Wear determination system, wear determination device, and information transmission device

Abstract

The invention provides a wear determination system, a wear determination device, and an information transmission device. A wear determination system determines wear of a target wheel, which is a steered wheel provided in a vehicle. The wear determination system calculates the ground speed of the target wheel and the rotation speed of the target wheel in the same section in which the vehicle is turning right or left, and calculates a turning forward radius based on the ground speed and the rotation speed. The turning forward radius refers to the dynamic load radius of the target wheel when the vehicle is turning right or left. The wear determination system determines wear of the shoulder portion of the target wheel on the basis of the forward turning radius.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a wear judgment system, a wear judgment device, and an information transmission device. BACKGROUND

[0002] A wear judgment system is described in Japanese Patent Application Publication No. 2021-172280. The wear judgment system judges wear of a wheel based on a distance moved by the wheel as a vehicle travels and a number of rotations of the wheel when the distance is moved. SUMMARY

[0003] PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] A wheel has a tread portion that contacts the ground when the vehicle is straight ahead, and a shoulder portion that contacts the ground when the vehicle is turning right or left. The wear judgment system of the above-described publication does not judge the wear condition in a manner that distinguishes between the tread portion and the shoulder portion. Therefore, the wear judgment system of the above-described publication cannot focus on the shoulder portion of the wheel to judge wear.

[0005] MEANS FOR SOLVING THE PROBLEMS

[0006] A wear judgment system according to one embodiment of the present disclosure judges wear of an object wheel that is a steered wheel provided to a vehicle, in which the wear judgment system is configured to calculate a ground speed of the object wheel and a rotational speed of the object wheel within the same interval in which the vehicle is turning right or left, calculate a turning straight-ahead radius that is a dynamic load radius of the object wheel when the vehicle is turning right or left, based on the ground speed and the rotational speed, and judge wear of a shoulder portion of the object wheel based on the turning straight-ahead radius.

[0007] A wear judgment device according to one embodiment of the present disclosure judges wear of an object wheel that is a steered wheel provided to a vehicle, in which the wear judgment device is configured to judge wear of a shoulder portion of the object wheel based on a turning straight-ahead radius that is a dynamic load radius of the object wheel when the vehicle is turning right or left, the turning straight-ahead radius being calculated based on a ground speed of the object wheel and a rotational speed of the object wheel that are acquired within the same interval in which the vehicle is turning right or left.

[0008] An information sending device involved in one embodiment of the present invention is configured to communicate with a wear judgment device, wherein the information sending device is configured to calculate the ground speed of the object wheel and the rotational speed of the object wheel in the same section where the vehicle is turning right or left, calculate the radius of the turning forward based on the ground speed and the rotational speed, and send the radius of the turning forward to the wear judgment device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram showing the structure of a wear determination system according to one embodiment.

[0010] Figure 2 A diagram showing wheels included in a vehicle.

[0011] Figure 3 A diagram showing the state of the steering wheels of a vehicle when the vehicle is moving straight ahead.

[0012] Figure 4 A diagram showing the state of the steering wheels of a vehicle when the vehicle is turning right.

[0013] Figure 5 To indicate the use Figure 1 A timing diagram of the communication format for judging the steering angle of a steering wheel of a vehicle in a wear judgment system.

[0014] Figure 6 This is a graph showing an example of the transition of the steering angle of the steering wheel caused by the user's operation of the vehicle.

[0015] Figure 7 To indicate the use Figure 1 A flowchart of a wear judgment system for calculating the radius of a target wheel when moving in a straight line.

[0016] Figure 8 To indicate the use Figure 1 A flowchart of a process for calculating the turning forward radius of a target wheel in a wear judgment system.

[0017] Figure 9 This diagram shows the relationship between the yaw angle of the steering wheel of a vehicle and the turning center when the vehicle turns right.

[0018] Figure 10 To indicate the use Figure 1 A timing diagram of the communication mode in which the wear judgment device in the wear judgment system judges the wear of the shoulder portion of the target wheel.

[0019] Figure 11 To express in Figure 1Table of one example of information transmitted from the information transmitting device to the wear judging device in the wear judging system of the first modification.

[0020] Figure 12 A timing chart showing a communication form for the wear judging device to judge wear of the shoulder portion of the object wheel in the wear judging system of the first modification. DETAILED DESCRIPTION

[0021] One embodiment of the wear judging system will be described below with reference to Figures 1 to 11

[0022] Structure of the wear judging system 100

[0023] As shown in Figure 1 , the wear judging system 100 includes the vehicle 10 and the wear judging device 25.

[0024] As shown in Figure 1 , the vehicle 10 includes the information transmitting device 11. The information transmitting device 11 includes the brake ECU 12 and the communication device 13.

[0025] The brake ECU 12 is an electronic control device that controls a brake included in the vehicle 10. The brake ECU 12 generates information related to the vehicle 10 on the basis of information from a plurality of sensors included in the vehicle 10.

[0026] The brake ECU 12 includes a storage device 33 in which a program is stored, and a processing circuit 32 that executes the program stored in the storage device 33 to perform various processes. The processing circuit 32 includes a processor.

[0027] The information transmitting device 11 can be connected to the wear judging device 25 by wire or wirelessly. The communication device 13 transmits the information related to the vehicle 10 generated by the brake ECU 12 to the wear judging device 25. In this way, the information transmitting device 11 transmits the information related to the vehicle 10 to the wear judging device 25. The information transmitted by the information transmitting device 11 will be described later.

[0028] The brake ECU 12 acquires information from the steering angle sensor 14, the yaw rate sensor 15, the vehicle speed sensor 16, and a plurality of wheel speed sensors in order to generate the information related to the vehicle 10.

[0029] The steering angle sensor 14 measures a steering angle of a steering wheel on the vehicle 10. The steering angle sensor 14 transmits the measured steering angle to the brake ECU 12.

[0030] The yaw rate sensor 15 measures a yaw rate of the vehicle 10. The yaw rate sensor 15 transmits the measured yaw rate to the brake ECU 12.​

[0031] The vehicle speed sensor 16 measures the speed of the vehicle 10. Specifically, the vehicle speed sensor 16 measures the speed of the vehicle 10 based on the rotational speed of any of the engine crankshaft, the transmission, the motor, etc. The vehicle speed sensor 16 transmits the measured speed of the vehicle 10 to the brake ECU 12.

[0032] like Figure 1 As shown, the vehicle 10 includes four wheel speed sensors: an FL wheel speed sensor 17 , an FR wheel speed sensor 18 , an RL wheel speed sensor 19 , and an RR wheel speed sensor 20 .

[0033] The FL wheel speed sensor 17 measures the rotation speed of the FL wheel 21. The FL wheel 21 is arranged on the front left side of the vehicle 10. The FL wheel speed sensor 17 transmits the measured rotation speed of the FL wheel 21 to the brake ECU 12.

[0034] The FR wheel speed sensor 18 measures the rotation speed of the FR wheel 22. The FR wheel 22 is disposed on the front right side of the vehicle 10. The FR wheel speed sensor 18 transmits the measured rotation speed of the FR wheel 22 to the brake ECU 12.

[0035] The RL wheel speed sensor 19 measures the rotation speed of the RL wheel 23. The RL wheel 23 is disposed on the rear left side of the vehicle 10. The RL wheel speed sensor 19 transmits the measured rotation speed of the RL wheel 23 to the brake ECU 12.

[0036] The RR wheel speed sensor 20 measures the rotation speed of the RR wheel 24. The RR wheel 24 is disposed on the rear right side of the vehicle 10. The RR wheel speed sensor 20 transmits the measured rotation speed of the RR wheel 24 to the brake ECU 12.

[0037] like Figure 1 As shown, the wear determination device 25 includes a storage device 27 storing a program and a processing circuit 26 that executes various processes by executing the program stored in the storage device 27. The processing circuit 26 includes a processor. The wear determination device 25 is, for example, a server installed outside the vehicle 10.

[0038] Each of the processing circuit 26 and the processing circuit 32 can also include one or more dedicated hardware circuits such as an application specific integrated circuit (ASIC) that performs at least a part of the various processes. Alternatively, each of the processing circuit 26 and the processing circuit 32 can also include a combination of one or more processors and one or more dedicated hardware circuits. The processor can include a CPU, and a memory such as a RAM and a ROM. The memory can store program codes or instructions that are structured in such a way as to cause the CPU to perform processes. The memory, i.e., the computer readable medium, includes all available media that can be accessed by a general or specific computer.

[0039] Summary of the shoulder portion 29 of the subject wheel

[0040] The wear judging device 25 judges the wear of the shoulder portion 29 of the subject wheel based on the information related to the vehicle 10 received from the information transmitting device 11.

[0041] The subject wheel refers to a wheel that becomes an object of judgment by the wear judging device 25 and the wear judging system 100. The wear judging device 25 and the wear judging system 100 set the steering wheels possessed by the vehicle 10 as objects of judgment. The steering wheels in the vehicle 10 are the FL wheel 21 and the FR wheel 22. The subject wheels in the wear judging device 25 and the wear judging system 100 are the FL wheel 21 and the FR wheel 22.

[0042] Figure 2 Indicates the subject wheel possessed by the vehicle 10. Figure 2 The wheel shown is, for example, the FL wheel 21. As Figure 2 As shown, the subject wheel possesses a tread portion 28 and a shoulder portion 29. The shoulder portion 29 includes a shoulder portion 29 that is on the right side toward the direction of travel, and a shoulder portion 29 that is on the left side toward the direction of travel. In the following description, the shoulder portion 29 that is on the right side toward the direction of travel will be simply referred to as the right shoulder portion 29, and the shoulder portion 29 that is on the left side toward the direction of travel will be simply referred to as the left shoulder portion 29.

[0043] In the case where the vehicle 10 is straight ahead, in the subject wheel, the tread portion 28 is in contact with the ground. Figure 3 The configuration of the subject wheel when the vehicle 10 is straight ahead is shown. For example, Figure 3 The wheel shown is the FL wheel 21.

[0044] In the case where the vehicle 10 is right turning, the portion of the subject wheel that is in contact with the ground changes in accordance with the deflection angle of the subject wheel, by tilting the subject wheel with respect to the ground. During a period in which the deflection angle of the subject wheel is smaller than a certain angle, the portion between the tread portion 28 and the right shoulder portion 29 in the subject wheel is in contact with the ground. When the deflection angle of the subject wheel is larger than the certain angle, the right shoulder portion 29 is in contact with the ground.

[0045] Figure 4 The configuration of the subject wheel when the vehicle 10 is right turning is shown in a state in which the deflection angle of the subject wheel is larger than the certain angle. For example, Figure 4 The wheel shown is the FL wheel 21. In the case where the vehicle 10 is right turning, as shown in Figure 4 The subject wheel is tilted to the right with respect to the ground. When the deflection angle of the subject wheel is larger than the certain angle, the right shoulder portion 29 is in contact with the ground.

[0046] In the case where the vehicle 10 is left turning, as in the case where the vehicle 10 is right turning, the portion of the subject wheel that is in contact with the ground changes in accordance with the deflection angle of the subject wheel. During a period in which the deflection angle of the subject wheel is smaller than a certain angle, the portion between the tread portion 28 and the left shoulder portion 29 in the subject wheel is in contact with the ground. When the deflection angle of the subject wheel is larger than the certain angle, the left shoulder portion 29 is in contact with the ground.

[0047] Figure 3 The symbol "a1" in the formula (1) indicates the straight-ahead radius of the subject wheel. The straight-ahead radius refers to the dynamic load radius of the subject wheel when the vehicle 10 is straight ahead.

[0048] Figure 4 The symbol "a2" in the formula (2) indicates the turning-ahead radius of the subject wheel. The turning-ahead radius refers to the dynamic load radius of the subject wheel when the vehicle 10 is right or left turning.

[0049] The more worn the shoulder portion 29 of the subject wheel is, the smaller the turning-ahead radius becomes. The wear judging device 25 judges the wear of the shoulder portion 29 of the subject wheel on the basis of the turning-ahead radius.

[0050] <Communication configuration for calculating the straight-ahead radius and the turning-ahead radius>

[0051] The information transmitting device 11 transmits information indicating the radius when straight traveling and the radius when cornering traveling, as information related to the vehicle 10. As described earlier, the brake ECU 12 generates the information related to the vehicle 10. The brake ECU 12 generates the information related to the vehicle 10 by calculating the radius when straight traveling and the radius when cornering traveling based on information from a plurality of sensors possessed by the vehicle 10.

[0052] Figure 5 The form of communication performed by the brake ECU 12 for calculating the radius when straight traveling and the radius when cornering traveling is shown. In Figure 5 , the processing performed by the brake ECU 12 is performed by the processing circuit 32.

[0053] The brake ECU 12 calculates the radius when straight traveling and the radius when cornering traveling based on values measured by a plurality of sensors possessed by the vehicle 10 during a calculation period. The calculation period is a specific period among periods during which the vehicle 10 is traveling.

[0054] As shown in Figure 5 , the steering angle sensor 14 transmits information indicating the steering angle of the steering wheel resulting from the operation of the user of the vehicle 10 to the brake ECU 12. The steering angle sensor 14 transmits information indicating the progress of the steering angle of the steering wheel during the calculation period to the brake ECU 12. Hereafter, in the drawings, the value of the steering angle indicated by the information transmitted by the steering angle sensor 14 is denoted by δ.

[0055] As shown in Figure 5 , the brake ECU 12 that receives the information indicating the steering angle from the steering angle sensor 14 performs a steering angle judgment process. The steering angle judgment process refers to a process of dividing the calculation period based on the steering angle indicated by the information received from the steering angle sensor 14.

[0056] Figure 6 The progress of the steering angle of the steering wheel during the calculation period indicated by the information received by the brake ECU 12 from the steering angle sensor 14 is shown.

[0057] In the graph of Figure 6 , the vertical axis indicates the steering angle of the steering wheel measured by the steering angle sensor 14. In the graph of Figure 6 , the horizontal axis indicates time.

[0058] In the graph of Figure 6 , during the period in which the steering angle is zero, the steering wheel is not deflected to either of right and left. In the graph of Figure 6 , during the period in which the steering angle is on the upper side compared with the horizontal axis, the steering wheel is deflected to the right. In the graph of Figure 6In the graph, the steering wheel is deflected to the left during the period in which the steering angle is lower than the horizontal axis.

[0059] The brake ECU 12 divides the calculation period into the "X" period and the "Y" period in the steering angle judgment processing. Figure 6 The "X" period is a period in which the steering angle of the steering wheel is 0 degrees or more and less than 90 degrees.

[0060] Figure 6 The "X" period is a period in which the steering angle of the steering wheel is 0 degrees or more and less than 90 degrees. Figure 5 The "Y" period is a period in which the steering angle of the steering wheel is 90 degrees or more.

[0061] As shown in Figure 5 After the steering angle judgment processing is executed, the brake ECU 12 executes different processing according to the type of period.

[0062] As shown in Figure 5 The brake ECU 12 calculates the straight-ahead radius based on information measured by the plurality of sensors provided in the vehicle 10 during a period in which the steering angle of the steering wheel is 0 degrees or more and less than 90 degrees. That is, the brake ECU 12 calculates the straight-ahead radius based on information measured by the plurality of sensors provided in the vehicle 10 during the "X" period. In the present embodiment, the wear judgment system 100 judges that the vehicle 10 is straight-ahead traveling when the steering angle of the steering wheel is 0 degrees or more and less than 90 degrees.

[0063] As shown in Figure 7 The brake ECU 12 calculates the turning radius based on information measured by the plurality of sensors provided in the vehicle 10 during a period in which the steering angle of the steering wheel is 90 degrees or more. That is, the brake ECU 12 calculates the turning radius based on information measured by the plurality of sensors provided in the vehicle 10 during the "Y" period. In the present embodiment, the wear judgment system 100 judges that the vehicle 10 is right-turning or left-turning when the steering angle of the steering wheel is 90 degrees or more.

[0064] <Processing Mode Executed in Order to Calculate the Straight-Ahead Radius>

[0065] Figure 5 A series of processes executed by the brake ECU 12 in order to calculate the straight-ahead radius is shown. After the steering angle judgment processing shown in Figure 7 is executed, the brake ECU 12 executes a series of processes shown in Figure 7 based on information measured by the plurality of sensors provided in the vehicle 10 during the "X" period. Figure 7 The series of processes shown in

[0066] As described above, the target wheels are the FL wheel 21 and the FR wheel 22. The brake ECU 12 executes the brake control for each of the FL wheel 21 and the FR wheel 22. Figure 7 In the following, with reference to Figure 6 A first example will be described as an example in which the brake ECU 12 calculates the radius of the FL wheel 21 when moving straight ahead.

[0067] In the process of step S10, the brake ECU 12 calculates the ground speed of the target wheel when the vehicle 10 is moving straight ahead. In the first example, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is moving straight ahead.

[0068] To calculate the ground speed of the FL wheel 21 when the vehicle 10 is moving straight ahead, the brake ECU 12 stores the radius of the wheels on the vehicle 10 that are not the target wheels, i.e., the non-target wheels. The brake ECU 12 stores the average of the radii of the RL wheel 23 and the RR wheel 24 as the radius of the non-target wheel.

[0069] To calculate the ground speed of the FL wheel 21 while the vehicle 10 is moving straight ahead, the brake ECU 12 obtains the rotational speed of the wheels on the vehicle 10 that are not the target wheels during a period "X." The brake ECU 12 obtains the average rotational speed of the RL wheel 23 and the RR wheel 24 during the period "X" as the rotational speed of the non-target wheels. The brake ECU 12 obtains the rotational speed of the RL wheel 23 during the period "X" from the RL wheel speed sensor 19. The brake ECU 12 obtains the rotational speed of the RR wheel 24 during the period "X" from the RR wheel speed sensor 20.

[0070] When the vehicle 10 is moving straight, the ground speed of the target wheel is the same as the ground speed of the non-target wheel. When the vehicle 10 is moving straight, the ground speed of the FL wheel 21 is V1, the average value of the radius of the RL wheel 23 and the RR wheel 24 is r, and Figure 8 When the average value of the rotation speeds of the RL wheel 23 and the RR wheel 24 during the "X" period is set to N, the following relationship holds.

[0071] Mathematical formula 1

[0072] V1=2πr×N

[0073] In this way, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is moving straight ahead.

[0074] In the processing of step Sll, the brake ECU 12 calculates the angular velocity of the target wheel when the vehicle 10 is straight-ahead running. In the first example, the brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is straight-ahead running.

[0075] In order to calculate the angular velocity of the FL wheel 21 when the vehicle 10 is straight-ahead running, the brake ECU 12 acquires the rotational speed of the FL wheel 21 during the period "X" from the FL wheel speed sensor 17.

[0076] When the angular velocity of the FL wheel 21 when the vehicle 10 is straight-ahead running is denoted by ωl, and the rotational speed of the FL wheel 21 during the period "X" is denoted by Nl, the following relation holds.

[0077] Math. 2

[0078] ωl = 2π x Nl

[0079] In this way, the brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is straight-ahead running.

[0080] In the processing of step S12, the brake ECU 12 calculates the straight-ahead running time radius of the target wheel. In the first example, the brake ECU 12 calculates the straight-ahead running time radius of the FL wheel 21.

[0081] When the straight-ahead running time radius of the FL wheel 21 is denoted by bl, the following relation holds.

[0082] Math. 3

[0083]

[0084] In this way, the brake ECU 12 calculates the straight-ahead running time radius of the FL wheel 21.

[0085] The wear judgment system 100 calculates the straight-ahead running time radius on the basis of the ground speed of the target wheel and the rotational speed of the target wheel acquired during the same period when the vehicle 10 is straight-ahead running.

[0086] <Outline of Judgment Period Extraction Processing>

[0087] Figure 5 A series of processes performed by the brake ECU 12 in order to calculate the turning running time radius is shown. The brake ECU 12 performs a series of processes shown in Figure 8 after the steering angle judgment processing shown in Fig. 6, on the basis of information measured by a plurality of sensors possessed by the vehicle 10 during the period "Y". Figure 8 Figure 8 ​The series of processes shown are executed by the processing circuit 32 .

[0088] The brake ECU 12 calculates the radius of the tire when turning for each of the right shoulder portion 29 and the left shoulder portion 29 of the FL wheel 21. The brake ECU 12 calculates the radius of the tire when turning for each of the right shoulder portion 29 and the left shoulder portion 29 of the FR wheel 22. The brake ECU 12 executes the following operation for each shoulder portion 29 of the target wheel: Figures 2 to 4 A series of processing shown.

[0089] In the process of step S20, the brake ECU 12 executes a determination period extraction process. The determination period extraction process is a process of extracting a period for calculating a radius when turning from the "Y" period.

[0090] The brake ECU 12 extracts a period that satisfies the following three conditions as a period for calculating the radius during the turning process.

[0091] The first condition is that the deflection angle of the target wheel is large. Although it will be described later, the brake ECU 12 uses the ground speed of the target wheel when the vehicle 10 is turning left or right to calculate the radius when turning forward. Figure 6 As shown and described, the shoulder portion 29 of the target wheel contacts the ground when the yaw angle of the target wheel is greater than a specific angle. The forward turning radius calculated based on the target wheel's ground speed when the yaw angle is less than the specific angle may not accurately reflect the wear condition of the shoulder portion 29 of the target wheel.

[0092] The brake ECU 12 extracts the period during which the yaw angle of the FL wheel 21 is greater than a predetermined angle reference value as the period used to calculate the turning radius. In this embodiment, the angle reference value is not limited thereto, but may be, for example, the yaw angle of the target wheel when the steering angle of the vehicle 10 is 180 degrees.

[0093] The deflection angle of the target wheel relative to the steering wheel's steering angle differs between the FL wheel 21 and the FR wheel 22. The deflection angle of the target wheel relative to the steering wheel's steering angle also differs depending on whether the steering wheel is turned left or right. Therefore, the angle reference value varies depending on the direction of the steering wheel's rotation and the position of the target wheel.

[0094] The yaw angle of the target wheel increases as the steering angle of the vehicle 10's steering wheel increases. The brake ECU 12 extracts the period during which the yaw angle of the target wheel exceeds the reference angle by extracting the period during which the steering angle exceeds 180 degrees from the "Y" period. The wear determination system 100 does not calculate the forward turning radius if the yaw angle of the target wheel is below the reference angle when the vehicle 10 is turning right or left.

[0095] The second condition is that the yaw angle of the target wheel is constant. Although described later, the brake ECU 12 uses the yaw angle of the target wheel to calculate the turning radius. If the yaw angle of the target wheel changes, the brake ECU 12 cannot accurately calculate the turning radius.

[0096] The third condition is that the vehicle 10 is moving at a slow speed. When the vehicle 10 turns right or left while moving at a high speed, the vehicle 10 may slip. When the vehicle 10 slips, the brake ECU 12 cannot accurately calculate the ground speed of the target wheel.

[0097] The brake ECU 12 extracts a period during which the moving speed of the vehicle 10 is lower than a predetermined speed reference value when the vehicle 10 is turning right or left, as a period for calculating the turning radius.

[0098] In this embodiment, the speed reference value is 15 km / h. Based on the moving speed of the vehicle 10 received from the vehicle speed sensor 16, the brake ECU 12 extracts the period during which the moving speed is below the speed reference value from the "Y" period. The wear determination system 100 does not calculate the turning radius when the moving speed of the vehicle 10 is greater than the speed reference value while the vehicle 10 is turning right or left. The speed reference value is not limited to 15 km / h.

[0099] exist Figures 2 to 4 The two portions surrounded by the one-dot chain line correspond to the period extracted by the brake ECU 12 as the period for calculating the radius during the turning process.

[0100] like Figure 6 As shown and described, when the vehicle 10 is turning right, the right shoulder portion 29 comes into contact with the ground when the deflection angle of the target wheel is greater than a specific angle. The wear determination system 100 can determine the wear of the right shoulder portion 29 by calculating the turning radius when the vehicle 10 is turning right. Figures 2 to 4 One of the two portions enclosed by the one-dot chain line corresponds to the right turn determination period 30 for calculating the turning radius when the vehicle 10 is turning right.

[0101] As Figure 6 illustrated and described, in the case where the vehicle 10 is making a left turn, the shoulder portion 29 on the left side comes into contact with the ground when the deflection angle of the subject wheel is greater than a certain angle. The wear judgment system 100 is able to judge the wear of the shoulder portion 29 on the left side by calculating the radius of the turning progress when the vehicle 10 is making a left turn. In Figure 8 one of the two portions enclosed by the single-dot chain line in the middle corresponds to the left-turn judgment period 31 for calculating the radius of the turning progress when the vehicle 10 is making a left turn.

[0102] In step S21, the brake ECU 12 judges whether or not the extraction of the period for calculating the radius of the turning progress has been successful in the judgment period extraction processing of step S20.

[0103] The brake ECU 12 is unable to extract the period for calculating the radius of the turning progress in the case where there is no period within the calculation period that satisfies the three conditions described above. The brake ECU 12 judges that the extraction of the period has not been successful in the judgment period extraction processing in the case where it is unable to extract the period for calculating the radius of the turning progress.

[0104] The brake ECU 12 judges that the extraction of the period has not been successful in the case where it is unable to extract the right-turn judgment period 30 in the case where it executes the processing of Figure 8 in order to make the judgment of the presence or absence of wear on the shoulder portion 29 on the right side. The brake ECU 12 judges that the extraction of the period has not been successful in the case where it is unable to extract the left-turn judgment period 31 in the case where it executes the processing of Figure 8 in order to make the judgment of the wear on the shoulder portion 29 on the left side.

[0105] The brake ECU 12 ends the series of processing illustrated in Figure 8 in the case where it judges that the extraction of the period has not been successful (step S21: No).

[0106] On the other hand, the brake ECU 12 judges that the extraction of the period has been successful in the case where it extracts the period for calculating the radius of the turning progress in the judgment period extraction processing. The brake ECU 12 causes the processing to proceed to the next step S22 in the case where it judges that the extraction of the period has been successful (step S21: Yes).

[0107] In the processing after step S22, the brake ECU 12 calculates the turning-while-advancing radius on the FL wheel 21 and the FR wheel 22 when the vehicle 10 is right-turning, on the basis of the information of the plurality of sensors within the right-turning-time judgment period 30. In the processing after step S22, the brake ECU 12 calculates the turning-while-advancing radius on the FL wheel 21 and the FR wheel 22 when the vehicle 10 is left-turning, on the basis of the information of the plurality of sensors within the left-turning-time judgment period 31.

[0108] <Mode of processing performed in order to calculate turning-while-advancing radius>

[0109] Hereinafter, a second case, which is a case of calculating the turning-while-advancing radius when the vehicle 10 is right-turning, with respect to the FL wheel 21 among the object wheels possessed by the vehicle 10, will be described while referring to Figure 9 and Figure 9

[0110] In the processing of step S22, the brake ECU 12 performs a steering angle conversion process. The deflection angle of the object wheel corresponding to the steering angle of the steering wheel possessed by the vehicle 10 is predetermined. The brake ECU 12 stores the deflection angle of the steered wheel corresponding to the steering angle of the steering wheel possessed by the vehicle 10. In the steering angle conversion process, the brake ECU 12 calculates the deflection angle of the object wheel within the period for calculating the turning-while-advancing radius, on the basis of the steering angle of the steering wheel within the period for calculating the turning-while-advancing radius. In the second case, the brake ECU 12 calculates the deflection angle of the FL wheel 21 within the right-turning-time judgment period 30, on the basis of the steering angle of the steering wheel within the right-turning-time judgment period 30.

[0111] In the processing of step S23, the brake ECU 12 calculates the turning radius of the object wheel when the vehicle 10 is right-turning or left-turning. In the second case, the brake ECU 12 calculates the turning radius of the FL wheel 21 when the vehicle 10 is right-turning.

[0112] Figure 9 The relationship between the deflection angle of the steered wheel and the turning center when the vehicle 10 is right-turning is shown. In Figure 9 , the point O represents the turning center. In Figure 9 , L represents the length of the wheelbase of the vehicle 10.

[0113] In Figure 9 , Ro represents the turning radius of the FL wheel 21 when the vehicle 10 is right-turning. In Figure 9 , Ri represents the turning radius of the FR wheel 22 when the vehicle 10 is right-turning.

[0114] In Figure 9 ​In the present embodiment, δ0 represents the deflection angle of the FL wheel 21 when the vehicle 10 is making a right turn. In the present embodiment, δ0 is calculated by the following equation. Figure 9 In the present embodiment, δi represents the deflection angle of the FR wheel 22 when the vehicle 10 is making a right turn.

[0115] As shown in FIG. 6, the angle formed by the straight line connecting the RL wheel 23 and the RR wheel 24 and the straight line representing the turning radius of the FL wheel 21 is equal in size to the deflection angle of the FL wheel 21. Figure 9 As shown in FIG. 7, the angle formed by the straight line connecting the RL wheel 23 and the RR wheel 24 and the straight line representing the turning radius of the FR wheel 22 is equal in size to the deflection angle of the FR wheel 22. Figure 9 As shown in FIG. 7, the angle formed by the straight line connecting the RL wheel 23 and the RR wheel 24 and the straight line representing the turning radius of the FR wheel 22 is equal in size to the deflection angle of the FR wheel 22.

[0116] By the relationship as shown in FIG. 6, the following relationship holds. Figure 10

[0117] Mathematical expression 4

[0118]

[0119] In this way, the brake ECU 12 calculates the turning radius of the FL wheel 21 when the vehicle 10 is making a right turn.

[0120] In the processing of step S24, the brake ECU 12 calculates the ground speed of the target wheel when the vehicle 10 is making a right turn or a left turn. In the second example, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is making a right turn.

[0121] The brake ECU 12, in order to calculate the ground speed of the FL wheel 21 when the vehicle 10 is making a right turn, acquires the yaw rate of the vehicle 10 during the right-turn-time determination period 30 from the yaw rate sensor 15.

[0122] When the ground speed of the FL wheel 21 when the vehicle 10 is making a right turn is set as V2, and the yaw rate of the vehicle 10 during the right-turn-time determination period 30 is set as Y, the following relationship holds.

[0123] Mathematical expression 5

[0124] V2 = Ro x Y

[0125] In this way, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is making a right turn. The wear determination system 100 calculates the ground speed of the target wheel when the vehicle 10 is making a right turn or a left turn, based on the yaw rate of the vehicle 10 and the deflection angle of the target wheel acquired during the same period when the vehicle 10 is making a right turn or a left turn, and the length of the wheelbase of the vehicle 10.

[0126] ​In the processing of step S25, the brake ECU 12 calculates the angular velocity of the target wheel when the vehicle 10 is turning right or left. In the second example, the brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is turning right.

[0127] The brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is turning right, and acquires the rotational speed of the FL wheel 21 during the right-turning determination period 30 from the FL wheel speed sensor 17.

[0128] When the angular velocity of the FL wheel 21 when the vehicle 10 is turning right is set as ω2, and the rotational speed of the FL wheel 21 during the right-turning determination period 30 is set as N2, the following relation holds.

[0129] Mathematical expression 6

[0130] w2= 2π x N2

[0131] In this way, the brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is turning right.

[0132] In the processing of step S26, the brake ECU 12 calculates the turning-advance radius of the target wheel. In the second example, the brake ECU 12 calculates the turning-advance radius of the FL wheel 21 when the vehicle 10 is turning right.

[0133] When the turning-advance radius of the FL wheel 21 when the vehicle 10 is turning right is set as b2, the following relation holds.

[0134] Mathematical expression 7

[0135]

[0136] In this way, the brake ECU 12 calculates the turning-advance radius of the FL wheel 21 when the vehicle 10 is turning right. The wear determination system 100 and the information transmitting device 11 calculate the turning-advance radius based on the ground speed of the target wheel and the rotational speed of the target wheel acquired during the same period when the vehicle 10 is turning right or left.

[0137] <Communication form for the wear determination device 25 to make a determination>

[0138] Figure 10 A communication form that the wear determination device 25 performs in order to determine the wear of the shoulder portion 29 of the target wheel is shown. Figure 5 The communication of the shown form is performed after the communication of the first example. Figure 10 The communication of the shown form is performed after the communication of the first example. Figure 10The communication in the illustrated mode is performed after the processing for calculating the radius at straight-ahead travel and the radius at cornering travel is performed.

[0139] In Figure 10 , the processing performed by the brake ECU 12 is performed by the processing circuit 32. In Figure 10 , the processing performed by the wear judging device 25 is performed by the processing circuit 26.

[0140] As Figure 11 indicated in the upper paragraph, the brake ECU 12 transmits information indicating the radius at straight-ahead travel and the radius at cornering travel to the communication device 13. The communication device 13 transmits the information indicating the radius at straight-ahead travel and the radius at cornering travel received from the brake ECU 12 to the wear judging device 25. The information transmitting device 11 transmits the information indicating the radius at straight-ahead travel and the radius at cornering travel to the wear judging device 25.

[0141] Figure 7 One example of the radius at straight-ahead travel and the radius at cornering travel indicated by the information transmitted by the information transmitting device 11 to the wear judging device 25 is shown.

[0142] As Figure 11 indicated and explained, the brake ECU 12 transmits information indicating the radius at straight-ahead travel for each of the FL wheel 21 and the FR wheel 22. In Figure 11 , the radius at straight-ahead travel of the FL wheel 21 calculated by the brake ECU 12 is "bl". In Figure 8 , the radius at straight-ahead travel of the FR wheel 22 calculated by the brake ECU 12 is "cl".

[0143] As Figure 11 indicated and explained, the brake ECU 12 calculates the radius at cornering travel based on the values of the plurality of sensors during the right-turning time judging period 30 in order to judge the wear of the right shoulder portion 29 of the FL wheel 21 and the FR wheel 22. In Figure 11 , the radius at cornering travel of the FL wheel 21 calculated during the right-turning time judging period 30 is "b2". In Figure 8 , the radius at cornering travel of the FR wheel 22 calculated during the right-turning time judging period 30 is "c2".

[0144] As Figure 11 indicated and explained, the brake ECU 12 calculates the radius at cornering travel based on the values of the plurality of sensors during the left-turning time judging period 31 in order to judge the wear of the left shoulder portion 29 of the FL wheel 21 and the FR wheel 22. In Figure 11In the left turn determination period 31, the turning forward radius of the FL wheel 21 calculated is "b3". Figure 10 In FIG. 3 , the forward turning radius of the FR wheel 22 calculated within the left turn determination period 31 is “ c3 ”.

[0145] like Figure 5 As shown in the upper section of , when the brake ECU 12 calculates both the straight-line radius and the turning radius, it transmits information indicating the straight-line radius and the turning radius to the communication device 13. When the brake ECU 12 cannot calculate at least one of the straight-line radius and the turning radius, it does not transmit either the information indicating the straight-line radius or the information indicating the turning radius.

[0146] exist Figure 11 In the steering angle determination process shown in FIG. 1 , if there is no period during which the steering wheel steering angle is greater than or equal to zero degrees and less than 90 degrees within the calculation period, the brake ECU 12 cannot calculate the steering angle. Figure 8 In the "b1" and "c1". Figure 11 In the judgment period extraction process shown in FIG. 1 , if the right turn judgment period 30 cannot be extracted, the brake ECU 12 cannot calculate the Figure 8 In the "b2" and "c2". Figure 11 In the judgment period extraction process shown in FIG. 1 , if the left turn judgment period 31 cannot be extracted, the brake ECU 12 cannot calculate the left turn judgment period 31. Figure 10 "b3" and "c3" in the game.

[0147] If the brake ECU 12 successfully calculates all of "b1," "b2," "b3," "c1," "c2," and "c3," it transmits information indicating all of the calculated values ​​to the wear determination device 25. Alternatively, the brake ECU 12 may be configured such that, even if the turning radius when the vehicle 10 is turning right cannot be calculated, if the turning radius when the vehicle 10 is turning left and the straight-ahead radius are calculated, the information indicating the calculated values ​​is transmitted to the wear determination device 25. Alternatively, the brake ECU 12 may be configured such that, even if the turning radius when the vehicle 10 is turning left cannot be calculated, if the turning radius when the vehicle 10 is turning right and the straight-ahead radius are calculated, the information indicating the calculated values ​​is transmitted to the wear determination device 25.

[0148] like Figure 10As shown in the upper paragraph of the above section, the wear judging device 25 that receives the information indicating the radius when straight traveling and the radius when cornering traveling performs a wear judging process. The wear judging process refers to a process of judging the wear of the shoulder portion 29 in the subject wheel based on the radius when straight traveling and the radius when cornering traveling calculated by the information transmitting device 11.

[0149] The wear judging device 25 observes the difference between the radius when straight traveling and the radius when cornering traveling in the wear judging process. The wear judging device 25 observes the difference between "bl" and "b2" when judging the wear of the right-side shoulder portion 29 in the FL wheel 21. The wear judging device 25 observes the difference between "bl" and "b3" when judging the wear of the left-side shoulder portion 29 in the FL wheel 21. The wear judging device 25 observes the difference between "cl" and "c2" when judging the wear of the right-side shoulder portion 29 in the FR wheel 22. The wear judging device 25 observes the difference between "cl" and "c3" when judging the wear of the left-side shoulder portion 29 in the FR wheel 22.

[0150] The more worn the shoulder portion 29 is, the smaller the radius when cornering traveling becomes, so that the difference between the radius when straight traveling and the radius when cornering traveling becomes larger. As shown in the lower paragraph of the above section, the wear judging device 25 judges that the shoulder portion 29 in the subject wheel is worn when the difference between the radius when straight traveling and the radius when cornering traveling is equal to or greater than a threshold value. Figure 10

[0151] The wear judging device 25 judges that the right-side shoulder portion 29 in the FL wheel 21 is worn when the difference between "bl" and "b2" is equal to or greater than a threshold value. The wear judging device 25 judges that the right-side shoulder portion 29 in the FL wheel 21 is worn, for example, when the difference between "bl" and "b2" is greater than the size of 2% of "bl".

[0152] Thus, the wear judging system 100 calculates the radius when straight traveling that is the dynamic load radius of the subject wheel when the vehicle 10 is straight traveling. Thereafter, the wear judging system 100 judges that the shoulder portion 29 of the subject wheel is worn when the difference between the radius when cornering traveling and the radius when straight traveling is equal to or greater than a threshold value.

[0153] In the case where the radius when cornering traveling is significantly smaller than the radius when straight traveling, the shoulder portion 29 of the subject wheel is more worn than the tread portion 28 of the subject wheel. That is, in the case where the radius when cornering traveling is significantly smaller than the radius when straight traveling, uneven wear occurs on the shoulder portion 29 in the subject wheel. The wear judging system 100 can particularly effectively judge the case where uneven wear of the shoulder portion 29 in the subject wheel occurs.

[0154] ​The wear determination device 25 similarly determines wear on the other shoulder portions 29 based on the difference between the straight-line radius and the turning radius. The wear determination system 100 determines wear on the right shoulder portion 29 of the target wheel using the turning radius calculated based on the ground speed and rotational speed of the vehicle 10 when turning right. The wear determination system 100 determines wear on the left shoulder portion 29 of the target wheel using the turning radius calculated based on the ground speed and rotational speed of the vehicle 10 when turning left.

[0155] like Figure 8 As shown in the lower section of FIG, after determining the wear of the tire shoulder portion 29, the wear determination device 25 stores the turning radius received from the information transmission device 11 in the storage device 27. As the wear of the tire shoulder portion 29 of the target wheel progresses, the turning radius gradually decreases. The change in the turning radius of the target wheel is useful data for confirming the progress of wear of the tire shoulder portion 29 of the target wheel. By storing the turning radius, the wear determination device 25 can confirm the change in the turning radius of the target wheel.

[0156] <Function of this embodiment>

[0157] When the shoulder portion 29 of the target wheel wears, the target wheel's turning radius decreases. The wear determination system 100 calculates the turning radius based on the ground speed and rotational speed of the target wheel when the vehicle 10 is turning right or left. The wear determination system 100 determines the wear of the target wheel based on the turning radius.

[0158] <Effects of this embodiment>

[0159] (1) The wear determination system 100 can determine the wear of the shoulder portion 29 of the target wheel based on the radius during turning, which is the dynamic load radius of the shoulder portion 29 of the target wheel.

[0160] (2) The wear determination system 100 calculates the ground speed of the target wheel while the vehicle 10 is turning right or left based on the yaw rate of the vehicle 10 and the yaw angle of the target wheel, which are obtained within the same section in which the vehicle 10 is turning right or left, and the length of the wheelbase of the vehicle 10. Thus, the wear determination system 100 can obtain the ground speed of the target wheel while the vehicle 10 is turning right or left.

[0161] (3) The wear judging system 100 calculates the straight-ahead radius, which is the dynamic load radius of the subject wheel when the vehicle 10 is straight ahead. The wear judging system 100 judges that the shoulder portion 29 of the subject wheel is worn when the difference between the cornering-ahead radius and the straight-ahead radius is equal to or greater than a threshold value.

[0162] The more worn the shoulder portion 29 of the subject wheel is, the smaller the dynamic load radius of the vehicle 10 when the vehicle 10 is right or left turning becomes compared to the dynamic load radius of the vehicle 10 when the vehicle 10 is straight ahead. The wear judging system 100 is able to judge the wear of the shoulder portion 29 of the subject wheel by observing the difference between the straight-ahead radius and the cornering-ahead radius.

[0163] (4) The wear judging system 100 calculates the straight-ahead radius based on the ground speed of the subject wheel and the rotational speed of the subject wheel acquired in the same section when the vehicle 10 is straight ahead. Thus, the wear judging system 100 is able to calculate the dynamic load radius of the subject wheel when the vehicle 10 is straight ahead.

[0164] (5) The wear judging system 100 does not calculate the cornering-ahead radius when the deflection angle of the subject wheel is equal to or less than a predetermined angle reference value.

[0165] The shoulder portion 29 of the subject wheel comes into contact with the ground when the deflection angle of the subject wheel is greater than a certain angle. Thus, there is a possibility that the cornering-ahead radius calculated based on the ground speed of the subject wheel when the deflection angle of the subject wheel is less than the certain angle does not accurately reflect the wear condition of the shoulder portion 29 of the subject wheel.

[0166] The wear judging system 100 calculates the cornering-ahead radius based on the ground speed when the deflection angle of the subject wheel is greater than the angle reference value. Thus, the wear judging system 100 is able to more accurately judge the wear of the shoulder portion 29 of the subject wheel.

[0167] (6) The wear judging system 100 does not calculate the cornering-ahead radius when the moving speed of the vehicle 10 when the vehicle 10 is right or left turning is equal to or greater than a predetermined speed reference value.

[0168] In the case where right or left turning is performed in a state where the moving speed of the vehicle 10 is high, the vehicle 10 slips. When the vehicle 10 slips, the wear judging system 100 is unable to accurately calculate the ground speed of the wheel. The wear judging system 100 calculates the cornering-ahead radius based on the ground speed of the subject wheel when the vehicle 10 is right or left turning and the moving speed of the vehicle 10 is low. Thus, the wear judging system 100 is able to more accurately judge the wear of the shoulder portion 29 of the subject wheel.

[0169] (7) The wear judging system 100 judges the wear of the right shoulder portion 29 in the subject wheel using the turning-while-progressing radius calculated based on the ground speed and the rotational speed when the vehicle 10 is right-turning. The wear judging system 100 judges the wear of the left shoulder portion 29 in the subject wheel using the turning-while-progressing radius calculated based on the ground speed and the rotational speed when the vehicle 10 is left-turning.

[0170] The right shoulder portion 29 in the subject wheel lands when the vehicle 10 is right-turning. The left shoulder portion 29 in the subject wheel lands when the vehicle 10 is left-turning. The wear judging system 100 changes the shoulder portion 29 for which the wear is judged depending on the direction in which the vehicle 10 is progressing. Thus, the wear judging system 100 can more accurately judge the wear of the left and right shoulder portions 29 in the subject wheel.

[0171] (8) The wear judging system 100 includes the wear judging device 25 and the information transmitting device 11. The information transmitting device 11 calculates the turning-while-progressing radius based on the ground speed of the subject wheel and the rotational speed of the subject wheel acquired in the same section when the vehicle 10 is right-turning or left-turning. The information transmitting device 11 transmits the turning-while-progressing radius to the wear judging device 25. The wear judging device 25 judges the wear of the shoulder portion 29 of the subject wheel based on the turning-while-progressing radius.

[0172] In the wear judging system 100, the information transmitting device 11 calculates the turning-while-progressing radius. In the wear judging system 100, the wear judging device 25 observes the turning-while-progressing radius calculated by the information transmitting device 11. Thus, the wear judging system 100 can judge the wear of the shoulder portion 29 in the subject wheel.

[0173] (9) In the wear judging system 100, the wear judging device 25 includes the storage device 27. The wear judging device 25 stores the turning-while-progressing radius received from the information transmitting device 11 in the storage device 27.

[0174] The turning-while-progressing radius gradually becomes smaller as the wear of the shoulder portion 29 of the subject wheel progresses. The progress of the turning-while-progressing radius of the subject wheel is useful data for confirming the progress of the wear of the shoulder portion 29 of the subject wheel.

[0175] In the wear judging system 100, the wear judging device 25 stores the turning-while-progressing radius calculated for the subject wheel. According to the wear judging system 100, it is possible to confirm the progress of the turning-while-progressing radius of the subject wheel.

[0176] (10) The wear judging device 25 sets the steered wheel of the vehicle 10 as the object wheel that is the object of judgment. The wear judging device 25 judges the wear of the shoulder portion 29 of the object wheel based on the turning-while-advancing radius that is the dynamic load radius of the object wheel when the vehicle 10 is right- or left-turning. The turning-while-advancing radius is calculated based on the ground speed of the object wheel and the rotational speed of the object wheel that are acquired within the same section when the vehicle 10 is right- or left-turning.

[0177] When the object wheel wears the shoulder portion 29, the dynamic load radius of the object wheel when the vehicle 10 is right- or left-turning becomes smaller. The wear judging device 25 observes the dynamic load radius of the object wheel when the vehicle 10 is right- or left-turning. Thus, the wear judging device 25 can judge the wear of the shoulder portion 29 of the object wheel.

[0178] (11) The information transmitting device 11 can communicate with the wear judging device 25. The information transmitting device 11 calculates the turning-while-advancing radius that is the dynamic load radius of the object wheel when the vehicle 10 is right- or left-turning based on the ground speed of the object wheel and the rotational speed of the object wheel that are acquired within the same section when the vehicle 10 is right- or left-turning. The information transmitting device 11 transmits the turning-while-advancing radius to the wear judging device 25.

[0179] The information transmitting device 11 calculates the dynamic load radius of the object wheel when the vehicle 10 is right- or left-turning. Thus, the information transmitting device 11 can cause the wear judging device 25 to judge the wear of the shoulder portion 29 of the object wheel.

[0180] <Changes>

[0181] The present embodiment can be implemented in the following manner. The present embodiment and the following changes can be implemented in combination with each other within a range that does not contradict in technology.

[0182] • In the above embodiment, the wear judging system 100 sets both the FL wheel 21 and the FR wheel 22 that are the steered wheels of the vehicle 10 as the object wheels. The wear judging system 100 can set one of the steered wheels of the vehicle 10 as the object wheel.

[0183] • In the above embodiment, the vehicle 10 is provided with the yaw rate sensor 15. The brake ECU 12 acquires the yaw rate when the vehicle 10 is left- or right-turning from the yaw rate sensor 15. In the wear judging system 100, the vehicle 10 can not be provided with the yaw rate sensor 15. For example, the brake ECU 12 can acquire the yaw rate by dividing the difference between the ground speed of the RL wheel 23 and the ground speed of the RR wheel 24 by the length between the RL wheel 23 and the RR wheel 24 when the vehicle 10 is left- or right-turning.

[0184] In the above-described embodiment, the vehicle 10 is provided with the vehicle speed sensor 16. The brake ECU 12 acquires the moving speed of the vehicle 10 from the vehicle speed sensor 16. In the wear judgment system 100, the vehicle 10 can also be provided with no vehicle speed sensor 16. The brake ECU 12 can also acquire the ground speed of the wheels provided in the vehicle 10 as the moving speed of the vehicle 10. The brake ECU 12 can also acquire the moving speed of the vehicle 10 from the position information of the vehicle 10.

[0185] In the above-described embodiment, the brake ECU 12 extracts the period in which the deflection angle of the target wheel is greater than the angle reference value as the period for calculating the straight-ahead travel radius in the judgment period extraction process. Figure 5 In the above-described embodiment, the brake ECU 12 extracts the period in which the deflection angle of the target wheel is greater than the angle reference value as the period for calculating the straight-ahead travel radius in the judgment period extraction process.

[0186] In the above-described embodiment, the wear judgment system 100 judges that the vehicle 10 is straight-ahead traveling when the steering angle of the steering wheel is 0 degrees or greater and less than 90 degrees in the steering angle judgment process. Figure 10 In the above-described embodiment, the wear judgment system 100 judges that the vehicle 10 is straight-ahead traveling when the steering angle of the steering wheel is 0 degrees or greater and less than 90 degrees in the steering angle judgment process.

[0187] In the above-described embodiment, the information transmission device 11 transmits information indicating the straight-ahead travel radius and the turn travel radius when both the straight-ahead travel radius and the turn travel radius are successfully calculated, as shown in FIG. 9. Figure 5 In the above-described embodiment, the information transmission device 11 transmits information indicating the straight-ahead travel radius and the turn travel radius when both the straight-ahead travel radius and the turn travel radius are successfully calculated, as shown in FIG. 9.

[0188] In the above-described embodiment, the wear judgment device 25 judges the wear with respect to each of the right and left shoulder portions 29 of the target wheel. The wear judgment device 25 can also judge the wear with respect to the shoulder portion 29 of the target wheel without distinguishing the right side and the left side.

[0189] • The information transmission device 11 in the above-described embodiment transmits information indicating the radius at straight-ahead travel and the radius at cornering travel to the wear judging device 25 as information related to the vehicle 10. The information related to the vehicle 10 transmitted by the information transmission device 11 is not limited to the above-described embodiment. For example, the information transmission device 11 can also not transmit information indicating the difference between the radius at straight-ahead travel and the radius at cornering travel to the wear judging device 25.

[0190] • In the above-described embodiment, the wear judging device 25 judges the wear of the shoulder portion 29 after the information transmission device 11 calculates the radius at straight-ahead travel and the radius at cornering travel. In the wear judging system 100, the wear judging device 25 can also calculate the radius at straight-ahead travel and the radius at cornering travel.

[0191] In this case, the wear judging device 25 acquires values measured by the plurality of sensors of the vehicle 10 during the calculation period. The wear judging device 25 instead performs the processing performed by the brake ECU 12 in Figure 7 Figure 8 and Figure 5 .

[0192] In the case where the wear judging device 25 calculates the radius at straight-ahead travel and the radius at cornering travel, a mode can also be considered in which the brake ECU 12 performs part of the processing in Figure 7 Figure 8 and Figure 5 , and the wear judging device 25 performs the remaining processing.

[0193] For example, the brake ECU 12 can also transmit information indicating the measured values of the sensors in each of the divided periods to the wear judging device 25 after performing the steering angle judging processing in Figure 5 . For example, the brake ECU 12 can also transmit information indicating values required for calculating the radius at straight-ahead travel and the radius at cornering travel to the wear judging device 25 after performing the steering angle judging processing in Figure 8 , and the judgment period extraction processing in Figure 12 .

[0194] • In the above-described wear judging system 100, the wear judging device 25 is a server provided outside the vehicle 10. The wear judging device 25 can also be a device on board. In this case, the information transmission device 11 need not be provided with the communication device 13.

[0195] ​​• In the above embodiment, the wear judging system 100 is provided with the information transmitting device 11 that calculates the straight-ahead-time radius and the cornering-time radius, and the wear judging device 25 that judges the wear of the shoulder portion 29. In the wear judging system 100, the calculation of the straight-ahead-time radius and the cornering-time radius and the judgment of the wear of the shoulder portion 29 can also be performed by one device provided with a processing circuit.

[0196] • In the above embodiment, the wear judging system 100 judges the wear of the shoulder portion 29 by comparing the straight-ahead-time radius and the cornering-time radius. The wear judging system 100 can also not use the straight-ahead-time radius in order to judge the wear of the shoulder portion 29. The wear judging system 100 can also judge that the shoulder portion 29 has worn away when the cornering-time radius is less than a threshold value. The wear judging system 100 can also judge that the shoulder portion 29 has worn away when the difference between the cornering-time radius and a value that is prescribed in advance is equal to or greater than a threshold value. The wear judging system 100 stores the calculated cornering-time radius, and can also judge the wear of the shoulder portion 29 based on the progress of the cornering-time radius.

[0197] • In the above embodiment, the wear judging device 25 judges the wear of the shoulder portion 29 based on the difference between the straight-ahead-time radius and the cornering-time radius. The wear judging device 25 judges the wear of the shoulder portion 29 based on the proportion of the cornering-time radius with respect to the straight-ahead-time radius.

[0198] Figure 10 The form of communication that the wear judging device 25 performs in order to judge the wear of the shoulder portion 29 of the subject wheel in the wear judging system 100 of the first modification example is shown. In the first modification example, the form of communication shown in Figure 12 is performed instead of the form of communication shown in Figure 12 .

[0199] In Figure 10 , the form in which the communication device 13 transmits information to the wear judging device 25 after the brake ECU 12 transmits information indicating the straight-ahead-time radius and the cornering-time radius to the communication device 13 is the same as Figure 12 .

[0200] As shown in the upper paragraph of Figure 10 , the wear judging device 25 performs the wear judging process similarly to the upper paragraph of Figure 12 .

[0201] The wear judging device 25 observes the ratio of the turning travel radius to the straight travel radius in the wear judging process. The wear judging device 25 observes the ratio of "b2" to "bl" when judging the wear of the right shoulder portion 29 in the FL wheel 21. The wear judging device 25 observes the ratio of "b3" to "bl" when judging the wear of the left shoulder portion 29 in the FL wheel 21. The wear judging device 25 observes the ratio of "c2" to "cl" when judging the wear of the right shoulder portion 29 in the FR wheel 22. The wear judging device 25 observes the ratio of "c3" to "cl" when judging the wear of the left shoulder portion 29 in the FR wheel 22.

[0202] The more worn the shoulder portion 29, the smaller the turning travel radius becomes, so that the ratio of the turning travel radius to the straight travel radius becomes smaller. As shown in the lower segment of Figure 12 The wear judging device 25 judges that the shoulder portion 29 in the subject wheel is worn when the ratio of the turning travel radius to the straight travel radius is below the threshold value.

[0203] The wear judging device 25 judges that the right shoulder portion 29 in the FL wheel 21 is worn when the ratio of "b2" to "bl" is below the threshold value. The wear judging system 100 calculates the straight travel radius, which is the dynamic load radius of the subject wheel when the vehicle 10 is straight traveling. The wear judging system 100 judges that the shoulder portion 29 of the subject wheel is worn when the ratio of the turning travel radius to the straight travel radius is below the threshold value.

[0204] As shown in the lower segment of Figure 10 The wear judging device 25 stores the turning travel radius received from the information transmitting device 11 in the storage device 27 after judging the wear of the shoulder portion 29. This process is the same as the process performed by the wear judging device 25 in the lower segment of ​

[0205] In this case, the wear judging system 100 calculates the straight travel radius, which is the dynamic load radius of the subject wheel when the vehicle 10 is straight traveling. The wear judging system 100 judges that the shoulder portion 29 of the subject wheel is worn when the ratio of the turning travel radius to the straight travel radius is below the threshold value.

[0206] ​The more worn the shoulder portion 29 of the subject wheel is, the smaller the dynamic load radius when the vehicle 10 is turning right or left becomes compared to the dynamic load radius when the vehicle 10 is going straight. The wear judging system 100 observes the ratio of the radius when turning to the radius when going straight. Thus, the wear judging system 100 is able to judge the wear of the shoulder portion 29 of the subject wheel.

Claims

1. A wear judging system that judges wear of an object wheel that is a steering wheel provided to a vehicle, wherein the wear judging system is configured to, calculate a ground speed of the object wheel and a rotational speed of the object wheel in the same interval in which the vehicle is right-turning or left-turning, calculate a turning progress time radius that is a dynamic load radius of the object wheel when the vehicle is right-turning or left-turning, based on the ground speed and the rotational speed, and judge wear of a shoulder portion of the object wheel based on the turning progress time radius.

2. The wear judging system according to claim 1, wherein the wear judging system is configured to, calculate the ground speed of the object wheel when the vehicle is right-turning or left-turning, based on a yaw rate of the vehicle and a deflection angle of the object wheel, and a length of a wheelbase of the vehicle, which are acquired in the same interval in which the vehicle is right-turning or left-turning.

3. The wear judging system according to claim 1, wherein the wear judging system is configured to, calculate a straight progress time radius that is the dynamic load radius of the object wheel when the vehicle is straight-progressing, judge that the shoulder portion of the object wheel has been worn when a difference between the turning progress time radius and the straight progress time radius is equal to or greater than a threshold value.

4. The wear judging system according to claim 1, wherein the wear judging system is configured to, calculate a straight progress time radius that is the dynamic load radius of the object wheel when the vehicle is straight-progressing, judge that the shoulder portion of the object wheel has been worn when a ratio of the turning progress time radius with respect to the straight progress time radius is equal to or less than a threshold value.

5. The wear judging system according to claim 3 or claim 4, wherein the wear judging system is configured to, calculate the straight progress time radius based on the ground speed of the object wheel and the rotational speed of the object wheel, which are acquired in the same interval in which the vehicle is straight-progressing.

6. The wear judging system according to any one of claims 1 to 4, wherein the wear judging system is configured to, not calculate the turning progress time radius when a deflection angle of the object wheel is equal to or less than a predetermined angle reference value.

7. The wear judging system according to any one of claims 1 to 4, wherein the wear judging system is configured to, not calculate the turning progress time radius when a moving speed of the vehicle when the vehicle is right-turning or left-turning is equal to or greater than a predetermined speed reference value.

8. The wear judging system according to any one of claims 1 to 4, wherein the wear judging system is configured to, judge wear of the shoulder portion of the object wheel that is on a right side toward a traveling direction, using the turning progress time radius calculated based on the ground speed and the rotational speed when the vehicle is right-turning, and ​ ​ ​ ​ ​ ​ ​ ​ The wear of the shoulder portion of the object wheel toward the left side in the traveling direction is determined using the cornering progression radius calculated based on the ground speed of the vehicle when the vehicle is turning left and the rotational speed of the vehicle.

9. The wear determination system according to any one of claims 1 to 4, wherein the wear determination device and the information transmission device are provided, the information transmission device is configured to the ground speed of the object wheel and the rotational speed of the object wheel in the same interval when the vehicle is turning right or left are calculated, the cornering progression radius is calculated based on the ground speed and the rotational speed, the cornering progression radius is transmitted to the wear determination device, the wear determination device is configured to determine the wear of the shoulder portion of the object wheel based on the cornering progression radius.

10. The wear determination system according to claim 9, wherein the wear determination device is configured to have a storage device and store the cornering progression radius received from the information transmission device in the storage device.

11. A wear determination device that determines the wear of an object wheel that is a steering wheel provided in a vehicle, wherein the wear determination device is configured to determine the wear of the shoulder portion of the object wheel based on a cornering progression radius that is a dynamic load radius of the object wheel when the vehicle is turning right or left, the cornering progression radius is calculated based on the ground speed of the object wheel and the rotational speed of the object wheel obtained in the same interval when the vehicle is turning right or left.

12. An information transmission device configured to communicate with the wear determination device according to claim 11, wherein the information transmission device is configured to the ground speed of the object wheel and the rotational speed of the object wheel in the same interval when the vehicle is turning right or left are calculated, the cornering progression radius is calculated based on the ground speed and the rotational speed, and the cornering progression radius is transmitted to the wear determination device.

Images