Braking control device

Abstract

To reduce uneven abrasion of a braking member caused by rust removal control.SOLUTION: A braking control device (BC) comprises: an identifying unit (102) that identifies a wheel whose load is comparatively small among a plurality of wheels (W); and a control unit (103) that designates, as a target wheel, the wheel (W) whose load is identified to be comparatively small by the identifying unit (102), and makes a wheel braking unit (8) apply friction braking force to the target wheel, in order to remove rust formed on the wheel braking unit (8) corresponding to the target wheel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a braking control device. [Background technology]

[0002] Patent Document 1 discloses a vehicle control device that estimates the amount of rust that has developed on the friction surface of a braking rotating member from the amount of time the vehicle has been left standing, and when the vehicle starts moving after the main power is turned on, increases the time for applying frictional braking force according to the estimated amount of rust. This vehicle control device compensates for the reduction in running force due to the frictional braking force with driving force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-126288 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, rust removal is performed by setting the control amounts of friction braking force and driving force according to the estimated amount of rust regardless of the state of the vehicle when starting. However, when rust removal control such as that in Patent Document 1 is performed, there is a risk of uneven wear occurring in the braking members. One aspect of the present disclosure aims to reduce uneven wear of braking members by controlling rust removal. [Means for solving the problem]

[0005] In order to solve the above problems, a braking control device according to one embodiment of the present disclosure is applied to a vehicle having a plurality of wheels, and includes a plurality of wheel braking units provided on each of the plurality of wheels and applying a frictional braking force to each of the wheels, an identification unit that identifies a wheel among the plurality of wheels that has a relatively light load, and a control unit that sets the wheel identified by the identification unit as having a relatively light load as a target wheel, and causes the wheel braking unit to apply the frictional braking force to the target wheel in order to remove rust that has occurred in the wheel braking unit corresponding to the target wheel. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, uneven wear of braking members can be reduced by rust removal control. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a plan view schematically showing the overall configuration of a vehicle equipped with a braking control device according to a first embodiment of the present disclosure. [Figure 2] FIG. 10 is a diagram used to explain refresh control executed when the vehicle is accelerating. [Figure 3] FIG. 10 is a diagram used to explain refresh control executed when the vehicle suddenly accelerates. [Figure 4] 10A and 10B are diagrams used to explain refresh control that is executed when the accelerator pedal is released after rapid acceleration of the vehicle. [Figure 5] 10 is a flowchart showing the flow of processing by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Embodiment 1] Fig. 1 is a plan view schematically showing the overall configuration of a vehicle equipped with a brake control device according to a first embodiment of the present disclosure. The vehicle V shown in Fig. 1 is a four-wheel drive vehicle, and includes a plurality of wheels W, an ECU (Electronic Control Unit) 1, a wheel braking unit 8, a brake pedal 10, a brake switch 12, a brake booster 14, a master cylinder 15, a first hydraulic pipe 16, an H / U (Hydraulic Unit) 17, a second hydraulic pipe 18, a hydraulic pump 19, a third hydraulic pipe 20, a hydraulic sensor 21, and a load sensor SE. The braking control device BC according to the first embodiment of the present disclosure is configured by, for example, a wheel braking unit 8 and an ECU 1.

[0009] The wheel braking units 8 are provided on the plurality of wheels W, respectively, and each include a brake disc 8a and a brake caliper 8b. The load sensor SE is provided for each wheel W and detects the load applied to each wheel W from the contact surface of each wheel W. The load sensor SE is disposed, for example, on a suspension of the vehicle V. The load sensor SE is electrically connected to the ECU 1.

[0010] The master cylinder 15 is connected to the H / U 17 via a first hydraulic pipe 16. Four second hydraulic pipes 18 and one third hydraulic pipe 20 are connected to the H / U 17. The four second hydraulic pipes 18 each connect the H / U 17 to the wheel braking unit 8. The third hydraulic pipe 20 connects the H / U 17 to a hydraulic pump 19. The master cylinder 15 is provided with a hydraulic pressure sensor 21. The hydraulic pressure sensor 21 detects the hydraulic pressure inside the master cylinder 15. The hydraulic pressure sensor 21 is electrically connected to the ECU 1.

[0011] A master cylinder 15 is connected to the brake pedal 10 via a brake booster 14. When the driver of the vehicle V depresses the brake pedal 10, hydraulic pressure corresponding to the amount of depression of the brake pedal 10 is generated in the master cylinder 15. The hydraulic pressure generated in the master cylinder 15 is supplied to each wheel braking unit 8 via a first hydraulic piping 16, a H / U 17, and a second hydraulic piping 18. This hydraulic pressure presses the brake pads against the brake discs 8a in the brake calipers 8b of each wheel braking unit 8, generating a frictional braking force, which is applied to the wheels W.

[0012] The drive of the hydraulic pump 19 is controlled by the ECU 1. By driving the hydraulic pump 19, the ECU 1 can supply hydraulic pressure to the wheel braking unit 8 even when the brake pedal 10 is not depressed.

[0013] The ECU 1 functions as an operation amount obtaining unit 100 , a load obtaining unit 101 , an identifying unit 102 , and a control unit 103 . The operation amount obtaining unit 100 obtains the operation amount of an operation member operated by a driver of the vehicle V. The operation members include, for example, a brake pedal 10, an accelerator pedal, and a steering wheel.

[0014] The load acquisition unit 101 receives a detection signal from the load sensor SE, and thereby acquires the load applied to each wheel W from the contact surface of each wheel W. The identifying unit 102 identifies a wheel W having a relatively small load acquired by the load acquiring unit 101 from among the plurality of wheels W. Hereinafter, the wheel W identified by the identifying unit 102 will be referred to as a target wheel W.

[0015] The control unit 103 causes the wheel braking unit 8 corresponding to the target wheel W to apply a friction braking force to the target wheel W, thereby removing rust that has occurred on the wheel braking unit 8 corresponding to the target wheel W. The rust that has occurred on the wheel braking unit 8 is, for example, rust that has occurred on the friction surface of the brake disc 8a. Hereinafter, the control that the control unit 103 performs to remove rust from the wheel braking unit 8 will be referred to as refresh control.

[0016] The refresh control will be described with reference to FIGS. Fig. 2 is a diagram used to explain the refresh control executed when accelerating a vehicle V. In the situation shown in Fig. 2, the vehicle V is accelerating at a rate that does not cause squat due to the driving force A1 applied to the wheels W. Squat occurs when the front part of the vehicle lifts up and the rear part sinks when the vehicle suddenly starts moving.

[0017] In the state shown in FIG. 2, the load on all wheels W of the vehicle V is approximately uniform, and the difference between the maximum and minimum loads on the wheels W is less than a predetermined value. The identification unit 102 identifies all wheels W of the vehicle V as target wheels W for refresh control. The control unit 103 supplies hydraulic pressure from the hydraulic pump 19 to all wheel brake units 8 of the vehicle V, applies frictional braking force B1 to all wheels W of the vehicle V, and removes rust that has occurred in all wheel brake units 8 of the vehicle V. The control unit 103 applies driving force A2 to all wheels W of the vehicle V to compensate for the reduction in the running force of the vehicle V caused by the refresh control.

[0018] FIG. 3 is a diagram used to explain the refresh control executed when the vehicle suddenly accelerates. In the situation shown in FIG. 3, the vehicle V suddenly accelerates due to a driving force A1 applied to the wheels W, causing the front portion of the vehicle V to lift, and the load on the front portion becomes smaller than the load on the rear portion. The identification unit 102 identifies the left and right front wheels W of the wheels W of the vehicle V as target wheels W for the refresh control. The wheel brake units 8 of the left and right front wheels of the vehicle V are an example of a first wheel brake unit. The control unit 103 supplies hydraulic pressure from the hydraulic pump 19 to the wheel brake units 8 of the left and right front wheels, applies a frictional braking force B1 to the left and right front wheels, and removes rust that has occurred in the wheel brake units 8 of the left and right front wheels. The control unit 103 applies a driving force A2 to the left and right rear wheels to compensate for the reduction in the running force of the vehicle V caused by the refresh control.

[0019] FIG. 4 is a diagram used to explain the refresh control executed when the accelerator pedal is released after sudden acceleration and the vehicle V is decelerating. In the situation shown in FIG. 4, the vehicle V is decelerating after sudden acceleration, the rear portion of the vehicle V begins to lift, and the load on the rear portion is smaller than the load on the front portion. The identification unit 102 identifies the left and right rear wheels W of the wheels W of the vehicle V as target wheels W for the refresh control. The wheel brake units 8 of the left and right rear wheels of the vehicle V are an example of a second wheel brake unit. The control unit 103 supplies hydraulic pressure from the hydraulic pump 19 to the wheel brake units 8 of the left and right rear wheels, applies frictional braking force B1 to the left and right rear wheels, and removes rust that has occurred in the wheel brake units 8 of the left and right rear wheels. The control unit 103 applies driving force A2 to the left and right front wheels to compensate for the reduction in the running force of the vehicle V caused by the refresh control.

[0020] The refresh control executed when the vehicle V is decelerating is equivalent to the refresh control executed when the vehicle V is accelerating or rapidly accelerating. More specifically, the friction braking force B1 applied to the left and right rear wheels in the refresh control executed when the vehicle V is decelerating is approximately the same as the friction braking force B1 applied to the left and right front wheels in the refresh control executed when the vehicle V is accelerating or rapidly accelerating.

[0021] 5 is a flowchart showing the flow of processing by the control unit. The ECU 1 repeatedly executes the processing of FIG. 5 while the vehicle V is running, and once the processing of FIG. 5 is completed, the ECU 1 starts the processing of the next cycle.

[0022] In S100, ECU1 determines whether or not the vehicle V is in an unstable state. The vehicle V is in an unstable state, for example, when the vehicle is traveling at high speed, when the vehicle V is turning, when the vehicle V is traveling on a road surface with a small friction coefficient μ, etc. Here, when the vehicle V is traveling at high speed, it means, for example, that the speed of the vehicle V is 80 km / h or more. A road surface with a small friction coefficient μ is, for example, a snowy road. If the vehicle V is not in an unstable state (S100: NO), ECU1 proceeds to processing S110, and if the vehicle V is in an unstable state (S100: YES), it proceeds to processing S190.

[0023] In S110, the ECU 1 determines whether the speed of the vehicle V is equal to or less than a predetermined threshold value. Here, the threshold value is the vehicle speed during creeping, for example, 5 to 10 km / h. If the speed of the vehicle V is greater than the predetermined threshold value (S110: NO), the ECU 1 proceeds to the processing of S120, and if the speed of the vehicle V is equal to or less than the predetermined threshold value (S110: YES), the ECU 1 proceeds to the processing of S190.

[0024] In S120, the ECU 1 determines whether the temperature of the brake pad of the brake caliper 8b is low. The ECU 1 estimates the temperature of the brake pad of the brake caliper 8b based on, for example, the number of control operations of the refresh control, the number of braking operations by the wheel braking unit 8, etc. If the estimated temperature of the brake pad of the brake caliper 8b is equal to or lower than a predetermined value, the ECU 1 determines that the temperature of the brake pad of the brake caliper 8b is low. If the temperature of the brake pad of the brake caliper 8b is low (S120: YES), the ECU 1 proceeds to the processing of S130, and if the temperature of the brake pad of the brake caliper 8b is not low (S120: NO), the ECU 1 proceeds to the processing of S190.

[0025] In S130, the ECU 1 determines whether the accelerator pedal has been operated. For example, the ECU 1 acquires the accelerator pedal operation amount using the operation amount acquisition unit 100, and determines whether the accelerator pedal has been operated based on the acquired operation amount. If the accelerator pedal has been operated (S130: YES), the ECU 1 proceeds to processing of S140, and if the accelerator pedal has not been operated (S130: NO), the ECU 1 proceeds to processing of S150.

[0026] In S140, the ECU 1 determines whether the load on the front wheels of the vehicle V acquired by the load acquisition unit 101 is smaller by a predetermined value or more than the load on the rear wheels of the vehicle V. If the load on the front wheels of the vehicle V is smaller by a predetermined value or more than the load on the rear wheels of the vehicle V (S140: YES), for example, in the situation described using FIG. 3, the ECU 1 proceeds to processing of S160, and if the load on the front wheels of the vehicle V is not smaller by a predetermined value or more than the load on the rear wheels of the vehicle V, that is, if the load on the front wheels of the vehicle V is substantially the same as the load on the rear wheels of the vehicle V, the ECU 1 proceeds to processing of S170.

[0027] In S160, the ECU 1 performs refresh control to apply a friction braking force B1 to the left and right front wheels of the vehicle V and a driving force A2 to the left and right rear wheels, as shown in FIG. In S170, the ECU 1 performs refresh control to apply a friction braking force B1 to all the wheels W of the vehicle V and apply a driving force A2 to all the wheels W of the vehicle V, as shown in FIG.

[0028] In S150, the ECU 1 determines whether the accelerator pedal is no longer being operated immediately after the vehicle V accelerates. If a predetermined time has not elapsed since the accelerator pedal was no longer being operated after the vehicle V accelerated (S150: YES), the ECU 1 proceeds to the processing of S180. If a predetermined time has elapsed since the vehicle V accelerated (S150: NO), the ECU 1 proceeds to the processing of S190.

[0029] In S180, the ECU 1 performs refresh control to apply a friction braking force B1 to the left and right rear wheels of the vehicle V and a driving force A2 to the left and right front wheels, as shown in FIG. In S190, the ECU 1 does not perform refresh control.

[0030] [Embodiment 2] A second embodiment of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the first embodiment, and the description thereof will not be repeated. The second embodiment of the present disclosure differs from the first embodiment in that the vehicle V is a front-engine, front-wheel drive (FF) vehicle. In the second embodiment, the rear wheels of the vehicle V are driven wheels, and therefore the driving force A2 cannot be applied to the left and right rear wheels of the vehicle V. Therefore, the second embodiment differs from the first embodiment in that the driving force A2 is applied only to the left and right front wheels of the vehicle V in the refresh control performed when the vehicle V accelerates and in the refresh control performed when the vehicle suddenly accelerates.

[0031] [Embodiment 3] A second embodiment of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the first and second embodiments, and the description thereof will not be repeated. The third embodiment of the present disclosure differs from the first and second embodiments in that the vehicle V is a front-engine, rear-wheel-drive (FR) vehicle. Because the front wheels of the vehicle V are driven wheels, the driving force A2 cannot be applied to the left and right front wheels of the vehicle V. Therefore, in the refresh control executed when the vehicle V accelerates and when the accelerator pedal is released after rapid acceleration of the vehicle V, the driving force A2 is applied only to the left and right rear wheels of the vehicle V, which differs from the first and second embodiments.

[0032] (Variation) In the above embodiment, when the accelerator pedal is released after sudden acceleration of the vehicle V and the vehicle V is decelerating, a frictional braking force B1 is applied to the left and right rear wheels and a driving force A2 is applied to the left and right front wheels, as shown in Fig. 4. However, the situation in which the frictional braking force B1 is applied to the left and right rear wheels and the driving force A2 is applied to the left and right front wheels is not limited to when the accelerator pedal is released after sudden acceleration of the vehicle V and the vehicle V is decelerating. For example, when the brake pedal 10 of the vehicle V is operated and the vehicle V is decelerating, a frictional braking force B1 may be applied to the left and right rear wheels and a driving force A2 may be applied to the left and right front wheels.

[0033] In the above embodiment, the vehicle V is described as being four-wheel drive, front engine / front drive, or front engine / rear drive, but the vehicle V is not limited to these. For example, the vehicle V may be a rear engine / rear drive or a rear engine / front drive vehicle.

[0034] In the above embodiment, the ECU 1 makes the determination in S140 of FIG. 5 based on the load on the wheels W of the vehicle V acquired by the load acquisition unit 101. However, this is not limiting. For example, the ECU 1 may make the determination in S140 of FIG. 5 based on the amount of accelerator pedal operation. For example, the ECU 1 may determine that the vehicle V is rapidly accelerating when the amount of accelerator pedal operation is equal to or greater than a predetermined value, or when the rate at which the amount of accelerator pedal operation is increasing is equal to or greater than a predetermined value. For example, in S140, the ECU 1 may proceed to processing in S160 when the amount of accelerator pedal operation is equal to or greater than the predetermined value, and may proceed to processing in S170 when the amount of accelerator pedal operation is less than the predetermined value. The determination that the vehicle V is rapidly decelerating may be based on, for example, the rate at which the amount of accelerator pedal operation decreases due to a sudden accelerator release from a state in which the amount of accelerator pedal operation is equal to or greater than a predetermined value.

[0035] In the above embodiment, the load obtaining unit 101 obtains the load applied to each wheel W from the contact surface of each wheel W by receiving a detection signal from the load sensor SE, but this is not limiting. For example, the load obtaining unit 101 may obtain an estimated value of the load on each wheel W based on an actual value or an estimated value of a longitudinal G sensor or a wheel speed sensor of the vehicle V.

[0036] In the above embodiment, the refresh control executed when the vehicle V is decelerating is equivalent to the refresh control executed when the vehicle V is accelerating or rapidly accelerating. However, the refresh control executed when the vehicle V is accelerating or rapidly accelerating may be equivalent to the refresh control executed when the vehicle V is decelerating. The friction braking force B1 applied to the left and right front wheels in the refresh control executed when the vehicle V is accelerating or rapidly accelerating may be approximately the same as the friction braking force B1 applied to the left and right rear wheels in the refresh control executed when the vehicle V is decelerating.

[0037] 〔summary〕 A braking control device according to one aspect of the present disclosure is applied to a vehicle having a plurality of wheels, and includes a plurality of wheel braking units provided on each of the plurality of wheels and applying a frictional braking force to each of the wheels; an identification unit that identifies a wheel among the plurality of wheels that has a relatively light load; and a control unit that designates the wheel identified by the identification unit as having a relatively light load as a target wheel, and causes the wheel braking unit to apply the frictional braking force to the target wheel in order to remove rust that has occurred in the wheel braking unit corresponding to the target wheel. When applying braking force to a wheel, uneven wear of the braking member may occur if the braking force is applied when there is a large disturbance on the wheel, i.e., when the load on the wheel is large. According to the above embodiment, the load acquisition unit acquires the load of each wheel, the identification unit identifies a wheel with a relatively small load based on the acquired load, and the control unit selects the wheel identified by the identification unit as the target wheel for control and activates the wheel braking unit of the target wheel to remove rust. This allows rust to be removed from the target wheel, which is in a relatively small and stable state, such as the front wheel when accelerating the vehicle and the rear wheel when decelerating, thereby reducing uneven wear of the braking member due to the application of the above-mentioned braking force.

[0038] In one embodiment of the braking control device of the present disclosure, when the vehicle is accelerating, the identification unit identifies the front wheel of the vehicle as the wheel with a relatively small load, and the control unit causes the first wheel braking unit to apply the frictional braking force to the front wheel in order to remove rust that has occurred in the first wheel braking unit, which is the wheel braking unit corresponding to the front wheel. When the vehicle is accelerating, the front wheels of the vehicle may lift up. In the above embodiment, braking force is applied to the wheels that are least susceptible to external disturbances when the vehicle is accelerating, so uneven wear of the braking members that accompanies the application of braking force for rust removal can be reduced.

[0039] In one embodiment of the braking control device of the present disclosure, when the vehicle is decelerating, the identification unit identifies the rear wheel of the vehicle as the wheel with a relatively small load, and the control unit causes the second wheel braking unit to apply the frictional braking force to the rear wheel in order to remove rust that has occurred in the second wheel braking unit, which is the wheel braking unit corresponding to the rear wheel. When a vehicle is decelerating, the front wheels of the vehicle may sink and the rear wheels of the vehicle may rise. In the above embodiment, braking force is applied to the wheels that are least susceptible to external disturbances when the vehicle is decelerating, so uneven wear of the braking members that accompanies the application of braking force for rust removal can be reduced.

[0040] In one embodiment of the braking control device of the present disclosure, the control unit makes the braking force of the control performed to remove rust that has occurred in the second wheel braking section when the vehicle decelerates equal to the braking force of the control performed to remove rust that has occurred in the first wheel braking section when the vehicle accelerates. Since the control performed to remove rust that has developed on the second wheel braking unit when the vehicle is decelerating and the control performed to remove rust that has developed on the first wheel braking unit when the vehicle is accelerating are equivalent controls, control to remove rust can be performed evenly on the wheel braking units of the vehicle.

[0041] [Additional Notes] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0042] 1 ECU 8 Wheel brake 8a Brake disc 8b Brake caliper 10. Brake pedal 101 Load acquisition section 102 Specific part 103 Control Unit A1, A2 driving force B1 Friction braking force BC Braking Control Device W wheels

Claims

1. Applied to vehicles with multiple wheels, a plurality of wheel braking units provided on each of the plurality of wheels and applying friction braking forces to the wheels; an identification unit that identifies a wheel with a relatively light load among the plurality of wheels; a control unit that sets the wheel identified by the identification unit as having a relatively small load as a target wheel, and causes the wheel braking unit corresponding to the target wheel to apply the friction braking force to the target wheel in order to remove rust that has occurred in the wheel braking unit; A braking control device comprising:

2. the identification unit identifies a front wheel of the vehicle as the wheel with a relatively small load when the vehicle is accelerating, 2. The braking control device according to claim 1, wherein the control unit applies the frictional braking force to the front wheels by the first wheel braking unit, which is the wheel braking unit corresponding to the front wheels, in order to remove rust that has occurred in the first wheel braking unit.

3. the identifying unit identifies a rear wheel of the vehicle as the wheel with a relatively small load when the vehicle is decelerating, 3. The braking control device according to claim 2, wherein the control unit applies the frictional braking force to the rear wheel by the second wheel braking unit, which is the wheel braking unit corresponding to the rear wheel, in order to remove rust that has occurred in the second wheel braking unit.

4. 4. The braking control device according to claim 3, wherein the control unit makes the braking force of the control performed to remove rust that has occurred in the second wheel braking portion when the vehicle decelerates equal to the braking force of the control performed to remove rust that has occurred in the first wheel braking portion when the vehicle accelerates.

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