JP2015116971A - Tire position determination system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire position determination system that can determine a tire position with a simple constitution using no initiator (trigger instrument).SOLUTION: The calculation of a locus which indicates how much tires in a diagonal relation generate an angular lag during the period of a first clock t1 to a second clock t2 is carried out by an auto location functional part, where steering angle information and vehicle speed information are utilized for such a calculation. Tires from which aspects following the locus are obtained are determined as a pair with tires in a diagonal relation that has assumed the locus, and front-rear wheels are judged with respect to each tire constituting this pair.

Description

  The present invention relates to a tire position determination system that determines the position of a tire.

  Conventionally, a tire pressure detector that detects tire pressure and wirelessly transmits it is attached to each tire, and the tire pressure signal transmitted from the tire pressure detector is received by the vehicle body receiver to monitor the tire pressure. Direct tire pressure monitoring systems are well known. In the case of this type of tire pressure monitoring system, there is a need to know the tire position in order to notify the position of the low-pressure tire, but the tire is replaced or replaced with a new tire. Therefore, it is considered to install an auto-location function that periodically checks the tire position. As an auto-location function, for example, there is a method of determining the position of the tire by attaching an initiator (trigger) to each tire house and selectively transmitting a radio wave to the tire pressure detector by a radio wave transmitted from the initiator. It is well known (see Patent Documents 1 and 2).

JP 2006-062516 A JP 2012-126341 A

  However, the auto-location function using an initiator requires that an initiator be provided in each tire house. Therefore, in the auto location function using the initiator, there are concerns about problems such as an increase in the number of parts and an increase in parts cost.

  The present invention has been made paying attention to such problems, and an object thereof is a tire position determination system capable of determining a tire position with a simple configuration that does not use an initiator (trigger). Is to provide.

  A tire position determination system that solves the above problems is a tire position determination system that determines the position of a tire. In the tire position determination system, each tire transmitter transmits a transmission signal that includes identification information unique to the transmitter along with tire rotation information. The vehicle body receiver is provided with a control unit, and the reception timing of the last transmission signal is defined as the first time on the assumption that the transmission signals are received from all the transmitters within one rotation of the reference tire. One rotation of the reference tire traced back from time 1 is defined as a first rotation opportunity, and an angle shift of each tire is detected from the reception timing of each transmission signal in the first rotation opportunity. Assuming that transmission signals have been received from all transmitters within one rotation, the reception timing of transmission signals from the transmitter that transmitted the last transmission signal at the first rotation opportunity is An angle at which one rotation of the reference tire retroactive from the second time is defined as a second rotation opportunity, and the angle deviation of each tire is detected from the reception timing of each transmission signal at the second rotation opportunity. An angle deviation calculation unit that calculates an increase / decrease amount of the angle deviation at the second time with respect to the angle deviation at the first time, with respect to the tires in a diagonal relationship with respect to the deviation detection unit, and a front wheel or a rear wheel; From the combination of tires detected by the angle deviation detection unit, the angle deviation calculation unit calculates an increase / decrease amount of the angle deviation in the second rotation opportunity with respect to the angle deviation in the first rotation opportunity. A combination of tires that matches the amount of increase / decrease in the angle deviation selected is selected, and the combination of the tires in a diagonal relationship that are targeted for calculation by the angle deviation calculation unit. And a front-rear wheel determination unit that determines a front tire and a rear tire for each diagonal tire determined as a pair by the diagonal pair determination unit. Is the gist.

  According to this configuration, the angle deviation calculation unit calculates the trajectory indicating how much the angle deviation occurs between the diagonally related tires from the first time to the second time. The calculation uses rudder angle information and vehicle speed information. Then, the tires obtained by detecting the mode following the trajectory calculated by the angle deviation calculating unit are determined to be a pair of diagonally related tires that are the premise of the trajectory, and each of the tires forming the pair Front and rear wheels are determined for the tire. Therefore, the tire position can be determined with a simple configuration that does not use an initiator (trigger).

  In particular, since a method of first finding a pair of diagonally related tires is employed, erroneous determination can be reduced as compared with a method of individually determining a tire position. That is, a pair of diagonal relations can be found on the assumption that the tire positions of the four wheels by the right front wheel (FR), the left front wheel (FL), the right rear wheel (RR), and the left rear wheel (RL) are determined. If possible, the probability that an error will occur in the determination of the front and rear wheels is ½, and the probability of erroneous determination is lower than the remaining 3/4, which is obtained by subtracting the accuracy rate ¼ when determined individually from 1.

  Regarding the tire position determination system, on the assumption that the steering wheel is rotated to the right with a right turn or the steering wheel is rotated to the left with a left turn, the front wheels on the outer side and the outer side with respect to the steering direction are arranged in order from the tire with the highest rotational speed. A rear wheel, an inner front wheel, and an inner rear wheel are defined, and the front / rear wheel determination unit assumes that the front wheel is a reference in the calculation by the angle deviation calculation unit, and the amount of increase / decrease in the angle deviation is positive. When the tire with the higher rotational speed is determined as the front wheel and the remaining tires forming a diagonal pair are determined as the rear wheels, when the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotational speed is determined. Assuming that the tire is a rear wheel, the remaining tires that form a diagonal pair are determined to be front wheels, and the amount of increase / decrease in angle deviation is based on the assumption that the rear wheel is used as a reference in the calculation by the angle deviation calculation unit. When is positive, rotation speed The tire with the faster speed is determined as the rear wheel, and the remaining tires forming a diagonal pair are determined as the front wheels, while when the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotational speed is determined as the front wheel. While determining, it is good also as determining with the remaining tire which makes the pair of diagonal relationship being a rear wheel.

According to this configuration, it is possible to accurately determine the front and rear wheels of each tire forming a diagonal pair by monitoring the rotational speed of the tire.
Regarding the tire position determination system, on the assumption that the steering wheel is rotated to the right with a right turn or the steering wheel is rotated to the left with a left turn, the front wheels on the outer side and the outer side with respect to the steering direction are arranged in order from the tire with the highest rotational speed. The rear wheel, the inner front wheel, and the inner rear wheel are defined, and the front / rear wheel determination unit assumes that the right front wheel is used as a reference in the calculation by the angle deviation calculation unit. In this case, the tire with the higher rotational speed is determined as the right front wheel, and the remaining tires forming a diagonal pair are determined as the left rear wheel. Assuming that the faster tire is the left rear wheel, the remaining tires that form a diagonal pair are determined as the right front wheel, and the left front wheel is used as a reference in the calculation by the angle deviation calculation unit, Increase / decrease amount of angle deviation is positive The tire with the higher rotational speed is determined as the left front wheel, and the remaining tires forming a diagonal pair are determined as the right rear wheel. On the other hand, when the amount of increase / decrease in the angle deviation is negative, the rotational speed is high. The tire on the other side is determined as the right rear wheel, and the remaining tires that form a diagonal pair are determined as the left front wheel, and on the assumption that the right rear wheel is used as a reference in the calculation by the angle deviation calculation unit, When the amount of increase / decrease in angle deviation is positive, the tire with the faster rotational speed is determined as the right rear wheel, and the remaining tires that form a diagonal pair are determined as the left front wheel, while the amount of increase / decrease in angle deviation is When negative, the tire with the higher rotational speed is determined as the left front wheel, and the remaining tire forming the diagonal pair is determined as the right rear wheel, and the left rear wheel is the reference in the calculation by the angle deviation calculation unit. Assuming that the angle deviation increase / decrease is positive, The tire with the faster rotation speed is determined as the left rear wheel, and the remaining tires that form a diagonal pair are determined as the right front wheel. The tire may be determined as the right front wheel, and the remaining tires that form a diagonal pair may be determined as the left rear wheel.

According to this configuration, the tire positions of all four wheels can be accurately determined by monitoring the rotational speed of the tire.
With respect to the tire position determination system, the angle shift calculation unit is configured to calculate an increase / decrease amount of the angle shift at the second time with respect to the angle shift at the first time with reference to a front wheel or a rear wheel. It may be performed for each pair of tires.

  According to this configuration, as a result of determining the front and rear wheels in pairs, the tire positions of all four wheels can be determined smoothly.

  According to the present invention, the tire position can be determined by a simple configuration that does not use an initiator (trigger).

The block diagram which shows the structure of a tire pressure monitoring system. The conceptual diagram which shows the reception timing of the UHF electromagnetic wave from each transmitter. The table | surface which shows the detection aspect of the angle shift | offset | difference of each tire. The graph which shows the locus | trajectory of the angle shift | offset | difference between the tires of diagonal relation. The conceptual diagram which shows the rotational speed of each tire for every steering direction.

Hereinafter, an embodiment of a tire position determination system will be described.
As shown in FIG. 1, the vehicle 1 includes a tire pressure monitor for monitoring the air pressure of each tire 2 (right front wheel tire 2a, left front wheel tire 2b, right rear wheel tire 2c, left rear wheel tire 2d). System (TPMS: Tire Pressure Monitoring System) 3 is installed. The tire pressure monitoring system 3 includes the tires corresponding to the transmitters 4 (the transmitter 4a of the tire 2a, the transmitter 4b of the tire 2b, the transmitter 4c of the tire 2c, and the transmitter 4d of the tire 2d) provided in each tire 2. 2 is received and received by the receiver 6 on the vehicle body 5 side, and the air pressure of each tire 2 is monitored. The monitoring result is displayed on the display unit 7 on the vehicle body 5 side.

  The transmitter 4 of each tire 2 is provided with a controller 11 that performs overall control of the transmitter 4. The controller 11 includes a nonvolatile memory 12. The memory 12 stores ID (identification) that is identification information unique to the transmitter 4. For convenience, the ID of the transmitter 4a for the right front wheel is defined as ID1, and the ID of the transmitter 4b for the left front wheel is defined as ID2. The ID of the right rear wheel transmitter 4c is defined as ID3, and the ID of the left rear wheel transmitter 4d is defined as ID4.

  The controller 11 is electrically connected to a pressure sensor 13 that detects the air pressure of the tire 2, a temperature sensor 14 that detects the internal temperature of the tire 2, and an acceleration sensor 15 that detects acceleration generated in the transmitter 4. ing. The controller 11 is connected to an antenna 16 serving as a medium for transmitting UHF (Ultra High Frequency) radio waves.

  When the controller 11 analyzes the detection signal from the acceleration sensor 15 and detects that the transmitter 4 has reached the upper pole position (position at 12 o'clock) as the tire 2 rotates, the detection of the tire 2 is triggered by the detection. The UHF radio wave including the air pressure information Stp is transmitted. The UHF radio wave includes the ID and temperature information of the tire 2 in addition to the air pressure information Stp. When the controller 11 detects that the transmitter 4 has reached the pole position, a UHF radio wave is transmitted from the transmitter 4. When the UHF radio wave is received by the receiver 6 on the vehicle body 5 side, the UHF radio wave is transmitted. The receiver 6 recognizes that the transmitted transmitter 4 is approaching the pole position. That is, the rotation state of the tire 2 is grasped. Therefore, the UHF radio wave from the transmitter 4 is defined as including rotation information of the corresponding tire 2. The controller 11 corresponds to a transmission control unit.

  The receiver 6 on the vehicle body 5 side is provided with a TPMS ECU (Electronic Control Unit) 21 for controlling the receiver 6 and an antenna 22 as a medium for receiving UHF radio waves. . The ECU 21 includes a nonvolatile memory 23. In the memory 23, the ID of the transmitter 4 of the tire 2 to be monitored is registered as a reference ID. The ID (ID1) of the transmitter 4a is registered as the reference ID of the right front wheel, and the ID (ID2) of the transmitter 4b is registered as the reference ID of the left front wheel. Further, the ID (ID3) of the transmitter 4c is registered as the reference ID of the right rear wheel, and the ID (ID4) of the transmitter 4d is registered as the reference ID of the left rear wheel.

  For example, a display unit 7 installed on an instrument panel in the vehicle is electrically connected to the receiver 6. When the UHF radio wave is received by the antenna 22, the ECU 21 checks the ID included therein with the reference ID. When the ID matches, the ECU 21 compares the air pressure value (pressure value) suggested by the air pressure information Stp included in the UHF radio wave with a threshold value. When the pressure value is less than the threshold, the ECU 21 outputs to the display unit 7 a control signal instructing display of content indicating that the tire 2 provided with the transmitter 4 having the ID with the matching ID is low. . As a result, the above contents are displayed on the display unit 7 and a notification operation for the user is performed.

  By the way, the vehicle body 5 includes a wheel speed sensor 8 (right front wheel speed sensor 8a, left front wheel speed sensor 8b, right rear wheel speed sensor 8c, left rear wheel speed sensor corresponding to each wheel. 8d) is provided. The wheel speed sensor 8 outputs a pulse Spl indicating the rotational speed of the corresponding wheel to an ECU (not shown) of an ABS (Anti lock Brake System). This pulse Spl is also input to the ECU 21 of the TPMS. The ECU 21 obtains reference rotation information of the tire 2 attached to each wheel from the pulse Spl by each wheel speed sensor 8.

  The ECU 21 includes a transmitter 4 that transmits the rotation information based on the correlation between the rotation information of the tire 2 obtained from each transmitter 4 and the reference rotation information of the tire 2 obtained from each wheel speed sensor 8. The position of the tire 2 is determined. The ECU 21 individually monitors the air pressure of each tire 2 while reflecting the determination result in the registered contents of the memory 23. The function of determining the position of the tire 2 is defined as an auto-location function, and this function is realized by the auto-location function unit 24.

Next, the operation of the tire position determination system will be described.
As shown on the left side of FIG. 2, on the assumption that the receiver 6 of the vehicle body 5 has received UHF radio waves from all the transmitters 4 within one rotation of the reference tire (any of the tires 2a to 2d), The UHF radio wave reception timing (the UHF radio wave reception timing including the ID identified as the other by # 1 for convenience) is defined as the first time t1. In addition, one rotation of the reference tire that goes back from the first time t1 is defined as a first rotation opportunity. In this first rotation opportunity, UHF radio waves are received in the order of # 4, # 3, # 2, and # 1.

  As shown on the right side of FIG. 2, on the assumption that the receiver 6 of the vehicle body 5 has received UHF radio waves from all the transmitters 4 within another one rotation of the reference tire, the last rotation opportunity is completed. The reception timing of the UHF radio wave from the transmitter 4 that transmitted the UHF radio wave (the reception timing of the UHF radio wave including the ID of # 1) is defined as the second time t2. Further, one rotation of the reference tire going back from the second time t2 is defined as a second rotation opportunity. In this second rotation opportunity, UHF radio waves are received in the order of # 4, # 2, # 3, and # 1.

  As shown in FIG. 3, the auto-location function unit 24 of the ECU 21 detects the angular deviation of each tire 2 from the reception timing of each UHF radio wave according to FIG. 2 for each of the first rotation opportunity and the second rotation opportunity. . Referring to the left side of FIG. 2, the angle shift between # 1 and # 2 in the first rotation opportunity is 60 °, and referring to the right side of FIG. 2, # 1 and # 2 in the second rotation opportunity. The angle shift of 2 is 210 °. Therefore, as shown in FIG. 3, with respect to # 1- # 2, it is detected that an angle shift of 150 ° has occurred between the first time t1 and the second time t2 (for convenience, other combinations) About omitted).

  As shown in FIG. 4, the auto-location function unit 24 is a trajectory indicating how much angular misalignment occurs between diagonally related tires between the first time t1 and the second time t2. Is calculated for each pair of diagonally related tires. That is, the trajectory is calculated for both the pair of the right front wheel (FR) and the left rear wheel (RL) and the pair of the left front wheel (FL) and the right rear wheel (RR).

  As shown on the left side of FIG. 5, on the premise that the steering wheel is rotated to the right in accordance with a right turn, FL (outer front wheel with respect to the steering direction) and RL (outer rear wheel) in order from the higher rotation speed of the tire 2 ), FR (inner front wheel), and RR (inner rear wheel). On the other hand, as shown on the right side of FIG. 5, on the assumption that the steering wheel is rotated counterclockwise in accordance with the left turn, FR (outer front wheel with respect to the steering direction), RR (outer side of the steering direction) in order from the fastest rotation speed of the tire 2. Rear wheel), FL (inner front wheel), and RL (inner rear wheel) are defined. Among the pairs of diagonally related tires, with respect to the pair of the right front wheel (FR) and the left rear wheel (RL), if the left rear wheel (RL) is used as a reference, the angle deviation value is positive (v2-v3) when turning right ), And the value of the angle deviation becomes negative (v4-v1) when turning left.

  Therefore, the trajectory of FIG. 4 indicates which of the pair of the right front wheel (FR) and the left rear wheel (RL) is between the first time t1 and the second time t2 with reference to the left rear wheel (RL). This is a trajectory indicating whether or not the angle deviation has occurred (for the sake of convenience, the remaining pairs are omitted). The trajectory is defined as including the integrated value of the steering angle information and the vehicle speed information. The higher the vehicle speed, the steeper the inclination, and the falling part from + 360 ° to 0 ° and the rising part from −360 ° to 0 °. The part suggests that a lap delay has occurred.

  The autolocation function unit 24 illuminates the detection mode according to FIG. 3 with the locus according to FIG. 4, and the increase / decrease of the angle shift (−150 °) at the second time t2 with respect to the angle shift (0 °) at the first time t1. A combination of tires that matches the amount (−150 °) is selected. In this example, since the detection mode of # 1 to # 2 according to FIG. 3 follows the pair trajectory by the right front wheel (FR) and the left rear wheel (RL) according to FIG. A combination of # 1 and # 2 is determined as a pair of a right front wheel (FR) and a left rear wheel (RL). The autolocation function unit 24 compares # 1 and # 2 with reference to FIG. 2 and FIG. 3 and # 2 advances by 150 °. Therefore, refer to # 2 on the right side of FIG. The FR (right front wheel) with the higher rotational speed is determined, and # 1 is determined as the remaining RL (left rear wheel) forming a diagonal pair.

  Similarly, for the combination of # 3 and # 4, a pair of the left front wheel (FL) and the right rear wheel (RR) is first found, and the front and rear wheels are determined for the pair. As a result, the determination of the tire positions for all four wheels is completed. The auto-location function unit 24 corresponds to the four of an angle shift detection unit, an angle shift calculation unit, a diagonal pair determination unit, and a front and rear wheel determination unit.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The autolocation function unit 24 calculates a trajectory indicating how much angle deviation occurs between the diagonally related tires from the first time t1 to the second time t2 (FIG. 4), the steering angle information and the vehicle speed information are used for the calculation. Then, the tires for which detection of the mode following the trajectory is obtained are determined as a pair of diagonally related tires which are the premise of the trajectory, and front and rear wheels are determined for each tire forming the pair. The Therefore, the tire position can be determined with a simple configuration that does not use an initiator (trigger).

  (2) Since a method of first finding a pair of diagonally related tires is employed, erroneous determination can be reduced compared to a method of individually determining a tire position. That is, a pair of diagonal relations can be found on the assumption that the tire positions of the four wheels by the right front wheel (FR), the left front wheel (FL), the right rear wheel (RR), and the left rear wheel (RL) are determined. If possible, the probability that an error will occur in the determination of the front and rear wheels is ½, and the probability of erroneous determination is lower than the remaining 3/4, which is obtained by subtracting the accuracy rate ¼ when determined individually from 1.

  (3) By monitoring the rotational speed of the tire 2 (see FIG. 5), it is possible to accurately determine the front and rear wheels of each tire forming a diagonal pair, and to accurately determine the tire positions of all four wheels. Can be determined.

(4) A trajectory is calculated for each pair of diagonally related tires. Thereby, as a result of determining the front and rear wheels in pairs, the tire positions of all four wheels can be determined smoothly.
In addition, the said embodiment can also be changed and actualized as follows.

  For the pair of the right front wheel (FR) and the left rear wheel (RL), instead of using the left rear wheel (RL) as a reference, the first time t1 to the second time t2 based on the right front wheel (FR) Alternatively, a trajectory indicating how much angle deviation has occurred during the time period may be calculated. That is, with respect to the diagonally related tires, the increase / decrease amount of the angle shift at the second time t2 with respect to the angle shift at the first time t1 may be calculated based on the front wheels.

  In the above embodiment, on the assumption that the left rear wheel (RL) is used as a reference in the calculation of the trajectory by the auto-location function unit 24, when the increase / decrease amount of the angular deviation is negative, the tire with the higher rotational speed Is determined as the right front wheel (FR), and the remaining tires forming a diagonal pair are determined as the left rear wheel (RL). Instead of this principle, the front and rear wheels may be determined for each tire that forms a diagonal relationship based on the following principles.

  ○ On the assumption that the left rear wheel (RL) is used as a reference in the calculation of the trajectory by the auto-location function unit 24, when the increase / decrease amount of the angular deviation is positive, the tire with the higher rotational speed is set to the left rear wheel (RL). ), And the principle of determining the remaining tires forming a diagonal pair as the right front wheel (FR) may be employed.

  ○ Assuming that the right rear wheel (RR) is used as a reference in the calculation of the trajectory by the auto location function unit 24, when the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotation speed is set to the left front wheel (FL). And the principle of determining the remaining tire forming a diagonal pair as the right rear wheel (RR) may be adopted.

  ○ Assuming that the right rear wheel (RR) is used as the reference in the calculation of the trajectory by the auto-location function unit 24, when the amount of increase / decrease in the angle deviation is positive, the tire with the higher rotational speed is attached to the right rear wheel (RR). ) And the principle of determining the remaining tires forming a diagonal pair as the left front wheel (FL) may be employed.

  ○ Assuming that the left front wheel (FL) was used as the reference in the calculation of the trajectory by the auto-location function unit 24, when the amount of increase / decrease in the angle deviation is negative, the tire with the faster rotation speed is set to the right rear wheel (RR). And the principle of determining the remaining tires that form a diagonal pair as the left front wheel (FL) may be employed.

  ○ Assuming that the left front wheel (FL) is used as the reference in the calculation of the trajectory by the auto-location function unit 24, when the amount of increase / decrease in the angle deviation is positive, the tire with the higher rotational speed is designated as the left front wheel (FL). While determining, the principle which determines the remaining tire which makes the pair of diagonal relationship as a right rear wheel (RR) may be employ | adopted.

  ○ On the premise that the right front wheel (FR) is used as a reference in the calculation of the trajectory by the auto-location function unit 24, when the increase / decrease amount of the angular deviation is negative, the tire with the higher rotational speed is set to the left rear wheel (RL). And the principle of determining the remaining tire forming a diagonal pair as the right front wheel (FR) may be adopted.

  ○ Assuming that the right front wheel (FR) is used as a reference in the trajectory calculation by the auto-location function unit 24, when the amount of increase / decrease in the angle deviation is positive, the tire with the higher rotational speed is referred to as the right front wheel (FR). While determining, the principle which determines the remaining tire which makes the pair of diagonal relationship as a left rear wheel (RL) may be employ | adopted.

  -In the case of four wheels, once a pair of diagonally related tires is determined, a pair of diagonally related tires is also automatically determined. Therefore, assuming that one pair is determined, the other pair For the above, a configuration for determining only the front and rear wheels may be adopted. In this case, the trajectory may be calculated for one pair, and the trajectory calculation may be omitted for the other pair.

Next, a technical idea that can be grasped from the above embodiment and another example will be described.
(A) In the tire position determination method for determining the position of the tire, the diagonal pair determination stage for finding a pair of diagonally related tires and each diagonally related tire determined as a pair in the diagonal pair determination stage A tire position determination method comprising: a front and rear wheel determination stage for determining a front tire and a rear tire.

  According to this configuration, since a method of first finding a pair of diagonally related tires is employed, erroneous determination can be reduced as compared with a method of individually determining a tire position. That is, a pair of diagonal relations can be found on the assumption that the tire positions of the four wheels by the right front wheel (FR), the left front wheel (FL), the right rear wheel (RR), and the left rear wheel (RL) are determined. If possible, the probability that an error will occur in the determination of the front and rear wheels is ½, and the probability of erroneous determination is lower than the remaining 3/4, which is obtained by subtracting the accuracy rate ¼ when determined individually from 1.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2, 2a-2d ... Tire, 3 ... Tire pressure monitoring system, 4, 4a-4d ... Transmitter, 5 ... Vehicle body, 6 ... Receiver, 7 ... Display part, 8, 8a-8d ... Wheel speed Sensor, 11 ... Controller (transmission control unit), 12 ... Memory, 13 ... Pressure sensor, 14 ... Temperature sensor, 15 ... Acceleration sensor, 16 ... Antenna, 21 ... ECU, 22 ... Antenna, 23 ... Memory, 24 ... Autolocation Functional units (angle shift detection unit, angle shift calculation unit, diagonal pair determination unit, front and rear wheel determination unit).

Claims (4)

In the tire position determination system for determining the position of the tire,
Each tire transmitter includes a transmission control unit that transmits a transmission signal including identification information unique to the transmitter together with tire rotation information,
The receiver of the vehicle body defines the reception timing of the last transmission signal as the first time on the assumption that the transmission signals have been received from all the transmitters within one rotation of the reference tire, and goes back from the first time. One rotation of the reference tire is defined as a first rotation opportunity, and the angular deviation of each tire is detected from the reception timing of each transmission signal in the first rotation opportunity, and all within one other rotation of the reference tire Assuming that a transmission signal has been received from the transmitter, the reception timing of the transmission signal from the transmitter that transmitted the last transmission signal at the first rotation opportunity is defined as a second time, An angle deviation detection unit that defines one rotation of the reference tire going back from the time as a second rotation opportunity, and detects an angle deviation of each tire from the reception timing of each transmission signal in the second rotation opportunity;
An angle shift calculation unit that calculates an increase / decrease amount of the angle shift at the second time with respect to the angle shift at the first time with respect to the tires in a diagonal relationship with respect to the front wheel or the rear wheel
From the combination of tires detected by the angle deviation detection unit, the angle deviation calculation unit calculates an increase / decrease amount of the angle deviation in the second rotation opportunity with respect to the angle deviation in the first rotation opportunity. A pair of tires that match the amount of increase / decrease of the angle deviation, and a diagonal pair determination unit that determines the combination as a pair of diagonally related tires that are targets of calculation by the angle deviation calculation unit;
A tire position determination system comprising a front and rear wheel determination unit that determines a front tire and a rear tire for each of the diagonally determined tires determined by the diagonal pair determination unit. Assuming that the steering wheel is rotated to the right with a right turn or the steering wheel is rotated to the left with a left turn, the outer front wheel, the outer rear wheel, and the inner front wheel with respect to the steering direction, in order from the fastest tire rotation speed The inner rear wheel is defined,
The front and rear wheel determination unit, on the premise that the front wheel is used as a reference in the calculation by the angle deviation calculation unit, when the increase / decrease amount of the angle deviation is positive, the tire having the faster rotational speed is determined as the front wheel, While the remaining tires forming a diagonal pair are determined as rear wheels, when the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotational speed is determined as the rear wheel, and the diagonal pair is formed. Determine the remaining tires as front wheels,
Assuming that the rear wheel is used as a reference in the calculation by the angle deviation calculation unit, when the increase / decrease amount of the angle deviation is positive, the tire having the higher rotational speed is determined as the rear wheel, and the pair of diagonal relations When the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotational speed is determined as the front wheel, and the remaining tire forming the diagonal pair is determined as the rear wheel. The tire position determination system according to claim 1. Assuming that the steering wheel is rotated to the right with a right turn or the steering wheel is rotated to the left with a left turn, the outer front wheel, the outer rear wheel, and the inner front wheel with respect to the steering direction, in order from the fastest tire rotation speed The inner rear wheel is defined,
The front / rear wheel determination unit determines that the tire having the higher rotational speed is the right front wheel when the increase / decrease amount of the angle shift is positive on the assumption that the right front wheel is used as a reference in the calculation by the angle shift calculation unit. At the same time, the remaining tire forming the diagonal pair is determined as the left rear wheel, and when the increase / decrease amount of the angle deviation is negative, the tire having the higher rotational speed is determined as the left rear wheel, and the diagonal relationship is determined. The remaining tires that make a pair are determined as the right front wheel,
On the premise that the left front wheel is used as a reference in the calculation by the angle deviation calculation unit, when the increase / decrease amount of the angle deviation is positive, the tire having the higher rotation speed is determined as the left front wheel, and the diagonal pair The remaining tire that forms a right rear wheel is judged as the right rear wheel, while when the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotational speed is judged as the right rear wheel, and the remaining tires that form a diagonal pair Is the left front wheel,
Assuming that the right rear wheel is used as a reference in the calculation by the angle deviation calculation unit, when the increase / decrease amount of the angle deviation is positive, the tire having the higher rotational speed is determined as the right rear wheel, and the diagonal relationship When the remaining tire forming the pair is determined to be the left front wheel, when the amount of increase / decrease in the angle deviation is negative, the tire having the higher rotational speed is determined to be the left front wheel and the remaining tire forming the diagonal pair Is the right rear wheel,
On the premise that the left rear wheel is used as a reference in the calculation by the angle deviation calculation unit, when the increase / decrease amount of the angle deviation is positive, the tire having the higher rotational speed is determined as the left rear wheel, and the diagonal relationship While the remaining tire forming the pair is determined as the right front wheel, when the amount of increase / decrease in the angle deviation is negative, the tire with the higher rotational speed is determined as the right front wheel, and the remaining tire forming the diagonal pair The tire position determination system according to claim 1 or 2, wherein the tire position is determined as a left rear wheel. The angle shift calculation unit calculates the increase / decrease amount of the angle shift at the second time with respect to the angle shift at the first time on the basis of the front wheel or the rear wheel for each pair of diagonally related tires. The tire position determination system according to any one of claims 1 to 3.