CN-121989885-A - Method and device for determining contact point position of brake disc and friction plate and vehicle

CN121989885ACN 121989885 ACN121989885 ACN 121989885ACN-121989885-A

Abstract

The invention discloses a method and a device for determining the position of a contact point between a brake disc and a friction plate and a vehicle, and relates to the technical field of vehicle braking systems. The method comprises the steps of obtaining a rotation angle of a brake motor of a vehicle, calculating a rotation angle change rate of the brake motor, and outputting a current learned contact point position or a contact point position at the last moment according to the rotation angle change rate of the brake motor. The invention can realize the improvement of the braking efficiency of the vehicle and the braking safety of the vehicle by utilizing the rotation angle identification of the braking motor to determine the position of the contact point, and does not need to increase additional cost.

Inventors

LI GUANGYA
ZUO MENGNAN
TONG BING

Assignees

耐世特汽车系统（苏州）有限公司

Dates

Publication Date: 20260508
Application Date: 20241108

Claims (10)

1. A method of determining a location of a contact point between a brake disc and a friction plate, the method comprising: Acquiring state information of a current vehicle, and judging whether the vehicle meets the learning condition of a contact point position according to the state information, wherein the contact point position is a point where a brake disc of the vehicle contacts a friction plate but does not generate clamping force; If so, acquiring the rotation angle of a brake motor of the vehicle, and calculating the rotation angle change rate of the brake motor; And outputting the current learned contact point position or the contact point position at the last moment according to the rotation angle change rate of the brake motor.
2. The method for determining the position of a contact point between a brake disc and a friction plate according to claim 1, wherein outputting the current learned position of the contact point or the position of the contact point at the previous time based on the rotation angle change rate of the brake motor comprises: Judging whether the abrupt change value of the rotation angle change rate of the brake motor is in a preset threshold range or not; When the abrupt change value of the rotation angle change rate of the brake motor is in the preset threshold range, taking the current piston position as the contact point position at the current moment, and outputting the contact point position at the current moment; And outputting the contact point position at the last moment when the abrupt change value of the rotation angle change rate of the brake motor is not in the preset threshold range.
3. The method for determining the position of a contact point between a brake disc and a friction plate according to claim 1, wherein acquiring state information of a current vehicle, and determining whether the vehicle satisfies a learning condition of the contact point position based on the state information, comprises: Acquiring steering state information of a current vehicle, and judging whether the vehicle meets the enabling condition of contact point position learning according to the steering state information; if so, acquiring the trampling angle change rate of the vehicle brake pedal; judging the braking state of the current vehicle according to the trampling angle change rate, and judging whether the vehicle meets the activation condition of contact point position learning according to the braking state of the current vehicle; wherein the state information includes steering state information and the pedal angle change rate, and the learning condition includes an activation condition of the contact point position learning and an enabling condition of the contact point position learning.
4. The method for determining the position of a contact point between a brake disc and a friction plate according to claim 3, wherein the step of acquiring the steering state information of the current vehicle and determining whether the vehicle satisfies the enabling condition for the contact point position learning based on the steering state information comprises: Acquiring the steering state information of the current vehicle; when all signals in the steering state information meet corresponding preset threshold conditions, judging that the enabling conditions of the contact point position learning are met, wherein the steering system basic information comprises steering wheel angles, steering wheel angular acceleration, yaw rate, four-wheel left and right wheel speeds and lateral acceleration of the vehicle, and the preset threshold conditions of the vehicles of different models are different.
5. The method for determining the position of the contact point between the brake disc and the friction plate according to claim 3, wherein the step-on angle change rate is used for determining the braking state of the current vehicle, judging whether the vehicle meets the activation condition of the contact point position learning according to the current braking state of the vehicle, and further comprising: and determining the braking state of the current vehicle according to the trampling angle change rate, and determining that the activation condition for the contact point position learning is met when the braking state of the current vehicle is a non-emergency braking state.
6. The method for determining the position of the contact point between the brake disc and the friction plate according to claim 5, wherein the determining the braking state of the current vehicle according to the rate of change of the pedal angle includes: When the trampling angle change rate is larger than the preset trampling angle change rate, judging that the braking state of the current vehicle is an emergency braking state; And when the trampling angle change rate is smaller than the preset trampling angle change rate, judging that the current braking state of the vehicle is the non-emergency braking state.
7. A method for determining a contact point position of a brake disc and a friction plate according to claim 3, wherein the obtaining a tread angle change rate of a brake pedal of a vehicle includes: And acquiring the real-time position of the vehicle brake pedal, and performing differential calculation according to the real-time position of the vehicle brake pedal to obtain the trampling angle change rate.
8. A brake disc and friction plate contact point position determining apparatus for performing the brake disc and friction plate contact point position determining method according to any one of claims 1 to 7, the determining apparatus comprising: the learning judgment module is used for acquiring the state information of the current vehicle and judging whether the vehicle meets the learning condition of the contact point position according to the state information, wherein the contact point position is a point where a brake disc of the vehicle contacts a friction plate but does not generate clamping force; the calculation module is used for acquiring the rotation angle of the braking motor of the vehicle and calculating the rotation angle change rate of the braking motor if the state information judges that the vehicle meets the learning condition of the contact point position; and the output module is used for outputting the current learned contact point position or the contact point position at the last moment according to the change rate of the rotation angle of the brake motor.
9. The brake disc and friction plate contact point position determining device of claim 8, wherein the output module comprises: The judging unit is used for judging whether the abrupt change value of the rotation angle change rate of the brake motor is in a preset threshold range or not; The first output unit is used for taking the current piston position as the contact point position at the current moment and outputting the contact point position at the current moment when the abrupt change value of the rotation angle change rate of the brake motor is in the preset threshold range; And the second output unit is used for outputting the contact point position at the last moment when the abrupt change value of the rotation angle change rate of the brake motor is not in the preset threshold range.
10. A vehicle comprising a brake disc and friction plate contact point position determining device according to any one of claims 8 to 9.

Description

Method and device for determining contact point position of brake disc and friction plate and vehicle Technical Field The embodiment of the invention relates to the technical field of vehicle braking systems, in particular to a method and a device for determining the position of a contact point between a brake disc and a friction plate and a vehicle. Background In recent years, new energy automobiles are increasingly widely applied, and the braking performance is one of important performance indexes of the automobiles and directly relates to traffic safety. The electromechanical brake system (Electronic Mechanical Brake, EMB) is one of the hot spots of current drive-by-wire chassis research, and the use of an electronic controller and a mechanical actuator to directly apply braking force to the wheel end significantly reduces system components, has faster response speed and higher wheel end execution flexibility, and is a high-integration solution of the brake system. In EMB, the piston pushes the friction plate through a hydraulic force transmission pipeline to overcome friction generated by a braking gap between the piston and a brake disc, so that mechanical braking is realized, and when hydraulic pressure is released, the piston returns through a hydraulic elastic element to prevent dragging. However, as the vehicle travels, the friction plates wear and become thinner, and when the friction plates wear to a limit, the friction plates need to be replaced. However, before the friction plate wears to the limit, a point (simply referred to as a contact point) where the brake disc contacts the friction plate but does not generate a clamping force is generated between the brake disc and the friction plate, and as the friction plate wears, the contact point also changes, and the change of the contact point affects position control in EMB operation, such as pre-clamping function, rollback and tightening force, so that the braking efficiency of the vehicle is reduced, and the braking safety of the vehicle is affected. Disclosure of Invention The invention provides a method and a device for determining the position of a contact point between a brake disc and a friction plate and a vehicle, so as to improve the braking efficiency of the vehicle, improve the braking safety of the vehicle and avoid the addition of extra cost. In a first aspect, an embodiment of the present invention provides a method for determining a contact point position between a brake disc and a friction plate, where the method includes: Acquiring state information of a current vehicle, and judging whether the vehicle meets the learning condition of a contact point position according to the state information, wherein the contact point position is a point where a brake disc of the vehicle contacts a friction plate but does not generate clamping force; If so, acquiring the rotation angle of a brake motor of the vehicle, and calculating the rotation angle change rate of the brake motor; And outputting the current learned contact point position or the contact point position at the last moment according to the rotation angle change rate of the brake motor. Further, the outputting the current learned contact point position or the contact point position at the previous moment according to the change rate of the rotation angle of the brake motor includes: Judging whether the abrupt change value of the rotation angle change rate of the brake motor is in a preset threshold range or not; When the abrupt change value of the rotation angle change rate of the brake motor is in the preset threshold range, taking the current piston position as the contact point position at the current moment, and outputting the contact point position at the current moment; And outputting the contact point position at the last moment when the abrupt change value of the rotation angle change rate of the brake motor is not in the preset threshold range. Further, acquiring state information of a current vehicle, and judging whether the vehicle meets learning conditions of contact point positions according to the state information, wherein the method comprises the following steps: Acquiring steering state information of a current vehicle, and judging whether the vehicle meets the enabling condition of contact point position learning according to the steering state information; if so, acquiring the trampling angle change rate of the vehicle brake pedal; judging the braking state of the current vehicle according to the trampling angle change rate, and judging whether the vehicle meets the activation condition of contact point position learning according to the braking state of the current vehicle; wherein the state information includes steering state information and the pedal angle change rate, and the learning condition includes an activation condition of the contact point position learning and an enabling condition of the contact point position learning. Optionally, the obtaining t