for managing the transmission operation of the tire communication device by an initiator installed in each tire house has been devised in the tire pressure monitoring system (see Patent Document 1). In this case, the vehicle body selectively activates the tire communication device by the initiator, and authenticates the correctness of the signal by the tire ID in the tire air pressure signal transmitted at the time of activation.

JP 2006-062516 A

  However, when the tire pressure monitoring system is a direct system, an initiator must be installed in each tire house, so a total of four initiators are required: right front, left front, right rear, and left rear. For this reason, since a large number of initiators are required, there is a problem that the structure of the system related to grasping the tire position becomes complicated. Therefore, there was a need to develop a simple tire position registration system with a small number of parts. Further, when a large number of initiators are required, there is a problem that the cost of the parts is increased accordingly.

  An object of the present invention is to provide a tire position registration system capable of simplifying the system configuration by making it possible to register tire positions with one initiator.

  In order to solve the above problems, in the present invention, a tire pressure detecting means for detecting tire pressure is attached to each tire, a tire pressure signal is transmitted from the tire pressure detecting means to the vehicle body wirelessly, and the pressure of each tire is measured. In a tire position registration system that is used in a tire condition monitoring system that monitors a vehicle body, and that registers the position of the tire in the vehicle body, a trigger signal that activates the tire air pressure detecting means can be transmitted at different transmission strengths. An initiator and a receiving means for receiving radio waves transmitted from the tire pressure detecting means closest to the receiver at different reception signal strengths by opening or closing a door located between the tire pressure detecting means and the tire pressure detecting means; The tire empty in each case when the trigger signal is transmitted from the initiator while changing the transmission intensity. Based on the response result of the pressure detection means and the change that occurs in the received signal strength when the receiving means receives the radio wave from the tire air pressure detecting means when the door is closed and the received signal strength when the reception means is opened when the door is opened, The gist of the invention is that it comprises a registration means for registering the position of the tire.

  According to the configuration of the present invention, by transmitting the trigger signal from one initiator with the transmission intensity changed, for example, only one tire air pressure detecting means is activated by a trigger signal having a weak transmission intensity, and a trigger signal having a strong transmission intensity is obtained. A plurality of tire pressure detecting means are activated. Also, the tire pressure detecting means is activated by one initiator both when the door is closed and opened, and when the receiving means receives the radio wave from the tire air pressure detecting means when the door is closed, the received signal strength and the same radio wave are opened. Check the change that occurs between the received signal strength and the occasional reception.

  Therefore, in the configuration of the present invention, when the trigger signal is transmitted from the initiator by changing the transmission intensity, the response result of each of the tire pressure detection means and the radio wave from the tire pressure detection means are received when the door is closed. The tire air pressure detecting means is specified based on the change in the received signal strength when the door is opened and the received signal strength when the door is opened. For this reason, since it is possible to register the position of the tire with one initiator, the system structure can be simplified.

  In the present invention, the change in the received signal intensity includes the received signal intensity when the receiving means receives the radio wave from the tire air pressure detecting means when the door is closed, and the received signal intensity when the radio wave is received when the door is opened. The gist of this is the difference. According to this configuration, since the tire position is specified using the received signal intensity difference, it is possible to specify the tire position with high accuracy by a simple process of confirming the difference.

  In the present invention, the registration means causes the initiator to send the trigger signal weakly, thereby starting the air pressure detection means nearest to the initiator and identifying the nearest tire of the initiator; , By causing the initiator to send a stronger trigger signal at each opening and closing of the door, a plurality of tire air pressure detecting means including a tire air pressure detecting means nearest to the initiator are activated, and when the door is closed, the tire air pressure is Based on the change in the received signal strength received from the detecting means and the received signal strength received from the tire air pressure detecting means when the door is opened, among the plurality of tires activated by the stronger trigger signal, the closest to the initiator A second registration means for registering a position of a tire other than the tire; Of the radio waves received from the tire air pressure detecting means, and summarized in that and a third register means for specifying the registered ones as the other tires. According to this configuration, first, the tire pressure detecting means is activated by a weak trigger signal, the nearest tire of the initiator is specified, and then a plurality of tire pressure detecting means are activated by a strong trigger signal when the door is closed. Then, these received signal strengths are measured. Then, when the door is opened, a plurality of tire air pressure detection means are activated with the same strong trigger signal, and the received signal strength is measured, and the change between the received signal strength when the door is closed and the received signal strength when the door is opened. From this, the tire position is specified. Finally, the remaining tires are identified from the tire air pressure signal received from the tire air pressure detecting means during traveling. For this reason, it is possible to smoothly register the tire position in the vehicle body in the flow until the parked and stopped vehicle shifts to running.

  In the present invention, the initiator can form the first registration means when transmitting the weak trigger signal and can form the second registration means when transmitting the strong trigger signal. The receiving means is arranged in the vicinity of the tire pressure detecting means that responds only when the initiator transmits the strong trigger signal, and the radio wave transmitted by the tire pressure detecting means is transmitted. The gist is that they are arranged at positions that receive signals with different received signal strengths depending on whether the nearest door is opened or closed. By devising the positions of the initiator and the receiving means, it is possible to register the tire position with a simple structure.

  According to the present invention, the system configuration can be simplified by making it possible to register the tire position with one initiator.

The block diagram of the tire position registration system of one Embodiment. Explanatory drawing which shows the communication aspect before and behind the door opening / closing of a tire communication apparatus. The conceptual diagram which shows the outline of the communication area which an initiator forms. The flowchart performed at the time of tire position registration. Operation diagram when registering the nearest tire of the initiator. Operation diagram when three wheels are activated by a strong trigger signal when the door is closed. The operation | movement figure when starting 3 wheels with a strong trigger signal at the time of a door opening. The operation | movement figure when registering the last tire during driving | running | working.

Hereinafter, an embodiment of a tire position registration system embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the vehicle 1 is equipped with a tire pressure monitoring system (TPMS: Tire Pressure Monitoring System) 3 that monitors the tire pressure of each tire 2 (2a to 2d). The tire pressure monitoring system 3 detects the tire pressure and the like by the tire communication device 4 attached to each tire 2a to 2d, and transmits the detection result to the vehicle body 5 as a tire pressure signal Stp. The tire pressure monitoring system 3 confirms the tire pressure from the tire pressure signal Stp and notifies the driver of the result. Note that the tire communication device 4 corresponds to tire air pressure detecting means.

  The tire communication device 4 is provided with a controller 6 that manages the tire communication device 4 in an integrated manner. In the memory (not shown) of the controller 6, tire IDs are registered as unique IDs of the tires 2a to 2d. The tire communication device 4 is provided with a pressure sensor 7 that detects tire air pressure, a temperature sensor 8 that detects tire temperature, and an acceleration sensor 9 that detects rotation of the tire 2, and these are connected to the controller 6. These sensors output detection signals to the controller 6. The controller 6 is connected to a transmitter 10 capable of transmitting UHF (Ultra High Frequency) band radio waves.

  The vehicle body 5 is provided with a receiver (hereinafter referred to as a TPMS receiver) 11 that monitors the air pressure of the tire 2 based on the tire air pressure signal Stp received from the tire communication device 4. The TPMS receiver 11 is provided with a tire air pressure monitoring ECU (Electronic Control Unit) 12 that comprehensively manages the operation of the TPMS receiver 11 and a receiving unit 13 that can receive UHF radio waves. In the memory (not shown) of the tire pressure monitoring ECU 12, tire IDs of the tires 2a to 2d are registered in association with tire positions. The receiving unit 13 includes an antenna 14 and a receiving circuit 15 that demodulates and amplifies received radio waves. The TPMS receiver 11 is connected to a display unit 16 installed on, for example, an in-vehicle instrument panel. The TPMS receiver 11 corresponds to a receiving unit.

  When the tire communication device 4 detects that the tire 2 has entered a rotating state (the vehicle 1 is in a traveling state) based on the acceleration signal output from the acceleration sensor 9, the tire communication device 4 starts transmitting the tire air pressure signal Stp. That is, the tire pressure monitoring system 3 of this example is a direct method in which the tire communication device 4 transmits the tire pressure signal Stp to the vehicle body 5 by itself while the vehicle is traveling. The tire pressure signal Stp includes a tire ID, tire information (air pressure, temperature), and the like. Each tire communication device 4 transmits radio waves with a random time difference so that radio transmission does not overlap with other tire communication devices 4.

  When the tire pressure monitoring ECU 12 receives the tire pressure signal Stp at the receiving unit 13, the tire pressure monitoring ECU 12 executes ID verification based on the tire ID in the tire pressure signal Stp. When the tire pressure monitoring ECU 12 confirms that the ID verification is established, the tire pressure monitoring ECU 12 confirms the tire pressure based on the tire information included in the same signal. When the tire air pressure monitoring ECU 12 confirms that the tire air pressure is less than the threshold value, the tire air pressure monitoring ECU 12 displays the low pressure tire in association with the tire position on the display unit 16.

  The tire pressure monitoring system 3 of this example is provided with a tire position registration system capable of registering the position of each tire 2 in the vehicle body 5 with only one initiator 17. By the way, as shown in FIG. 2, the TPMS receiver 11 is often mounted near the C pillar 18 of the vehicle body 5. The C pillar 18 is a pillar located on the rear side of the rear door. In this example, the C pillar 18 is on the right side of the rear part of the vehicle body. Therefore, it is assumed that the TPMS receiver 11 of this example is attached to the right rear C pillar 18.

  As a feature when the TPMS receiver 11 is mounted at this place, the right rear door 19 is opened and closed when the TPMS receiver 11 receives the tire pressure signal Stp from the right rear tire communication device 4c close to the C pillar 18. Before and after, the received signal strength (RSSI: Receive Signal Strength Indication) of the tire pressure signal Stp changes greatly. In other words, when the right rear door 19 is open, the TPMS receiver 11 can receive the radio wave from the right rear tire communication device 4c without being blocked by the right rear door 19, so that the received signal strength is closed by the right rear door 19. Compared to when it is. Therefore, the position of the right rear tire 2c on the C pillar 18 side to which the TPMS receiver 11 is attached should be able to be determined by comparing the received signal strength before and after the right rear door 19 is opened and closed. Therefore, the tire position registration system of the present example uses this principle to specify the positions of the four tires 2a to 2d in the front, rear, left, and right directions.

  The initiator 17 is a component that activates the tire communication device 4 by wireless communication. The initiator 17 is connected to the tire pressure monitoring ECU 12, and the transmission operation is managed by the tire pressure monitoring ECU 12. When the initiator 17 receives an activation command from the tire pressure monitoring ECU 12, the initiator 17 transmits a trigger signal Str that activates the tire communication device 4 using a radio wave in the LF (Low Frequency) band. The initiator 17 is disposed at a position on the left rear side in the vehicle body 5 and is disposed obliquely with respect to the vehicle body longitudinal direction so that the antenna shaft forms a predetermined angle with respect to a line in the vehicle body longitudinal direction. This is to select and activate a predetermined one of the four tire communication devices 4a to 4d on the front, rear, left, and right.

  The tire communication device 4 is provided with a receiving unit 20 capable of receiving LF radio waves. The tire communication device 4 is activated when the receiving unit 20 receives the trigger signal Str from the initiator 17 and transmits a tire air pressure signal Stp to the vehicle body 5. Note that the response radio wave from the tire communication device 4 at this time is not necessarily limited to the tire pressure signal Stp itself, but may be a signal of only the tire ID that does not include the tire pressure information.

  The tire pressure monitoring ECU 12 is provided with a transmission radio wave variable unit 21 that causes the initiator 17 to variably transmit the trigger signal Str. The transmission radio wave variable section 21 can form the trigger signal Str in two areas, a weak transmission area Ea and a strong transmission area Eb shown in FIG. The weak transmission area Ea is formed in a range in which only the left rear tire communication device 4d can be activated. Further, the strong transmission area Eb is formed in a range in which three of the left front tire communication device 4b, the right rear tire communication device 4c, and the left rear tire communication device 4d can be activated. The transmission radio wave variable unit 21 constitutes registration means (first registration means, second registration means).

  The tire pressure monitoring ECU 12 is provided with a received signal strength measuring unit 22 that measures the received signal strength of the received radio wave. The reception signal strength measurement unit 22 measures the reception signal strength at this time when the reception unit 13 receives the tire air pressure signal Stp. The received signal strength measuring unit 22 constitutes registration means (second registration means).

  The tire pressure monitoring ECU 12 is provided with a first tire ID registration unit 23 that registers the ID of the nearest tire of the initiator 17 in the vehicle body 5. The first tire ID registration unit 23 causes the transmission radio wave variable unit 21 to form a trigger signal Str in the weak transmission area Ea, and the tire pressure signal Stp transmitted by the tire communication device 4 activated by the trigger signal Str is transmitted. The tire ID is registered in the vehicle body 5 as the ID of the left rear tire 2d. In addition, the 1st tire ID registration part 23 comprises a registration means (1st registration means).

  In the tire pressure monitoring ECU 12, the ID of the two tires 2 b and 2 c other than the one nearest to the initiator 17 among the three tires 2 b to 2 d located in the strong transmission area Eb of the initiator 17 is given to the vehicle body 5. A second tire ID registration unit 24 for registration is provided. The second tire ID registration unit 24 closes and opens the right rear door 19, and each tire communication device 4 b to 3 wheels (left front tire 2 b, right rear tire 2 c, left rear tire 2 d) by the strong transmission area Eb. Activate 4d. Here, since the left rear tire 2d closest to the initiator 17 has already been registered in the vehicle body 5 by the first tire ID registration unit 23, if the remaining two wheels (left front tire 2b, right rear tire 2c) are specified. Good. Therefore, the second tire ID registration unit 24 measures the difference between the received signal strength of each tire air pressure signal Stp before and after the door opening / closing for two wheels other than the left rear tire 2d (the left front tire 2b and the right rear tire 2c). A tire ID having a large intensity difference is registered in the vehicle body 5 as an ID of the right rear tire 2c, and a tire ID having a small intensity difference is registered in the vehicle body 5 as an ID of the left front tire 2b. In addition, the 2nd tire ID registration part 24 comprises a registration means (2nd registration means).

  The tire pressure monitoring ECU 12 is provided with a third tire ID registration unit 25 that registers the tire ID of the last one of the four tires 2a to 2d. By the way, each tire communicator 4 periodically transmits the tire pressure signal Stp at regular intervals while the vehicle is traveling. Therefore, among the tire IDs received during traveling, the first tire ID registration unit 23 and the first tire ID signal are registered. The ID that could not be registered by the two-tire ID registration unit 24 can be identified as the last one wheel (right front tire 2a). Therefore, the 3rd tire ID registration part 25 registers tire ID which is not registered into self among tire ID received during driving | running | working in the vehicle body 5 as ID of the right front tire 2a. In addition, the 3rd tire ID registration part 25 comprises a registration means (3rd registration means).

  Next, operation | movement of the tire position registration system of this example is demonstrated using the flowchart of FIG. The flowchart of FIG. 4 is executed at a predetermined time when the vehicle 1 is parked and stopped, for example, and is continued until the four-wheel tire ID is registered in the vehicle body 5.

  In step 101, the first tire ID registration unit 23 transmits a weak trigger signal Str from the initiator 17 to activate the nearest wheel of the initiator 17, and the tire ID in the tire pressure signal Stp received at this time is The tire ID of the left rear tire 2d is registered in the vehicle body 5. That is, as shown in FIG. 5, the trigger signal Str of the weak transmission area Ea is formed in the initiator 17, and ID4 of the left rear tire communication device 4d activated by the trigger signal Str is used as the left rear tire 2d to the vehicle body 5. sign up.

  In step 102, when the right rear door 19 is in the closed state, the second tire ID registration unit 24 transmits a strong trigger signal Str from the initiator 17, thereby including a total of three wheels including the left rear tire 2d for which ID registration has been completed. Start up. That is, as shown in FIG. 6, when the right rear door 19 is closed, the trigger signal Str of the strong transmission area Eb is formed in the initiator 17, and the left rear tire communicator 4d in which the ID registration is completed and the left front tire communication The tire pressure signal Stp is transmitted to the machine 4b and the right rear tire communication machine 4c, respectively. At this time, each tire pressure signal Stp is transmitted with a random predetermined time difference so that radio transmission is not overlapped with other tire pressure signals Stp.

  Here, among the three wheels activated at this time, the tire communication device 4d closest to the initiator 17 has already undergone ID registration, so the operation proceeds to ID registration for the remaining two wheels. At this time, the second tire ID registration unit 24 receives the tire pressure signal Stp from each of the tire communication devices 4b to 4d, but measures the received signal strength for the two tire communication devices 4b and 4c for which the ID registration has not been completed. These are stored as the received signal strength when the door is closed. That is, the second tire ID registration unit 24 stores the received signal strength when the door of ID2 is closed and the received signal strength when the door of ID3 is closed.

  In Step 103, the second tire ID registration unit 24 determines whether or not an opening operation has been performed on the rear door of the TPMS receiver 11 side. That is, the second tire ID registration unit 24 determines whether the right rear door 19 has been opened or closed. If there is a door opening operation, the process proceeds to step 104, and if there is no door opening operation, the process returns to step 102.

  When returning from step 103 to step 102, the received signal strength measurement when the door is closed is not limited to being performed every time the step is returned. For example, the received signal strength measurement may be re-executed only when a certain time has passed since the previous measurement.

  In Step 104, when the right rear door 19 is in the open state, the second tire ID registration unit 24 transmits a strong trigger signal Str from the initiator 17, thereby including a total of three wheels including the left rear tire 2d whose ID has been registered. Start up. That is, as shown in FIG. 7, when the right rear door 19 is open, the trigger signal Str of the strong transmission area Eb is formed in the initiator 17, and the left rear tire communicator 4d in which the ID registration is completed and the left front tire communication The tire pressure signal Stp is transmitted to the machine 4b and the right rear tire communication machine 4c, respectively. Also at this time, each tire pressure signal Stp is transmitted with a random predetermined time difference so that the other tire pressure signals Stp and radio wave transmission do not overlap.

  At this time, the second tire ID registration unit 24 receives the tire pressure signal Stp from each of the tire communication devices 4b to 4d, but measures the received signal strength for the two tire communication devices 4b and 4c for which the ID registration has not been completed. These are stored as the received signal strength when the door is opened. That is, the second tire ID registration unit 24 stores the received signal strength when the door of ID2 is opened and the received signal strength when the door of ID3 is opened.

  Subsequently, in Step 105, the second tire ID registration unit 24 calculates the received signal strength difference before and after the door opening / closing for each ID (ID2, ID3). That is, the second tire ID registration unit 24 calculates the strength difference before and after the door opening / closing for ID2 and also calculates the strength difference before and after the door opening / closing for ID3.

  In step 106, the second tire ID registration unit 24 identifies the tire positions of ID2 and ID3 based on the calculated difference in received signal intensity. Here, the difference in the received signal strength between before and after the door opening / closing can be determined as the right rear tire communication device 4c in which the received signal strength increases when the door is opened. Therefore, the second tire ID registration unit 24 registers ID3 having a large strength difference before and after the door opening / closing as the right rear tire 2c in the vehicle body 5 and ID2 having a small strength difference before and after the door opening / closing as the left front tire 2b. Register in the car body 5.

  In Step 107, the third tire ID registration unit 25 registers, in the vehicle body 5, as the right front tire 2a, the ID1 that is not registered in the vehicle body 5 among the tire IDs acquired by the periodic reception while the vehicle is traveling. That is, among the tire IDs received from the respective tire communication devices 4a to 4d by regular reception while the vehicle is running, the tire IDs not registered in the vehicle body 5 can be determined as the IDs of the remaining tires, and this is registered as the ID of the right front tire 2a To do.

  As described above, in this example, it is possible to specify the tire position even if the number of initiators 17 is one, so that only one initiator 17 is installed in the vehicle 1. Therefore, the system configuration of the tire position registration system can be simplified. In addition, since only one initiator 17 is installed, the parts cost required for the tire position registration system can be reduced.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) The vehicle body 5 is provided with only one initiator 17, and the initiator 17 is caused to generate the trigger signal Str of the weak transmission area Ea, thereby registering the ID of the left rear tire 2 d in the vehicle body 5. Next, the trigger signal Str of the strong transmission area Eb is formed by the initiator 17 before and after the opening and closing of the right rear door 19, and the IDs of the left front tire 2b and the right rear tire 2c are assigned to the vehicle body 5 from the difference in received signal strength before and after the door opening and closing. Register with. Then, among the IDs acquired from the periodic reception while the vehicle is traveling, an unregistered one is registered in the vehicle body 5 as the right front tire 2a. Therefore, since only one initiator 17 is installed, the system configuration can be simplified, and the component cost can be reduced.

  (2) When specifying the tire position using the received signal strength as a parameter in the second tire ID registering unit 24, the tire position is specified by the received signal strength difference, and thus a simple process of confirming the received signal strength difference, and The tire position can be specified with high accuracy.

  (3) As a feature when the TPMS receiver 11 is installed in the right rear C-pillar 18, when the right rear door 19 is opened and closed, the radio wave received from the right rear tire communication device 4c when the TPMS receiver 11 is closed. It has been found that there is a large difference in strength between the received signal strength and the received signal strength of the radio wave received from the right rear tire communication device 4c when the door is opened. Therefore, since the TPMS receiver 11 of this example is attached to the C pillar 18 in which such a large difference in received signal strength occurs, the tire position can be specified with high accuracy.

  (4) The tire position registration system automatically starts at predetermined time intervals and automatically executes a tire position registration operation. Therefore, since the tire position is automatically registered (auto-location) in the vehicle body 5 without imposing a separate registration operation on the user, convenience can be ensured.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
-The start timing of tire position registration can be appropriately changed to other modes. Further, the tire position registration may be started when a predetermined operation is performed on the vehicle body 5, for example.

The change in received signal strength is not limited to the received signal strength difference. For example, the received signal strength itself may be monitored and the received signal strength may be compared with a threshold value.
The TPMS receiver 11 may be arranged at the C pillar at the left rear part, and the initiator 17 may be arranged at a position on the right side of the rear part of the vehicle body 5.

The location of the TPMS receiver 11 is not limited to the C pillar 18 and may be changed to another position such as a B pillar.
The location of the initiator 17 is not limited to the position on the left side of the rear part of the vehicle body 5. That is, the initiator 17 may be located anywhere as long as it can form the LF band communication area forming the first registration unit and the second registration unit of this example.

  The initiator 17 is not limited to be disposed obliquely with respect to the vehicle longitudinal direction line. In short, if the area of the trigger signal Str that can activate a predetermined one of the tire communication devices 4a to 4d can be formed, the arrangement direction can be changed as appropriate.

-Tires that are subject to tire position registration are not limited to 2a to 2d attached to the vehicle body 5 as drive wheels, and spare tires may be added.
The frequency of the tire pressure signal Stp is not limited to UHF, and the frequency of the trigger signal Str is not limited to LF. That is, the frequency used wirelessly can be changed as appropriate.

The receiving means is not limited to the TPMS receiver 11 itself, and may be the receiving unit 13, for example.
The procedure for registering the tire position is not limited to the contents and procedure described in the embodiment, and can be appropriately changed if the idea of claim 1 is included.

  2 (2a to 2d) ... tyre, 3 ... tyre pressure monitoring system, 4 (4a to 4d) ... tyre communication device as tire pressure detection means, 5 ... body, 11 ... TPMS receiver as receiving means, 17 ... initiator , 18 ... C pillar, 19 ... Right rear door as a door, 21 ... Registering means, first registration means, transmission radio wave variable section constituting second registration means, 22 ... Reception means constituting registration means, second registration means Signal intensity measuring unit, 23... Registration unit, first tire ID registration unit constituting first registration unit, 24... Registration unit, second tire ID registration unit constituting second registration unit, 25. Third tire ID registration unit constituting registration means, Stp ... tire pressure signal, Str ... trigger signal.

Claims (4)

A tire pressure detecting means for detecting tire pressure is attached to each tire, a tire pressure signal is wirelessly transmitted from the tire pressure detecting means to the vehicle body, and used for a tire pressure monitoring system for monitoring the tire pressure by the vehicle body, In the tire position registration system for registering the position of the tire in the vehicle body,
One initiator capable of transmitting a trigger signal for activating the tire air pressure detecting means with varying transmission intensity;
Receiving means for receiving radio waves transmitted from the tire pressure detecting means closest to itself at different reception signal strengths by opening or closing a door located between the tire pressure detecting means and itself.
When the trigger signal is transmitted from the initiator by changing the transmission intensity, the response result of the tire air pressure detecting means in each case, and the radio wave from the tire air pressure detecting means is received when the door is closed A tire position registration system, comprising: a registration means for registering the position of the tire based on a change in the received signal intensity and a received signal intensity when the door is opened. The change in the received signal intensity is the difference between the received signal intensity when the receiving means receives the radio wave from the tire pressure detecting means when the door is closed and the received signal intensity when the radio wave is received when the door is opened. The tire position registration system according to claim 1, wherein the tire position registration system is provided. The registration means includes
A first registration means for starting the air pressure detecting means nearest to the initiator and identifying the nearest tire of the initiator by transmitting the trigger signal weakly from the initiator;
By causing the initiator to send a stronger trigger signal at each opening and closing of the door, a plurality of tire air pressure detecting means including a tire air pressure detecting means nearest to the initiator are activated, and when the door is closed, these tire air pressure detecting means are detected. Based on the change in the received signal strength received from the means and the received signal strength received from the tire air pressure detecting means when the door is opened, the nearest tire of the initiator among the plurality of tires activated by the stronger trigger signal Second registration means for registering the positions of other tires other than
3. The tire position registration system according to claim 1, further comprising: a third registration unit that identifies an unregistered radio wave received from the tire air pressure detection unit during traveling as a remaining tire. 4. . The initiator is disposed at a position where the first registration means can be formed when the weak trigger signal is transmitted and the second registration means can be formed when the strong trigger signal is transmitted. ,
The receiving means is arranged in the vicinity of the tire pressure detecting means that responds only when the initiator sends the strong trigger signal, and the radio wave transmitted by the tire pressure detecting means 4. The tire position registration system according to claim 3, wherein the tire position registration system is arranged at a position for receiving signals with different received signal strengths depending on whether the door is opened or closed. 5.

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