CN118046875A - Braking clearance compensation method, braking system and vehicle - Google Patents

Abstract

The invention relates to a braking clearance compensation method, a braking system and a vehicle, and relates to the technical field of vehicle braking. The method comprises the steps of obtaining a braking instruction and sending a clamping instruction according to the braking instruction; determining the position of a piston, wherein the initial position of the piston is a zero position, and when the friction plate is not worn, the piston pushes the friction plate to reach the initial movement distance of the contact surface of the brake disc, wherein the initial movement distance is S0; when the clamping instruction is executed, the piston position is synchronously calculated, and the contact point is identified; the contact point position when the friction plate is not worn is the initial contact point position; when the piston moves towards the direction of the brake disc by a distance S1, a contact point refreshing condition is met, the contact point position is refreshed into a first contact point position, and the first contact point position is sent to a release control module; the release instruction is acquired, the release control module controls the piston to move for a distance S0 away from the direction of the brake disc, the position of the piston is controlled at a position S1-S0 away from the zero position, consistency of braking feeling is guaranteed, automatic compensation of braking clearance is achieved, and stability and safety of the whole vehicle braking process are improved.

Description

Braking clearance compensation method, braking system and vehicle

Technical Field

The present invention relates to the technical field of vehicle braking systems, and in particular to a braking clearance compensation method, a braking system and a vehicle.

Background technique

In recent years, new energy vehicles have been used more and more widely. Braking performance is one of the important performance indicators of automobiles and is directly related to traffic safety. The electronic mechanical brake system (EMB) is one of the hot spots in the field of wire-controlled chassis. It uses electronic controllers and mechanical actuators to directly apply braking force to the wheel end, significantly reducing system components. At the same time, it has faster response speed and higher wheel end execution flexibility. It is a highly integrated solution for the braking system. The original hydraulic brake system uses hydraulic power transmission pipelines to make the piston push the friction lining to overcome the friction caused by the brake clearance with the brake disc to achieve mechanical braking. When the hydraulic pressure is released, the piston is returned to its position through the hydraulic elastic element to prevent dragging. When the friction lining is worn, the relative displacement of the hydraulic elastic element and the piston is also used to achieve automatic adjustment of the brake clearance. However, the electronic mechanical brake system cancels the hydraulic power transmission pipeline and the related hydraulic elastic element, thereby losing the automatic adjustment mechanism of the brake clearance. If there is no clearance self-adjustment mechanism, the brake clearance will increase with the wear of the friction lining, resulting in braking delay. It is urgent to enable the electronic mechanical brake system to have a clearance self-adjustment function through software control algorithms.

Therefore, it is desired to provide a brake clearance compensation method, a brake system and a vehicle, comprising obtaining a brake instruction, sending a clamping instruction according to the brake instruction; determining the piston position, wherein the initial position of the piston is the zero position, and when the friction plate is not worn, the initial movement distance of the piston pushing the friction plate to reach the contact surface of the brake disc is S0; when the clamping instruction is executed, the piston position is synchronously calculated, and the contact point is identified; the contact point position when the friction plate is not worn is the initial contact point position; when the piston moves toward the brake disc for a distance of S1, the contact point refresh condition is met, the contact point position is refreshed to the first contact point position, and is sent to a release control module; obtaining a release instruction, the release control module controls the piston to move away from the brake disc for a distance of S0, and controls the piston position at a distance of S1-S0 from the zero position, so as to ensure the consistency of the braking feeling and realize automatic compensation of the brake clearance, so as to improve the stability and safety of the braking process of the whole vehicle.

Summary of the invention

According to a first aspect of some embodiments of the present invention, a brake clearance compensation method is provided, which may include obtaining a brake instruction, sending a clamping instruction according to the brake instruction; determining a piston position, wherein an initial position of the piston is a zero position, and when the friction plate is not worn, an initial movement distance S0 of the piston pushing the friction plate to reach a contact surface of a brake disc is; when the clamping instruction is executed, the piston position is synchronously calculated, and contact point identification is performed; the contact point position when the friction plate is not worn is an initial contact point position; when the piston moves a distance S1 toward the brake disc, a contact point refresh condition is satisfied, the contact point position is refreshed to a first contact point position, and is sent to a release control module; obtaining a release instruction, the release control module controls the piston to move a distance S0 away from the brake disc, and controls the piston position at a distance S1-S0 from the zero position.

In some embodiments, the first contact point position is the contact point position when the friction plate is worn; when the braking command is obtained again, the piston completes the clamping command when it moves a distance S0 toward the brake disc from the zero position S1-S0, thereby compensating for the gap between the friction plate and the brake disc when the friction plate is worn.

In some embodiments, the determining of the piston position specifically includes: acquiring a real-time sensor motor angle through a position sensor of the motor, and determining the piston position by performing integral calculation according to actuator parameters.

In some embodiments, the step of determining the piston position by integrating the actuator parameters specifically includes: Wherein, S is the piston position, θ is the mechanical angle of rotation of the motor, k is the transmission ratio of the speed reduction and torque increase mechanism, p is the thread pitch, and r is the pitch circle radius.

In some embodiments, the contact point identification specifically includes S201, determining the real-time clamping force, and judging whether the real-time clamping force is credible; S202, if credible, judging whether the real-time clamping force is less than a first clamping force threshold; S203, if less than, determining the real-time piston position, and judging whether the real-time piston position is less than the first piston position threshold; S204, if less than, increasing the real-time clamping force to the second clamping force, and judging whether the second clamping force is greater than the second clamping force threshold; S205, if greater than, refreshing the contact point position and sending it to the release control module.

In some embodiments, if the real-time clamping force is not reliable, the real-time clamping force is determined by the current of the motor.

In some embodiments, if the real-time clamping force is not less than the first clamping force threshold, or if the real-time piston position is not less than the first piston position threshold, or if the second clamping force is not greater than the second clamping force threshold, the contact point position is not updated.

According to a second aspect of some embodiments of the present invention, a braking system is provided for executing the braking clearance compensation method of the present application, wherein the system may include an upper-level control system for sending instructions to an execution control system according to a braking intention; an execution control system for controlling an actuator according to the instructions of the upper-level control system; an actuator for executing the braking intention according to the control of the execution control system; the instructions of the upper-level control system include clamping instructions and release instructions, and the actuator specifically includes a motor and a motor controller, and the motor controller drives the motor to rotate forward according to the clamping instruction to complete clamping, or drives the motor to rotate reversely according to the release instruction to complete release; the motor includes a deceleration and torque-increasing mechanism, and the deceleration and torque-increasing mechanism includes a motion conversion mechanism, which pushes the friction plate to press the brake disc through the translation of the screw nut.

In some embodiments, the execution control system specifically includes a piston position calculation module, which calculates the piston position according to the angle of the motor and the parameters of the actuator; a contact point identification module, which refreshes the contact point position according to the clamping force, current and piston position of the actuator; a clamping control module, which drives the motor to rotate forward based on the piston position and the clamping force of the actuator according to the clamping instruction, thereby completing the clamping of the actuator; a release control module, which drives the motor to reverse based on the piston position and the contact point position according to the release instruction, thereby controlling the piston position to be at a position within a preset threshold distance from the contact point position; and a clamping or release arbitration module, which determines the torque of the motor according to the instructions of the upper control system.

A vehicle provided according to the present invention applies the braking system of the present application and executes the braking clearance compensation method of the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

To better understand and illustrate some embodiments of the present invention, the following description of the embodiments will be made with reference to the accompanying drawings, in which like reference numerals indicate corresponding parts throughout the drawings.

FIG. 1 is an exemplary schematic diagram of a first embodiment of a braking system provided according to some embodiments of the present invention.

FIG. 2 is an exemplary schematic diagram of a second embodiment of a braking system provided according to some embodiments of the present invention.

FIG. 3 is an exemplary schematic diagram of a third embodiment of a braking system provided according to some embodiments of the present invention.

FIG. 4 is an exemplary schematic diagram of a brake system actuator according to some embodiments of the present invention.

FIG. 5 is an exemplary flow chart of a brake clearance compensation method according to some embodiments of the present invention.

FIG. 6 is an exemplary flow chart of contact point identification according to some embodiments of the present invention.

Detailed ways

The following description with reference to the accompanying drawings is intended to facilitate a comprehensive understanding of various embodiments of the present invention as defined by the claims and their equivalents. These embodiments include various specific details to facilitate understanding, but these are only considered exemplary. Therefore, it will be appreciated by those skilled in the art that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present invention. In addition, in order to briefly and clearly describe the present invention, the present invention will omit the description of known functions and structures.

The terms and phrases used in the following specification and claims are not limited to the literal meanings, but are only to enable a clear and consistent understanding of the present invention. Therefore, it will be appreciated by those skilled in the art that the description of various embodiments of the present invention is provided only for the purpose of illustration, rather than to limit the present invention defined by the appended claims and their equivalents.

The following will be combined with the drawings in some embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that the terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms of "one", "a", "a kind of", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and/or" used in the present invention refers to and includes any or all possible combinations of one or more bound listed items. The expressions "first", "second", "the first" and "the second" are used to modify the corresponding elements without considering the order or importance, and are only used to distinguish one element from another element, without limiting the corresponding elements.

The embodiment of the present invention provides a brake clearance compensation method, a brake system and a vehicle. To facilitate understanding of the embodiment of the present invention, the embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG1 is an exemplary schematic diagram of a braking system embodiment 1 provided according to some embodiments of the present invention. As shown in FIG1 , the braking system may include an upper control system that sends instructions to an execution control system according to a braking intention; an execution control system that controls an actuator according to the instructions of the upper control system; and an actuator that executes the braking intention according to the control of the execution control system. In some embodiments, the upper control system is connected in communication with the execution control system, and the execution control system is connected in communication with the actuator.

According to some embodiments of the present application, the actuator may include a motor and a motor controller, and the motor or the motor controller may integrate an angle sensor and a current sensor. The angle sensor is used to obtain the real-time angle of the motor, and the current sensor is used to obtain the real-time current of the motor. In some embodiments, the instructions of the upper control system include clamping instructions and release instructions, and the motor controller drives the motor to rotate forward to complete clamping according to the clamping instruction, or drives the motor to rotate reversely to complete release according to the release instruction.

In some embodiments, the motor may include a deceleration and torque-increasing mechanism, and the deceleration and torque-increasing mechanism includes a motion conversion mechanism, which pushes the friction plate to press the brake disc through the translation of the screw nut. As an example, the motion conversion mechanism determines the clamping force of the friction plate on the brake disc through the position, speed or current of the motor. For another example, the motion conversion mechanism may further integrate a force sensor, and the force sensor is used to obtain the clamping force of the friction plate on the brake disc.

According to some embodiments of the present application, the execution control system may include a piston position calculation module, which calculates the piston position based on the angle of the motor and the parameters of the actuator; a contact point identification module, which refreshes the contact point position based on the clamping force, current and piston position of the actuator; a clamping control module, which drives the motor to rotate forward based on the piston position and the clamping force of the actuator according to a clamping instruction, thereby completing the clamping of the actuator; a release control module, which drives the motor to reverse based on the piston position and the contact point position according to a release instruction, thereby controlling the piston position to be at a position within a preset threshold distance from the contact point position; and a clamping or releasing arbitration module, which determines the torque of the motor according to the instructions of the upper control system.

According to some embodiments of the present application, the instructions sent by the upper control system may include clamping instructions and release instructions, and the clamping or release instructions are sent to the clamping or release arbitration module, contact point identification module, etc. of the execution control system. In some embodiments, the piston position calculation module can obtain the position information such as the motor angle fed back by the actuator, and send it to the clamping control module, the release control module, and the contact point identification module after determining the piston position. The contact point identification module can obtain the clamping or release instructions, piston position, clamping force fed back by the actuator, motor current, etc. sent by the upper control system, and send it to the release control module after determining the contact point position. The clamping control module can obtain the piston position, the clamping force fed back by the actuator, etc., determine the clamping torque and send it to the clamping or release arbitration module. The release control module can obtain the piston position, the contact point position, the clamping force fed back by the actuator, etc., determine the release torque and send it to the clamping or release arbitration module. The clamping or release arbitration module obtains the clamping or release instructions, the clamping torque, and the release torque, and determines the motor torque and sends it to the actuator. The actuator obtains the motor torque and executes the clamping or releasing instruction, and feeds back the clamping force, motor current, motor angle and other information to the clamping control module, release control module, contact point identification module, piston position calculation module, etc.

FIG2 is an exemplary schematic diagram of a second embodiment of a braking system provided according to some embodiments of the present invention. As shown in FIG2 , the braking system may include an upper control system, an execution control system, an actuator, and further include a brake pedal, an after-sales diagnostic instrument, a human-computer interaction interface, etc. In some embodiments, the upper control system may include a braking intention recognition module, an upper clamping or releasing arbitration module, a friction lining replacement control module, a wear alarm module, a braking force distribution module, etc. The wear alarm module is used for friction lining wear alarm; the friction lining replacement control module is used to send a friction lining (friction lining) replacement request, etc. In some embodiments, the clamping or releasing arbitration module of the execution control system is specifically an execution layer clamping or releasing arbitration module. As an example, the upper control system may send instructions including clamping instructions and releasing instructions, and the clamping or releasing instructions are sent to the execution layer clamping or releasing arbitration module of the execution control system through the upper clamping or releasing arbitration module of the upper control system. The execution control system may include a first execution control system (execution control system 1), a second execution control system (execution control system 2), a third execution control system (execution control system 3), and a fourth execution control system (execution control system 4).

FIG3 is an exemplary schematic diagram of a third embodiment of a brake system provided according to some embodiments of the present invention. As shown in FIG3, a first execution control system (execution control system 1), a second execution control system (execution control system 2), a third execution control system (execution control system 3), and a fourth execution control system (execution control system 4) can be respectively arranged at the wheel ends of the vehicle and communicated with the upper control system. In some embodiments, the upper control system can communicate with a brake pedal, a human-computer interaction interface, an after-sales diagnostic instrument, etc., and obtain information such as the brake pedal, the human-computer interaction interface, and the after-sales diagnostic instrument.

According to some embodiments of the present application, the upper control system can be used to determine the driver's braking intention and the system control mode, etc. The execution control system can be used to control the actuator to complete clamping or releasing, and feed back the actuator state to the upper control system. As an example, each wheel is integrated with a set of actuators, and the braking system is correspondingly integrated with four sets of execution control systems, and the four sets of execution control systems have the same system architecture. The brake pedal can be used to obtain the driver's braking intention. The after-sales diagnostic instrument can be used to send a friction plate replacement start request to the upper control system when replacing the friction plate; when the friction plate replacement is completed, a friction plate replacement end request is sent to the upper control system. The human-computer interaction interface can prompt the driver with alarm information through indicator lights or text when receiving the alarm flag.

FIG4 is an exemplary schematic diagram of a brake system actuator according to some embodiments of the present invention. As shown in FIG4 , the actuator may include a piston, a friction plate, a brake disc, a transmission mechanism, etc. In some embodiments, a force sensor may be integrated inside the transmission mechanism. For example, the force sensor is used to obtain the clamping force of the friction plate on the brake disc.

FIG5 is an exemplary flow chart of a brake clearance compensation method according to some embodiments of the present invention. As shown in FIG5 , the process 100 of the brake clearance compensation method may include:

S101, obtaining a braking instruction, and sending a clamping instruction according to the braking instruction. In some embodiments, the upper control system may send a clamping instruction or a releasing instruction to the execution control system according to the braking intention of the user (driver) or the intelligent driving system.

S102, determine the piston position, the initial position of the piston is the zero position, when the friction plate is not worn, the initial movement distance of the piston pushing the friction plate to the brake disc contact surface is S0. In some embodiments, the piston position calculation module can calculate the piston position according to the angle of the motor and the parameters of the actuator. As an example, the piston position can be determined by obtaining the real-time sensor motor angle through the position sensor of the motor, and the piston position can be determined by performing integral calculation according to the parameters of the actuator:

Wherein, S is the piston position, θ is the mechanical angle of rotation of the motor, k is the transmission ratio of the speed reduction and torque increase mechanism, p is the thread pitch, and r is the pitch circle radius.

S103, when executing the clamping instruction, synchronously calculate the piston position and perform contact point identification; the contact point position when the friction plate is not worn is the initial contact point position. In some embodiments, the contact point identification module can refresh the contact point position according to the clamping force and current of the actuator and the piston position. In some embodiments, when executing the clamping instruction, it specifically includes the upper control system choosing to enable or disable contact point identification, if disabled, no contact point identification is performed, or if enabled, contact point identification is performed. When the upper control system chooses to enable contact point identification, the contact point identification process 200 is specifically shown in Figure 6.

S104, when the piston moves toward the brake disc for a distance of S1, the contact point refresh condition is satisfied, the contact point position is refreshed to the first contact point position, and sent to the release control module. In some embodiments, the contact point recognition module can determine that the contact point refresh condition is satisfied and refresh the contact point position, and synchronously send the refreshed contact point position to the release control module. As an example, the movement direction of the piston can be perpendicular to the direction of the brake disc, and when the clamping command is executed, the piston moves toward the brake disc along an axis perpendicular to the brake disc.

S105, obtain a release instruction, and the release control module controls the piston to move a distance S0 away from the brake disc, and controls the piston position at a distance S1-S0 from the zero position. In some embodiments, the release control module can drive the motor to reverse based on the piston position and the contact point position according to the release instruction, and control the piston position to a position away from the contact point position by a preset threshold. As an example, when the release instruction is executed, the piston moves away from the brake disc along an axis perpendicular to the brake disc. It should be noted that the piston position is controlled at a distance S1-S0 from the zero position, and the distance between the piston position and the brake disc is shortened by S1-S0 relative to the zero position.

According to some embodiments of the present application, the first contact point position is the contact point position when the friction plate is worn; when the braking command is obtained again, the piston moves S0 distance from the zero position S1-S0 toward the brake disc to complete the clamping command, compensate the gap between the friction plate and the brake disc when it is worn, and realize automatic compensation of the brake clearance. As an example, the initial position of the piston is the zero position, the contact point position when the friction plate is not worn is the initial contact point position, and the initial movement distance of the piston pushing the friction plate to reach the brake disc contact surface (initial contact point position) is S0; the contact point position when the friction plate is worn is the first contact point position, and the movement distance of the piston pushing the friction plate to reach the brake disc contact surface (first contact point position) is S1; according to the release command, the release control module controls the piston to move S0 distance away from the brake disc, that is, the piston position is controlled at the distance S1-S0 from the zero position, and when the clamping command is executed again, the piston movement distance is S1-(S1-S0)=S0, so as to realize automatic compensation of the brake clearance. It should be noted that the values corresponding to S0, S1, etc. are distances, and S1-S0 is the difference calculation of the distances.

FIG6 is an exemplary flow chart of contact point identification according to some embodiments of the present invention. As shown in FIG6 , the process 200 of contact point identification may include:

S201, determine the real-time clamping force, and judge whether the real-time clamping force is credible. In some embodiments, the contact point identification module can judge whether the real-time clamping force is credible based on the clamping instruction of the upper control system, the clamping force fed back by the actuator, etc. As an example, if the real-time clamping force is credible, proceed to S202; if the real-time clamping force is not credible, proceed to S206.

S202, if credible, determine whether the real-time clamping force is less than the first clamping force threshold. In some embodiments, the first clamping force threshold may be a larger clamping force threshold. If the current clamping force is greater than the threshold, the piston position is far beyond the contact point position, and the contact point cannot be identified during this braking. As an example, the larger clamping threshold of the first clamping force threshold may be 2000N. If the current real-time clamping force is less than the threshold, proceed to S203; if the current real-time clamping force is greater than or equal to the threshold, proceed to S207.

S203, if less than, determine the real-time piston position, and judge whether the real-time piston position is less than the first piston position threshold. In some embodiments, the first piston position threshold can be a larger piston position threshold. The current piston position is greater than the threshold. At this time, the piston position has far exceeded the theoretical maximum contact point position, and the contact point cannot be identified during this braking. As an example, the piston position threshold of the first piston position threshold can be 10mm or 40mm reversed. If the current real-time piston position is less than the threshold, enter S204; if the current real-time piston position is greater than or equal to the threshold, enter S207.

S204, if it is less than, increase the real-time clamping force to the second clamping force, and determine whether the second clamping force is greater than the second clamping force threshold. In some embodiments, the second clamping force threshold can be a smaller clamping force threshold. If the current clamping force is slightly larger than the threshold, it means that the piston with friction plate has slightly contacted the brake disc at this time, and this position can be used as the contact point. As an example, the smaller clamping threshold of the second clamping force threshold can be 50N. If the current real-time clamping force is greater than the threshold, enter S205; if the current real-time clamping force is less than or equal to the threshold, enter S207.

S205, if greater than, refresh the contact point position and send it to the release control module. In some embodiments, the contact point identification module can determine that the contact point refresh condition is met and refresh the contact point position, and synchronously send the refreshed contact point position to the release control module.

If the real-time clamping force is not credible, the process proceeds to S206, where the real-time clamping force is determined by the current of the motor. In some embodiments, the motion conversion mechanism can determine the clamping force of the friction plate on the brake disc by the position, speed or current of the motor. For another example, the motion conversion mechanism can be integrated with a force sensor, which is used to obtain the clamping force of the friction plate on the brake disc. As an example, when the brake is applied twice in succession, the first brake is not released (there is braking), and the clamping force associated with the second brake is not credible, then the brake is not applied.

If the real-time clamping force is not less than the first clamping force threshold, or if the real-time piston position is not less than the first piston position threshold, or if the second clamping force is not greater than the second clamping force threshold, enter S207 and do not update the contact point position. As an example, when the motor reverses and drives the piston to move, causing the actual clamping force to not match the actual piston position, the clamping force is too large, for example, greater than the first clamping force threshold, and the contact point position is not updated.

According to some embodiments of the present application, the vehicle of the present application may include a braking system applying the present application and execute the above-mentioned braking clearance compensation method. The braking system may include an upper control system that sends instructions to an execution control system according to a braking intention; an execution control system that controls an execution mechanism according to the instructions of the upper control system; and an execution mechanism that executes the braking intention according to the control of the execution control system.

It should be noted that the above description of the brake system and the brake clearance compensation method is only for convenience of description and does not limit the present invention to the scope of the embodiments. It is understandable that for those skilled in the art, based on the principle of the present device, it is possible to arbitrarily combine the various structures, or to form a substructure and combine it with other structures, and to make various modifications and changes in form and details to the functions of implementing the above-mentioned devices and operations without departing from the principle. For example, the brake system may further include a friction plate wear alarm and/or replacement function. Such variations are all within the scope of protection of the present invention.

In summary, the brake clearance compensation method, brake system and vehicle of the present invention include obtaining a brake instruction, sending a clamping instruction according to the brake instruction; determining the piston position, the initial position of the piston is the zero position, when the friction plate is not worn, the initial movement distance of the piston pushing the friction plate to reach the brake disc contact surface is S0; when the clamping instruction is executed, the piston position is synchronously calculated, and the contact point is identified; the contact point position when the friction plate is not worn is the initial contact point position; when the piston moves toward the brake disc for a distance of S1, the contact point refresh condition is met, the contact point position is refreshed to the first contact point position, and sent to the release control module; obtaining a release instruction, the release control module controls the piston to move away from the brake disc for a distance of S0, and controls the piston position at a distance of S1-S0 from the zero position, so as to ensure the consistency of the braking feeling and realize automatic compensation of the brake clearance, so as to improve the stability and safety of the braking process of the whole vehicle.

It should be noted that the above-described embodiments are merely examples, and the present invention is not limited to such examples but can be variously modified.

It should be noted that, in this specification, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

The above disclosures are only some preferred embodiments of the present invention, which cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the structures of the above embodiments and equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims (10)

1. A brake clearance compensation method, characterized in that: Obtaining a braking instruction, and sending a clamping instruction according to the braking instruction; Determine the piston position, the initial position of the piston is the zero position, when the friction plate is not worn, the initial movement distance of the piston pushing the friction plate to reach the brake disc contact surface is S0; When the clamping instruction is executed, the piston position is calculated synchronously and the contact point is identified; the contact point position when the friction plate is not worn is the initial contact point position; When the piston moves toward the brake disc by a distance of S1 and the contact point refresh condition is met, the contact point position is refreshed to the first contact point position and sent to the release control module; A release instruction is obtained, and the release control module controls the piston to move a distance S0 away from the brake disc, and controls the piston position to be at a distance S1-S0 from the zero position. 2. The method according to claim 1 is characterized in that the first contact point position is the contact point position when the friction plate is worn; when the braking command is obtained again, the piston completes the clamping command when it moves a distance S0 toward the brake disc from the zero position S1-S0, thereby compensating for the gap between the friction plate and the brake disc when the friction plate is worn. 3. The method according to claim 1 is characterized in that the determining of the piston position specifically comprises: obtaining a real-time sensor motor angle through a motor position sensor, and determining the piston position by performing integral calculation according to the parameters of the actuator. 4. The method according to claim 3, characterized in that the step of determining the piston position by integrating the parameters of the actuator comprises: Wherein, S is the piston position, θ is the mechanical angle of rotation of the motor, k is the transmission ratio of the speed reduction and torque increase mechanism, p is the thread pitch, and r is the pitch circle radius. 5. The method according to claim 1, wherein the contact point identification specifically comprises: S201, determining the real-time clamping force and judging whether the real-time clamping force is credible; S202, if credible, determine whether the real-time clamping force is less than a first clamping force threshold; S203, if less than, determine the real-time piston position, and judge whether the real-time piston position is less than the first piston position threshold; S204, if it is less than, increase the real-time clamping force to the second clamping force, and determine whether the second clamping force is greater than the second clamping force threshold; S205: If it is greater, refresh the contact point position and send it to the release control module. 6 . The method according to claim 5 , characterized in that, if the real-time clamping force is not credible, the real-time clamping force is determined by the current of the motor. 7. The method according to claim 5 is characterized in that if the real-time clamping force is not less than the first clamping force threshold, or if the real-time piston position is not less than the first piston position threshold, or if the second clamping force is not greater than the second clamping force threshold, the contact point position is not refreshed. 8. A braking system, executing the method according to any one of claims 1 to 7, characterized in that it comprises: The upper control system sends instructions to the execution control system according to the braking intention; the instructions of the upper control system include clamping instructions and release instructions; An execution control system controls the execution mechanism according to the instructions of the upper control system; An actuator executes the braking intention according to the control of the execution control system; the actuator specifically includes a motor and a motor controller, and the motor controller drives the motor to rotate forward to complete clamping according to the clamping instruction, or drives the motor to rotate reversely to complete release according to the release instruction; the motor includes a deceleration and torque-increasing mechanism, and the deceleration and torque-increasing mechanism includes a motion conversion mechanism, which pushes the friction plate to press the brake disc through the translation of the screw nut. 9. The system according to claim 8, characterized in that the execution control system specifically comprises: A piston position calculation module, which calculates the piston position according to the angle of the motor and the parameters of the actuator; A contact point identification module, which updates the contact point position according to the clamping force and current of the actuator and the piston position; A clamping control module drives the motor to rotate forward according to the clamping instruction based on the piston position and the clamping force of the actuator to complete the clamping of the actuator; a release control module, which drives the motor to reverse according to the release instruction and based on the piston position and the contact point position, and controls the piston position to be at a position away from the contact point position by a preset threshold; The clamping or releasing arbitration module determines the torque of the motor according to the instruction of the upper control system. 10. A vehicle, characterized in that: the braking system described in any one of claims 8 to 9 is applied, or the braking clearance compensation method described in any one of claims 1 to 7 is executed.