Motor control method and device for static brake-by-wire system of vehicle

Abstract

The present application relates to a motor control method and device for a brake-by-wire system in a static state of a vehicle, which is applied to the technical field of brake-by-wire technology. The method includes: when the vehicle is static and the electronic parking brake is in the pulled-up state, detecting whether the brake-by-wire system is in a pressure-building state, and if so, judging whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, and if both are yes, judging whether the actual speed of the motor is greater than the first preset pressure-building speed threshold, and if so, adopting the preset speed reduction strategy to reduce the actual speed of the motor, and judging whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold, if not, returning to the above judgment step, and if so, setting the actual speed of the motor to 0. The present application can reduce the noise of the vehicle in a static state.

Description

Technical Field

[0001] The present application relates to the technical field of brake-by-wire control, and in particular to a motor control method and device for a brake-by-wire control system of a static vehicle. Background Art

[0002] The fully decoupled brake-by-wire system (DBS) can achieve a fully decoupled state due to the isolation of the solenoid valve. That is, the pedal feel will not be affected by the execution circuit at all. The pedal depression depth and the final output hydraulic pressure can be completely decoupled in the corresponding relationship. Therefore, it is convenient to perform many complex and intelligent control logics.

[0003] For the fully decoupled brake-by-wire system, noise is generated when the driver presses the brake pedal to build pressure and lifts the brake pedal to release pressure, affecting the driving experience. The noise is especially obvious when the vehicle is static. Therefore, how to optimize the noise when the vehicle is static has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a motor control method, device and storage medium of a static brake-by-wire system of a vehicle.

[0005] According to a first aspect of the present application, a motor control method of a static brake-by-wire system of a vehicle is provided, comprising:

[0006] When the vehicle is in a static state, check whether the electronic parking brake is in the pulled state;

[0007] If the electronic parking brake is not in the pulled-up state, determining the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder, so as to control the operation of the motor according to the target speed;

[0008] If the electronic parking brake is in the pulled-up state, determining whether the brake-by-wire system is in the pressure-building state;

[0009] If the brake-by-wire system is in a pressure-building state, determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building threshold;

[0010] If the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than or equal to the pressure building pressure threshold, the target speed of the motor is determined according to the target pressure and the actual pressure of the servo cylinder to control the operation of the motor according to the target speed;

[0011] If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, then determine whether the actual speed of the motor is greater than the first preset pressure-building speed threshold;

[0012] If the actual speed of the motor is greater than the first preset pressure-building speed threshold, a preset speed reduction strategy is adopted to reduce the actual speed of the motor, and determine whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold; the target pressure threshold is greater than the pressure-building pressure threshold;

[0013] If the actual speed of the motor is less than or equal to the first preset pressure-building speed threshold, then determining whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold;

[0014] If the actual pressure of the servo cylinder is less than the target pressure threshold, return to the step of determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold;

[0015] If the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold, the actual speed of the motor is set to 0;

[0016] If the brake-by-wire system is not in a pressure-building state, determining whether the brake-by-wire system is in a pressure-releasing state;

[0017] If the brake-by-wire system is not in a pressure relief state, determining a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder, so as to control the operation of the motor according to the target speed;

[0018] If the brake-by-wire system is in a pressure relief state, determining whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than a pressure relief threshold;

[0019] If the actual pressure of the servo cylinder in the current cycle is greater than the actual pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is greater than or equal to the pressure relief pressure threshold, the target speed of the motor is determined according to the target pressure and the actual pressure of the servo cylinder to control the operation of the motor according to the target speed;

[0020] If the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold, then determine whether the actual speed of the motor is greater than the first preset pressure relief speed threshold;

[0021] If the actual speed of the motor is greater than the first preset pressure relief speed threshold, a preset speed reduction strategy is adopted to reduce the actual speed of the motor, and it is determined whether the actual pressure of the servo cylinder is 0;

[0022] If the actual speed of the motor is less than or equal to the first preset pressure relief speed threshold, determining whether the actual pressure of the servo cylinder is 0;

[0023] If the actual pressure of the servo cylinder is greater than 0, return to the step of determining whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold;

[0024] If the actual pressure of the servo cylinder is 0, the actual speed of the motor is set to 0.

[0025] Optionally, the adopting a preset speed reduction strategy to reduce the actual speed of the motor includes:

[0026] Every m cycles, the actual speed of the motor is reduced by v 0 , m is a positive integer.

[0027] Optionally, before determining whether the brake-by-wire system is in a pressure-building state, the method further includes:

[0028] If the electronic parking brake is in the pulled-up state, obtaining the current gear position information of the vehicle;

[0029] If the current gear information of the vehicle is P gear or N gear, the pressure-building pressure threshold is P1, and the first preset pressure-building speed threshold is V1; the pressure-releasing pressure threshold is P3, and the first preset pressure-releasing speed threshold is V3;

[0030] If the current gear information of the vehicle is R gear or D gear, the pressure-building pressure threshold is P2, and the first preset pressure-building speed threshold is V2; the pressure-releasing pressure threshold is P4, and the first preset pressure-releasing speed threshold is V4;

[0031] Among them, P1 <P2,V1<V2,P3> P4, V3 <V4。

[0032] Optionally, before determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold, the method further includes:

[0033] Determine whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the previous cycle;

[0034] If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, then obtaining a first integral parameter to calculate the target speed of the motor according to the first integral parameter;

[0035] If the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than the actual pressure of the servo cylinder in the previous cycle, then obtaining a second integral parameter to calculate the target speed of the motor according to the second integral parameter;

[0036] Wherein, the second integral parameter is greater than the first integral parameter.

[0037] Optionally, before determining whether the actual speed of the motor is greater than the first preset voltage building speed threshold, the method further includes:

[0038] If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, then determine whether the actual speed of the motor is greater than the second preset pressure-building speed threshold, and the second preset pressure-building speed threshold is greater than the first preset pressure-building speed threshold;

[0039] If the actual speed of the motor is greater than the second preset pressure-building speed threshold, the actual speed of the motor is set to the second preset pressure-building speed threshold;

[0040] If the actual speed of the motor is less than or equal to the second preset pressure-building speed threshold, the step of determining whether the actual speed of the motor is greater than the first preset pressure-building speed threshold is performed.

[0041] Optionally, before determining whether the actual rotation speed of the motor is greater than the first preset pressure relief rotation speed threshold, the method further includes:

[0042] If the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold, then determine whether the actual speed of the motor is greater than the second preset pressure relief speed threshold; the second preset pressure relief speed threshold is greater than the first preset pressure relief speed threshold;

[0043] If the actual speed of the motor is greater than the second preset pressure relief speed threshold, setting the actual speed of the motor to the second preset pressure relief speed threshold;

[0044] If the actual speed of the motor is less than or equal to the second preset pressure relief speed threshold, the step of determining whether the actual speed of the motor is greater than the first preset pressure relief speed threshold is performed.

[0045] According to a second aspect of the present application, a motor control device of a static brake-by-wire system of a vehicle is provided, comprising:

[0046] The parking brake pull-up state detection module is used to detect whether the electronic parking brake is in the pull-up state when the vehicle is in a static state;

[0047] a normal control module, for determining a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder if the electronic parking brake is not in an applied state, so as to control the operation of the motor according to the target speed;

[0048] a pressure-building state judgment module, configured to judge whether the brake-by-wire system is in a pressure-building state if the electronic parking brake is in an engaged state;

[0049] A first pressure judgment module is used to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building pressure threshold if the wire control brake system is in a pressure building state;

[0050] The normal control module is further configured to determine the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder if the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than or equal to the pressure building pressure threshold, so as to control the operation of the motor according to the target speed;

[0051] A first pressure-building speed threshold judgment module is used to judge whether the actual speed of the motor is greater than a first preset pressure-building speed threshold if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold;

[0052] A first speed reduction module, configured to adopt a preset speed reduction strategy to reduce the actual speed of the motor if the actual speed of the motor is greater than a first preset voltage-building speed threshold;

[0053] A target pressure threshold judgment module is used to judge whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold after the actual speed of the motor is reduced; the target pressure threshold is greater than the pressure building threshold;

[0054] The target pressure threshold judgment module is further used to judge whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold if the actual speed of the motor is less than or equal to the first preset pressure building speed threshold;

[0055] A first return module, configured to return to the first pressure judgment module to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold if the actual pressure of the servo cylinder is less than the target pressure threshold;

[0056] The motor speed setting module is used to set the actual speed of the motor to 0 if the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold;

[0057] a pressure relief state judgment module, configured to judge whether the brake-by-wire system is in a pressure relief state if the brake-by-wire system is not in a pressure building state;

[0058] The normal control module is further configured to determine a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder if the brake-by-wire system is not in a pressure relief state, so as to control the operation of the motor according to the target speed;

[0059] a second pressure judgment module, for judging, if the brake-by-wire system is in a pressure relief state, whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than a pressure relief threshold;

[0060] The normal control module is further configured to determine a target speed of the motor according to the target pressure and the actual pressure of the servo cylinder if the actual pressure of the servo cylinder in the current cycle is greater than the actual pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is greater than or equal to the pressure relief pressure threshold, so as to control the operation of the motor according to the target speed;

[0061] A first pressure relief speed threshold judgment module, used to judge whether the actual speed of the motor is greater than a first preset pressure relief speed threshold if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold;

[0062] A second speed reduction module, configured to adopt a preset speed reduction strategy to reduce the actual speed of the motor if the actual speed of the motor is greater than a first preset pressure relief speed threshold;

[0063] A zero pressure judgment module is used to judge whether the actual pressure of the servo cylinder is 0 after reducing the actual speed of the motor;

[0064] The zero pressure judgment module is further used to judge whether the actual pressure of the servo cylinder is 0 if the actual speed of the motor is less than or equal to the first preset pressure relief speed threshold;

[0065] A second return module, configured to return to the second pressure judgment module to judge whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold if the actual pressure of the servo cylinder is greater than 0;

[0066] The motor speed setting module is used to set the actual speed of the motor to 0 if the actual pressure of the servo cylinder is 0.

[0067] Optionally, the first speed reduction module and the second speed reduction module are specifically configured to reduce the actual speed of the motor by v every m cycles. 0 , m is a positive integer.

[0068] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0069] A gear information acquisition module, used for acquiring the current gear information of the vehicle if the electronic parking brake is in the pulled state;

[0070] A first threshold setting module, for setting, if the current gear information of the vehicle is P gear or N gear, the pressure-building pressure threshold is P1, and the first preset pressure-building speed threshold is V1; the pressure-releasing pressure threshold is P3, and the first preset pressure-releasing speed threshold is V3;

[0071] A second threshold setting module is used for, if the current gear information of the vehicle is R gear or D gear, the pressure-building pressure threshold is P2, and the first preset pressure-building speed threshold is V2; the pressure-releasing pressure threshold is P4, and the first preset pressure-releasing speed threshold is V4;

[0072] Among them, P1 <P2,V1<V2,P3> P4, V3 <V4。

[0073] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0074] A third pressure judgment module is used to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure in the previous cycle;

[0075] A first integral parameter acquisition module, used for acquiring a first integral parameter if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, so as to calculate the target speed of the motor according to the first integral parameter;

[0076] a second integral parameter acquisition module, used for acquiring a second integral parameter if the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than the actual pressure of the servo cylinder in the previous cycle, so as to calculate the target speed of the motor according to the second integral parameter;

[0077] Wherein, the second integral parameter is greater than the first integral parameter.

[0078] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0079] A second pressure-building speed threshold judgment module is used to judge whether the actual speed of the motor is greater than a second preset pressure-building speed threshold if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, and the second preset pressure-building speed threshold is greater than the first preset pressure-building speed threshold;

[0080] The motor speed setting module is further used to set the actual speed of the motor to the second preset pressure building speed threshold if the actual speed of the motor is greater than the second preset pressure building speed threshold;

[0081] The first voltage-building speed threshold judgment module is specifically used to execute the step of judging whether the actual speed of the motor is greater than the first preset voltage-building speed threshold if the actual speed of the motor is less than or equal to the second preset voltage-building speed threshold.

[0082] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0083] A second pressure relief speed threshold judgment module is used to judge whether the actual speed of the motor is greater than a second preset pressure relief speed threshold if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold; the second preset pressure relief speed threshold is greater than the first preset pressure relief speed threshold;

[0084] The motor speed setting module is further configured to set the actual speed of the motor to the second preset pressure relief speed threshold if the actual speed of the motor is greater than the second preset pressure relief speed threshold;

[0085] The first pressure relief speed threshold judgment module is specifically used to execute the step of judging whether the actual speed of the motor is greater than the first preset pressure relief speed threshold if the actual speed of the motor is less than or equal to the second preset pressure relief speed threshold.

[0086] According to a third aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method described in the first aspect is implemented.

[0087] According to a fourth aspect of the present application, a computer program product is provided. When the computer program product is run on a computer, the computer is enabled to execute the method described in the first aspect.

[0088] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following advantages:

[0089] When the vehicle is in a static state and in a parking state, the brake-by-wire system can be judged whether it is in a pressure-building state or a pressure-releasing state according to the displacement signal of the brake pedal. If it is in a pressure-building state, it is judged whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold. If both are yes, it means that the target pressure has reached the maximum value of the servo cylinder pressure set when the vehicle is static, and a certain degree of pressure has been established at this time. In this case, if the actual speed of the motor is greater than the first preset pressure-building speed threshold, the preset speed reduction strategy is adopted to reduce the actual speed of the motor. If the actual pressure of the motor is less than the target pressure threshold, the above process is executed cyclically until the actual pressure of the motor is greater than or equal to the target pressure threshold, and the actual speed of the motor is set to 0. Similarly, if the brake-by-wire system is in a pressure-releasing state, it is judged whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure-releasing pressure threshold. If both are yes, it means that it is currently in the actual pressure reduction stage, and the pressure has dropped to a certain extent. If the actual speed of the motor is greater than the first preset pressure relief speed threshold, the preset speed reduction strategy is used to reduce the actual speed of the motor. If the actual pressure of the motor is greater than 0, the above process is executed cyclically until the actual pressure of the motor is equal to 0, and the actual speed of the motor is set to 0. It can be seen that by applying a speed reduction strategy to the motor speed, the noise impact caused by the motor speed in the pressure building and pressure relief stages is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0091] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0092] Figure 1 A schematic diagram of a fully decoupled brake-by-wire system in an embodiment of the present application;

[0093] Figure 2 A flow chart of a motor control method of a static brake-by-wire system of a vehicle in an embodiment of the present application;

[0094] Figure 3 This is a schematic diagram of the actual pressure and actual speed of the servo cylinder changing with time during normal wire control braking;

[0095] Figure 4 This is a schematic diagram of the actual pressure and actual speed of the servo cylinder changing over time when the preset speed reduction strategy is adopted in the embodiment of the present application;

[0096] Figure 5 A schematic diagram of the structure of a motor control device of a static brake-by-wire system of a vehicle in an embodiment of the present application. DETAILED DESCRIPTION

[0097] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0098] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present application, rather than all of the embodiments.

[0099] See also Figure 1 , Figure 1 This is a schematic diagram of the principle of a fully decoupled wire control brake system in the embodiment of the present application. The wire control brake system includes: a fluid reservoir 1, a manual cylinder 2, a brake pedal 3, a servo cylinder pressure sensor 4, a servo cylinder 5, a servo motor 6, a transmission mechanism 7, a servo cylinder circuit isolation valve 8, a servo cylinder circuit isolation valve 9, a simulation cylinder 10, a manual cylinder circuit isolation valve 11, a manual cylinder circuit isolation valve 12 and a simulation cylinder circuit isolation valve 13. The remaining parts are the brake fluid circuit and the related filter and one-way valve. The circuit is full of brake fluid, and the liquid level in the fluid reservoir is between the MIN and MAX positions; the transmission mechanism of the wire control brake system is a ball screw mechanism. The ball screw is connected to the motor rotor, and the nut of the ball screw moves in translation with the rotation of the motor under the restriction of the guide sleeve, pushing the servo cylinder piston to build pressure. The electronic stability control system (ESC, Electronic Stability Control) is connected to the two circuits of DBS and is connected to the four wheel side brakes.

[0100] The working states of the wire control brake system include: backup braking mode and wire control brake mode.

[0101] In the backup braking mode, the vehicle is in a power-off state, the servo cylinder circuit isolation valve 8, the servo cylinder circuit isolation valve 9 and the simulation cylinder circuit isolation valve 13 are all closed, the manual cylinder circuit isolation valve 11 and the manual cylinder circuit isolation valve 12 are both opened, the driver steps on the brake pedal 3, the mechanical push rod moves forward, driving the two pistons of the manual cylinder to move forward to build pressure. At this time, the pressure in the simulation cylinder 10 and the servo cylinder 5 is 0, the servo motor 6 and its connected transmission mechanism do not move, and the noise generated by the movement of the manual cylinder piston is very small and cannot be felt by the human ear.

[0102] In the online control braking mode, the servo cylinder circuit isolation valve 8, the servo cylinder circuit isolation valve 9 and the analog cylinder circuit isolation valve 13 are powered on and opened, and the manual cylinder circuit isolation valve 11 and the manual cylinder circuit isolation valve 12 are powered on and closed. When the driver steps on the pedal 3, the pressure generated by manpower will be maintained in the manual cylinder circuit. ESC calculates the target pressure, outputs the motor target speed to drive the servo motor 6 to rotate, and drives the transmission mechanism to push the servo cylinder piston forward to build pressure. At this time, driven by the motor, during the movement of the ball screw nut, the friction between the metal parts and the rolling of the internal steel balls will generate certain noise.

[0103] It can be seen that when the vehicle is static, obvious noise is generated when the driver steps on the brake pedal to build pressure and lifts the brake pedal to release pressure. In order to solve this technical problem, the embodiment of the present application provides a motor control method, device and storage medium of a static vehicle brake-by-wire system to reduce the above noise.

[0104] See also Figure 2 , Figure 2 This is a flow chart of a motor control method of a static brake-by-wire system of a vehicle in an embodiment of the present application, which may include the following steps:

[0105] Step S202: When the vehicle is in a static state, detecting whether the electronic parking brake is in an engaged state.

[0106] In the embodiment of the present application, a deceleration logic is added to the process of building pressure of the vehicle brake as described below, so the pressure building process is slower than the normal wire control brake pressure building process. If the electronic parking brake is not in the pulled-up state, step S204 is executed, that is, the normal wire control brake process; if the electronic parking brake is in the pulled-up state, step S206 is executed. In this way, when the vehicle is parked on a slope, it can be avoided that the vehicle slips due to the slow pressure building process caused by the addition of the deceleration logic.

[0107] Step S204, determining the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder, so as to control the operation of the motor according to the target speed.

[0108] The calculation process of the target pressure of the servo cylinder is as follows: when the driver steps on the brake pedal, the displacement signal of the brake pedal and the pressure signal of the analog circuit can be measured. The electronic control unit can calculate the first target pressure based on the displacement signal and the pressure signal. The external request can also input the second target pressure to the electronic control unit, and the electronic control unit selects the larger value of the first target pressure and the second target pressure as the final target pressure.

[0109] The pressure difference between the target pressure of the servo cylinder and the actual pressure can be converted into the target speed of the motor through the conversion between pressure and brake fluid volume, and between servo cylinder volume and motor stroke. The target speed is transmitted to the underlying software, that is, the internal control logic of the motor, so that the motor can run and generate the actual speed of the motor.

[0110] Step S206, determining whether the brake-by-wire system is in a pressure-building state.

[0111] It is possible to determine whether the brake-by-wire system is in a pressure-building state according to the displacement signal of the brake pedal. If the brake-by-wire system is in a pressure-building state, step S208 is executed; if the brake-by-wire system is not in a pressure-building state, step S220 is executed.

[0112] Step S208, determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold.

[0113] If the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle, it means that the target pressure is still rising, that is, it has not reached the maximum servo cylinder pressure set under the static state of the vehicle, that is, the target pressure threshold. Alternatively, if the actual pressure of the servo cylinder in the current cycle is less than or equal to the pressure-building pressure threshold, it means that the pressure of the servo cylinder has not reached a certain level, and step S204 is executed. If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, it means that the target pressure has reached the maximum servo cylinder pressure set under the static state of the vehicle, and the pressure of the servo cylinder has reached a certain level, and step S210 is executed.

[0114] Step S210, determining whether the actual rotation speed of the motor is greater than a first preset voltage-building rotation speed threshold.

[0115] If the actual speed of the motor is greater than the first preset pressure building speed threshold, it means that the actual speed of the motor is relatively large, and step S212 is executed; if the actual speed of the motor is less than or equal to the first preset pressure building speed threshold, step S214 is executed.

[0116] Step S212: using a preset speed reduction strategy to reduce the actual speed of the motor.

[0117] In an embodiment of the present application, a preset speed reduction strategy reduces the actual speed of the motor at an appropriate speed to avoid speed reduction that is too fast or too slow. Optionally, the actual speed of the motor can be reduced by v0 every m cycles, where m is a positive integer. For example, m is 2, assuming that the current cycle is the first cycle, the actual speed of the motor is not reduced in the first cycle and the second cycle, and if the actual speed of the motor is greater than the first preset pressure-building speed threshold in the third cycle, the actual speed of the motor is reduced by v0 in the third cycle. Similarly, if the actual speed of the motor is still greater than the first preset pressure-building speed threshold in the sixth cycle, the actual speed of the motor will continue to be reduced by v0 in the sixth cycle until the actual speed of the motor is less than or equal to the first preset pressure-building speed threshold.

[0118] Among them, m and v0 determine the speed rhythm of the motor deceleration. If m is too small and v0 is too large, the motor will quickly decelerate to the first preset pressure-building speed threshold, while the actual pressure P is far from the target pressure threshold, and the pressure-building time will be very long. On the contrary, if the motor speed is reduced too slowly, the actual pressure P will quickly reach the target pressure threshold, and the motor will still have a relatively high speed, which will easily cause pressure overshoot and cause obvious collision noise between the mechanisms. Therefore, appropriate m and v0 can be selected to reduce the actual speed of the motor to avoid the above problems.

[0119] In some embodiments, the actual speed of the motor may also be reduced in each cycle. For example, the actual speed of the motor may be reduced by v1 in each cycle, where v0 is m+1 times of v1.

[0120] See also Figure 3 and Figure 4 , it can be seen that Figure 4 After adopting the speed reduction strategy, the curve changes of the actual pressure and actual speed of the servo cylinder are similar to Figure 3 Different pictures. Figure 4 The A and B moments in the figure are the triggering moments of the motor speed reduction strategy during pressure buildup and pressure relief, respectively. The period after the A and B moments is the process of motor speed reduction during pressure buildup and pressure relief, and the corresponding actual pressure change trend is also the same as Figure 3 Different, there is a phenomenon that both the pressure increase and decrease slow down.

[0121] After the actual speed of the motor is reduced, step S214 is executed.

[0122] Step S214, determining whether the actual pressure of the servo cylinder is greater than or equal to a target pressure threshold; the target pressure threshold is greater than the pressure building threshold.

[0123] If the actual pressure of the servo cylinder is less than the target pressure threshold, return to step S208 to continue the pressure building process; if the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold, execute step S216.

[0124] Step S216, setting the actual speed of the motor to 0.

[0125] Step S218, determining whether the brake-by-wire system is in a pressure relief state.

[0126] If the brake-by-wire system is not in a pressure relief state, step S204 is executed; if the brake-by-wire system is in a pressure relief state, step S220 is executed.

[0127] Step S220, determining whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief threshold.

[0128] If the actual pressure of the servo cylinder in the current cycle is greater than the actual pressure of the servo cylinder in the previous cycle, it means that the actual pressure is still in the rising stage, or the actual pressure of the servo cylinder in the current cycle is greater than or equal to the pressure relief pressure threshold, indicating that the actual pressure is still large, then execute step S204; if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold, indicating that the actual pressure is still in the falling stage, and the actual pressure is small, then execute step S222.

[0129] Step S222, determining whether the actual rotation speed of the motor is greater than a first preset pressure relief rotation speed threshold.

[0130] If the actual speed of the motor is greater than the first preset pressure relief speed threshold, step S224 is executed; if the actual speed of the motor is less than or equal to the first preset pressure relief speed threshold, step S226 is executed.

[0131] Step S224: Use a preset speed reduction strategy to reduce the actual speed of the motor.

[0132] This step is the same as the deceleration method of step S212, and the specific description is in step S212. It should be noted that the rotation direction of the motor is opposite in the pressure building stage and the pressure relief stage. Therefore, the actual speed of the motor in the pressure building stage can be a positive value, and the actual speed of the motor in the pressure relief stage is a negative value. The larger the absolute value of the negative value, the greater the actual speed of the motor.

[0133] Step S226, determining whether the actual pressure of the servo cylinder is 0.

[0134] If the actual pressure of the servo cylinder is greater than 0, return to step S220; if the actual pressure of the servo cylinder is 0, execute step S216.

[0135] The motor control method of the brake-by-wire system of the vehicle in a static state of the embodiment of the present application, when the vehicle is in a static state, when the vehicle is in a parking state, can determine whether the brake-by-wire system is in a pressure-building state or a pressure-releasing state according to the displacement signal of the brake pedal. If it is in a pressure-building state, it is determined whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold. If both are yes, it means that the target pressure has reached the maximum value of the servo cylinder pressure set in the static state of the vehicle, and a certain degree of pressure has been established at this time. In this case, if the actual speed of the motor is greater than the first preset pressure-building speed threshold, the preset speed reduction strategy is adopted to reduce the actual speed of the motor. If the actual pressure of the motor is less than the target pressure threshold, the above process is executed cyclically until the actual pressure of the motor is greater than or equal to the target pressure threshold, and the actual speed of the motor is set to 0. Similarly, if the brake-by-wire system is in a pressure-releasing state, it is determined whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure-releasing pressure threshold. If both are yes, it means that it is currently in the actual pressure reduction stage, and the pressure has dropped to a certain extent. If the actual speed of the motor is greater than the first preset pressure relief speed threshold, the preset speed reduction strategy is used to reduce the actual speed of the motor. If the actual pressure of the motor is greater than 0, the above process is executed cyclically until the actual pressure of the motor is equal to 0, and the actual speed of the motor is set to 0. It can be seen that by applying a speed reduction strategy to the motor speed, the noise impact caused by the motor speed in the pressure building and pressure relief stages is reduced.

[0136] Optionally, before determining whether the brake-by-wire system is in a pressure-building state, if the electronic parking brake is in the pulled-up state, the current gear information of the vehicle can be obtained. If the current gear information of the vehicle is P gear or N gear, it means that the vehicle is static and has no intention to move, and the driver is highly sensitive to noise, then the pressure-building pressure threshold is P1, and the first preset pressure-building speed threshold is V1; the pressure-relieving pressure threshold is P3, and the first preset pressure-relieving speed threshold is V3. If the current gear information of the vehicle is R gear or D gear, it means that the vehicle is static but has the intention to move, and the driver is less sensitive to noise, then the pressure-building pressure threshold is P2, and the first preset pressure-building speed threshold is V2; the pressure-relieving pressure threshold is P4, and the first preset pressure-relieving speed threshold is V4.

[0137] In the R gear and D gear, when the driver steps on the brake pedal to build pressure, the driver may want to start the vehicle. The brake pressure can be quickly built up to facilitate the vehicle to start as soon as possible. Therefore, the pressure build-up pressure threshold in the R gear and D gear can be higher than that in the P gear and N gear, that is, P1 < P2. In this way, the established brake pressure is relatively large when the motor decelerates under the pressure build-up state, and the pressure can be quickly raised to the target pressure threshold. The pressure build-up is faster at a higher speed, so V1 < V2.

[0138] In the R gear and D gear, when the driver releases the brake pedal to relieve pressure, the driver may want to start the vehicle. The brake pressure can be quickly released to facilitate the vehicle to start as soon as possible. Therefore, the pressure relief pressure threshold in the R gear and D gear can be lower than that in the P gear and N gear, that is, P3 > P4. In this way, the brake pressure is relatively small when the motor decelerates under the pressure relief state, and the pressure can be quickly reduced to 0. The pressure relief is faster at a higher speed, so V3 < V4.

[0139] In the embodiments of the present application, different motor deceleration parameters are correspondingly adopted for noise reduction according to whether the gear is the P gear, N gear, or R gear, D gear, so as to improve the driving experience of the driver.

[0140] Optionally, before determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure build-up pressure threshold, it can be first determined whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle and whether the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure in the previous cycle.

[0141] If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, it means that the target pressure has reached the maximum value of the servo cylinder pressure set under the vehicle static state, that is, the target pressure threshold. And if the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, it means that the actual pressure is in the rising stage under the pressure build-up state at this time, then the first integral parameter is obtained to calculate the target speed of the motor according to the first integral parameter. If the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than the actual pressure of the servo cylinder in the previous cycle, then the second integral parameter is obtained to calculate the target speed of the motor according to the second integral parameter. Among them, the second integral parameter is greater than the first integral parameter.

[0142] In the process of calculating the target speed of the motor according to the pressure difference between the target pressure and the actual pressure, the PID control algorithm (proportional, integral, and differential adjustment methods) is used, and the corresponding adjustment parameters are proportional parameters, integral parameters, and differential parameters. Among them, the proportional parameter has a greater impact on the actual pressure, and when the adjustment amplitude is large, it is easy to cause system instability. The differential parameter has a smaller impact on the actual pressure, and excessive differential adjustment will affect the anti-interference ability of the system. The integral parameter is a cumulative calculation of the pressure difference, and the size of the integral parameter will affect the amplitude of the integral adjustment. Because the pressure difference changes all the time, when the integral parameter is large, the motor target speed will also change significantly at all times, and noise will be generated in the process of driving the transmission mechanism. Especially when the driver quickly steps on the brake pedal, the integral adjustment amplitude is large, resulting in a drastic change in the motor speed, and the transmission mechanism will emit obvious collision noise driven by the motor.

[0143] Based on this, if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, a smaller integral parameter is used to calculate the target speed of the motor; otherwise, a larger integral parameter is used to calculate the target speed of the motor. In this way, the noise caused by the motor speed fluctuation caused by the excessive integral link during the motor speed solution process can be reduced.

[0144] Optionally, before determining whether the actual speed of the motor is greater than the first preset pressure-building speed threshold, if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, first determine whether the actual speed of the motor is greater than the second preset pressure-building speed threshold, and the second preset pressure-building speed threshold is greater than the first preset pressure-building speed threshold. If the actual speed of the motor is greater than the second preset pressure-building speed threshold, the actual speed of the motor is set to the second preset pressure-building speed threshold to prevent the actual speed of the motor from being too high. If the actual speed of the motor is less than or equal to the second preset pressure-building speed threshold, the step of determining whether the actual speed of the motor is greater than the first preset pressure-building speed threshold is executed.

[0145] Optionally, before determining whether the actual speed of the motor is greater than the first preset pressure relief speed threshold, if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold, then determine whether the actual speed of the motor is greater than the second preset pressure relief speed threshold; the second preset pressure relief speed threshold is greater than the first preset pressure relief speed threshold. If the actual speed of the motor is greater than the second preset pressure relief speed threshold, then set the actual speed of the motor to the second preset pressure relief speed threshold to prevent the actual speed of the motor from being too high; if the actual speed of the motor is less than or equal to the second preset pressure relief speed threshold, then execute the step of determining whether the actual speed of the motor is greater than the first preset pressure relief speed threshold.

[0146] It should be noted that although the steps of the method in the present application are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0147] Corresponding to the above method embodiment, the present application embodiment also provides a motor control device for a static brake-by-wire system of a vehicle, see Figure 5 The motor control device 500 of the static brake-by-wire system of the vehicle comprises:

[0148] The parking brake applied state detection module 502 is used to detect whether the electronic parking brake is in an applied state when the vehicle is in a static state;

[0149] A normal control module 504 is used to determine a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder if the electronic parking brake is not in the pulled-up state, so as to control the operation of the motor according to the target speed;

[0150] A pressure building state judgment module 506 is used to judge whether the brake-by-wire system is in a pressure building state if the electronic parking brake is in an engaged state;

[0151] The first pressure judgment module 508 is used to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure threshold value of the pressure building if the wire control brake system is in the pressure building state;

[0152] The normal control module 504 is further configured to determine the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder if the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than or equal to the pressure-building pressure threshold, so as to control the operation of the motor according to the target speed;

[0153] A first pressure-building speed threshold judgment module 510 is used to judge whether the actual speed of the motor is greater than a first preset pressure-building speed threshold if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold;

[0154] A first speed reduction module 512 is used to adopt a preset speed reduction strategy to reduce the actual speed of the motor if the actual speed of the motor is greater than a first preset voltage building speed threshold;

[0155] The target pressure threshold judgment module 514 is used to judge whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold after the actual speed of the motor is reduced; the target pressure threshold is greater than the pressure building threshold;

[0156] The target pressure threshold judgment module 514 is further used to judge whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold if the actual speed of the motor is less than or equal to the first preset pressure building speed threshold;

[0157] A first return module 516 is used to return to the first pressure judgment module 508 to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold if the actual pressure of the servo cylinder is less than the target pressure threshold;

[0158] The motor speed setting module 518 is used to set the actual speed of the motor to 0 if the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold;

[0159] A pressure relief state determination module 520 is used to determine whether the brake-by-wire system is in a pressure relief state if the brake-by-wire system is not in a pressure building state;

[0160] The normal control module 504 is further configured to determine the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder if the brake-by-wire system is not in the pressure relief state, so as to control the operation of the motor according to the target speed;

[0161] The second pressure judgment module 522 is used to judge whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold if the wire control brake system is in the pressure relief state;

[0162] The normal control module 504 is further configured to determine the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder, so as to control the operation of the motor according to the target speed, if the actual pressure of the servo cylinder in the current cycle is greater than the actual pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is greater than or equal to the pressure relief pressure threshold;

[0163] A first pressure relief speed threshold judgment module 524 is used to judge whether the actual speed of the motor is greater than a first preset pressure relief speed threshold if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold;

[0164] A second speed reduction module 526 is configured to use a preset speed reduction strategy to reduce the actual speed of the motor if the actual speed of the motor is greater than a first preset pressure relief speed threshold;

[0165] The zero pressure determination module 528 is used to determine whether the actual pressure of the servo cylinder is 0 after reducing the actual speed of the motor;

[0166] The zero pressure determination module 528 is further configured to determine whether the actual pressure of the servo cylinder is 0 if the actual speed of the motor is less than or equal to the first preset pressure relief speed threshold;

[0167] A second return module 530 is used to return to the second pressure judgment module 522 to judge whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold if the actual pressure of the servo cylinder is greater than 0;

[0168] The motor speed setting module 518 is used to set the actual speed of the motor to 0 if the actual pressure of the servo cylinder is 0.

[0169] Optionally, the first speed reduction module and the second speed reduction module are specifically configured to reduce the actual speed of the motor by v every m cycles. 0 , m is a positive integer.

[0170] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0171] A gear information acquisition module, used to acquire the current gear information of the vehicle if the electronic parking brake is in the pulled state;

[0172] The first threshold setting module is used for setting the pressure threshold of pressure building to P1 and the first preset pressure building speed threshold to V1 if the current gear information of the vehicle is P gear or N gear; the pressure relief pressure threshold is P3 and the first preset pressure relief speed threshold is V3;

[0173] The second threshold setting module is used for setting the pressure threshold of pressure building to P2 and the first preset pressure building speed threshold to V2 if the current gear information of the vehicle is R gear or D gear; the pressure threshold of pressure relief to P4 and the first preset pressure relief speed threshold to V4;

[0174] Among them, P1 <P2,V1<V2,P3> P4, V3 <V4。

[0175] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0176] A third pressure judgment module is used to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure in the previous cycle;

[0177] A first integral parameter acquisition module, used for acquiring a first integral parameter if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, so as to calculate the target speed of the motor according to the first integral parameter;

[0178] a second integral parameter acquisition module, used for acquiring a second integral parameter if the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than the actual pressure of the servo cylinder in the previous cycle, so as to calculate the target speed of the motor according to the second integral parameter;

[0179] The second integral parameter is greater than the first integral parameter.

[0180] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0181] A second pressure-building speed threshold judgment module is used to judge whether the actual speed of the motor is greater than a second preset pressure-building speed threshold if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, and the second preset pressure-building speed threshold is greater than the first preset pressure-building speed threshold;

[0182] The motor speed setting module is further used to set the actual speed of the motor to the second preset pressure building speed threshold if the actual speed of the motor is greater than the second preset pressure building speed threshold;

[0183] The first voltage-building speed threshold judgment module is specifically used to execute the step of judging whether the actual speed of the motor is greater than the first preset voltage-building speed threshold if the actual speed of the motor is less than or equal to the second preset voltage-building speed threshold.

[0184] Optionally, the motor control device of the static brake-by-wire system of the vehicle further includes:

[0185] A second pressure relief speed threshold judgment module is used to judge whether the actual speed of the motor is greater than a second preset pressure relief speed threshold if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold; the second preset pressure relief speed threshold is greater than the first preset pressure relief speed threshold;

[0186] The motor speed setting module is further used to set the actual speed of the motor to the second preset pressure relief speed threshold if the actual speed of the motor is greater than the second preset pressure relief speed threshold;

[0187] The first pressure relief speed threshold judgment module is specifically used to execute the step of judging whether the actual speed of the motor is greater than the first preset pressure relief speed threshold if the actual speed of the motor is less than or equal to the second preset pressure relief speed threshold.

[0188] The specific details of each module or unit in the above device have been described in detail in the corresponding method, so they will not be repeated here.

[0189] It should be noted that, although several modules or units of the equipment for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into being embodied by multiple modules or units.

[0190] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the motor control method of the static brake-by-wire system of the vehicle is implemented.

[0191] It should be noted that the computer-readable storage medium shown in the present application may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, radio frequency, etc., or any suitable combination of the above.

[0192] In an embodiment of the present application, a computer program product is also provided. When the computer program product is run on a computer, the computer executes the motor control method of the static brake-by-wire system of the vehicle.

[0193] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants 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, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0194] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A motor control method for a static brake-by-wire system of a vehicle, characterized in that: include: When the vehicle is in a static state, check whether the electronic parking brake is in the pulled state; If the electronic parking brake is not in the pulled-up state, determining the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder, so as to control the operation of the motor according to the target speed; If the electronic parking brake is in the pulled-up state, determining whether the brake-by-wire system is in the pressure-building state; If the brake-by-wire system is in a pressure-building state, determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building threshold; If the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than or equal to the pressure building pressure threshold, the target speed of the motor is determined according to the target pressure and the actual pressure of the servo cylinder to control the operation of the motor according to the target speed; If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, then determine whether the actual speed of the motor is greater than the first preset pressure-building speed threshold; If the actual speed of the motor is greater than the first preset pressure-building speed threshold, a preset speed reduction strategy is adopted to reduce the actual speed of the motor, and it is determined whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold; The target pressure threshold is greater than the pressure building threshold; If the actual speed of the motor is less than or equal to the first preset pressure-building speed threshold, then determining whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold; If the actual pressure of the servo cylinder is less than the target pressure threshold, return to the step of determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold; If the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold, the actual speed of the motor is set to 0; If the brake-by-wire system is not in a pressure-building state, determining whether the brake-by-wire system is in a pressure-releasing state; If the brake-by-wire system is not in a pressure relief state, determining a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder, so as to control the operation of the motor according to the target speed; If the brake-by-wire system is in a pressure relief state, determining whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than a pressure relief threshold; If the actual pressure of the servo cylinder in the current cycle is greater than the actual pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is greater than or equal to the pressure relief pressure threshold, the target speed of the motor is determined according to the target pressure and the actual pressure of the servo cylinder to control the operation of the motor according to the target speed; If the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold, then determine whether the actual speed of the motor is greater than the first preset pressure relief speed threshold; If the actual speed of the motor is greater than the first preset pressure relief speed threshold, a preset speed reduction strategy is adopted to reduce the actual speed of the motor, and it is determined whether the actual pressure of the servo cylinder is 0; If the actual speed of the motor is less than or equal to the first preset pressure relief speed threshold, determining whether the actual pressure of the servo cylinder is 0; If the actual pressure of the servo cylinder is greater than 0, return to the step of determining whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold; If the actual pressure of the servo cylinder is 0, the actual speed of the motor is set to 0.

2. The method according to claim 1, characterized in that The adopting a preset speed reduction strategy to reduce the actual speed of the motor includes: Every m cycles, the actual rotation speed of the motor is reduced by v0, where m is a positive integer.

3. The method according to claim 1, characterized in that Before determining whether the brake-by-wire system is in a pressure-building state, the method further includes: If the electronic parking brake is in the pulled-up state, obtaining the current gear position information of the vehicle; If the current gear information of the vehicle is P gear or N gear, the pressure-building pressure threshold is P1, and the first preset pressure-building speed threshold is V1; the pressure-releasing pressure threshold is P3, and the first preset pressure-releasing speed threshold is V3; If the current gear information of the vehicle is R gear or D gear, the pressure-building pressure threshold is P2, and the first preset pressure-building speed threshold is V2; the pressure-releasing pressure threshold is P4, and the first preset pressure-releasing speed threshold is V4; Among them, P1 <P2,V1<V2,P3> P4, V3 <V4。 4. The method according to claim 1, characterized in that Before determining whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold, the method further includes: Determine whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the previous cycle; If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, then obtaining a first integral parameter to calculate the target speed of the motor according to the first integral parameter; If the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than the actual pressure of the servo cylinder in the previous cycle, then obtaining a second integral parameter to calculate the target speed of the motor according to the second integral parameter; Wherein, the second integral parameter is greater than the first integral parameter.

5. The method according to claim 1, characterized in that: Before determining whether the actual speed of the motor is greater than the first preset voltage-building speed threshold, the method further includes: If the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold, then determine whether the actual speed of the motor is greater than the second preset pressure-building speed threshold, and the second preset pressure-building speed threshold is greater than the first preset pressure-building speed threshold; If the actual speed of the motor is greater than the second preset pressure-building speed threshold, the actual speed of the motor is set to the second preset pressure-building speed threshold; If the actual speed of the motor is less than or equal to the second preset pressure-building speed threshold, the step of determining whether the actual speed of the motor is greater than the first preset pressure-building speed threshold is performed.

6. The method according to claim 1, characterized in that Before determining whether the actual speed of the motor is greater than the first preset pressure relief speed threshold, the method further includes: If the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold, then determine whether the actual speed of the motor is greater than the second preset pressure relief speed threshold; the second preset pressure relief speed threshold is greater than the first preset pressure relief speed threshold; If the actual speed of the motor is greater than the second preset pressure relief speed threshold, setting the actual speed of the motor to the second preset pressure relief speed threshold; If the actual speed of the motor is less than or equal to the second preset pressure relief speed threshold, the step of determining whether the actual speed of the motor is greater than the first preset pressure relief speed threshold is performed.

7. A motor control device for a static brake-by-wire system of a vehicle, characterized in that: include: The parking brake pull-up state detection module is used to detect whether the electronic parking brake is in the pull-up state when the vehicle is in a static state; a normal control module, for determining a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder if the electronic parking brake is not in an applied state, so as to control the operation of the motor according to the target speed; a pressure-building state judgment module, configured to judge whether the brake-by-wire system is in a pressure-building state if the electronic parking brake is in an engaged state; A first pressure judgment module is used to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building pressure threshold if the wire control brake system is in a pressure building state; The normal control module is further configured to determine the target speed of the motor according to the target pressure and the actual pressure of the servo cylinder if the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than or equal to the pressure building pressure threshold, so as to control the operation of the motor according to the target speed; A first pressure-building speed threshold judgment module is used to judge whether the actual speed of the motor is greater than a first preset pressure-building speed threshold if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than the pressure-building pressure threshold; A first speed reduction module, configured to adopt a preset speed reduction strategy to reduce the actual speed of the motor if the actual speed of the motor is greater than a first preset voltage-building speed threshold; A target pressure threshold judgment module is used to judge whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold after reducing the actual speed of the motor; The target pressure threshold is greater than the pressure building threshold; The target pressure threshold judgment module is further used to judge whether the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold if the actual speed of the motor is less than or equal to the first preset pressure building speed threshold; A first return module, configured to return to the first pressure judgment module to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than the pressure building threshold if the actual pressure of the servo cylinder is less than the target pressure threshold; The motor speed setting module is used to set the actual speed of the motor to 0 if the actual pressure of the servo cylinder is greater than or equal to the target pressure threshold; a pressure relief state judgment module, configured to judge whether the brake-by-wire system is in a pressure relief state if the brake-by-wire system is not in a pressure building state; The normal control module is further configured to determine a target speed of the motor according to a target pressure and an actual pressure of the servo cylinder if the brake-by-wire system is not in a pressure relief state, so as to control the operation of the motor according to the target speed; a second pressure judgment module, for judging, if the brake-by-wire system is in a pressure relief state, whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than a pressure relief threshold; The normal control module is further configured to determine a target speed of the motor according to the target pressure and the actual pressure of the servo cylinder if the actual pressure of the servo cylinder in the current cycle is greater than the actual pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is greater than or equal to the pressure relief pressure threshold, so as to control the operation of the motor according to the target speed; A first pressure relief speed threshold judgment module, used to judge whether the actual speed of the motor is greater than a first preset pressure relief speed threshold if the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold; A second speed reduction module, configured to adopt a preset speed reduction strategy to reduce the actual speed of the motor if the actual speed of the motor is greater than a first preset pressure relief speed threshold; A zero pressure judgment module is used to judge whether the actual pressure of the servo cylinder is 0 after reducing the actual speed of the motor; The zero pressure judgment module is further used to judge whether the actual pressure of the servo cylinder is 0 if the actual speed of the motor is less than or equal to the first preset pressure relief speed threshold; A second return module, configured to return to the second pressure judgment module to judge whether the actual pressure of the servo cylinder in the current cycle is less than or equal to the actual pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is less than the pressure relief pressure threshold if the actual pressure of the servo cylinder is greater than 0; The motor speed setting module is used to set the actual speed of the motor to 0 if the actual pressure of the servo cylinder is 0.

8. The device according to claim 7, characterized in that The first speed reduction module and the second speed reduction module are specifically used to reduce the actual speed of the motor by v0 every m cycles, where m is a positive integer.

9. The device according to claim 8, characterized in that Also includes: A gear information acquisition module, used for acquiring the current gear information of the vehicle if the electronic parking brake is in the pulled state; A first threshold setting module, for setting, if the current gear information of the vehicle is P gear or N gear, the pressure-building pressure threshold is P1, and the first preset pressure-building speed threshold is V1; the pressure-releasing pressure threshold is P3, and the first preset pressure-releasing speed threshold is V3; A second threshold setting module is used for, if the current gear information of the vehicle is R gear or D gear, the pressure-building pressure threshold is P2, and the first preset pressure-building speed threshold is V2; the pressure-releasing pressure threshold is P4, and the first preset pressure-releasing speed threshold is V4; Among them, P1 <P2,V1<V2,P3> P4, V3 <V4。 10. The device according to claim 8, characterized in that Also includes: A third pressure judgment module is used to judge whether the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and whether the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure in the previous cycle; A first integral parameter acquisition module, used for acquiring a first integral parameter if the target pressure of the servo cylinder in the current cycle is less than or equal to the target pressure of the servo cylinder in the previous cycle, and the actual pressure of the servo cylinder in the current cycle is greater than or equal to the actual pressure of the servo cylinder in the previous cycle, so as to calculate the target speed of the motor according to the first integral parameter; a second integral parameter acquisition module, used for acquiring a second integral parameter if the target pressure of the servo cylinder in the current cycle is greater than the target pressure of the servo cylinder in the previous cycle or the actual pressure of the servo cylinder in the current cycle is less than the actual pressure of the servo cylinder in the previous cycle, so as to calculate the target speed of the motor according to the second integral parameter; Wherein, the second integral parameter is greater than the first integral parameter.

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