Braking system and method for controlling a braking system for a motor vehicle

Abstract

Braking system (10) for a motor vehicle, comprising: a control unit (18) capable of independently controlling the brake pressure at each wheel (12A, 12B, 14A, 14B) of the motor vehicle when a driver of the motor vehicle applies the brakes; a first sensor (22) capable of measuring the angular position (28) of a steering wheel (30) of the motor vehicle and transmitting the angular position (28) of the steering wheel (30) to the control unit (18); and a second sensor (24) capable of measuring the speed of the vehicle and transmitting the speed of the vehicle to the control unit (18); the control unit (18) is further designed to reduce the brake pressure at an inside wheel (14B) when the speed of the vehicle is zero and the angular position of the steering wheel (30) exceeds a predetermined value;and a third sensor (26) configured to measure the force required to rotate the inner wheel (14B) of the motor vehicle and transmitting the force to the control unit (18), the control unit (18) being configured to reduce the brake pressure on the inner wheel (14B) when the speed of the vehicle is zero and the force required to rotate the inner wheel (14B) of the motor vehicle exceeds a predetermined value.

Description

INTRODUCTION

[0001] The present disclosure relates to a braking system for a motor vehicle and a method for controlling a braking system for a motor vehicle, which provides for a reduction of the brake pressure on an inside wheel in order to reduce the force required to turn the inside wheel.

[0002] A multi-link suspension is desirable for vehicles because it improves handling compared to a conventional suspension system. A significant disadvantage of a multi-link suspension is the higher static steering effort. Higher static steering effort results from the displacement of the kingpin axis relative to the tire sidewall as the wheel rotates, causing the tire to drag or rub against the road surface. This drag or rub increases the force required to turn the wheel and necessitates a more powerful power steering module, as well as more robust steering components and linkages capable of withstanding the increased forces.

[0003] While current braking systems and methods for controlling braking systems fulfill their purpose, there is a need for an improved braking system and method for controlling braking systems that allows a reduction in brake pressure on an inside wheel so that the inside wheel can rotate freely while being turned, and reduces or eliminates tire rubbing / scraping against the road surface, thereby decreasing the force required to turn the inside wheel. DESCRIPTION

[0004] According to several aspects of the present disclosure, a braking system for a motor vehicle comprises a control unit configured to independently control the brake pressure at each wheel of the motor vehicle when a driver of the motor vehicle applies the brakes, a first sensor configured to measure the angular position of a steering wheel of the motor vehicle and transmit the angular position of the steering wheel to the control unit, and a second sensor configured to measure the speed of the vehicle and transmit the speed of the vehicle to the control unit, the control unit further being configured to reduce the brake pressure at an inward-facing wheel when the speed of the vehicle is zero and the angular position of the steering wheel exceeds a predetermined value.

[0005] According to another aspect, the braking system further includes a third sensor suitable for measuring a force required to rotate the vehicle's inner wheel and transmitting the force to the control unit, the control unit being suitable for reducing the brake pressure on the inner wheel when the vehicle's speed is zero and the force required to rotate the vehicle's inner wheel exceeds a predetermined value.

[0006] According to another aspect, the control system is designed to increase the brake pressure at each remaining wheel of the motor vehicle when the brake pressure at the inside wheel is reduced.

[0007] According to another aspect, the control system reduces the pressure on the inside wheel, with the control system being designed to reduce the brake pressure on the inside wheel to zero.

[0008] Another aspect is that when the control system reduces the pressure on the inner wheel, it gradually reduces the brake pressure on the inner wheel from a normal brake pressure to zero.

[0009] According to another aspect, the control system is designed to gradually reduce the brake pressure at the inner wheel from a normal brake pressure to zero when the control system reduces the pressure at the inner wheel.

[0010] According to another aspect, the control system is designed to reduce the brake pressure on the inside wheel when the vehicle's speed is zero and the steering wheel angle exceeds a predetermined value and the force required to turn the inside wheel of the vehicle exceeds a predetermined value.

[0011] According to several aspects of the present disclosure, a method for controlling a braking system for a motor vehicle comprises independently controlling the brake pressure at each wheel of the motor vehicle with a controller when a driver of the motor vehicle applies the brakes, detecting a speed of the motor vehicle with a second sensor and transmitting the speed of the motor vehicle to the controller, detecting an angular position of a steering wheel inside the vehicle with a first sensor and transmitting the angular position of the steering wheel to the controller, and reducing the brake pressure at an inward-facing wheel with the controller when the speed of the vehicle is zero and the angular position of the steering wheel exceeds a predetermined value.

[0012] According to another aspect, the method further includes detecting a force required to rotate the inner wheel of the motor vehicle with a third sensor and transmitting the force to the control unit, and reducing the brake pressure on the inner wheel with the control unit when the speed of the vehicle is zero and the force required to rotate the inner wheel of the motor vehicle exceeds a predetermined value.

[0013] According to another aspect, the procedure also includes increasing the brake pressure at each remaining wheel of the motor vehicle with the steering system when the brake pressure at the inner wheel of the motor vehicle with the steering system is reduced.

[0014] According to another aspect, reducing the brake pressure at the inner wheel with the controller when the vehicle speed is zero and the steering wheel angle exceeds a predetermined value, and reducing the brake pressure at the inner wheel with the controller when the vehicle speed is zero and the force required to turn the inner wheel of the motor vehicle exceeds a predetermined value, furthermore includes reducing the brake pressure at the inner wheel with the controller to zero.

[0015] According to another aspect, reducing the brake pressure at the inner wheel with the regulator when the vehicle speed is zero and the steering wheel angle exceeds a predetermined value, and reducing the brake pressure at the inner wheel with the regulator when the vehicle speed is zero and the force required to turn the inner wheel of the motor vehicle exceeds a predetermined value, furthermore includes the gradual reduction of the brake pressure at the inner wheel from a normal brake pressure to zero.

[0016] According to another aspect, reducing the brake pressure on the inside wheel when the vehicle speed is zero and the steering wheel angle exceeds a predetermined value, and reducing the brake pressure on the inside wheel when the vehicle speed is zero and the force required to turn the inside wheel exceeds a predetermined value, furthermore includes reducing the brake pressure on the inside wheel from normal brake pressure to zero as a step function.

[0017] According to another aspect, the procedure also includes reducing the brake pressure on the inner wheel with the control when the speed of the vehicle is zero and the angular position of the steering wheel exceeds a predetermined value and the force required to turn the inner wheel of the motor vehicle exceeds a predetermined value.

[0018] According to another aspect, the procedure also includes carrying out a verification test before reducing the brake pressure on the inner rotary wheel.

[0019] Further areas of application will become apparent from the present description. It should be understood that the description and specific examples serve only for illustration and are not intended to limit the scope of this disclosure. List of characters

[0020] The figures described here serve only for illustration and are not intended to limit the scope of the present revelation in any way. Fig. Figure 1 is a schematic view of a braking system for a motor vehicle according to an exemplary embodiment of the present disclosure, wherein the rotating wheels of the motor vehicle are straight; Fig. Figure 2 is a schematic view of a braking system for a motor vehicle according to an exemplary embodiment of the present disclosure, in which the wheels of the motor vehicle are rotated; Fig. Figure 3 is a perspective view of a steering wheel for a motor vehicle with a braking system according to the present disclosure, wherein the rotating wheels of the motor vehicle are straight; Fig. Figure 4 is a perspective view of a steering wheel for a motor vehicle with a braking system according to the present disclosure, in which the wheels of the motor vehicle are turned; Fig. 5A is a diagram of the brake pressure on an inside wheel of a motor vehicle as a function of time, wherein the brake pressure on the inside wheel is reduced to zero as a step function; Fig. Figure 5B is a diagram of the brake pressure on an inside wheel of a motor vehicle as a function of time, where the brake pressure on the inside wheel is gradually reduced to zero; Fig. 5C is a diagram of the brake pressure at the other wheels of a motor vehicle as a function of time; Fig. Figure 6 is a diagram of the force required to turn the inner wheel as a function of time, including a dashed diagram where the pressure on the inner wheel is not reduced, and a solid diagram where the pressure on the inner wheel is reduced; and Fig. Figure 7 is a flowchart showing a method for controlling a braking system in accordance with the present disclosure. DETAILED DESCRIPTION

[0021] The following description is merely exemplary and is not intended to limit the present disclosure, application or use.

[0022] In Fig. 1 is a braking system for a motor vehicle, generally shown with 10. As in Fig. As shown in Figure 1 and for the purposes of description here, the automobile is a typical four-wheeled vehicle with two rear wheels 12A, 12B which are not steerable and remain in a straight orientation at all times, and two front wheels 14A, 14B which are articulated so that the car can be turned, as shown in Figure 1. Fig. 2 shown. It should be understood that the novel concepts of the present disclosure are applicable to an automobile with more than four wheels and to automobiles in which either the front wheels or the rear wheels or both the front and rear wheels are articulated to enable the automobile to turn.

[0023] Each of the wheels 12A, 12B, 14A, 14B contains a braking device 16 that can slow down or stop the rotation of the wheel 12A, 12B, 14A, 14B. The braking device 16 can be any suitable device, such as, but is not limited to, a shoe-saddle arrangement or a shoe-drum arrangement. The braking system 10 includes a control 18 designed to independently control the brake pressure at each wheel 12A, 12B, 14A, 14B of the motor vehicle when a driver of the motor vehicle applies the brakes.

[0024] In an exemplary embodiment, the brake system 10 comprises a master cylinder 20 that supplies each of the brake devices 16 with pressurized brake fluid. The control unit 18 is connected to the master cylinder 20 and actuates several valves located in the master cylinder 20 and at each brake device 16, so that the control unit 18 can independently control the pressure of the brake fluid supplied to each brake device 16, irrespective of any operator input.

[0025] The braking system 10 comprises sensors 22, 24, 26, which provide information to the control unit 18. A first sensor 22 is capable of measuring the angular position 28 of a steering wheel 30 of the vehicle and transmitting this angular position 28 to the control unit 18. (Referring to) Fig. 3. The steering wheel is centered when the front wheels 14A, 14B of the vehicle are straight, as shown in Fig. Figure 1 shows that a center line 32 of the steering wheel 30 is parallel to the direction of travel. When the front wheels 14A, 14B of the vehicle are turned as shown in Figure 1, the steering wheel 30 is parallel to the direction of travel. Fig. As shown in Figure 2, the center line 32 of the steering wheel is drawn from the in Fig. rotated to the central position shown in section 3 (see Fig. 4) The first sensor 22 measures the angular position 28 of the steering wheel 30 relative to the center position.

[0026] A second sensor 24 is designed to measure the vehicle's speed and transmit this speed to the controller 18. A third sensor 26 is designed to measure the force required to rotate an inner wheel 14B of the vehicle and transmit this force to the controller 18. When the vehicle's front wheels 14A, 14B are turned to the right, the left front wheel 14A is an outer wheel 14A and the right front wheel 14B is an inner wheel 14B (see Fig. 2) The third sensor 26 measures the force required to actuate the steering linkage 34 of the motor vehicle and to steer the front wheels 14A, 14B. The steering linkage 34 can be any suitable steering arrangement, such as a rack and pinion or other such linkage, actuated either directly by the steering wheel 30 or via a power steering unit.

[0027] The control 18 is designed to reduce the brake fluid pressure and thus the braking force at the brake device 16 of the inner wheel 14B when certain conditions are present during the turning of the vehicle, so that the inner wheel 14B can rotate freely when turning and the rubbing / scraping of the tire on the road surface is reduced or eliminated, thereby reducing the force required to turn the inner wheel 14B.

[0028] In an exemplary embodiment, the control unit 18 is designed to reduce the brake pressure on the inwardly rotating wheel 14B when the second sensor 24 indicates that the vehicle speed is zero and the first sensor 22 indicates that the angular position 28 of the steering wheel 30 exceeds a predetermined value. The predetermined value of the angular position 28 of the steering wheel 30 depends on aspects of the vehicle and its suspension system. For example, in one vehicle, the predetermined value of the angular position 28 of the steering wheel 30 might be 15 degrees, while in another application, for a different vehicle with a different suspension system, the predetermined value of the angular position 28 of the steering wheel 30 might be 30 degrees.For each application, the predetermined value of the angular position 28 of the steering wheel 30 is suitable to effect a pressure reduction of the brake fluid at the brake device 16 of the inner rotary wheel 14B when the forces required to turn the inner rotary wheel 14B begin to increase.

[0029] In another exemplary embodiment, the control unit 18 is designed to reduce the brake pressure at the inner rotary wheel 14B when the second sensor 24 indicates that the vehicle speed is zero, and the third sensor 26 indicates that the force required to rotate the inner rotary wheel 14B exceeds a predetermined value. The predetermined value of the force required to rotate the inner rotary wheel 14B depends on aspects of the automobile and its suspension system. The use of the brake system 10 and the method disclosed herein makes it possible to design a motor vehicle's suspension system to withstand lower forces, thereby reducing costs and weight.For each application, the predetermined value of the force required to rotate the inner wheel 14B is suitable to reduce the pressure of the brake fluid at the brake device 16 of the inner wheel 14B when the forces required to rotate the inner wheel 14B begin to increase, and in particular to keep the forces within the limits of the suspension system.

[0030] In another exemplary embodiment, the control unit 18 is designed to reduce the brake pressure on the inner rotary wheel 14B when the second sensor 24 indicates that the vehicle speed is zero, the first sensor 22 indicates that the angular position 28 of the steering wheel 30 exceeds a predetermined value, and the third sensor 26 indicates that the force required to turn the inner rotary wheel 14B exceeds a predetermined value.

[0031] When the control unit 18 reduces the pressure on the inner rotary wheel 14B, the control unit 18 can reduce the brake pressure at the brake device 16 of the inner rotary wheel 14B to zero. By effectively disengaging the brake device 16 of the inner rotary wheel 14B, the inner rotary wheel 14B can rotate freely while being turned, thereby greatly reducing or eliminating any rubbing or chafing of the tire on the road surface and thus decreasing the force required to turn the inner rotary wheel 14B.

[0032] Referring to Fig. In an exemplary embodiment, when the control unit 18 reduces the pressure of the brake fluid at the brake device 16 of the inwardly rotating wheel 14B, the control unit 18 is designed to gradually reduce the brake pressure at the inwardly rotating wheel 14B from a normal brake pressure 36 to zero. Diagram 38 of the brake pressure as a function of time illustrates the gradual pressure drop.

[0033] Referring to Fig. In another exemplary embodiment, when the control unit 18 reduces the pressure of the brake fluid at the brake device 16 of the inner rotating wheel 14B, the control unit 18 is designed to reduce the brake pressure at the inner rotating wheel 14B in stages from the normal brake pressure 36 to zero. The diagram 40 of the brake pressure as a function of time illustrates the gradual or near-instantaneous decrease of the brake pressure from the normal brake pressure 40 to zero.

[0034] As in Fig. As shown in Figure 5C, the brake pressure at each of the remaining wheels 14A, 12A, 12B is increased when the brake pressure at the inner wheel 14B is reduced. The increase in brake pressure at the brake devices 16 of the remaining wheels 14A, 12A, 12B provides additional braking force to compensate for the reduced brake pressure at the inner wheel 14B. Graph 42, showing the brake pressure at each of the remaining wheels 14A, 12A, 12B as a function of time, illustrates the increase in brake pressure at each of the remaining wheels 14A, 12A, 12B when the brake pressure at the inner wheel 14B is simultaneously reduced.

[0035] With reference to Fig. Figure 6 shows a diagram of the force required to rotate the inner rotating wheel 14B, where the dashed line in Figure 44 represents the force versus time when the inner rotating wheel 14B is rotated without reducing the brake pressure on the inner rotating wheel 14B, and the solid line in Figure 46 represents the force versus time when the inner rotating wheel 14B is rotated with a reduction in brake pressure on the inner rotating wheel 14B. Because the inner wheel 14B is allowed to rotate freely during rotation, the rubbing or chafing of the tire on the road surface is reduced, thereby reducing the force required to rotate the inner wheel 14B, as shown in Figure 6. Fig. 6 at Fig. Figure 46 shows that it may be possible to reduce the force required to turn the inner wheel 14B by up to 10%, as shown in Fig. 6 at Fig. 48 shown.

[0036] In Fig.Figure 7 describes a method 100 for controlling a braking system for a motor vehicle. Starting with block 110, the method includes the independent control of the brake pressure at each wheel 12A, 12B, 14A, 14B of the vehicle by a controller 18 when a driver of the vehicle applies the brakes. In block 112, the method includes detecting the vehicle's speed with a second sensor 24 and transmitting the vehicle's speed to the controller 18. In block 114, the controller 18 determines whether the vehicle's speed is zero. If the vehicle's speed is not zero, the braking system 10 operates normally in block 116. If the vehicle's speed is zero, the method in block 118 includes detecting the angular position 28 of a steering wheel 30 inside the vehicle with a first sensor 22 and transmitting the angular position 28 of the steering wheel 30 to the controller 18.

[0037] In an exemplary embodiment, the controller 18 in block 120 determines whether the angular position 28 of the steering wheel 30 exceeds a predetermined value. If the angular position 28 of the steering wheel 30 does not exceed the predetermined value, the braking system 10 in block 122 operates normally. If the angular position 28 of the steering wheel 30 exceeds the predetermined value, the procedure in block 124 performs a verification check. If the verification check fails, the braking system 10 in block 126 returns to normal operation. If the verification check is successful, in block 128 the brake pressure at an inner wheel 14B is reduced by means of the controller 18, and simultaneously in block 130 the brake pressure at each of the other wheels 14A, 12A, 12B of the vehicle is increased by means of the controller 18.

[0038] In another exemplary embodiment, the method, after detecting the angular position 28 of a steering wheel 30 within the vehicle in block 118 and transitioning to block 132, includes detecting a force required to rotate the vehicle's inner wheel 14B with a third sensor 26 and transmitting the force to the controller 18. In block 134, the controller 18 determines whether the force required to rotate the vehicle's inner wheel 14B exceeds a predetermined value. If the force required to rotate the vehicle's inner wheel 14B does not exceed the predetermined value, the braking system 10 operates normally in block 136. If the force required to rotate the vehicle's inner wheel 14B exceeds the predetermined value, the method performs a verification check in block 124.If the verification test fails, the brake system 10 in block 126 returns to normal operation. If the verification test is successful, in block 128 the brake pressure at the inner wheel 14B is reduced by means of the regulator 18, and simultaneously in block 130 the brake pressure at each other wheel 14A, 12A, 12B of the vehicle is increased by means of the regulator 18.

[0039] In another exemplary embodiment, after detecting the angular position 28 of the steering wheel 30 inside the motor vehicle in block 118 and detecting a force required to turn the inner steering wheel 14B of the motor vehicle in block 138, the control unit 18 determines whether the angular position 28 of the steering wheel 30 exceeds the predetermined value and whether the force required to turn the inner steering wheel 14B of the motor vehicle exceeds the predetermined value. If either the angular position 28 of the steering wheel 30 does not exceed the predetermined value or the force required to turn the inward-facing wheel 14B of the vehicle does not exceed the predetermined value, the braking system 10 operates normally when proceeding to block 140.If both the angular position 28 of the steering wheel 30 exceeds the predetermined value and the force required to turn the inner wheel 14B of the vehicle exceeds the predetermined value, then the procedure in block 124 performs a verification check. If the verification check fails, the brake system 10 in block 126 switches to normal operation. If the verification check is successful, in block 128 the brake pressure at the inner wheel 14B is reduced by the controller 18, and simultaneously in block 130 the brake pressure at each other wheel 14A, 12A, 12B of the vehicle is increased by the controller 18.

[0040] The verification test includes the diagnostic evaluation of the data received from the first, second, and third sensors 22, 24, 26 to check whether the sensors 22, 24, 26 are functioning correctly. If no data is received from one or more of the sensors 22, 24, 26, or if the received data is unreliable, the verification test fails and the brake system returns to normal operation.

[0041] To ensure that the inner rotary wheel 14B can rotate freely while being turned, the following measures are taken: reducing the brake pressure on the inner rotary wheel 14B with the control 18 when the vehicle speed is zero and the angular position 28 of the steering wheel 30 exceeds a predetermined value; reducing the brake pressure on the inner rotary wheel 14B with the control 18 when the vehicle speed is zero and the force required to turn the inner rotary wheel 14B exceeds a predetermined value; reducing the brake pressure on the inner turning wheel 14B with the controller 18 when the vehicle speed is zero and the force required to turn the inner turning wheel 14B of the vehicle exceeds a predetermined value; and further reducing the brake pressure on the inner turning wheel 14B to zero with the controller 18.In one exemplary embodiment, the brake pressure at the inner rotary wheel 14B is gradually reduced from a normal brake pressure to zero. In another exemplary embodiment, the brake pressure at the inner rotary wheel 14B is gradually reduced from a normal brake pressure to zero.

[0042] A braking system 10 and a method 100 of the present disclosure offer the advantage that the inner wheel can rotate freely while it is being turned, and that the rubbing / scraping of the tire on the road surface is reduced or eliminated, thereby reducing the force required to turn the inner wheel.

[0043] The description of the present revelation is merely exemplary, and variations that do not deviate from the core of the present revelation are to fall within its scope. Such variations are not to be considered a deviation from the spirit and scope of the present revelation.

Claims

[1] A braking system for a motor vehicle, comprising: a control system capable of independently controlling the brake pressure at each wheel of the motor vehicle when a driver of the motor vehicle applies the brakes; a first sensor suitable for measuring the angular position of a motor vehicle's steering wheel and transmitting the steering wheel's angular position to the control unit; and a second sensor suitable for measuring the speed of the vehicle and transmitting the speed of the vehicle to the control unit; The control system is further designed to reduce the brake pressure on an inside wheel when the vehicle speed is zero and the steering wheel angle exceeds a predetermined value. [2] Braking system according to claim 1, further comprising a third sensor configured to measure a force required to rotate the inner wheel of the motor vehicle and transmitting the force to the control unit, the control unit being configured to reduce the brake pressure on the inner wheel when the speed of the vehicle is zero and the force required to rotate the inner wheel of the motor vehicle exceeds a predetermined value. [3] Braking system according to claim 2, wherein the control is designed to increase the brake pressure at each remaining wheel of the motor vehicle when the brake pressure at the inner wheel is reduced. [4] Braking system according to claim 3, wherein the control, when it reduces the pressure of the inner wheel, reduces the brake pressure at the inner wheel to zero. [5] Braking system according to claim 4, wherein, when the control reduces the pressure of the inner wheel, the control can gradually reduce the brake pressure at the inner wheel from a normal brake pressure to zero. [6] Braking system according to claim 4, wherein the control, when reducing the pressure of the inner wheel, can reduce the brake pressure at the inner wheel as a step function from a normal brake pressure to zero. [7] Braking system according to claim 6, wherein the control is designed to reduce the brake pressure on the inside wheel when the speed of the vehicle is zero and the angle of the steering wheel exceeds a predetermined value and the force required to turn the inside wheel of the motor vehicle exceeds a predetermined value. [8] Method for controlling a braking system for a motor vehicle comprising: Independent control of the brake pressure at each wheel of the motor vehicle with a control unit when a driver of the motor vehicle applies the brakes; Detecting the vehicle's speed with a second sensor and transmitting the vehicle's speed to the control system; Detecting the angular position of a steering wheel within the motor vehicle using a first sensor and transmitting the angular position of the steering wheel to the control unit; and The control system reduces the brake pressure on an inward-facing wheel when the vehicle speed is zero and the steering wheel angle exceeds a predetermined value. [9] Method according to claim 8, further comprising detecting a force required to rotate the inner wheel of the motor vehicle with a third sensor and transmitting the force to the control unit, and reducing the brake pressure on the inner wheel with the control unit when the speed of the vehicle is zero and the force required to rotate the inner wheel of the motor vehicle exceeds a predetermined value. [10] Method according to claim 9, wherein the brake pressure at each remaining wheel of the motor vehicle with the control is increased when the brake pressure at the inner wheel of the motor vehicle with the control is decreased.

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