Abrasion determination system, abrasion determination device and information transmission device

Abstract

To provide an abrasion determination system capable of determining abrasion of a shoulder part of a steering wheel included in a vehicle.SOLUTION: An abrasion determination system uses a steering wheel included in a vehicle as a target wheel that is a target for determination. The abrasion determination system calculates a curving radius on the basis of a ground speed when the vehicle turns left or right and a rotational speed in a section where the ground speed of the target wheel is calculated when the vehicle turns left or right (step S26). The curving radius is a dynamic load radius of the target vehicle when the vehicle turns left or right. The abrasion determination system determines abrasion of a shoulder part of the target wheel on the basis of the curving radius.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a wear determination system, a wear determination device, and an information transmission device. [Background technology]

[0002] Patent Document 1 describes a wear determination system that determines wheel wear based on the distance traveled by the wheel as the vehicle travels and the number of rotations made when the wheel travels that distance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-172280 Summary of the Invention [Problem to be solved by the invention]

[0004] A wheel has a tread portion that comes into contact with the ground when the vehicle is traveling straight, and a shoulder portion that comes into contact with the ground when the vehicle is turning right or left. The wear assessment system described in Patent Document 1 does not distinguish between the tread portion and the shoulder portion when assessing the degree of wear, and therefore cannot assess wear by focusing on the shoulder portion of the wheel. [Means for solving the problem]

[0005] A wear determination system for solving the above problem uses a steered wheel of a vehicle as a target wheel to be determined. The wear determination system calculates a turning radius based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle is turning right or left is calculated. The turning radius is the dynamic load radius of the target wheel when the vehicle is turning right or left. The wear determination system determines wear on the shoulder portion of the target wheel based on the turning radius.

[0006] The wear determination device for solving the above problem determines the wear of the shoulder portion of a vehicle's steered wheel as a target wheel. The wear determination device determines the wear of the shoulder portion of the target wheel based on a turning radius calculated based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed is calculated. The turning radius is the dynamic load radius of the target wheel when the vehicle is turning right or left.

[0007] An information transmission device for solving the above problem is capable of communicating with a wear determination device that determines the steered wheels of a vehicle as target wheels. The information transmission device calculates a turning radius based on the ground speed of the target wheels when the vehicle is turning right or left and the rotational speed of the target wheels in the section where the ground speed is calculated. The turning radius is the dynamic load radius of the target wheels when the vehicle is turning right or left. The information transmission device transmits the turning radius to the wear determination device. [Effects of the Invention]

[0008] The wear determination system, wear determination device, and information transmission device described above make it possible to determine the wear on the shoulder portion of the wheel. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing the configuration of a wear determination system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing wheels provided on a vehicle. [Figure 3] FIG. 3 is a diagram showing the state of the steering wheels of the vehicle when the vehicle is traveling straight. [Figure 4] FIG. 4 is a diagram showing the state of the steering wheels of a vehicle when the vehicle is turning right. [Figure 5] FIG. 5 is a sequence diagram showing a communication mode for determining the steering angle of a steering wheel provided in a vehicle in the wear determination system of the embodiment. [Figure 6] FIG. 6 is a graph showing an example of the transition of the steering angle of the steering wheel in response to the operation of the vehicle by the user. [Figure 7] FIG. 7 is a flowchart showing the process for the wear determination system of the embodiment to calculate the straight-ahead radius of the target wheel. [Figure 8] FIG. 8 is a flowchart showing the process for the wear determination system of the embodiment to calculate the turning radius of the target wheel. [Figure 9] FIG. 9 is a diagram showing the relationship between the steering angle of the steering wheels of a vehicle and the turning center when the vehicle turns right. [Figure 10] FIG. 10 is a sequence diagram showing a communication mode for the wear determination device to determine the wear of the shoulder portion of the target wheel in the wear determination system of the embodiment. [Figure 11] FIG. 11 is a table showing information transmitted from the information transmitting device 11 to the wear determining device 25 in the wear determining system of the embodiment. [Figure 12] FIG. 12 is a sequence diagram showing a communication mode for the wear determining device to determine the wear of the shoulder portion of the target wheel in the wear determining system of the first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a wear determination system will be described below with reference to FIGS. <Configuration of wear determination system 100> As shown in FIG. 1, the wear determination system 100 includes a vehicle 10 and a wear determination device 25.

[0011] 1, a vehicle 10 includes an information transmission device 11. The information transmission device 11 includes a brake ECU 12 and a communication device 13. The brake ECU 12 is an electronic control unit (ECU) that controls brakes provided in the vehicle 10. The brake ECU 12 generates information related to the vehicle 10 based on information from sensors provided in the vehicle 10.

[0012] The communication device 13 transmits information about the vehicle 10 generated by the brake ECU 12 to the wear determination device 25. In this way, the information transmission device 11 is communicably connected to the wear determination device 25. The information transmission device 11 then transmits information about the vehicle 10 to the wear determination device 25. The information transmitted by the information transmission device 11 will be described later.

[0013] To generate information about the vehicle 10, the brake ECU 12 obtains information from a steering angle sensor 14, a yaw rate sensor 15, a speed sensor 16, and a plurality of wheel speed sensors.

[0014] The steering angle sensor 14 measures the steering angle of the steering wheel of the vehicle 10. The steering angle sensor 14 then transmits the measured steering angle to the brake ECU 12. The yaw rate sensor 15 measures the yaw rate of the vehicle 10. Then, the yaw rate sensor 15 transmits the measured yaw rate to the brake ECU 12.

[0015] The speed sensor 16 measures the traveling speed of the vehicle 10. Specifically, the speed sensor 16 measures the traveling speed of the vehicle 10 based on the rotation speed of the crankshaft of the engine, the transmission, the motor, etc. of the vehicle 10. The speed sensor 16 then transmits the measured traveling speed of the vehicle 10 to the brake ECU 12.

[0016] As shown in FIG. 1, the vehicle 10 is provided with four wheel speed sensors: an FL wheel speed sensor 17, a FR wheel speed sensor 18, a RL wheel speed sensor 19, and a RR wheel speed sensor 20. The FL wheel speed sensor 17 measures the rotation speed of the FL wheel 21. The FL wheel 21 is a wheel located 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.

[0017] The FR wheel speed sensor 18 measures the rotation speed of the FR wheels 22. The FR wheels 22 are wheels located on the front right side of the vehicle 10. The FR wheel speed sensor 18 transmits the measured rotation speed of the FR wheels 22 to the brake ECU 12.

[0018] The RL wheel speed sensor 19 measures the rotation speed of the RL wheel 23. The RL wheel 23 is a wheel located 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.

[0019] The RR wheel speed sensor 20 measures the rotation speed of the RR wheel 24. The RR wheel 24 is a wheel located 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.

[0020] 1, the wear determination device 25 includes a storage device 27 in which a program is stored, and a processing circuit 26 that executes the program stored in the storage device 27 to perform various processes. The processing circuit 26 includes a processor. The wear determination device 25 is, for example, a server installed outside the vehicle 10.

[0021] <Outline of shoulder part 29 of the target wheel> The wear determining device 25 determines the wear of the shoulder portion 29 of the target wheel based on the information about the vehicle 10 received from the information transmitting device 11.

[0022] The target wheels are wheels that are the subject of judgment by the wear judgment device 25 and the wear judgment system 100. The wear judgment device 25 and the wear judgment system 100 judge the steered wheels of the vehicle 10. The steered wheels of the vehicle 10 are the FL wheel 21 and the FR wheel 22. Therefore, the target wheels in the wear judgment device 25 and the wear judgment system 100 are the FL wheel 21 and the FR wheel 22.

[0023] Fig. 2 shows a target wheel provided on the vehicle 10. The wheel shown in Fig. 2 is, for example, an FL wheel 21. As shown in Fig. 2, the target wheel includes a tread portion 28 and a shoulder portion 29.

[0024] When the vehicle 10 is traveling straight, the tread portion 28 of the target wheel comes into contact with the ground. Figure 3 shows the state of the target wheel when the vehicle 10 is traveling straight. For example, the wheel shown in Figure 3 is the FL wheel 21.

[0025] When the vehicle 10 is turning right, the target wheel tilts relative to the ground depending on the turning angle of the target wheel, and the part of the target wheel that comes into contact with the ground changes. Specifically, when the turning angle of the target wheel is small, the part between the tread portion 28 and the shoulder portion 29 on the right side of the target wheel in the direction of travel comes into contact with the ground. When the turning angle of the target wheel is large, the shoulder portion 29 on the right side of the target wheel in the direction of travel comes into contact with the ground.

[0026] Fig. 4 shows the state of the target wheel when the vehicle 10 is turning right with a large turning angle of the target wheel. For example, the wheel shown in Fig. 4 is the FL wheel 21. When the vehicle 10 is turning right and the turning angle of the target wheel is large, the target wheel tilts to the right with respect to the ground, as shown in Fig. 4, and the right shoulder portion 29 of the target wheel in the traveling direction is in contact with the ground.

[0027] When the vehicle 10 is turning left, the contact point between the target wheel and the ground changes depending on the turning angle of the target wheel, just as when the vehicle 10 is turning right. That is, when the turning angle of the target wheel is small, the contact point between the tread 28 and the shoulder 29 on the left side of the target wheel in the direction of travel comes into contact with the ground. When the turning angle of the target wheel is large, the contact point between the shoulder 29 on the left side of the target wheel in the direction of travel comes into contact with the ground.

[0028] The arrow a1 in Fig. 3 indicates the straight-ahead radius, which is the dynamic load radius of the target wheel when the vehicle 10 is traveling straight. On the other hand, the arrow a2 in Fig. 4 indicates the turning radius, which is the dynamic load radius of the target wheel when the vehicle 10 is turning right or left.

[0029] The more the shoulder portion 29 of the target wheel wears, the smaller the turning radius becomes. In the wear determination system 100, the wear determination device 25 determines the wear of the shoulder portion 29 of the target wheel based on the turning radius.

[0030] <Communication mode for calculating straight and curved radius> In the wear determination system 100, the information transmission device 11 transmits the straight radius and the turning radius as information about the vehicle 10. As described above, the brake ECU 12 generates information about the vehicle 10. The brake ECU 12 generates information about the vehicle 10 by calculating the straight radius and the turning radius based on information from sensors provided in the vehicle 10.

[0031] 5 shows a mode of communication executed in the wear determination system 100 so that the brake ECU 12 in the information transmission device 11 can calculate the straight and cornering radii. The brake ECU 12 calculates the straight and cornering radii based on values ​​measured by sensors provided in the vehicle 10 during a calculation period. The calculation period is a specific period during which the vehicle 10 is traveling.

[0032] 5, the steering angle sensor 14 transmits the steering angle of the steering wheel operated by the user of the vehicle 10 to the brake ECU 12. At this time, the steering angle sensor 14 transmits the transition of the steering angle of the steering wheel during the calculation period to the brake ECU 12. Hereinafter, in the drawings, the value of the steering angle transmitted by the steering angle sensor 14 is represented as δ.

[0033] 5, the brake ECU 12 receives the steering angle from the steering angle sensor 14 and executes a steering angle determination process. The steering angle determination process is a process for dividing a calculation period based on the steering angle received from the steering angle sensor 14.

[0034] FIG. 6 shows the transition of the steering angle of the steering wheel received by the brake ECU 12 from the steering angle sensor 14 within the calculation period. In the graph of Fig. 6, the vertical axis represents the steering angle of the steering wheel measured by the steering angle sensor 14. In addition, in the graph of Fig. 6, the horizontal axis represents time.

[0035] In the graph of Figure 6, in the section where the steering angle value is zero, the steering wheel is not turned to either the left or the right. In the graph of Figure 6, in the section where the steering angle value is above the horizontal axis, the steering wheel is turned to the right. On the other hand, in the graph of Figure 6, in the section where the steering angle value is below the horizontal axis, the steering wheel is turned to the left.

[0036] The brake ECU 12 divides the calculation period into periods "X" and "Y" shown in FIG. 6 by the steering angle determination process. The period "X" shown in Fig. 6 is the period when the steering angle is equal to or greater than 0 degrees and less than 90 degrees. The period "Y" shown in Fig. 6 is the period when the steering angle is equal to or greater than 90 degrees.

[0037] As shown in FIG. 5, after executing the steering angle determination process, the brake ECU 12 executes different processes depending on the divided period. As shown in Fig. 5, the brake ECU 12 calculates the straight-driving radius based on information measured by a sensor provided in the vehicle 10 during a period when the steering angle is equal to or greater than zero degrees and less than 90 degrees. In other words, the brake ECU 12 calculates the straight-driving radius based on information measured by the sensor during the period "X" in Fig. 6. In this way, in this embodiment, the wear determination system 100 determines that the vehicle 10 is traveling straight when the steering angle is equal to or greater than zero degrees and less than 90 degrees.

[0038] As shown in Fig. 5, the brake ECU 12 calculates the turning radius based on information measured by a sensor provided in the vehicle 10 during a period when the steering angle of the steering wheel is 90 degrees or more. In other words, the brake ECU 12 calculates the turning radius based on information measured by a sensor provided in the vehicle 10 during the period "Y" in Fig. 6. In this way, in this embodiment, the wear determination system 100 determines that the vehicle 10 is turning right or left when the steering angle of the steering wheel is 90 degrees or more.

[0039] <Processing executed to calculate straight-line radius> Fig. 7 shows a series of processing steps executed by the brake ECU 12 to calculate the straight-ahead radius. After executing the steering angle determination processing shown in Fig. 5, the brake ECU 12 executes the series of processing steps shown in Fig. 7 based on information measured by a sensor provided in the vehicle 10 during the period "X" in Fig. 6.

[0040] As described above, the target wheels in the wear determination system 100 are the FL wheel 21 and the FR wheel 22. The brake ECU 12 executes a series of processes shown in Fig. 7 for each of the FL wheel 21 and the FR wheel 22. Below, with reference to Fig. 7, a first example will be described, which is an example of calculating the straight-ahead radius of the FL wheel 21.

[0041] In the process of step S10, the brake ECU 12 calculates the ground speed of the target wheel when the vehicle 10 is traveling straight. In the first example, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is traveling straight.

[0042] The brake ECU 12 stores the radii of the wheels of the vehicle 10 that are not the target wheels in order to calculate the ground speed of the FL wheels 21 when the vehicle 10 is traveling straight. In this embodiment, the brake ECU 12 stores the average of the radii of the RL wheels 23 and the RR wheels 24.

[0043] Furthermore, in order to calculate the ground speed of the FL wheels 21 when the vehicle 10 is traveling straight, the brake ECU 12 acquires the rotational speeds of the wheels of the vehicle 10 that are not the target wheels during the period "X" in Fig. 6. In this embodiment, the brake ECU 12 acquires the average of the rotational speeds of the RL wheels 23 and the RR wheels 24 during the period "X" in Fig. 6. At this time, the brake ECU 12 acquires the rotational speed of the RL wheels 23 during the period "X" in Fig. 6 from the RL wheel speed sensor 19. Furthermore, the brake ECU 12 acquires the rotational speed of the RR wheels 24 during the period "X" in Fig. 6 from the RR wheel speed sensor 20.

[0044] The ground speed of the target wheel when the vehicle 10 is traveling straight is the same as the ground speed of the other wheels of the vehicle 10. Therefore, if the ground speed of the FL wheel 21 when the vehicle 10 is traveling straight is V1, the average radius of the RL wheel 23 and the RR wheel 24 is r, and the average rotational speed of the RL wheel 23 and the RR wheel 24 during the period "X" in Figure 6 is N, the following relationship holds:

[0045]

number

[0046] In this way, the brake ECU 12 calculates the ground speed of the FL wheels 21 when the vehicle 10 is traveling straight. In the process of step S11, the brake ECU 12 calculates the angular velocity of the target wheel when the vehicle 10 is traveling straight. In the first example, the brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is traveling straight.

[0047] The brake ECU 12 acquires the rotational speed of the FL wheels 21 from the FL wheel speed sensor 17 during the period "X" in FIG. 6 in order to calculate the angular speed of the FL wheels 21 when the vehicle 10 is traveling straight.

[0048] If the angular velocity of the FL wheels 21 when the vehicle 10 is traveling straight is ω1 and the rotational speed of the FL wheels 21 in the period "X" in FIG. 6 is N1, the following relationship holds.

[0049]

number

[0050] In this way, the brake ECU 12 calculates the angular velocity of the target wheel when the vehicle 10 is traveling straight. In the process of step S12, the brake ECU 12 calculates the radius of the target wheel when it is traveling straight. In the first example, the brake ECU 12 calculates the radius of the FL wheel 21 when it is traveling straight.

[0051] If the radius of the FL wheel 21 when traveling straight is b1, the following relationship holds:

[0052]

number

[0053] In this way, the brake ECU 12 calculates the radius of the FL wheels 21 when traveling straight. In this way, the wear determination system 100 calculates the straight-ahead radius based on the ground speed of the target wheel when the vehicle 10 is traveling straight and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle 10 is traveling straight is calculated.

[0054] <Outline of the judgment period extraction process> Fig. 8 shows a flow of a series of processes executed by the brake ECU 12 to calculate the turning radius. After executing the steering angle determination process shown in Fig. 5, the brake ECU 12 executes the series of processes shown in Fig. 8 based on information measured by a sensor provided in the vehicle 10 during the period "Y" in Fig. 6.

[0055] The brake ECU 12 calculates a turning radius for determining wear for each of the right shoulder portion 29 and the left shoulder portion 29 of the FL wheel 21, as viewed in the direction of travel. The brake ECU 12 also calculates a turning radius for determining wear for each of the right shoulder portion 29 and the left shoulder portion 29 of the FR wheel 22, as viewed in the direction of travel. The brake ECU 12 executes the series of processes shown in FIG. 8 for each shoulder portion 29 of the target wheel.

[0056] In the process of step S20, the brake ECU 12 executes a determination period extraction process, which is a process for extracting a period during which the brake ECU 12 calculates the turning radius during the period "Y" in FIG.

[0057] The brake ECU 12 extracts a period in which the three conditions are satisfied as a period for calculating the turning radius. The first condition is that the turning angle of the target wheel is large. As 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 turning radius. As explained with reference to FIGS. 2 to 4, the shoulder portion 29 of the target wheel comes into contact with the ground when the turning angle of the target wheel is large. A turning radius calculated based on the ground speed of the target wheel when the turning angle of the target wheel is small may not accurately reflect the degree of wear on the shoulder portion 29 of the target wheel.

[0058] The brake ECU 12 extracts a period during which the turning angle of the FL wheel 21 is greater than a predetermined angle reference value as a period for calculating the turning radius. In this embodiment, the angle reference value is the turning angle of the target wheel when the steering angle of the steering wheel of the vehicle 10 is 180 degrees. Note that the possible values ​​of the angle reference value are not limited to those in the above embodiment.

[0059] The turning angle of the target wheel relative to the steering angle of the steering wheel differs between the FL wheels 21 and the FR wheels 22. The turning angle of the target wheel relative to the steering angle also differs depending on whether the steering wheel is turned to the left or right. Therefore, the angle reference value in this embodiment differs depending on the direction the steering wheel is turned and the target wheel.

[0060] The turning angle of the target wheel increases according to the steering angle of the steering wheel of the vehicle 10. The brake ECU 12 extracts the period during which the steering angle of the steering wheel is greater than 180 degrees, thereby extracting the period during which the steering angle is greater than the angle reference value. In this way, the wear determination system 100 does not calculate the turning radius when the turning angle of the target wheel when the vehicle 10 is turning right or left is equal to or less than the angle reference value, which is a predetermined value.

[0061] The second condition is that the turning angle of the target wheel must be constant. As will be described later, the brake ECU 12 calculates the turning radius using the turning angle of the target wheel. However, when the turning angle of the target wheel is changing, the brake ECU 12 cannot accurately calculate the turning radius.

[0062] The third condition is that the moving speed of the vehicle 10 is slow. If the vehicle 10 turns right or left while moving at a fast speed, the vehicle 10 will slip. If the vehicle 10 slips, the ground speed of the target wheel cannot be calculated accurately.

[0063] The brake ECU 12 extracts, as a period for calculating the turning radius, a period during which the moving speed of the vehicle 10 when the vehicle 10 is turning right or left is lower than a predetermined speed reference value.

[0064] In this embodiment, the speed reference value is 15 km / h. Based on the moving speed of the vehicle 10 received from the speed sensor 16, the brake ECU 12 extracts a period during which the moving speed is lower than the speed reference value. In this manner, the wear determination system 100 does not calculate the turning radius when the moving speed of the vehicle 10 while turning right or left is equal to or greater than the speed reference value, which is a predetermined value. Note that the possible values ​​of the speed reference value are not limited to those in the above embodiment.

[0065] In FIG. 6, the portion surrounded by the dashed line is a period extracted by the brake ECU 12 as a period for calculating the turning radius. As explained with reference to Figures 2 to 4, when vehicle 10 is turning right, if the turning angle of the target wheel is large, the shoulder portion 29 on the right side of the target wheel as viewed in the direction of travel will come into contact with the ground. In wear determination system 100, wear on shoulder portion 29 on the right side of the target wheel as viewed in the direction of travel can be determined by calculating the turning radius when vehicle 10 is turning right. Of the portion enclosed by the dashed dotted line in Figure 6, right turn determination period 30 is a period for calculating the turning radius when vehicle 10 is turning right.

[0066] As explained with reference to Figures 2 to 4, when vehicle 10 is turning left, if the turning angle of the target wheel is large, shoulder portion 29 on the left side of the target wheel as viewed in the direction of travel will come into contact with the ground. In wear determination system 100, wear on shoulder portion 29 on the left side of the target wheel as viewed in the direction of travel can be determined by calculating the turning radius when vehicle 10 is turning left. Of the portion enclosed by the dashed dotted line in Figure 6, left turn determination period 31 is a period for calculating the turning radius when vehicle 10 is turning left.

[0067] In step S21, the brake ECU 12 determines whether or not the extraction of the period for calculating the turning radius has been successful in the determination period extraction process in step S20. If there is no period that satisfies the above three conditions within the calculation period, the brake ECU 12 cannot extract a period for calculating the turning radius. If the brake ECU 12 does not extract a period for calculating the turning radius in the determination period extraction process, the brake ECU 12 determines that the extraction of the period was unsuccessful.

[0068] 8 to determine wear on the shoulder portion 29 on the right side of the target wheel in the traveling direction, the brake ECU 12 determines that the extraction of the period was unsuccessful if the right-turn determination period 30 was not extracted. On the other hand, when the brake ECU 12 executes the process of FIG. 8 to determine wear on the shoulder portion 29 on the left side of the target wheel in the traveling direction, the brake ECU 12 determines that the extraction of the period was unsuccessful if the left-turn determination period 31 was not extracted.

[0069] If the brake ECU 12 determines that the extraction of the period has not been successful (step S21: NO), the brake ECU 12 ends the series of processes shown in FIG. On the other hand, if the brake ECU 12 extracts a period for calculating the turning radius in the determination period extraction process, the brake ECU 12 determines that the extraction of the period is successful. If the brake ECU 12 determines that the extraction of the period is successful (step S21: YES), the process proceeds to the next step S22.

[0070] In the processing from step S22 onwards, the brake ECU 12 calculates the turning radii of the FL wheels 21 and the FR wheels 22 when the vehicle 10 is turning right, based on the sensor information during the right turn determination period 30. On the other hand, in the processing from step S22 onwards, the brake ECU 12 calculates the turning radii of the FL wheels 21 and the FR wheels 22 when the vehicle 10 is turning left, based on the sensor information during the left turn determination period 31.

[0071] <Processing executed to calculate turning radius> Below, with reference to Figures 8 and 9, we will explain the second case in which the turning radius of the FL wheel 21, one of the target wheels equipped on the vehicle 10, is calculated when the vehicle 10 is turning right.

[0072] In the process of step S22, the brake ECU 12 executes a steering angle conversion process. The turning angle of the target wheel corresponding to the steering angle of the steering wheel of the vehicle 10 is determined in advance. The brake ECU 12 stores the turning angle of the steered wheel corresponding to the steering angle of the steering wheel of the vehicle 10. In the steering angle conversion process, the brake ECU 12 calculates the turning angle of the target wheel during the period for calculating the turning radius based on the steering angle of the steering wheel during the period for calculating the turning radius. In the second example, the brake ECU 12 calculates the turning angle of the FL wheel 21 during the right turn determination period 30 based on the steering angle of the steering wheel during the right turn determination period 30.

[0073] In the process of step S23, the brake ECU 12 calculates the turning radius of the target wheel when the vehicle 10 is turning right or left. In the second example, the brake ECU 12 calculates the turning radius of the FL wheel 21 when the vehicle 10 is turning right.

[0074] Fig. 9 shows the relationship between the steering angle of the steering wheels and the turning center when the vehicle 10 is turning right. In Fig. 9, point O indicates the turning center. Also in Fig. 9, L indicates the length of the wheelbase of the vehicle 10.

[0075] 9, Ro indicates the turning radius of the FL wheels 21 when the vehicle 10 is turning right. Also, in FIG. 9, Ri indicates the turning radius of the FR wheels 22 when the vehicle 10 is turning right.

[0076] In Fig. 9, δo indicates the turning angle of the FL wheels 21 when the vehicle 10 is turning right. Also in Fig. 9, δi indicates the turning angle of the FR wheels 22 when the vehicle 10 is turning right.

[0077] 9, the angle formed by the line connecting the RL wheel 23 and the RR wheel 24 and the line showing the turning radius of the FL wheel 21 is equal to the turning angle of the FL wheel 21. Also, as shown in FIG. 9, the angle formed by the line connecting the RL wheel 23 and the RR wheel 24 and the line showing the turning radius of the FR wheel 22 is equal to the turning angle of the FR wheel 22.

[0078] Based on the relationship shown in FIG. 9, the following relationship holds:

[0079]

number

[0080] In this way, the brake ECU 12 calculates the turning radius of the FL wheels 21 when the vehicle 10 is turning right. In the process of step S24, the brake ECU 12 calculates the ground speed of the target wheel when the vehicle 10 is turning right or left. In the second case, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is turning right.

[0081] The brake ECU 12 acquires the yaw rate of the vehicle 10 during the right turn determination period 30 from the yaw rate sensor 15 in order to calculate the ground speed of the FL wheels 21 when the vehicle 10 is turning right.

[0082] If the ground speed of the FL wheels 21 when the vehicle 10 is turning right is V2 and the yaw rate of the vehicle 10 during the right turn determination period 30 is Y, the following relationship holds:

[0083]

number

[0084] In this way, the brake ECU 12 calculates the ground speed of the FL wheel 21 when the vehicle 10 is turning right. In this way, the wear determination system 100 calculates the ground speed of the target wheel when the vehicle 10 is turning right or left, based on the yaw rate of the vehicle 10 when the vehicle 10 is turning right or left, the turning angle of the target wheel in the section where the yaw rate is measured, and the length of the wheelbase of the vehicle 10.

[0085] In the process 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 case, the brake ECU 12 calculates the angular velocity of the FL wheel 21 when the vehicle 10 is turning right.

[0086] The brake ECU 12 acquires the rotational speed of the FL wheels 21 during the right turn determination period 30 from the FL wheel speed sensor 17 in order to calculate the angular speed of the FL wheels 21 when the vehicle 10 is turning right.

[0087] If the angular velocity of the FL wheel 21 when the vehicle 10 is turning right is ω2 and the rotational speed of the FL wheel 21 during the right turn determination period 30 is N2, the following relationship holds.

[0088]

number

[0089] In this way, the brake ECU 12 calculates the angular velocity of the FL wheels 21 when the vehicle 10 is turning right. In the process of step S26, the brake ECU 12 calculates the turning radius of the target wheel. In the second example, the brake ECU 12 calculates the turning radius of the FL wheel 21 when the vehicle 10 is turning right.

[0090] When the vehicle 10 is turning right, the turning radius of the FL wheels 21 is set to b2, and the following relationship holds:

[0091]

number

[0092] In this way, the brake ECU 12 calculates the turning radius of the FL wheel 21 when the vehicle 10 is turning right. In this way, the wear determination system 100 and the information transmission device 11 calculate the turning radius based on the ground speed of the target wheel when the vehicle 10 is turning right or left and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle 10 is turning right or left is calculated.

[0093] <Communication Mode for Determination by Wear Determining Device 25> Fig. 10 shows the manner of communication executed by the wear determination device 25 in the wear determination system 100 to determine the wear of the shoulder portion 29 of the target wheel. The manner of communication shown in Fig. 10 is executed after the communication shown in Fig. 5 is performed. In other words, the manner of communication shown in Fig. 10 is executed after the processing for calculating the straight-ahead radius and the turning radius is performed.

[0094] 10, the brake ECU 12 transmits the calculated straight driving radius and cornering radius to the communication device 13. Then, the communication device 13 transmits the straight driving radius and cornering radius received from the brake ECU 12 to the wear determination device 25. In this way, the information transmission device 11 transmits the straight driving radius and cornering radius to the wear determination device 25.

[0095] FIG. 11 shows the straight and curved radii transmitted by the information transmitting device 11 to the wear determining device 25. As explained with reference to Fig. 7, the brake ECU 12 transmits the straight-ahead radius for each of the FL wheel 21 and the FR wheel 22. In Fig. 11, the straight-ahead radius of the FL wheel 21 calculated by the brake ECU 12 is "b1." In Fig. 11, the straight-ahead radius of the FR wheel 22 calculated by the brake ECU 12 is "c1."

[0096] As explained with reference to Fig. 8, the brake ECU 12 calculates the turning radius based on the sensor values ​​during the right turn determination period 30 in order to determine wear on the shoulder portion 29 on the right side (in the direction of travel) of the FL wheel 21 and the FR wheel 22. In Fig. 11, the turning radius of the FL wheel 21 calculated based on the sensor values ​​during the right turn determination period 30 is "b2." On the other hand, in Fig. 11, the turning radius of the FR wheel 22 calculated based on the sensor values ​​during the right turn determination period 30 is "c2."

[0097] As explained with reference to Fig. 8, the brake ECU 12 calculates the turning radius based on the sensor values ​​during the left turn determination period 31 in order to determine wear on the shoulder portion 29 on the left side (in the direction of travel) of the FL wheel 21 and the FR wheel 22. In Fig. 11, the turning radius of the FL wheel 21 calculated based on the sensor values ​​during the left turn determination period 31 is "b3." On the other hand, in Fig. 11, the turning radius of the FR wheel 22 calculated based on the sensor values ​​during the left turn determination period 31 is "c3."

[0098] 10, when the brake ECU 12 calculates both the straight radius and the turning radius, it transmits the calculated straight radius and turning radius to the communication device 13. In other words, when the brake ECU 12 does not calculate either or both of the straight radius and the turning radius, it does not transmit either the straight radius or the turning radius.

[0099] In the steering angle determination process shown in Fig. 5, if there is no period within the calculation period during which the steering angle of the steering wheel is equal to or greater than 0 degrees and less than 90 degrees, the brake ECU 12 cannot calculate "b1" and "c1" in Fig. 11. Furthermore, if the right-turn determination period 30 is not extracted in the determination period extraction process shown in Fig. 8, the brake ECU 12 cannot calculate "b2" and "c2" in Fig. 11. Furthermore, if the left-turn determination period 31 is not extracted in the determination period extraction process shown in Fig. 8, the brake ECU 12 cannot calculate "b3" and "c3" in Fig. 11.

[0100] 11 based on the sensor information within the calculation period, the brake ECU 12 transmits all of the calculated values ​​to the wear determination device 25. Note that the brake ECU 12 may be configured to transmit the calculated values ​​to the wear determination device 25 even if it is unable to calculate the turning radius when the vehicle 10 is turning right, if it is able to calculate the turning radius when the vehicle 10 is turning left and the straight-driving radius. Also, the brake ECU 12 may be configured to transmit the calculated values ​​to the wear determination device 25 even if it is unable to calculate the turning radius when the vehicle 10 is turning left, if it is able to calculate the turning radius when the vehicle 10 is turning right and the straight-driving radius.

[0101] 10, the wear determination device 25, which has received the straight-line radius and the turning radius, executes a wear determination process. The wear determination process is a process for determining the wear of the shoulder portion 29 of the target wheel based on the straight-line radius and the turning radius calculated by the information transmission device 11.

[0102] In the wear determination process, the wear determination device 25 observes the difference between the straight radius and the turning radius. When determining wear on the shoulder portion 29 on the right side of the FL wheel 21 as viewed in the direction of travel, the wear determination device 25 observes the difference between "b1" and "b2" in FIG. 11. When determining wear on the shoulder portion 29 on the left side of the FL wheel 21 as viewed in the direction of travel, the wear determination device 25 observes the difference between "b1" and "b3" in FIG. 11. When determining wear on the shoulder portion 29 on the right side of the FR wheel 22 as viewed in the direction of travel, the wear determination device 25 observes the difference between "c1" and "c2" in FIG. 11. When determining wear on the shoulder portion 29 on the left side of the FR wheel 22 as viewed in the direction of travel, the wear determination device 25 observes the difference between "c1" and "c3" in FIG. 11.

[0103] As the shoulder portion 29 wears, the turning radius becomes smaller than the straight driving radius. As shown in the lower part of Figure 10, the wear determination device 25 determines that the shoulder portion 29 of the target wheel is worn when the difference between the straight driving radius and the turning radius is equal to or greater than a threshold value.

[0104] Specifically, the wear determination device 25 determines that the shoulder portion 29 on the right side of the FL wheel 21 in the traveling direction is worn when the difference between "b1" and "b2" in Fig. 11 is equal to or greater than a threshold value. The wear determination device 25 determines that the shoulder portion 29 on the right side of the FL wheel 21 in the traveling direction is worn when, for example, the difference between "b1" and "b2" is greater than 2% of "b1".

[0105] In this way, the wear determination system 100 calculates the straight radius, which is the dynamic load radius of the target wheel when the vehicle 10 is traveling straight. Thereafter, the wear determination system 100 determines that the shoulder portion 29 of the target wheel is worn when the difference between the turning radius and the straight radius is equal to or greater than a threshold value.

[0106] If the turning radius is significantly smaller than the straight-ahead radius, this means that the shoulder portion 29 of the target wheel is more worn than the tread portion 28 of the target wheel, that is, uneven wear has occurred in the shoulder portion 29 of the target wheel. The wear determination system 100 can particularly effectively determine that uneven wear has occurred in the shoulder portion 29 of the target wheel.

[0107] The wear determination device 25 similarly determines the wear of the other shoulder portions 29 based on the difference between the straight-ahead radius and the turning radius. That is, the wear determination system 100 determines the wear of the right shoulder portion 29 of the target wheel in the traveling direction using the turning radius calculated based on the ground speed and rotational speed when the vehicle 10 is turning right. Then, the wear determination system 100 determines the wear of the left shoulder portion 29 of the target wheel in the traveling direction using the turning radius calculated based on the ground speed and rotational speed when the vehicle 10 is turning left.

[0108] As shown in the lower part of Figure 10, after determining the wear of the 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 shoulder portion 29 of the target wheel wears, the turning radius gradually becomes smaller. In other words, the change in the turning radius of the target wheel is useful data for checking the progress of wear of the shoulder portion 29 of the target wheel. By storing the turning radius in the wear determination device 25, it becomes possible to check the change in the turning radius of the target wheel.

[0109] <Operation of this embodiment> When the shoulder portion 29 of the target wheel wears, the turning radius, which is the dynamic load radius of the target wheel when the vehicle 10 is turning right or left, becomes smaller. 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 calculated turning radius.

[0110] <Effects of this embodiment> (1) The wear determination system 100 can determine the wear of the shoulder portion 29 of the target wheel based on the turning radius, which is the dynamic load radius of the shoulder portion 29 of the target wheel.

[0111] (2) The wear determination system 100 calculates the ground speed of the target wheel when the vehicle 10 is turning right or left, based on the yaw rate of the vehicle 10 when the vehicle 10 is turning right or left, the turning angle of the target wheel in the section where the yaw rate is measured, and the length of the wheelbase of the vehicle 10. In this way, the wear determination system 100 can obtain the value of the ground speed of the target wheel when the vehicle 10 is turning right or left.

[0112] (3) The wear determination system 100 calculates the straight radius, which is the dynamic load radius of the target wheel when the vehicle 10 is traveling straight. Then, the wear determination system 100 determines that the shoulder portion 29 of the target wheel is worn when the difference between the turning radius and the straight radius is equal to or greater than a threshold value.

[0113] The more worn the shoulder portion 29 of the target 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 traveling straight. The wear determination system 100 observes the difference between the radius when traveling straight and the radius when traveling curves. This allows the wear determination system 100 to determine the wear of the shoulder portion 29 of the target wheel.

[0114] (4) The wear determination system 100 calculates the straight-travel radius based on the ground speed of the target wheel when the vehicle 10 is traveling straight and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle 10 is traveling straight is calculated. This allows the wear determination system 100 to calculate the dynamic load radius of the target wheel when the vehicle 10 is traveling straight.

[0115] (5) The wear determination system 100 does not calculate the turning radius when the turning angle of the target wheel when the vehicle 10 is turning right or left is equal to or less than a predetermined reference angle value.

[0116] The shoulder 29 of the target wheel comes into contact with the ground when the turning angle of the target wheel is large. Therefore, the turning radius calculated based on the ground speed of the target wheel when the turning angle of the target wheel is small may not accurately reflect the degree of wear on the shoulder 29 of the target wheel.

[0117] The wear determination system 100 calculates the turning radius based on the ground speed when the turning angle of the target wheel is large, thereby enabling the wear determination system 100 to more precisely determine the wear of the shoulder portion 29 of the target wheel.

[0118] (6) The wear determination system 100 does not calculate the turning radius when the traveling speed of the vehicle 10 while turning right or left is equal to or greater than a predetermined speed reference value.

[0119] When the vehicle 10 turns right or left while traveling at a high speed, the vehicle 10 slips. When the vehicle 10 slips, the ground speed of the wheel cannot be accurately calculated. The wear determination system 100 calculates the turning radius based on the ground speed of the target wheel when the vehicle 10 is turning right or left and traveling at a low speed. This allows the wear determination system 100 to more precisely determine the wear of the shoulder portion 29 of the target wheel.

[0120] (7) The wear determination system 100 determines the wear of the shoulder portion 29 on the right side of the target wheel in the traveling direction, using the turning radius calculated based on the ground speed and rotational speed when the vehicle 10 is turning right. The wear determination system 100 determines the wear of the shoulder portion 29 on the left side of the target wheel in the traveling direction, using the turning radius calculated based on the ground speed and rotational speed when the vehicle 10 is turning left.

[0121] When the vehicle 10 is turning right, the shoulder portion 29 on the right side of the target wheel in the traveling direction comes into contact with the ground. When the vehicle 10 is turning left, the shoulder portion 29 on the left side of the target wheel in the traveling direction comes into contact with the ground. The wear determination system 100 changes the shoulder portion 29 for which wear is determined as described above depending on the traveling direction of the vehicle 10 when the ground speed and rotational speed are acquired. This allows the wear determination system 100 to more precisely determine wear on the shoulder portion 29 of the target wheel by distinguishing between the left and right sides.

[0122] (8) The wear determination system 100 includes a wear determination device 25 and an information transmission device 11. The information transmission device 11 calculates a turning radius based on the ground speed of the target wheel when the vehicle 10 is turning right or left and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle 10 is turning right or left is calculated. The information transmission device 11 transmits the turning radius to the wear determination device 25. The wear determination device 25 determines the wear of the shoulder portion 29 of the target wheel based on the turning radius.

[0123] In the wear determination system 100, the information transmission device 11 calculates the turning radius. In the wear determination system 100, the wear determination device 25 observes the turning radius calculated by the information transmission device 11. This allows the wear determination system 100 to determine the wear of the shoulder portion 29 of the target wheel.

[0124] (9) In the wear determination system 100, the wear determination device 25 includes a storage device 27. The wear determination device 25 stores the turning radius received from the information transmission device 11 in the storage device 27.

[0125] As the shoulder portion 29 of the target wheel wears, the turning radius gradually decreases. In other words, the change in the turning radius of the target wheel is useful data for checking the change in the wear progress of the shoulder portion 29 of the target wheel.

[0126] In the wear determination system 100, the wear determination device 25 stores the calculated turning radius for the target wheel. The wear determination system 100 described above makes it possible to check the transition of the turning radius for the target wheel.

[0127] (10) The wear determination device 25 determines the steered wheels of the vehicle 10 as the target wheels to be determined. The wear determination device 25 determines the wear of the shoulder portion 29 of the target wheel based on the turning radius, which is the dynamic load radius of the target wheel when the vehicle 10 is turning right or left. The turning radius is calculated based on the ground speed of the target wheel when the vehicle 10 is turning right or left and the rotational speed of the target wheel in the section where the ground speed is calculated.

[0128] When the shoulder portion 29 of the target wheel wears, the dynamic load radius of the target wheel becomes smaller when the vehicle 10 is turning right or left. The wear determination device 25 observes the dynamic load radius of the target wheel when the vehicle 10 is turning right or left. This allows the wear determination device 25 to determine the wear of the shoulder portion 29 of the target wheel.

[0129] (11) The information transmission device 11 is capable of communicating with a wear determination device 25 that determines the steered wheels of the vehicle 10 as target wheels. The information transmission device 11 calculates the turning radius, which is the dynamic load radius of the target wheel when the vehicle 10 is turning right or left, based on the ground speed of the target wheel when the vehicle 10 is turning right or left and the rotational speed of the target wheel in the section where the ground speed is calculated. The information transmission device 11 transmits the turning radius to the wear determination device 25.

[0130] The information transmitting device 11 calculates the dynamic load radius of the target wheel when the vehicle 10 is turning right or left. This enables the information transmitting device 11 to cause the wear determining device 25 to determine the wear of the shoulder portion 29 of the target wheel.

[0131] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0132] In the above embodiment, the wear determination system 100 targets the FL wheels 21 and FR wheels 22, which are the steered wheels of the vehicle 10. However, the wear determination system 100 may target either one of the steered wheels of the vehicle 10.

[0133] In the above embodiment, the vehicle 10 is equipped with a yaw rate sensor 15. The brake ECU 12 obtains the yaw rate when the vehicle 10 is turning left or right from the yaw rate sensor 15. On the other hand, in the wear determination system 100, the vehicle 10 does not need to be equipped with the yaw rate sensor 15. In this case, for example, the brake ECU 12 obtains 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 when the vehicle 10 is turning left or right by the length between the RL wheel 23 and the RR wheel 24.

[0134] In the above embodiment, the vehicle 10 is equipped with a speed sensor 16. The brake ECU 12 acquires the traveling speed of the vehicle 10 from the speed sensor 16. On the other hand, in the wear determination system 100, the vehicle 10 does not have to be equipped with the speed sensor 16. In this case, the brake ECU 12 may, for example, use the ground speed of the wheels of the vehicle 10 as the traveling speed of the vehicle 10. Furthermore, the brake ECU 12 may, for example, acquire the traveling speed of the vehicle 10 from position information of the vehicle 10.

[0135] In the above embodiment, the brake ECU 12 extracts the period during which the turning angle of the target wheel is large as the period for calculating the turning radius in the determination period extraction process of Fig. 8. On the other hand, the brake ECU 12 may extract the period during which it is determined that the vehicle is turning right or left as the period for calculating the turning radius regardless of the magnitude of the turning angle of the target wheel.

[0136] In the above embodiment, the wear determination system 100 determines that the vehicle 10 is traveling straight when the steering angle of the steering wheel is equal to or greater than 0 degrees and less than 90 degrees in the steering angle determination process of Fig. 5. In addition, the wear determination system 100 determines that the vehicle 10 is turning right or left when the steering angle of the steering wheel is equal to or greater than 90 degrees. The steering angle that the wear determination system 100 uses to determine whether the vehicle 10 is traveling straight or turning left or right is not limited to that in the above embodiment.

[0137] As shown in Fig. 10, the information transmitting device 11 in the above embodiment transmits the straight radius and the turning radius when both values ​​are calculated based on sensor information during the calculation period. Alternatively, the information transmitting device 11 may transmit the calculated value when only one of the straight radius and the turning radius is calculated. In this case, the wear determining device 25 may be configured to determine wear of the shoulder portion 29 when both the straight radius and the turning radius are obtained, even if the information transmitting device 11 receives the straight radius and the turning radius at different times.

[0138] The wear determination device 25 in the above embodiment determines wear on both the right and left sides of the shoulder portion 29 of the target wheel in the direction of travel. However, the wear determination device 25 may determine the presence or absence of wear on the shoulder portion 29 of the target wheel without distinguishing between the right and left sides in the direction of travel.

[0139] The information transmission device 11 in the above embodiment transmits the straight radius and the turning radius to the wear determination device 25 as information about the vehicle 10. However, the information about the vehicle 10 transmitted by the information transmission device 11 is not limited to that in the above embodiment. For example, the information transmission device 11 may transmit the difference between the straight radius and the turning radius to the wear determination device 25.

[0140] In the above embodiment, the information transmitting device 11 calculates the straight radius and the turning radius, and then the wear determining device 25 determines the wear of the shoulder portion 29. On the other hand, in the wear determining system 100, the wear determining device 25 may calculate the straight radius and the turning radius.

[0141] In this case, the wear determination device 25 acquires values ​​measured by sensors of the vehicle 10 during the calculation period. Then, the wear determination device 25 executes the processes executed by the brake ECU 12 in FIGS.

[0142] In addition, when the wear determination device 25 calculates the straight radius and the curved radius, it is also possible to consider an embodiment in which the brake ECU 12 executes part of the processing in Figures 5, 7, and 8, and the wear determination device 25 executes the rest.

[0143] For example, after executing the steering angle determination process in Fig. 5, the brake ECU 12 may transmit sensor information for each separated calculation period to the wear determination device 25. Furthermore, for example, after executing the steering angle determination process in Fig. 5, the brake ECU 12 may also execute the determination period extraction process in Fig. 8 and transmit values ​​required to calculate the straight-ahead radius and the cornering radius to the wear determination device 25.

[0144] In the wear determination system 100 for the first half of the year, the wear determination device 25 is a server installed outside the vehicle 10. On the other hand, the wear determination device 25 may be an in-vehicle device. In this case, the information transmission device 11 does not need to include the communication device 13.

[0145] In the above embodiment, the wear determination system 100 is composed of an information transmission device 11 that calculates the straight and turning radii, and a wear determination device 25 that determines the wear of the shoulder portion 29. On the other hand, the wear determination system 100 may be configured so that the calculation of the straight and turning radii and the determination of the wear of the shoulder portion 29 are completed by a single device.

[0146] In the above embodiment, the wear determination system 100 determines wear on the shoulder portion 29 by comparing the straight radius with the turning radius. However, the wear determination system 100 does not have to use the straight radius to determine wear on the shoulder portion 29. For example, the wear determination system 100 may determine that the shoulder portion 29 is worn when the turning radius is smaller than a threshold value. Alternatively, the wear determination system 100 may determine that the shoulder portion 29 is worn when the difference between the turning radius and a predetermined value is equal to or greater than a threshold value. Alternatively, the wear determination system 100 may store the calculated turning radius and determine wear on the shoulder portion 29 based on the change in the turning radius.

[0147] In the above embodiment, the wear determination device 25 determines the wear of the shoulder portion 29 based on the difference between the straight radius and the turning radius. Alternatively, the wear determination device 25 may determine the wear of the shoulder portion 29 based on the ratio of the turning radius to the straight radius.

[0148] 12 shows a mode of communication executed by the wear determination device 25 to determine the wear of the shoulder portion 29 of the target wheel in the wear determination system 100 of the first modified example. In the first modified example, the mode of communication shown in FIG. 12 is executed instead of the mode of communication shown in FIG. 10.

[0149] In Figure 12, after the brake ECU 12 transmits the straight-line radius and the cornering radius to the communication device 13, the communication device 13 transmits the straight-line radius and the cornering radius to the wear determination device 25 in the same manner as in Figure 10.

[0150] As shown in the upper part of FIG. 12, the wear determining device 25 executes the wear determining process in the same manner as in the upper part of FIG. In the wear determination system 100 of the first modified example, the wear determination device 25 observes the ratio of the turning radius to the straight radius in the wear determination process. When determining wear on the shoulder portion 29 on the right side of the FL wheel 21 as viewed in the direction of travel, the wear determination device 25 observes the ratio of "b2" to "b1" in FIG. 11. When determining wear on the shoulder portion 29 on the left side of the FL wheel 21 as viewed in the direction of travel, the wear determination device 25 observes the ratio of "b3" to "b1" in FIG. 11. When determining wear on the shoulder portion 29 on the right side of the FR wheel 22 as viewed in the direction of travel, the wear determination device 25 observes the ratio of "c2" to "c1" in FIG. 11. When determining wear on the shoulder portion 29 on the left side of the FR wheel 22 as viewed in the direction of travel, the wear determination device 25 observes the ratio of "c3" to "c1" in FIG. 11.

[0151] As the shoulder portion 29 wears, the turning radius becomes smaller than the straight radius. As shown in the lower part of Fig. 12, the wear determination device 25 determines that the shoulder portion 29 of the target wheel is worn when the ratio of the turning radius to the straight radius is equal to or less than a threshold value.

[0152] For example, the wear determination device 25 determines that the shoulder portion 29 on the right side of the FL wheel 21 in the traveling direction is worn when the ratio of "b2" to "b1" in Fig. 11 is equal to or less than a threshold value. In this way, the wear determination system 100 calculates the straight radius, which is the dynamic load radius of the target wheel when the vehicle 10 is traveling straight. Thereafter, the wear determination system 100 determines that the shoulder portion 29 of the target wheel is worn when the ratio of the turning radius to the straight radius is equal to or less than a threshold value.

[0153] As shown in the lower part of Fig. 12, the wear determination device 25 determines the wear of the shoulder portion 29, and then stores the turning radius received from the information transmission device 11 in the storage device 27. This process is similar to the process executed by the wear determination device 25 in the lower part of Fig. 10.

[0154] In this case, the wear determination system 100 calculates the straight radius, which is the dynamic load radius of the target wheel when the vehicle 10 is traveling straight. The wear determination system 100 determines that the shoulder portion 29 of the target wheel is worn when the ratio of the turning radius to the straight radius is equal to or less than a threshold value.

[0155] The more worn the shoulder portion 29 of the target 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 traveling straight. The wear determination system 100 observes the ratio of the turning radius to the straight traveling radius. This allows the wear determination system 100 to determine the wear of the shoulder portion 29 of the target wheel.

[0156] <Additional Notes> The technical ideas that can be understood from the above-described embodiment and modified examples will be described. [Appendix 1] A wear determination system in which the steering wheels of a vehicle are used as target wheels for determination, the system calculates a turning radius, which is the dynamic load radius of the target wheel when the vehicle is turning right or left, based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle is turning right or left is calculated, and determines the wear of the shoulder portion of the target wheel based on the turning radius.

[0157] [Appendix 2] A wear determination system described in [Appendix 1] that calculates the ground speed of the target wheel when the vehicle is turning right or left based on the yaw rate of the vehicle when the vehicle is turning right or left, the turning angle of the target wheel in the section where the yaw rate is measured, and the length of the wheelbase of the vehicle.

[0158] [Appendix 3] A wear determination system described in [Appendix 1] or [Appendix 2], which calculates the straight radius, which is the dynamic load radius of the target wheel when the vehicle is traveling straight, and determines that the shoulder portion of the target wheel is worn when the difference between the turning radius and the straight radius is equal to or greater than a threshold value.

[0159] [Appendix 4] A wear determination system described in [Appendix 1] or [Appendix 2], which calculates the straight radius, which is the dynamic load radius of the target wheel when the vehicle is traveling straight, and determines that the shoulder portion of the target wheel is worn when the ratio of the curved radius to the straight radius is equal to or less than a threshold value.

[0160] [Appendix 5] A wear determination system described in [Appendix 3] or [Appendix 4], which calculates the straight-travel radius based on the ground speed of the target wheel when the vehicle is traveling straight and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle is traveling straight is calculated.

[0161] [Appendix 6] A wear determination system described in any one of [Appendix 1] to [Appendix 5], wherein the turning radius is not calculated when the turning angle of the target wheel when the vehicle is turning right or left is equal to or less than a predetermined angle reference value.

[0162] [Appendix 7] A wear determination system described in any one of [Appendix 1] to [Appendix 6], in which the turning radius is not calculated when the vehicle's moving speed when turning right or left is equal to or greater than a predetermined speed reference value.

[0163] [Appendix 8] A wear determination system described in any one of [Appendix 1] to [Appendix 7], which determines wear on the shoulder portion on the right side of the target wheel in the direction of travel using the turning radius calculated based on the ground speed and the rotational speed when the vehicle is turning right, and determines wear on the shoulder portion on the left side of the target wheel in the direction of travel using the turning radius calculated based on the ground speed and the rotational speed when the vehicle is turning left.

[0164] [Appendix 9] A wear determination system as described in any one of [Appendix 1] to [Appendix 8], comprising a wear determination device and an information transmission device, wherein the information transmission device calculates the turning radius based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle is turning right or left is calculated, and transmits the turning radius to the wear determination device, and the wear determination device determines wear of the shoulder portion of the target wheel based on the turning radius.

[0165] [Appendix 10] The wear determination system described in [Appendix 9], wherein the wear determination device is provided with a storage device and stores the turning radius received from the information transmission device in the storage device. [Explanation of symbols]

[0166] 10...Vehicle 11...Information transmission device 12...Brake ECU 13...Communication equipment 14...Steering angle sensor 15...Yaw rate sensor 16...Speed ​​sensor 17...FL wheel speed sensor 18...FR wheel speed sensor 19...RL wheel speed sensor 20...RR wheel speed sensor 21…FL wheels 22...FR wheels 23…RL wheels 24…RR wheels 25...Wear detection device 26...Processing circuit 27…Storage device 28...Tread area 29...Shoulder 30…Right turn judgment period 31...Left turn judgment period 100...Wear assessment system

Claims

1. A wear determination system in which steering wheels of a vehicle are used as target wheels to be determined, calculating a turning radius, which is a dynamic load radius of the target wheel when the vehicle is turning right or left, based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed of the target wheel when the vehicle is turning right or left is calculated; The wear of the shoulder portion of the target wheel is determined based on the turning radius. Wear determination system.

2. Calculating the ground speed of the target wheel when the vehicle is turning right or left based on the yaw rate of the vehicle when the vehicle is turning right or left, the turning angle of the target wheel in the section where the yaw rate is measured, and the length of the wheelbase of the vehicle. The wear determination system according to claim 1 .

3. calculating a straight-travel radius, which is the dynamic load radius of the target wheel when the vehicle is traveling straight; When the difference between the radius when turning and the radius when going straight is equal to or greater than a threshold value, it is determined that the shoulder portion of the target wheel is worn. The wear determination system according to claim 1 .

4. calculating a straight-travel radius, which is the dynamic load radius of the target wheel when the vehicle is traveling straight; When the ratio of the turning radius to the straight radius is equal to or less than a threshold value, it is determined that the shoulder portion of the target wheel is worn. The wear determination system according to claim 1 .

5. The straight-travel radius is calculated based on the ground speed of the target wheel when the vehicle is traveling straight and the rotational speed of the target wheel in a section where the ground speed of the target wheel when the vehicle is traveling straight is calculated. The wear determination system according to claim 3 or 4.

6. When the turning angle of the target wheel when the vehicle is turning right or left is equal to or less than a predetermined reference angle value, the turning radius is not calculated. The wear determination system according to claim 1 .

7. When the moving speed of the vehicle when the vehicle is turning right or left is equal to or greater than a predetermined speed reference value, the turning radius is not calculated. The wear determination system according to claim 1 .

8. determining wear on the shoulder portion on the right side of the target wheel in the direction of travel using the turning radius calculated based on the ground speed and the rotational speed when the vehicle is turning right; The turning radius calculated based on the ground speed and the rotational speed when the vehicle is turning left is used to determine wear of the shoulder portion on the left side of the target wheel in the traveling direction. The wear determination system according to claim 1 .

9. The apparatus includes a wear determination device and an information transmission device, The information transmitting device calculating the turning radius based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in a section where the ground speed of the target wheel when the vehicle is turning right or left is calculated; transmitting the turning radius to the wear determination device; The wear determination device is The wear of the shoulder portion of the target wheel is determined based on the turning radius. The wear determination system according to claim 1 .

10. The wear determination device includes a storage device, The turning radius received from the information transmitting device is stored in the storage device. The wear determination system according to claim 9 .

11. A wear determination device that determines whether a steering wheel of a vehicle is a target wheel to be determined, The wear of the shoulder portion of the target wheel is determined based on a turning radius, which is a dynamic load radius of the target wheel when the vehicle is turning right or left, calculated based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed is calculated. Wear detection device.

12. An information transmission device capable of communicating with the wear determination device according to claim 11, wherein a steering wheel of a vehicle is set as a target wheel to be determined, calculating a turning radius, which is a dynamic load radius of the target wheel when the vehicle is turning right or left, based on the ground speed of the target wheel when the vehicle is turning right or left and the rotational speed of the target wheel in the section where the ground speed is calculated; The turning radius is transmitted to the wear determination device. Information transmission device.

Images