JP6507676B2 - Wheel position detection device and tire pressure detection system provided with the same - Google Patents

Description

  The present invention relates to a wheel position detection device that automatically detects at which position of a vehicle a target wheel is mounted. In particular, the present invention mounts a transmitter equipped with a pressure sensor on the wheel side, transmits the detection result of the pressure sensor from the transmitter, and receives it by a receiver mounted on the vehicle body side. It is suitable for application to a direct type tire pressure detection system that performs detection.

  Conventionally, there is a direct system as one of tire pressure detection systems (hereinafter referred to as TPMS: Tire Pressure Monitoring System). In this type of TPMS, a transmitter equipped with a sensor such as a pressure sensor is directly mounted on the wheel side on which the tire is mounted. In addition, an antenna and a receiver are provided on the vehicle body side, and when the detection signal from the sensor is transmitted from the transmitter, the detection signal is received by the receiver via the antenna, and the tire air pressure is detected. To be done.

  In such a direct TPMS, in the data transmitted by the transmitter, it can be determined whether the transmitted data is of the host vehicle and to which wheel the transmitter is attached. ID information is individually assigned to determine whether the vehicle is the own vehicle or another vehicle and to determine the wheel on which the transmitter is attached.

  In order to specify the position of the transmitter from the ID information included in the transmission data, it is necessary to associate the ID information of each transmitter with the position of each wheel and register in advance on the receiver side. For example, the barcode information attached to the transmitter is read by the barcode reader, and the ID information of the transmitter of the vehicle is registered by the method of performing the ID registration through the barcode reader. However, such a method requires a bar code reader and has a problem of increasing the number of steps for reading bar codes of transmitters attached to the respective wheels one by one.

  As described above, at the time of tire rotation, winter tire replacement, etc., it is necessary to re-register the transmitter's ID information and the positional relationship of the wheels with the receiver, so that the user can change the tire freely. Since it can not do, the system which can do registration work of ID information automatically is called for. Therefore, for example, Patent Document 1 proposes a technique for automatically performing ID information registration work.

  Specifically, in the device shown in Patent Document 1, it is detected that a wheel has reached a predetermined rotational position (rotational angle) based on an acceleration detection signal of an acceleration sensor provided in a transmitter on the wheel side. Frame transmission from. Then, when a user's registration instruction operation is performed, the wheel speed sensor detects the passage of the gear teeth rotated in conjunction with the wheel, and the wheel position is detected based on the variation width of the tooth position at the frame reception timing. Are identified.

  In addition, while the ID registration mode for registering ID information of the transmitter is in use, a trigger radio wave is used to send a predetermined radio wave from the vehicle body side to the transmitter side, and response data synchronized with that is received from the transmitter side There is also a method of specifying the wheel position based on sending to the aircraft. In addition, the transmitter is equipped with a 2-axis acceleration sensor, and the left and right wheels are specified based on the detection signal of the 2-axis acceleration sensor, and based on the reception intensity when frame reception from each transmitter is performed on the receiver side. There is also a method of identifying the wheel position by identifying the front and rear wheels. Furthermore, an antenna is arranged in the vicinity of each wheel, the strength of received radio waves (RSSI) when the antenna receives a frame is measured, and a large value is registered as ID information of the wheel in the vicinity of the antenna. is there.

Patent No. 5585595

  When performing automatic registration of the above-described transmitter ID information, basically, all ID information included in the received frame is treated as candidate ID information (hereinafter referred to as candidate ID) to be registered. Among them, the ID information of the transmitter of the own vehicle is to be sorted out. Therefore, the candidate ID is stored in the memory of the TPMS-ECU, the ID information of the transmitter of the own vehicle is selected from the candidate ID, and finally registered in association with the wheel.

  At this time, if the candidate ID is large, the amount of data stored in the memory of the TPMS-ECU reaches the memory capacity and overflows, so that a predetermined condition is set, and irrelevant ID information is excluded from the candidate ID It is preferable to

  On the other hand, the method using a trigger machine as another method requires an additional part called a trigger machine, and the method using a two-axis acceleration sensor requires a high-performance additional part called a two-axis acceleration sensor. Also in the case of the method of disposing the antenna in the vicinity of each wheel, an additional component called an antenna is required for each wheel, resulting in an increase in the number of parts and thus in cost.

  In view of the above-described point, the present invention suppresses the registration of the ID information of the transmitters of the wheels of other vehicles as candidate IDs, while the ID information of the transmitters of the wheels of the own vehicle is accurately registered as candidate IDs It is an object of the present invention to provide a wheel position detecting device and a TPMS provided with the same.

In order to achieve the above object, in the invention according to claim 1, the second control unit (33) measures, for each of the candidate identification information, the elapsed time from the previous reception of the frame including the candidate identification information. It is determined whether there is any time measurement means (S240, S255) and identification information included in the candidate identification information for which the elapsed time measured by the time measurement means has become equal to or longer than a predetermined time. And candidate deletion means (S205, S210) for deleting from the candidate identification information identification information whose elapsed time has become equal to or longer than a predetermined time.

  As described above, even if registration is made as candidate identification information, identification information that has not been received in a frame during a predetermined period is excluded from the candidate identification information as not being of the transmitter of the host vehicle. ing. This makes it possible to accurately register the identification information of the transmitter of the wheel of the own vehicle as the candidate identification information while suppressing the identification information of the transmitter of the wheel of the other vehicle being registered as the candidate identification information .

  In addition, the code | symbol in the parenthesis of each said means shows an example of the correspondence with the specific means as described in embodiment mentioned later.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the tire air pressure detection apparatus with which the wheel position detection apparatus concerning 1st Embodiment of this invention is applied. It is a figure which shows the block configuration of the transmitter 2. FIG. It is a figure which shows the block configuration of TPMS-ECU3. It is a timing chart for explaining wheel position detection. It is an image figure showing change of gear information. It is a schematic diagram illustrating wheel position decision logic. It is a schematic diagram illustrating wheel position decision logic. It is a schematic diagram illustrating wheel position decision logic. It is the graph which showed the evaluation result of the wheel position of ID1. It is the graph which showed the evaluation result of the wheel position of ID2. It is the graph which showed the evaluation result of the wheel position of ID3. It is the graph which showed the evaluation result of the wheel position of ID4. It is a flowchart of registration start determination processing. It is a flowchart of candidate ID selection processing.

  Hereinafter, an embodiment of the present invention will be described based on the drawings. In the following embodiments, parts that are the same as or equivalent to each other will be described with the same reference numerals.

First Embodiment
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing an entire configuration of a TPMS to which a wheel position detection device according to a first embodiment of the present invention is applied. The left direction of the drawing of FIG. 1 corresponds to the front of the vehicle 1 and the right direction of the drawing corresponds to the rear of the vehicle 1. The TPMS in this embodiment will be described with reference to this figure.

  As shown in FIG. 1, the TPMS is provided in the vehicle 1 and includes a transmitter 2, an ECU for TPMS acting as a receiver (hereinafter referred to as TPMS (Tire Pressure Monitoring System) -ECU) 3 and a meter 4. It is configured with. The wheel position detection device uses the transmitter 2 and the TPMS-ECU 3 provided in the TPMS, and the wheels provided corresponding to the respective wheels 5 (5a to 5d) from the brake control ECU (hereinafter referred to as a brake ECU) 10 The wheel position is specified by acquiring gear information obtained from the detection signals of the speed sensors 11a to 11d.

  As shown in FIG. 1, the transmitter 2 is attached to each of the wheels 5a to 5d, detects the air pressure of the tires attached to the wheels 5a to 5d, and indicates the information on the tire air pressure indicating the detection result. It is stored in a frame together with the unique ID information of the transmitter 2 and transmitted. On the other hand, the TPMS-ECU 3 is attached to the vehicle body 6 side of the vehicle 1 and receives the frame transmitted from the transmitter 2 and performs various processing, calculation, etc. based on the detection signal stored therein. To perform wheel position detection and tire air pressure detection.

  The transmitter 2 creates a frame by, for example, FSK (frequency shift keying), and the TPMS-ECU 3 demodulates the frame to read data in the frame, and performs wheel position detection and tire air pressure detection. The block configuration of the transmitter 2 and the TPMS-ECU 3 is shown in FIG.

  As shown in FIG. 2A, the transmitter 2 is configured to include a sensing unit 21, an acceleration sensor 22, a microcomputer 23, a transmission circuit 24, and a transmission antenna 25, and supplies power from a battery (not shown). Each part is driven based on.

  The sensing unit 21 is configured to include, for example, a pressure sensor 21a and a temperature sensor 21b of a diaphragm type, and outputs a detection signal according to the tire air pressure and a detection signal according to the temperature. The acceleration sensor 22 is used to detect the position of the sensor itself on the wheels 5a to 5d to which the transmitter 2 is attached, that is, to detect the position of the transmitter 2 and the vehicle speed. The acceleration sensor 22 according to the present embodiment detects, for example, the accelerations acting on the wheels 5a to 5d when the wheels 5a to 5d rotate, according to the acceleration in both directions perpendicular to the radial direction of the wheels 5a to 5d, that is, the circumferential direction. Output a signal.

  The microcomputer 23 is a known device including a control unit (first control unit) and the like, and executes predetermined processing according to a program stored in a memory in the control unit. The memory in the control unit stores individual ID information including transmitter-specific identification information for specifying each transmitter 2 and vehicle-specific identification information for specifying the own vehicle.

  The microcomputer 23 receives a detection signal concerning tire air pressure from the sensing unit 21, processes the signal and processes it as necessary, and stores the information about the tire air pressure in the frame together with the ID information of each transmitter 2 . Further, the microcomputer 23 monitors the detection signal of the acceleration sensor 22 and performs position detection (angle detection) of the transmitter 2 at the wheels 5a to 5d to which each transmitter 2 is attached, and performs vehicle speed detection. There is. When the microcomputer 23 creates a frame, it transmits the frame from the transmission antenna 25 to the TPMS-ECU 3 through the transmission circuit 24 based on the result of position detection of the transmitter 2 and the result of vehicle speed detection (data transmission (data transmission )I do.

  Specifically, the microcomputer 23 starts frame transmission on condition that the vehicle 1 is traveling, and the timing at which the angle of the acceleration sensor 22 becomes a predetermined angle based on the detection signal of the acceleration sensor 22. Repeated frame transmission is performed. Driving is determined based on the result of vehicle speed detection, and the angle of the acceleration sensor 22 is determined based on the result of position detection of the transmitter 2 based on the detection signal of the acceleration sensor 22. .

  That is, the microcomputer 23 detects the vehicle speed using the detection signal of the acceleration sensor 22 and determines that the vehicle 1 is traveling when the vehicle speed reaches a predetermined speed (for example, 5 km / h) or more. The output of the acceleration sensor 22 includes acceleration based on centrifugal force (centrifugal acceleration). By integrating the centrifugal acceleration and multiplying the coefficient, it is possible to calculate the vehicle speed. For this reason, in the microcomputer 23, the gravitational acceleration component is removed from the output of the acceleration sensor 22 to calculate the centrifugal acceleration, and the vehicle speed is calculated based on the centrifugal acceleration.

  Further, since the detection signal corresponding to the rotation of each of the wheels 5a to 5d is output by the acceleration sensor 22, when traveling, the gravity acceleration component is included in the detection signal, and the amplitude corresponding to the rotation of the wheel It becomes a signal that it has. For example, the amplitude of the detection signal is located at the maximum negative amplitude when the transmitter 2 is located at the upper position around the central axis of the wheels 5a to 5d, zero when at the horizontal position, and at the lower position. When it is positive, it has a maximum amplitude. Therefore, when the position of the acceleration sensor 22 can be detected based on this amplitude and the angle of the position of the transmitter 2, for example, the central axis of each of the wheels 5a to 5d, is located at the upper position The angle formed by the acceleration sensor 22 when 0 ° is set can be grasped.

  Therefore, frame transmission from each of the transmitters 2 is performed at the same time as the vehicle speed reaches a predetermined speed or when the acceleration sensor 22 reaches a predetermined angle after the vehicle speed reaches a predetermined speed. Then, at timing when the angle formed by the acceleration sensor 22 becomes the same as in the first frame transmission, frame transmission is repeatedly performed with the timing as the transmission timing. The transmission timing may be set whenever the angle formed by the acceleration sensor 22 is the same as in the first frame transmission, but in consideration of battery life, frame transmission is always performed each time the angle is reached. Preferably, for example, frame transmission is performed only once in a predetermined time (for example, 15 seconds).

  The transmission circuit 24 functions as an output unit that transmits the frame sent from the microcomputer 23 to the TPMS-ECU 3 through the transmission antenna 25. For frame transmission, for example, radio waves in the RF band are used.

  The transmitter 2 configured in this way is attached to, for example, an air injection valve in the wheel of each of the wheels 5a to 5d, and is disposed such that the sensing unit 21 is exposed to the inside of the tire. Then, the transmitter 2 detects the tire pressure of the wheel to which the transmitter 2 is attached, and as described above, when the vehicle speed exceeds the predetermined speed, the angle of the acceleration sensor 22 of each of the wheels 5a to 5d becomes the predetermined angle. At the timing, frame transmission is repeatedly performed through the transmitting antenna 25 provided in each transmitter 2. Even after that, frame transmission can be performed from the transmitter 2 at a timing when the angle of the acceleration sensor 22 of each of the wheels 5a to 5d becomes a predetermined angle, but it is better to increase the transmission interval in consideration of battery life. Since it is good, when the time assumed to be necessary for wheel position detection has elapsed, the wheel position determination mode is switched to the regular transmission mode, and frame transmission is performed every longer fixed cycle (for example, every one minute). Periodically send a signal related to tire pressure. At this time, for example, by providing a random delay for each transmitter 2, the transmission timing of each transmitter 2 can be shifted, and interference can be received on the TPMS-ECU 3 side due to interference of radio waves from a plurality of transmitters 2. It can prevent losing.

  Further, as shown in FIG. 2B, the TPMS-ECU 3 is configured to include a receiving antenna 31, a receiving circuit 32, a microcomputer 33, and the like. The TPMS-ECU 3 acquires the gear information from the brake ECU 10 as described later through the in-vehicle LAN such as CAN, and thereby indicates the number of teeth edges (or the number of teeth) of the gear teeth rotated with each of the wheels 5a to 5d. You have obtained a position.

  The receiving antenna 31 is for receiving a frame sent from each transmitter 2. The receiving antenna 31 may be an internal antenna fixed to the vehicle body 6 and disposed in the main body of the TPMS-ECU 3 or may be an external antenna in which the wiring is extended from the main body.

  The receiving circuit 32 functions as an input unit which receives the transmission frame from each of the transmitters 2 received by the receiving antenna 31 and sends the frame to the microcomputer 33. When receiving a signal (frame) through the receiving antenna 31, the receiving circuit 32 transmits the received signal to the microcomputer 33.

  The microcomputer 33 corresponds to a second control unit, and executes the wheel position detection in accordance with the program stored in the memory in the microcomputer 33. Specifically, the microcomputer 33 performs the wheel position detection based on the relationship between the information acquired from the brake ECU 10 and the reception timing at which the transmission frame from each transmitter 2 is received. From the brake ECU 10, in addition to the wheel speed information of the respective wheels 5a to 5d, gear information of the wheel speed sensors 11a to 11d provided corresponding to the respective wheels 5a to 5d is acquired for each predetermined cycle (for example, 10 ms) There is.

  The gear information is information indicating the tooth position of a gear (gear) rotated with each of the wheels 5a to 5d. The wheel speed sensors 11a to 11d are, for example, electromagnetic pick-up type sensors disposed opposite to the gear teeth, and change the detection signal as the gear teeth pass. In such a type of wheel speed sensor 11a to 11d, since a square pulse wave corresponding to the passage of a tooth is output as a detection signal, the rising and falling of the square pulse wave passes through the edge of the tooth of the gear Will represent. Therefore, the brake ECU 10 counts the number of edges of the gear teeth, that is, the number of passing edges, from the number of rising and falling of the detection signals of the wheel speed sensors 11a to 11d, and the edge of the teeth at that time The number is transmitted to the microcomputer 33 as gear information indicating the tooth position. Thus, the microcomputer 33 can grasp which tooth of the gear has passed.

  The number of tooth edges is reset each time the gear rotates. For example, when the number of teeth provided on the gear is 48 teeth, the number of edges is counted in a total of 96 from 0 to 95, and when the count value reaches 95, it is counted again to 0.

  Here, although the number of edges of the gear teeth is transmitted to the microcomputer 33 from the brake ECU 10 as gear information, it may be the count value of the number of passing teeth. Further, the number of edges or the number of teeth passed during a predetermined cycle is transmitted to the microcomputer 33, and the microcomputer 33 adds the number of edges or the number of teeth passed during the predetermined cycle to the number of edges or teeth up to the previous time. The number of edges or the number of teeth in that cycle may be counted. That is, it is sufficient if the microcomputer 33 can finally obtain the number of edges or the number of teeth in the cycle as gear information. In addition, the brake ECU 10 resets the number of teeth edges of the gear teeth (or the number of teeth) each time the power is turned off, but measures it again when the vehicle speed reaches a predetermined vehicle speed at the same time or when the power is turned on. ing. In this way, the same tooth is represented by the same number of edges (or the number of teeth) during power-on, even if the power is reset each time the power is turned off.

  Then, when the frame transmitted from each transmitter 2 is received, the microcomputer 33 measures the reception timing, and at the frame reception timing among the number of edges (or the number of teeth) of the acquired gear. Wheel position detection is performed based on the number of edges (or the number of teeth) of the gear. Thereby, it becomes possible to perform wheel position detection which specifies which of the wheels 5a to 5d each transmitter 2 is attached to. A specific method of this wheel position detection will be described in detail later.

  Further, based on the result of the wheel position detection, the microcomputer 33 associates and stores the ID information of each transmitter 2 and the position of each of the wheels 5a to 5d to which each transmitter 2 is attached. Then, based on the ID information and data on tire air pressure stored in the transmission frame from each transmitter 2, tire air pressure detection of each of the wheels 5a to 5d is performed, and an electrical signal corresponding to the tire air pressure is CAN or the like Output to the meter 4 through the in-vehicle LAN. For example, the microcomputer 33 detects a drop in tire pressure by comparing the tire pressure with a predetermined threshold value Th, and outputs a signal to that effect to the meter 4 when a drop in tire pressure is detected. Thereby, the meter 4 is notified that the tire pressure of any of the four wheels 5a to 5d has decreased.

  The meter 4 functions as an alarm unit, and as shown in FIG. 1, the meter 4 is disposed at a place where the driver can visually recognize, and is configured by, for example, a meter display installed in an instrument panel in the vehicle 1 . For example, when a signal indicating that the tire air pressure has dropped is sent from the microcomputer 33 in the TPMS-ECU 3, the meter 4 displays a message indicating a drop in the tire air pressure while specifying the wheels 5a to 5d. Informing the decrease of tire pressure of specific wheels.

  Subsequently, the operation of the TPMS of the present embodiment will be described. Hereinafter, although the operation of the TPMS will be described, the wheel position detection performed by the TPMS and the tire air pressure detection will be separately described. First, a specific method of detecting the wheel position will be described with reference to FIGS.

  On the transmitter 2 side, the microcomputer 23 monitors the detection signal of the acceleration sensor 22 every predetermined sampling cycle based on the power supply from the battery to thereby determine the vehicle speed and the angle of the acceleration sensor 22 at each of the wheels 5a to 5d. It is detected. Then, when the vehicle speed reaches a predetermined speed, the microcomputer 23 repeatedly performs frame transmission at timing when the angle of the acceleration sensor 22 becomes a predetermined angle. For example, frame transmission from each transmitter 2 is performed with a start angle when the vehicle speed reaches a predetermined speed as a predetermined angle, or when the acceleration sensor 22 reaches a predetermined angle after the vehicle speed reaches a predetermined speed. I have to. Then, at timing when the angle formed by the acceleration sensor 22 becomes the same as in the first frame transmission, frame transmission is repeatedly performed with the timing as the transmission timing.

  That is, when the gravity acceleration component of the detection signal of the acceleration sensor 22 is extracted, it becomes a sin wave as shown in FIG. The angle of the acceleration sensor 22 can be determined based on this sin wave. Therefore, frame transmission is performed at timing when the acceleration sensor 22 has the same angle based on the sin wave.

  On the other hand, on the TPMS-ECU 3 side, gear information of the wheel speed sensors 11a to 11d provided corresponding to the respective wheels 5a to 5d is acquired from the brake ECU 10 at predetermined intervals (for example, 10 ms). Then, the TPMS-ECU 3 measures the reception timing when the frame transmitted from each transmitter 2 is received, and at the frame reception timing from among the acquired number of edges (or the number of teeth) of the gear. Get the number of edges (or number of teeth) of the gear.

  At this time, the reception timing of the frame transmitted from each transmitter 2 does not necessarily coincide with the cycle in which the gear information is acquired from the brake ECU 10. Therefore, the number of gear edges (or the number of teeth) indicated by the gear information acquired in the period immediately before or after the frame reception timing among the periods in which the gear information is acquired from the brake ECU 10 Can be used as the number of edges (or the number of teeth) of the gear at the reception timing. In addition, at the frame reception timing, using the number of gear edges (or the number of teeth) indicated by the gear information acquired immediately before and after the frame reception timing among cycles in which gear information is acquired from the brake ECU 10 The number of edges (or the number of teeth) of the gear may be calculated. For example, an intermediate value of the number of gear edges (or the number of teeth) indicated by the gear information acquired in the cycle immediately before and after the frame reception timing is taken as the number of gear edges (or the number of teeth) at the frame reception timing. It can be used.

  The operation of acquiring the number of edges (or the number of teeth) of the gear at the reception timing of such a frame is repeated each time a frame is received, and the number of edges of the gear at the reception timing of the acquired frame (or Wheel position detection is performed based on the number of teeth). Specifically, the variation in the number of gear edges (or the number of teeth) at the frame reception timing is within a predetermined range set based on the number of the gear edges (or the number of teeth) at the previous reception timing. Wheel position detection is performed by determining whether there is any.

  As for the wheel that has received the frame, frame transmission is performed at a timing when the angle of the acceleration sensor 22 becomes a predetermined angle, so the tooth position indicated by the number of gear edges (or the number of teeth) at the frame reception timing. Is almost the same as the previous one. For this reason, the variation in the number of edges (or the number of teeth) of the gear at the reception timing of the frame is small and falls within the predetermined range. This holds true even when a frame is received a plurality of times, and the variation in the number of edges (or the number of teeth) of the gear at the reception timing of each frame is within the predetermined range determined at the first frame reception timing. Fit. On the other hand, with respect to a wheel different from the wheel that received the frame, the tooth position indicated by the number of edges (or the number of teeth) of the gear at the reception timing of the frame transmitted from the transmitter 2 of the other wheel varies.

  That is, since the rotation of the gears of the wheel speed sensors 11a to 11d is interlocked with each of the wheels 5a to 5d, the number of edges (or the number of teeth) of the gears at the frame reception timing is about the wheel receiving the frame. The tooth positions shown are approximately coincident. However, the rotational states of the wheels 5a to 5d can not be completely the same because the rotational states of the wheels 5a to 5d fluctuate due to road conditions, turning or lane change. For this reason, with respect to a wheel different from the wheel that has received the frame, the tooth positions indicated by the number of edges (or the number of teeth) of the gear at the reception timing of the frame are dispersed.

  Therefore, as shown in FIG. 4, from the state where the number of edges of the gears 12a to 12d was 0 at the beginning of turning on of the ignition switch (IG), a different wheel from the one receiving the frame gradually after the start of traveling In this case, a variation occurs in the tooth position indicated by the number of edges (or the number of teeth) of the gear at the reception timing of the frame. Wheel position detection is performed by determining whether this variation is within a predetermined range.

  For example, as shown in FIG. 5A, it is assumed that the position of the transmitter 2 at the time of the first frame transmission is the first reception angle. Also, the allowable variation range, which is an allowable range of the number of edges of the gear (or the number of teeth), is equivalent to a range of 180 ° centered on the first reception angle (range of first reception angle ± 90 °). Suppose that there is. In the case of the number of edges, it is assumed that the range is ± 24 of the number of edges centered on the number of edges at the first reception, and in the case of teeth, it is the range of the number of teeth of ± 12 about the number of teeth at the first reception. In this case, as shown in FIG. 5B, if the number of edges (or the number of teeth) of the gear at the time of the second frame reception is within the allowable range of variation determined by the first frame reception, The wheel with that number of edges (or the number of teeth) may be identical to the wheel on which the frame transmission was made and will be TRUE.

  However, also in this case, the allowable range of variation is determined centering on the second reception angle, which is the angle of the transmitter 2 at the second frame reception, and equivalent to 180 ° (± 90 °) centering on the second reception angle. It becomes a value. Therefore, the allowable variation width of 180 ° (± 90 °) centering on the first reception angle, which is the previous allowable variation width, and the allowable variance width of 180 ° (± 90 °) centering on the second reception angle The overlapping portion of becomes a new allowable variation range (the number of edges is 12 to 48), and the new allowable range can be narrowed to the overlapping range.

  Therefore, as shown in FIG. 5C, if the number of edges (or the number of teeth) of the gear at the time of the third frame reception is out of the range of the variation allowable width determined by the first and the second frame reception, Since the wheel with the number of edges (or the number of teeth) does not match the wheel on which the frame transmission is performed, it becomes FALSE (error). At this time, even if it is within the allowable range of variation determined by the first frame reception, it is determined as FALSE if it is outside the allowable range of variation determined by the first and second frame reception. There is. In this way, it is possible to specify to which of the wheels 5a to 5d the transmitter 2 that has transmitted the received frame is attached.

  That is, as shown in FIG. 6A, for a frame including ID1 as ID information, the number of gear edges (or the number of teeth) is acquired at each reception timing of the frame, and the corresponding wheel (The left front wheel FL, the right front wheel FR, the left rear wheel RL, and the right rear wheel RR) are stored. Then, each time a frame is received, it is determined whether or not the acquired number of edges (or number of teeth) of the gear is within the allowable range of variation, and a transmitter from which the frame is transmitted is out of the range We exclude from 2 attached wheel candidates. Then, the wheels that were not excluded until the end are registered as the mounted wheels of the transmitter 2 from which the frame was transmitted. In the case of the frame including ID1, the right front wheel FR, the right rear wheel RR, and the left rear wheel RL are excluded from the candidates in the order, and the left front wheel FL is finally attached to the transmitter 2 to which the frame was transmitted. The wheel is registered in association with the ID information.

  And as shown in FIG.6 (b)-(d), the process similar to the flame | frame in which ID1 was contained is performed also about the flame | frame in which ID2-ID4 was contained as ID information. Thereby, the attached wheel of the transmitter 2 to which each frame is transmitted can be identified, and all four wheels attached with the transmitter 2 can be identified.

  Thus, it is specified to which of the wheels 5a to 5d each frame is attached. Then, the microcomputer 33 stores the ID information of each transmitter 2 that has transmitted the frame in association with the position of the wheel to which it is attached.

  The TPMS-ECU 3 stores gear information at the reception timing by receiving a frame transmitted when the vehicle speed reaches a predetermined speed, but a predetermined traveling stop determination speed (for example, 5 km) / H) The gear information up to that point is discarded when it becomes lower. Then, when traveling is started again, wheel position detection is newly performed as described above.

  Basic wheel position detection is performed by the method as described above. Thereby, it becomes possible to detect the wheel position of the left front wheel FL, the right front wheel FR, the left rear wheel RL, and the right rear wheel RR, which are traveling wheels. When a frame transmitted from a transmitter of another vehicle is received at the time of wheel position detection, the ID information stored in the frame can also be a candidate ID. However, during the specification of the wheel position using the wheel position specifying logic described above, the timing at which the frame transmitted from the transmitter of the other vehicle is received does not coincide with the tooth position of the gear of any wheel of the own vehicle. Therefore, it is possible to register only the ID information of the transmitter 2 of the own vehicle while avoiding the registration of the ID information of the transmitters of other vehicles.

  In this case, for example, if the registration method shown in Patent Document 1 is adopted, it is possible to prevent the registration of ID information of transmitters of other vehicles. That is, in the above-described wheel position detection, when a frame including ID information from a transmitter attached to a wheel of another vehicle is received during wheel position detection when existing ID information of the own vehicle is not registered at all The ID information of the transmitter can also be a candidate ID. Similarly, even when the existing ID information of the own vehicle is registered, the number of ID information of the frames that can be received by replacing the transmitter 2 attached to the wheels 5a to 5d of the own vehicle is It may be smaller than the number of registered ID information. In such a case, when a frame including ID information from a transmitter attached to a wheel of another vehicle is received during wheel position detection, the ID information of the transmitter may also be a candidate ID.

  In these cases, only when the tooth position at the frame reception timing is continuously included a predetermined number of times (for example, 10 times) after the wheel has been identified, the ID information is included in the range of the allowable range of variation. To register.

  When a frame of a transmitter attached to a wheel of another vehicle is received, the number of gear edges (or teeth) acquired for each frame at the reception timing of the frame as well as the case of the host vehicle. It is determined whether or not the number is within the range of the allowable range of variation. And about the frame transmitted from the transmitter of the other vehicle as well as the transmitter 2 of the own vehicle, the wheel out of the range of the variation allowable range from the wheel candidate attached with the transmitter 2 to which the frame was transmitted It will be excluded. At this time, since the elimination method is used, when only one wheel finally remains without being excluded in each frame, a candidate wheel to which transmitter 2 has transmitted that frame transmitted the frame It becomes. If the ID information is registered at this time, the ID information of the transmitter attached to the wheel of the other vehicle is erroneously registered as that of the own vehicle. In particular, the frame transmitted from the transmitter attached to the wheel of the other vehicle is not the one of the own vehicle, and thus the variation is likely to occur, and the frame transmitted from the transmitter 2 attached to the wheels 5a to 5d of the own vehicle They tend to be excluded from the wheel candidates earlier. For this reason, most of the frames transmitted from the transmitters of the wheels of other vehicles are out of the variation tolerance range at an early stage, and the wheels not accidentally removed are specified as candidate wheels to which transmitters transmitted the frames are attached. It is easy to be

  However, if it is assumed that the tooth position at the frame reception timing is continuously included a predetermined number of times consecutively after the wheel is specified, as the ID information registration condition, the other vehicle is in between. The tooth position of the reception timing of the frame from the transmitter of (4) deviates from the variation tolerance range. Therefore, it is possible to prevent the ID information of the transmitter attached to the wheel of another vehicle from being erroneously registered as that of the own vehicle.

  Here, it is assumed that it is determined whether or not the tooth position at the frame reception timing is continuously included a predetermined number of times after the wheel is specified, within the allowable range of variation. Of course, it may be determined whether a predetermined number of times have been continued since the start of the wheel position detection.

  As described above, it is possible to detect the wheel position of the left front wheel FL, the right front wheel FR, the left rear wheel RL, and the right rear wheel RR, which are traveling wheels, by the above method. At this time, when wheel position detection is performed by the above-described method, basically, all ID information included in the received frame is treated as a candidate ID, and the transmitter 2 of the own vehicle is selected from among them. Become. Therefore, the candidate ID is stored in the memory of the TPMS-ECU 3, and the transmitter of the vehicle is finally registered from among the candidate ID.

  However, if the number of candidate IDs is large, the amount of data stored in the memory of the TPMS-ECU 3 reaches the memory capacity and overflows, so a predetermined condition is set, and irrelevant ID information is excluded from candidate IDs. It is preferable to do. In particular, when the wheel position is specified by the elimination method in which the tooth positions at the frame reception timing out of the variation allowable range are specified among the candidate IDs, even if there are candidate IDs that have not been received for a long time, There is a possibility that the wheel position can not be identified because it is not excluded. For this reason, in the present embodiment, during detection of the wheel position of the own vehicle, among candidate IDs for which the possibility of not being the ID information of the transmitter 2 of the own vehicle has become high, teeth at the frame reception timing. Even if the position is not out of the variation tolerance range, it is excluded from the candidate IDs. Specifically, the processes shown in FIGS. 7 and 8 are performed.

  First, by executing the registration start determination process shown in FIG. 7, it is determined whether or not the transition to the ID registration mode is necessary. When the transition to the ID registration mode is performed, the candidate ID selection process shown in FIG. By performing this, wheel position detection is performed while leaving only candidate IDs that should remain true. The processes shown in FIGS. 7 and 8 are executed, for example, at predetermined control cycles when the TPMS-ECU 3 is powered on by IG on.

  As shown in FIG. 7, in steps 100 to 130, it is determined whether or not a situation where transition to the ID registration mode is required is reached.

  Specifically, in step 100, it is determined whether a request for transition to the ID registration mode has been issued through an external tool (not shown) instructing execution of wheel position detection. The external tool transmits, for example, a command to request transition to the ID registration mode to the TPMS-ECU 3. Even if it is transmitted to the TPMS-ECU 3 using a radio wave, it is transmitted via the in-vehicle LAN such as CAN. It may be something.

  In step 110, it is determined whether a request for transition to the ID registration mode has been issued by operating a wheel position detection execution switch (not shown) or the like. The wheel position detection execution switch is provided, for example, on the instrument panel, and when the execution switch is operated by the user, it is transmitted to the TPMS-ECU 3 through the in-vehicle LAN such as CAN.

  In step 120, it is determined whether the ID information of the transmitter 2 of each of the wheels 5a to 5d is in an unregistered state. For example, immediately after the completion of vehicle manufacture, ID information of any transmitter 2 is not yet registered, and it is necessary to detect the wheel position.

  In step 130, it is determined based on comparison of the number of receptions of the registered ID information and the unregistered ID information whether or not it is assumed that tire replacement or the like has been made. Also in such a case, it is necessary to perform wheel position detection. For example, when the number of times of reception of the unregistered ID information increases more than the predetermined number more than the registered ID information, it is determined that it is assumed that tire replacement or the like is performed.

  Therefore, if any one of the determination processes in steps 100 to 130 described above is affirmed, the process proceeds to step 140, shifts to the ID registration mode and ends the process, and if both are determined negative, the process proceeds to step 100. Go back and repeat the above process. In this manner, registration start determination processing for determining whether or not to start registration of the ID information of the transmitter 2 of the vehicle is completed by performing the wheel position detection.

  Subsequently, in the candidate ID selection process shown in FIG. 8, first, in step 200, it is determined whether or not the ID registration mode is set. If the shift to the ID registration mode has been performed in step 140 of FIG. 7 described above, an affirmative determination is made in this step, and the process proceeds to step 205.

  In step 205, it is determined whether or not there is a candidate ID having a timer count value of a predetermined time or more among the candidate IDs. The timer count value here is the count value after the timer count is started in steps 240 and 255 described later, and is counted for each candidate ID, and a frame including each candidate ID is received last time Represents the elapsed time from

  The transmission interval of the frame from the transmitter 2 is basically fixed although it changes depending on the situation. For example, during a period in which wheel position detection may be performed, such as at the start of traveling of the vehicle, the frame transmission interval becomes relatively short in the wheel position determination mode. In addition, when the time assumed to be necessary for detecting the wheel position has elapsed, the mode is switched to the periodic transmission mode, and frame transmission is performed at longer constant cycles. Furthermore, while the vehicle is at a stop, there may be a case where a transmission mode during stop is set to set a transmission cycle longer than the periodic transmission mode, and frame transmission may be performed at a longer constant cycle. However, in any of these modes, frame transmission is performed within a certain period, and frame reception is performed on the TPMS-ECU 3 side.

  In particular, in TPMS, according to the system, the frame transmitted from the transmitter 2 of the own vehicle is specified to be received one or more times within a predetermined time, and there are also countries which are obliged by laws and the like. For example, it is defined that a frame transmitted from the transmitter 2 of the host vehicle is received during a predetermined period of 20 minutes in North America and 10 minutes in Europe.

  Therefore, at least during this predetermined period, the frames transmitted from each of the transmitters 2 of the own vehicle will be received by the TPMS-ECU 3, and for the candidate ID not received during the predetermined period, the vehicle transmission of the own vehicle It can be determined that it is not the ID information of the machine 2.

  Therefore, as described above, when it is determined in step 205 that there is the corresponding ID, the process proceeds to step 210, the corresponding ID is deleted from the candidate IDs, and then the process returns to step 205.

  In this way, ID information that has not been received in a predetermined period is excluded from candidate IDs. As a result, the amount of data to be stored in the memory of the TPMS-ECU 3 can be reduced, and it is possible to suppress the memory capacity and overflow. In addition, for candidate IDs that have not been received for a long time, even if the tooth positions at the frame reception timing are not out of the variation tolerance range, they can be excluded from candidate IDs, so wheel position detection can be performed faster. Become.

  On the other hand, if it is determined in step 205 that there is no corresponding ID, the process proceeds to step 220. And if RF reception, ie, the frame transmitted as a radio wave of RF band, is received, processing after Step 225 will be performed.

  In step 225, it is determined whether the vehicle state is traveling. That is, since the wheel position detection is performed by detecting the acceleration generated with the traveling of the own vehicle by the acceleration sensor 22 in this case, when the vehicle state is not traveling, it is not detected. Therefore, when an affirmative determination is made in step 225, the process proceeds to step 230, and when a negative determination is made, the process returns to step 205.

  Note that whether the vehicle state is traveling or not is determined by obtaining vehicle speed data from the brake ECU 10, for example, since the vehicle speed calculation is performed by the brake ECU 10 based on the detection signals of the wheel speed sensors 11a to 11d. can do. Therefore, for example, when the vehicle speed is generated, it can be determined that the vehicle state is traveling.

  In step 230, it is determined whether the ID information stored in the frame received this time is the ID received for the first time. Here, when an affirmative determination is made, the process proceeds to step 235 and is registered in the candidate ID. Then, the process proceeds to step 240, and timer counting for the candidate ID is started.

  On the other hand, if a negative determination is made in step 230, the ID information stored in the frame received this time has already been registered as a candidate ID, so the process proceeds to step 245 and the candidate ID registered has been registered. Update data Specifically, for the candidate ID, gear information at frame reception timing is acquired, and it is determined whether the number of edges (or the number of teeth) of the gear indicated by the candidate ID is included in the allowable range of variation, etc. Data update for wheel position detection is performed according to the wheel position specifying logic. Based on this, as shown in FIG. 6, each time a frame is received, the candidate ID is updated, and the wheel position detection is performed.

  Thereafter, the process proceeds to step 250 to temporarily reset the timer count for the candidate ID, and then proceeds to step 255 to start timer count for the candidate ID. As a result, the timer count for the candidate ID is performed again from the beginning.

  Finally, the process proceeds to step 260, in which it is determined whether registration of ID information has been completed for the transmitters 2 of all the wheels 5a to 5d. If the wheel position detection according to the wheel position specifying logic is completed, an affirmative determination is made in this step, and the present process is completed. Then, if the wheel position detection has not been completed yet, the process returns to step 205 again to repeat each of the above processes.

  After the wheel position detection is performed in this manner, tire air pressure detection is performed thereafter. Specifically, at the time of tire air pressure detection, a frame is transmitted from each transmitter 2 at a constant cycle, and each time a frame is transmitted from each transmitter 2, the frames for four traveling wheels are TPMS- It is received by the ECU 3. Then, the TPMS-ECU 3 identifies which of the transmitters 2 attached to the wheels 5a to 5d is the frame sent from, based on the ID information stored in each frame, and each information is related to the tire air pressure. The tire pressure of the wheels 5a to 5d is detected. Thereby, it is possible to detect a drop in tire air pressure of each of the wheels 5a to 5d, and it is possible to identify which tire air pressure of the wheels 5a to 5d is reduced. Then, when a drop in tire air pressure is detected, that effect is transmitted to the meter 4 to display a display indicating the drop in tire air pressure while specifying the wheels 5a to 5d by the meter 4, and displaying the tire pressure of the specific wheel to the driver. Inform the decrease of

  As described above, the tooth positions of the gears 12a to 12d are indicated based on the detection signals of the wheel speed sensors 11a to 11d that detect the passage of the teeth of the gears 12a to 12d rotated in conjunction with the wheels 5a to 5d. Gear information is acquired at predetermined intervals. Then, the variation allowable width is set based on the tooth position at the frame reception timing, and the tooth position at the frame reception timing after setting the variation allowable width is outside the range of the variation allowable width, The frame is excluded from the mounted wheel candidates of the transmitter 2 to which the frame is transmitted, and the remaining wheels are registered as the mounted wheels of the transmitter 2 to which the frame is transmitted. For this reason, it is possible to specify the wheel position of the traveling wheel even if a large amount of data is not available.

  And in this embodiment, even if it is registered as a candidate ID, ID information which has not been received a frame at least during a predetermined period is excluded from the candidate ID as not being of the transmitter 2 of the vehicle. It is like that. As a result, while suppressing that the ID information of the transmitters of the wheels of the other vehicle is registered as candidate IDs, the ID information of the transmitters 2 of the wheels 5a to 5d of the own vehicle is accurately registered as the candidate IDs You can Further, the amount of data stored in the memory of the TPMS-ECU 3 can be reduced, and the memory capacity can be prevented from reaching. In addition, for candidate IDs that have not been received for a long time, even if the tooth positions at the frame reception timing are not out of the variation tolerance range, they can be excluded from candidate IDs, so wheel position detection can be performed faster. Become.

  And since it is possible to register the ID information of the transmitter 2 of each of the wheels 5a to 5d in this way, it is not necessary to have an antenna or trigger device for each wheel, and the number of parts due to the need for additional parts. It is possible to avoid the increase and hence the cost. In addition, it is not necessary to provide high-performance additional parts such as a two-axis acceleration sensor.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and appropriate modifications can be made within the scope of the claims.

  For example, in the above embodiment, with regard to the ID information that has been registered as a candidate ID once, when no frame has been received during a predetermined period, the ID information is excluded from the candidate IDs. On the other hand, the elapsed time after the ID registration mode is set may be measured, and the ID information received for the first time after the elapsed time reaches a predetermined time may not be registered as a candidate ID.

  In the above embodiment, as the detection of the wheel position on the traveling wheel side, the variation allowable range is changed at each frame reception timing, and the variation allowable range is gradually narrowed. However, as a method of detecting the wheel position on the traveling wheel side, another method may be used, for example, a method in which the variation allowance width is fixed and not gradually narrowed.

  Further, in the above embodiment, the variation allowance width is changed for each frame reception timing to gradually narrow the variation allowance width, but the variation allowance width set around the tooth position is constant. . It is also possible to change the allowable variation range set around this tooth position. For example, the variation in tooth position may increase as the vehicle speed increases. For this reason, the variation tolerance range can be set more accurately by increasing the variation tolerance range as the vehicle speed increases. In addition, since the detection accuracy of the timing when the angle of the acceleration sensor 22 becomes a predetermined angle decreases as the sampling period when performing the acceleration detection by the acceleration sensor 22 becomes longer, the variation allowable width is changed accordingly. Thus, the variation tolerance range can be set more accurately. In that case, since the sampling period and the like are grasped on the transmitter 2 side, it is possible to transmit data including the data for determining the size of the variation allowable range in the frame transmitted by the transmitter 2.

  Further, in the above embodiment, as the angle at which the frame transmission is performed, the position where the angle is 0 ° is when the acceleration sensor 22 is located at the upper position with the central axes of the wheels 5a to 5d as the center. However, this is merely an example, and an arbitrary position in the circumferential direction of the wheel may be an angle of 0 °.

  In the above embodiment, the TPMS-ECU 3 obtains gear information from the brake ECU 10. However, since TPMS-ECU 3 only needs to be able to acquire the number of teeth edges or the number of teeth of the gear as gear information, it may be acquired from another ECU, or the detection signals of wheel speed sensors 11a to 11d are input. The number of teeth edges or number of teeth of the gear may be acquired from the detection signal. In particular, in the above embodiment, although the case where the TPMS-ECU 3 and the brake ECU 10 are configured as separate ECUs has been described, the TPMS-ECU 3 and the brake ECU 10 may be configured as a single ECU integrated with each other. In that case, the ECU directly inputs the detection signals of the wheel speed sensors 11a to 11d, and acquires the number of edges or the number of teeth of the gear teeth from the detection signals. Also, in this case, since the number of edges or the number of teeth of the gear teeth can always be acquired, unlike the case where such information is acquired for each predetermined cycle, based on the gear information of the frame reception timing just. It becomes possible to perform wheel position detection.

  Moreover, although the said embodiment demonstrated the wheel position detection apparatus provided with respect to the vehicle 1 provided with four wheel 5a-5d used as a driving | running | working wheel, also about the vehicle with many wheels of a driving | running wheel, The invention is equally applicable.

  In the present invention, it is sufficient that the wheel speed sensors 11a to 11d can detect the passage of the teeth of the gear that is rotated in conjunction with the rotation of the wheels 5a to 5d. For this reason, as the gear, any structure may be used as long as it has different magnetic reluctance in which a portion of a tooth whose outer peripheral surface is a conductor and a portion located between the teeth are alternately repeated. That is, the outer peripheral portion is not only a general one constituted by the convex portion which becomes the conductor and the space which becomes the nonconductive due to the unevenness of the outer edge portion, for example, the outer peripheral surface becomes the nonconductive with the portion which becomes the conductor The rotor switch etc. which were comprised with the insulator are also included (refer Unexamined-Japanese-Patent No. 10-048233, for example).

  The steps shown in each drawing correspond to means for executing various processes. That is, the part executing the processing of steps 205 and 210 corresponds to the candidate deleting means, the part executing the processing of step 225 corresponds to the first judging means, and the part executing the processing of step 230 corresponds to the second judging means. Further, the part executing the process of step 235 corresponds to the candidate registration means, and the part executing the process of steps 240 and 255 corresponds to the time measuring means.

1 Vehicle 2 Transmitter 3 TPMS-ECU (Receiver)
5a to 5d wheels (traveling wheels)
6 Vehicle Body 11a to 11d Wheel Speed Sensor 12a to 12d Gear 21 Sensing Unit 22 Acceleration Sensor

Claims (6)

The invention is applied to a vehicle (1) in which a plurality of wheels (5a to 5d) equipped with tires are attached to a vehicle body (6),
A transmitter (2) having a first control unit (23) provided on each of the plurality of wheels and creating and transmitting a frame including unique identification information;
After being provided on the vehicle body side and receiving the frame transmitted from the transmitter via the receiving antenna (31), the candidate identification information to be registered candidates is selected from the identification information included in the frame And, among the candidate identification information, identify ones corresponding to the transmitters provided on the plurality of wheels of the vehicle, and the plurality of wheels and the plurality of transmitters provided on the plurality of wheels. A wheel position detection apparatus comprising: a receiver (3) having a second control unit (33) that performs wheel position detection that associates and stores identification information;
The transmitter includes an acceleration sensor (22) that outputs a detection signal according to an acceleration including a gravity acceleration component that changes with rotation of a wheel to which the transmitter is attached.
In the transmitter, the first control unit is a detection signal of the acceleration sensor with the central axis of the wheel to which the transmitter is attached as a center, and an arbitrary position in the circumferential direction of the wheel as an angle of 0 °. Detecting the angle of the transmitter based on the gravity acceleration component included in the frame, and repeatedly transmitting the frame at timing when the angle becomes a predetermined transmission angle,
The second control unit is a gear having an outer circumferential surface having different magnetic resistances, in which a portion of a tooth which is rotated in conjunction with the plurality of wheels and which is a conductor and a portion located between the teeth are alternately repeated. The gear information indicating the tooth position of the gear is acquired based on the detection signal of the wheel speed sensor (11a to 11d) which detects the passage of the teeth of 12a to 12d), and the tooth at the reception timing of the frame The wheel position detection is performed by identifying and registering the attached wheel of the transmitter to which the frame has been transmitted, based on the position.
The second control unit is
Time measuring means (S240, S255) for measuring an elapsed time from the previous reception of the frame containing the candidate identification information for each of the candidate identification information;
It is determined whether or not there is any of the identification information included in the candidate identification information for which the elapsed time measured by the time measuring means has become equal to or longer than a predetermined time, and the elapsed time is the predetermined time And a candidate deletion means (S205, S210) for deleting the identification information as described above from the candidate identification information. The second control means is
First determining means (S225) for determining whether or not the vehicle is in a traveling state;
A second determination unit (S230) that determines whether the identification information stored in the received frame is received for the first time;
2. The wheel position detection device according to claim 1, further comprising candidate registration means (S235) for registering as the candidate identification information when the first determination means and the second determination means make a positive determination.   When the second control means is positively determined by the first determination means, and is negatively determined by the second determination means, the reception timing of the received frame of the identification information included in the received frame The wheel position detecting device according to claim 2, further comprising data updating means (S245) for updating data of tooth positions at the time of (4) as new data used for the wheel position detection.   The second control means measures an elapsed time from the start of the wheel position detection, and registers, as the candidate identification information, the identification information received for the first time after the elapsed time reaches the predetermined time or more. The wheel position detection device according to any one of claims 1 to 3, wherein the wheel position detection device is configured to prevent the wheel position detection.   The second control unit sets a variation allowance width based on the tooth position at the reception timing of the frame, and the tooth position at the reception timing of the frame after setting the variation allowance width is the above If it is out of the range of the variation tolerance range, it is excluded from the candidate of the attached wheel of the transmitter to which the frame is transmitted, and the remaining wheel is identified as the attached wheel of the transmitter to which the frame is transmitted. The wheel position detection is performed by registering the data, and the data updated by the data updating means is used as the data of the tooth position at the reception timing of the received frame. The wheel position detection device according to any one of 1 to 4. A tire pressure detection system comprising the wheel position detection device according to any one of claims 1 to 5, comprising:
The transmitter includes a sensing unit (21) for outputting a detection signal according to the air pressure of the tire provided on each of the plurality of wheels, and the first control unit processes the detection signal of the sensing unit. Storing information on tire pressure in a frame, and then transmitting the frame to the receiver;
The tire air pressure detection system according to claim 1, wherein the receiver detects the air pressure of the tire provided on each of the plurality of wheels from the information on the tire air pressure in the second control unit.

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