Fully decoupled brake-by-wire method and system

Abstract

The present application relates to a fully decoupled brake-by-wire method and system, which is applied to the field of brake-by-wire technology. The method includes: when the brake-by-wire system is normally powered on, detecting whether the brake-by-wire system has a fault; if so, entering a first mechanical backup braking mode; if not, detecting the mechanical zero point of the servo cylinder piston in the brake-by-wire system; determining whether the mechanical zero point detection of the servo cylinder piston is complete; if not, entering a second mechanical backup braking mode while continuing to detect the mechanical zero point of the servo cylinder piston; if so, determining whether the brake-by-wire system is allowed to enter a pedal-powered braking mode; if not, entering a normal brake-by-wire mode; if so, entering a pedal-powered braking mode; detecting whether the brake-by-wire system is powered off; if not, returning to the step of detecting whether the brake-by-wire system has a fault; if so, terminating the process. The present application can complete the servo cylinder piston power-on home position while ensuring the feel of the brake pedal.

Description

Technical Field

[0001] The present application relates to the technical field of wire-controlled braking, and in particular to a fully decoupled wire-controlled braking method and system. Background Art

[0002] Vehicles equipped with a brake-by-wire system without an additional travel sensor must calculate the servo cylinder piston position based on the rotor angle. Therefore, mechanical zeroing (homing) of the servo cylinder piston position is required each time the brake-by-wire system is powered on. This ensures accurate implementation of functions such as soft limit protection based on the mechanical zero point.

[0003] In related art, when a brake-by-wire system is powered on, it performs zeroing directly. Even when the brake pedal is pressed, zeroing is performed before the corresponding brake-by-wire braking is performed. Alternatively, when the brake pedal is pressed, zeroing and motor control are not performed, and the mechanical backup braking mode is directly used. Zeroing is not performed until the brake pedal is released.

[0004] However, when brake pressure output is required at the moment of pedaling and powering on, there may be a situation where the change has not been completed. Normal brake-by-wire mode will not be entered until the change is completed, which will cause a delay in brake pressure output. In addition, when the brake pedal is pressed and the normal brake-by-wire mode is directly entered, the pedal may suddenly sink, which is a poor experience. The deeper the brake pedal is pressed, the more obvious it is. Alternatively, if the mechanical backup braking mode is always used during the power-on phase of the brake pedal, when the PV (pressure-volume) characteristics of the vehicle's brake system are poor, there may be a problem of insufficient brake pressure output, affecting vehicle safety. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a fully decoupled wire-controlled braking method, system and storage medium.

[0006] According to a first aspect of the present application, a fully decoupled brake-by-wire method is provided, comprising:

[0007] Check whether the brake-by-wire system is powered on normally;

[0008] If the wire control brake system is not powered on normally, entering the first mechanical backup braking mode;

[0009] If the brake-by-wire system is powered on normally, detecting whether the brake-by-wire system has a fault;

[0010] If there is a fault in the brake-by-wire system, entering a first mechanical backup braking mode;

[0011] If there is no fault in the brake-by-wire system, detecting a mechanical zero point of a servo cylinder piston in the brake-by-wire system;

[0012] Determining whether the mechanical zero point of the servo cylinder piston is detected;

[0013] If the mechanical zero point of the servo cylinder piston is not detected, the second mechanical backup braking mode is entered, and in the second mechanical backup braking mode, the detection of the mechanical zero point of the servo cylinder piston is continued;

[0014] If the mechanical zero point of the servo cylinder piston has been detected, detecting whether the wire control brake system is allowed to enter the pedal-operated power-on braking mode;

[0015] If the brake-by-wire system is not allowed to enter the pedal-on-brake mode, entering the normal brake-by-wire mode;

[0016] If the brake-by-wire system is allowed to enter the pedal-on-electric braking mode, entering the pedal-on-electric braking mode;

[0017] In the pedal-powered braking mode, the analog cylinder circuit isolation valve and the servo cylinder circuit isolation valve are controlled to remain in a closed state, and the manual cylinder circuit isolation valve is controlled to change from an open state to a closed state after power is applied. A first target pressure is determined according to the stroke of the mechanical push rod; a second target pressure is determined according to the pressure detected by the manual cylinder pressure sensor, and the larger value of the first target pressure and the second target pressure is selected as the target braking pressure, and the braking pressure is output;

[0018] detecting whether the brake-by-wire system is powered off;

[0019] If it is detected that the brake-by-wire system is not powered off, returning to the step of detecting whether the brake-by-wire system has a fault;

[0020] If it is detected that the brake-by-wire system is powered off, the process ends.

[0021] Optionally, the method further includes:

[0022] In the pedal-operated electric braking mode, detecting whether the brake-by-wire system meets a preset exit condition, and if it is detected that the brake-by-wire system meets the preset exit condition, entering the normal brake-by-wire mode;

[0023] If it is detected that the brake-by-wire system does not meet the preset exit condition, the brake-by-wire system continues to be in the pedal-on electric braking mode.

[0024] Optionally, detecting whether the brake-by-wire system satisfies a preset exit condition includes:

[0025] Detect whether the stroke of the mechanical push rod is less than the preset stroke value;

[0026] If the stroke of the mechanical push rod is less than the preset stroke value, it is determined that the wire control brake system meets the preset exit condition;

[0027] If the stroke of the mechanical push rod is greater than or equal to the preset stroke value, it is determined that the wire control brake system does not meet the preset exit condition; or,

[0028] Check whether the pressure of the manual cylinder is less than the preset pressure value;

[0029] If the pressure of the manual cylinder is less than a preset pressure value, it is determined that the brake-by-wire system meets a preset exit condition;

[0030] If the pressure of the manual cylinder is greater than or equal to the preset pressure value, it is determined that the brake-by-wire system does not meet the preset exit condition.

[0031] Optionally, the detecting whether the brake-by-wire system is allowed to enter the pedal-on power-on braking mode includes:

[0032] Determine whether the brake pedal is pressed at the moment the change is completed and whether the brake pedal has not been fully released after the change is completed;

[0033] If the brake pedal is detected to be depressed at the moment when the change is completed, and the brake pedal has not been fully released after the change is completed, a flag that allows the brake-by-wire system to enter the pedal-on power-on braking mode is set to true;

[0034] When the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is true, if it is detected that the brake pedal has been completely released, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false; or if it is detected that the brake pedal is not depressed at the moment when the change is completed, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false;

[0035] When the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is true, the brake-by-wire system enters the pedal-on power-on braking mode; when the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is false, the brake-by-wire system enters the normal brake-by-wire mode.

[0036] Optionally, after entering the first mechanical backup braking mode, the method further includes:

[0037] Control the manual cylinder circuit isolation valve to remain in the open state, and control the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain in the closed state, so that the two piston chambers of the manual cylinder are connected to the electronic stability control system and the wheel-side brake circuit. When the brake pedal is stepped on to build up pressure, the connected brake circuit pressure is built up normally, and the pressure is greater than 0. The circuit pressure from the simulation cylinder circuit isolation valve to the simulation cylinder is 0, and the pressure before the servo cylinder circuit isolation valve and in the servo cylinder is also 0.

[0038] Optionally, after entering the normal brake-by-wire mode, the method further includes:

[0039] The manual cylinder circuit isolation valve is controlled to change from an open state to a closed state, and the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve are controlled to change from a closed state to an open state, and the pressure in the manual cylinder and the simulation cylinder is measured by the manual cylinder pressure sensor, and the pressure in the servo cylinder body, the hydraulic circuits before and after the servo cylinder circuit isolation valve, the electronic stability control system and the wheel side are measured by the servo cylinder pressure sensor.

[0040] According to a second aspect of the present application, a fully decoupled brake-by-wire system is provided, comprising:

[0041] Controller, brake pedal, mechanical push rod, travel sensor, fluid reservoir, manual cylinder including piston and spring, manual cylinder pressure sensor, manual cylinder circuit isolation valve, simulation cylinder circuit isolation valve, simulation cylinder, servo cylinder circuit isolation valve, servo cylinder pressure sensor, servo cylinder body, servo cylinder piston, ball screw transmission mechanism and servo motor;

[0042] The controller is configured to detect whether the brake-by-wire system is powered on normally; if the brake-by-wire system is not powered on normally, enter a first mechanical backup braking mode; if the brake-by-wire system is powered on normally, detect whether the brake-by-wire system has a fault; if the brake-by-wire system has a fault, enter the first mechanical backup braking mode; if the brake-by-wire system has no fault, detect a mechanical zero point of a servo cylinder piston in the brake-by-wire system; and,

[0043] Determine whether the mechanical zero point of the servo cylinder piston is detected; if the mechanical zero point of the servo cylinder piston is not detected, enter the second mechanical backup braking mode, and continue to detect the mechanical zero point of the servo cylinder piston in the second mechanical backup braking mode; if the mechanical zero point of the servo cylinder piston is detected, detect whether the wire control brake system is allowed to enter the pedal-powered braking mode; if the wire control brake system is not allowed to enter the pedal-powered braking mode, enter the normal wire control brake mode; if the wire control brake system is allowed to enter the pedal-powered braking mode, enter the pedal-powered braking mode; in the pedal-powered braking mode, control the analog cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain in a closed state, control the manual cylinder circuit isolation valve to change from an open state to a closed state after power is applied, determine the first target pressure according to the stroke of the mechanical push rod; determine the second target pressure according to the pressure detected by the manual cylinder pressure sensor, select the larger value of the first target pressure and the second target pressure as the target braking pressure, and output the braking pressure; and,

[0044] Detect whether the brake-by-wire system is powered off; if it is detected that the brake-by-wire system is not powered off, return to the step of detecting whether the brake-by-wire system is faulty; if it is detected that the brake-by-wire system is powered off, the process ends.

[0045] Optionally, the controller is also used to detect whether the wire control brake system meets the preset exit condition in the pedal-on electric braking mode. If it is detected that the wire control brake system meets the preset exit condition, the normal wire control brake mode is entered; if it is detected that the wire control brake system does not meet the preset exit condition, the normal wire control brake mode is continued to remain in the pedal-on electric braking mode.

[0046] Optionally, the controller detects whether the brake-by-wire system meets a preset exit condition by the following steps:

[0047] Detect whether the stroke of the mechanical push rod is less than the preset stroke value;

[0048] If the stroke of the mechanical push rod is less than the preset stroke value, it is determined that the wire control brake system meets the preset exit condition;

[0049] If the stroke of the mechanical push rod is greater than or equal to the preset stroke value, it is determined that the wire control brake system does not meet the preset exit condition; or,

[0050] Check whether the pressure of the manual cylinder is less than the preset pressure value;

[0051] If the pressure of the manual cylinder is less than a preset pressure value, it is determined that the brake-by-wire system meets a preset exit condition;

[0052] If the pressure of the manual cylinder is greater than or equal to the preset pressure value, it is determined that the brake-by-wire system does not meet the preset exit condition.

[0053] Optionally, the controller detects whether the brake-by-wire system is allowed to enter the pedal-on electric braking mode through the following steps, including:

[0054] Determine whether the brake pedal is pressed at the moment the change is completed and whether the brake pedal has not been fully released after the change is completed;

[0055] If the brake pedal is detected to be depressed at the moment when the change is completed, and the brake pedal has not been fully released after the change is completed, a flag that allows the brake-by-wire system to enter the pedal-on power-on braking mode is set to true;

[0056] When the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is true, if it is detected that the brake pedal has been completely released, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false; or if it is detected that the brake pedal is not depressed at the moment when the change is completed, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false;

[0057] When the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is true, the brake-by-wire system enters the pedal-on power-on braking mode; when the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is false, the brake-by-wire system enters the normal brake-by-wire mode.

[0058] Optionally, the controller is also used to control the manual cylinder circuit isolation valve to remain open, and control the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain closed after entering the first mechanical backup braking mode, so that the two piston chambers of the manual cylinder are connected to the electronic stability control system and the wheel-side braking circuit. When the brake pedal is stepped on to build pressure, the connected braking circuit pressure is established normally, and the pressure is greater than 0. The circuit pressure from the simulation cylinder circuit isolation valve to the simulation cylinder is 0, and the pressure before the servo cylinder circuit isolation valve and in the servo cylinder is also 0.

[0059] Optionally, the controller is also used to control the manual cylinder circuit isolation valve to change from an open state to a closed state, and control the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve to change from a closed state to an open state after entering the normal wire control braking mode, and measure the pressure in the manual cylinder and the simulation cylinder through the manual cylinder pressure sensor, and measure the pressure in the servo cylinder body, the hydraulic circuits before and after the servo cylinder circuit isolation valve, the electronic stability control system and the wheel side through the servo cylinder pressure sensor.

[0060] 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.

[0061] 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 caused to execute the method described in the first aspect.

[0062] The technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0063] After detecting that the brake-by-wire system is powered on normally and there is no fault, power-on balancing is performed immediately, and it is determined whether balancing is completed. In the case that balancing is not completed, the second mechanical backup braking mode is entered, and power-on balancing is continued in the second mechanical backup braking mode. After balancing is completed, the brake-by-wire system enters the pedal-powered braking mode or the normal brake-by-wire mode, depending on whether the brake-by-wire system is allowed to enter the pedal-powered braking mode. The present application gives priority to ensuring power-on balancing. When balancing is not completed, it is always in the mechanical backup braking mode. At this time, the pedal feel is continuous and there is a certain amount of brake pressure output. Moreover, when balancing is completed and the pedal-powered braking mode is entered, sufficient brake pressure can be output. In this way, the pedal feel can be guaranteed to be continuous, the normal execution of the motor control logic can be guaranteed, and the problem of insufficient pressure building stroke of the servo cylinder piston when the servo cylinder piston is too far away from the mechanical zero point due to abnormal power failure is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] 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.

[0065] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0066] Figure 1 A schematic diagram of a fully decoupled brake-by-wire system in an embodiment of the present application;

[0067] Figure 2 A flow chart of a fully decoupled brake-by-wire method in an embodiment of the present application;

[0068] Figure 3A A schematic diagram of a fully decoupled brake-by-wire system in mechanical backup braking mode;

[0069] Figure 3B A schematic diagram of a fully decoupled brake-by-wire system in normal brake-by-wire mode;

[0070] Figure 4 This is another flow chart of the fully decoupled brake-by-wire method in the embodiment of the present application;

[0071] Figure 5 Schematic diagram of the structure of a fully decoupled wire-controlled brake system in an embodiment of the present application. DETAILED DESCRIPTION

[0072] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0073] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application can also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present application, not all of the embodiments.

[0074] The brake-by-wire system of the embodiment of the present application is a fully decoupled brake-by-wire system (DBS, Decoupled Brake System). Because of the isolation of the solenoid valve, it can achieve a fully decoupled state, that is, the pedal feel will not be affected by the execution circuit at all, and 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.

[0075] See also Figure 1 , Figure 1 This is a schematic diagram of the principle of a fully decoupled, wire-controlled brake system in an embodiment of the present application. The wire-controlled brake system includes: a brake pedal 1, a mechanical push rod 2, a travel sensor 3, a fluid reservoir 4, a first piston and spring 5 in the manual cylinder, a second piston and spring 6 in the manual cylinder, a manual cylinder pressure sensor 7, a manual cylinder circuit isolation valve 8, a manual cylinder circuit isolation valve 9, a simulation cylinder circuit isolation valve 10, a simulation cylinder 11, a servo cylinder circuit isolation valve 12, a servo cylinder circuit isolation valve 13, a servo cylinder pressure sensor 14, a servo cylinder body 15, a servo cylinder piston 16, a ball screw drive mechanism 17, and a servo motor 18. The remaining components are the brake fluid circuit and the associated filter and one-way valve. The circuit is filled with brake fluid, and the fluid level in the fluid reservoir 4 is between the minimum and maximum positions. The manual cylinder circuit isolation valves 8 and 9 are both normally open valves, while the simulation cylinder circuit isolation valves 10, the servo cylinder circuit isolation valves 12, and the servo cylinder circuit isolation valves 13 are all normally closed valves.

[0076] Figure 1 In the car, the Electronic Stability Control (ESC) connects to the two circuits of the DBS and to the four wheel brakes. The symbols FL, FR, RL, and RR in the figure represent the four wheel brakes, respectively.

[0077] See also Figure 2 , Figure 2 This is a flow chart of a fully decoupled brake-by-wire method according to an embodiment of the present application, which may include the following steps:

[0078] Step S202 , detecting whether the brake-by-wire system is powered on normally.

[0079] If the brake-by-wire system is not powered on normally, step S204 is executed; if the brake-by-wire system is powered on normally, step S206 is executed.

[0080] Step S204: Entering the first mechanical backup braking mode.

[0081] In the first mechanical backup braking mode, no control strategy is involved. If the brake-by-wire system is not powered on properly, manual cylinder circuit isolation valves 8 and 9 are controlled to remain open, while simulated cylinder circuit isolation valves 10, servo cylinder circuit isolation valves 12, and servo cylinder circuit isolation valves 13 are controlled to remain closed.

[0082] Combine Figure 3A In the first mechanical backup braking mode, the brake pedal 1 is depressed, pushing the mechanical push rod 2 to the left. At this time, the piston in the manual cylinder moves to the left, and the piston spring is compressed. After the piston in the manual cylinder moves to the left, it passes the brake fluid circuit inlet of the two piston chambers in the manual cylinder. The brake fluid in the two piston chambers of the manual cylinder is sealed and compressed, and the further the piston is pushed to the left, the higher the pressure in the sealed circuit. At this time, since the manual cylinder circuit isolation valve 8 and the manual cylinder circuit isolation valve 9 are in the open state, the two piston chambers of the manual cylinder are connected to the electronic stability control system and the wheel side brake circuit. When the brake pedal is depressed to build pressure, the pressure of the connected brake circuit is built up normally, and the pressure is greater than 0. The circuit pressure from the simulation cylinder circuit isolation valve to the simulation cylinder is 0, and the pressure before the servo cylinder circuit isolation valve and in the servo cylinder is also 0.

[0083] Step S206 , detecting whether there is a fault in the brake-by-wire system.

[0084] In this embodiment of the present application, a fault in the brake-by-wire system can be determined by detecting whether the servo motor, the manual cylinder circuit isolation valve, and the servo cylinder circuit isolation valve are faulty. If none of the servo motor, the manual cylinder circuit isolation valve, and the servo cylinder circuit isolation valve are faulty, the brake-by-wire system is determined to be faulty. If at least one of the servo motor, the manual cylinder circuit isolation valve, and the servo cylinder circuit isolation valve is faulty, the brake-by-wire system is determined to be faulty.

[0085] If there is a fault in the wire control braking system, step S204 is executed. At this time, the motor and all solenoid valves (manual cylinder circuit isolation valve 8, manual cylinder circuit isolation valve 9, simulation cylinder circuit isolation valve 10, servo cylinder circuit isolation valve 12 and servo cylinder circuit isolation valve 13) are not controlled; if there is no fault in the wire control braking system, step S208 is executed.

[0086] Step S208 , detecting the mechanical zero point of the servo cylinder piston in the brake-by-wire system.

[0087] The method for detecting the mechanical zero point of the servo cylinder piston can be: when the wire control brake system is powered on normally and there is no fault, the servo motor 18 is directly reversed to drive the ball screw transmission mechanism 17 to make the servo cylinder piston 16 retreat to the mechanical zero point. At the same time, when the negative torque output by the motor exceeds a certain threshold, the servo motor 18 is stopped from reversing, and the servo cylinder piston position S0 at this time is marked as the mechanical zero point, and this value is usually a negative value.

[0088] Step S210: Determine whether the mechanical zero point detection of the servo cylinder piston is completed.

[0089] During the change process, it can be determined whether the mechanical zero point of the servo cylinder piston has been detected. If the mechanical zero point of the servo cylinder piston has been detected, step S212 is executed; if the mechanical zero point of the servo cylinder piston has not been detected, step S214 is executed.

[0090] Step S212 , detecting whether the brake-by-wire system is allowed to enter the pedal-on braking mode.

[0091] To avoid the pedal sinking problem caused by switching directly from the mechanical backup braking mode to the normal brake-by-wire mode when the brake pedal is depressed, a check can be performed to determine whether the brake-by-wire system is permitted to enter the pedal-on-electric braking mode. If the brake-by-wire system is not permitted to enter the pedal-on-electric braking mode, step S216 is executed, i.e., the system enters the normal brake-by-wire mode. Subsequent brake pedal depressions will be in the normal brake-by-wire mode. If the brake-by-wire system is permitted to enter the pedal-on-electric braking mode, step S218 is executed.

[0092] Alternatively, it may be determined whether the brake pedal is detected to be depressed at the moment the change is completed and the brake pedal has not been fully released after the change is completed. If the brake pedal is detected to be depressed at the moment the change is completed and the brake pedal has not been fully released after the change is completed, a flag allowing the brake-by-wire system to enter the pedal-on-brake mode is set to true.

[0093] When the flag allowing the brake-by-wire system to enter the pedal-on electric braking mode is true, if the brake pedal is detected to have been fully released, the flag allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false. Alternatively, if the brake pedal is detected to be unpressed at the moment of change completion, the flag allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false.

[0094] When the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is true, the brake-by-wire system enters the pedal-on power-on braking mode; when the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is false, the brake-by-wire system enters the normal brake-by-wire mode.

[0095] Step S214 , entering the second mechanical backup braking mode, and in the second mechanical backup braking mode, continuing to detect the mechanical zero point of the servo cylinder piston.

[0096] The second mechanical backup braking mode is identical to the first mechanical backup braking mode in terms of valve control, but differs in terms of motor control. In the second mechanical backup braking mode, since the valve control is identical to the first mechanical backup braking mode, the manual cylinder pressure buildup is consistent with the first mechanical backup braking mode. However, in the servo cylinder, the pressure before the servo cylinder circuit isolation valve and within the servo cylinder may not be zero due to the servo motor controlling the servo cylinder piston's zeroing process.

[0097] The homing action continues in the second mechanical backup braking mode, that is, the part of the wire control brake system that builds pressure on the wheel side is always in the second mechanical backup braking mode. At this time, the pedal feel is continuous and there is a certain brake pressure output; and because the servo cylinder isolation valve is in the closed state, the motor homing process will not affect the output of brake pressure.

[0098] Step S216, entering normal brake-by-wire mode.

[0099] Combine Figure 3B After entering the normal wire control braking mode, all solenoid valves are energized and activated, that is, the manual cylinder circuit isolation valve is controlled to change from an open state to a closed state, and the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve are controlled to change from a closed state to an open state. The pressure in the manual cylinder and the simulation cylinder can be measured by the manual cylinder pressure sensor, and the pressure in the servo cylinder body, the hydraulic circuits before and after the servo cylinder circuit isolation valve, the electronic stability control system and the wheel side can be measured by the servo cylinder pressure sensor.

[0100] When the brake pedal is depressed, human-generated hydraulic pressure builds up before the manual cylinder circuit isolation valves 8 and 9. At this point, the pressure measured by the manual cylinder pressure sensor 7 represents the pressure in the manual cylinder and the simulated cylinder. Furthermore, the pressure generated by the servo motor 18 driving the ball screw drive mechanism 17 forward to compress the brake fluid in the servo cylinder piston 16 builds up in the fluid circuit after the manual cylinder circuit isolation valves 8 and 9. At this point, the pressure measured by the servo cylinder pressure sensor 14 represents the pressure in the hydraulic circuits before and after the servo cylinder body 15, the servo cylinder circuit isolation valves 12 and 13, and the pressure in the ESC and wheel side.

[0101] Step S218, enter the pedal-on braking mode.

[0102] In the pedal-powered braking mode, the analog cylinder circuit isolation valve and the servo cylinder circuit isolation valve are controlled to remain in the closed state, and the manual cylinder circuit isolation valve is controlled to change from the open state to the closed state after power is applied. The first target pressure is determined according to the stroke of the mechanical push rod; the second target pressure is determined according to the pressure detected by the manual cylinder pressure sensor, and the larger value of the first target pressure and the second target pressure is selected as the target braking pressure, and the braking pressure is output.

[0103] In this mode, the manual cylinder circuit isolation valve 8 and the manual cylinder circuit isolation valve 9 are closed at the moment the brake pedal is powered on, and the simulation cylinder circuit isolation valve 10 is kept closed. In this way, the brake fluid in the manual cylinder will be isolated from the circuits after the simulation cylinder circuit isolation valve 10 and after the manual cylinder circuit isolation valve 8 and the manual cylinder circuit isolation valve 9, thereby preventing the pedal from suddenly sinking when the brake pedal is powered on when it is deeply depressed.

[0104] Although the brake pedal cannot be depressed any further after the manual cylinder circuit isolation valve 8, the manual cylinder circuit isolation valve 9 and the simulation cylinder circuit isolation valve 10 are closed, if the force of pressing the brake pedal 1 is further increased, the measurement value of the manual cylinder pressure sensor 7 will increase further. The increase in this value will be used as a control basis to increase the target pressure of the braking system, thereby generating a greater braking pressure at the wheel side to meet the braking requirements.

[0105] Step S220 , detecting whether the brake-by-wire system is powered off.

[0106] If it is detected that the brake-by-wire system is not powered off, the process returns to step S206; if it is detected that the brake-by-wire system is powered off, the process ends. Figure 1 The mode judgment in the system will be periodically cycled and tested, and the corresponding working mode will be entered according to the real-time status of the system.

[0107] The fully decoupled wire control braking method of the embodiment of the present application, after detecting that the wire control braking system is powered on normally and there is no fault, immediately performs power-on zeroing and determines whether zeroing is completed. If zeroing is not completed, the second mechanical backup braking mode is entered, and zeroing is continued in the second mechanical backup braking mode. After zeroing is completed, the power-on power-on braking mode or the normal wire control braking mode is entered according to whether the wire control braking system is allowed to enter the pedal power-on braking mode. The present application gives priority to ensuring power-on zeroing. When zeroing is not completed, it is always in the mechanical backup braking mode. At this time, the pedal feel is continuous and there is a certain amount of brake pressure output. In addition, when zeroing is completed and the pedal power-on braking mode is entered, sufficient brake pressure can be output. In this way, the pedal feel can be guaranteed to be continuous, the normal execution of the motor control logic can be guaranteed, and the problem of insufficient pressure building stroke of the servo cylinder piston when the servo cylinder piston is too far away from the mechanical zero point due to abnormal power failure is avoided.

[0108] In the pedal-operated braking mode, when the brake pedal is slightly released but not completely released, the vehicle may slip on a slope due to the reduction in the target pressure of the braking system. At this time, it is necessary to continue to press the pedal to increase the target braking force. However, because it is in the pedal-operated braking mode, the brake pedal cannot be continued to be pressed after it has been released to the point where it is not completely released, which may cause a poor experience.

[0109] In some embodiments, in order to avoid this problem, in the pedal-powered braking mode, if the preset exit condition (i.e., the condition for entering the normal brake-by-wire mode) is not met, the highest target braking pressure in this mode is always maintained (this highest target braking pressure will be subject to a maximum value limit, i.e., not exceeding the maximum braking pressure limit value in place) until the preset exit condition is met and the target braking pressure is released to 0. Subsequent braking enters the normal brake-by-wire mode, and the highest target pressure maintenance logic of the pedal-powered braking mode is no longer executed.

[0110] See also Figure 4 , Figure 4 This is another flow chart of the fully decoupled wire control brake method in the embodiment of the present application. Figure 2 Based on the embodiment, the following steps may also be included:

[0111] Step S219: In the pedal-operated electric braking mode, detecting whether the brake-by-wire system meets a preset exit condition.

[0112] If it is detected that the brake-by-wire system meets the preset exit condition, step S216 is executed, that is, the normal brake-by-wire mode is entered. If it is detected that the brake-by-wire system does not meet the preset exit condition, the brake-by-wire mode is maintained.

[0113] Alternatively, the brake-by-wire system may be detected by detecting the stroke of the mechanical push rod or the pressure of the manual cylinder. Specifically, the brake-by-wire system may be detected to determine whether the stroke of the mechanical push rod is less than a preset stroke value. If the stroke of the mechanical push rod is less than the preset stroke value, the brake-by-wire system is determined to have satisfied the preset exit condition. If the stroke of the mechanical push rod is greater than or equal to the preset stroke value, the brake-by-wire system is determined to have not satisfied the preset exit condition.

[0114] Alternatively, detect whether the pressure of the manual cylinder is less than a preset pressure value; if the pressure of the manual cylinder is less than the preset pressure value, determine that the wire control braking system meets the preset exit condition; if the pressure of the manual cylinder is greater than or equal to the preset pressure value, determine that the wire control braking system does not meet the preset exit condition.

[0115] By adopting the above method, it is possible to avoid the problem of poor experience caused by the inability to continue pressing the brake pedal after the brake pedal is released to a point where it is not completely released in the pedal-operated electric braking mode.

[0116] It should be noted that although the steps of the method of 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 steps 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.

[0117] The present application also provides a fully decoupled wire-controlled brake system. Figure 5 The fully decoupled brake-by-wire system 500 includes a controller 502, a brake pedal 504, a mechanical push rod 506, a travel sensor 508, a fluid reservoir 510, a manual cylinder 512 including a piston and a spring, a manual cylinder pressure sensor 514, a manual cylinder circuit isolation valve 516, a simulation cylinder circuit isolation valve 518, a simulation cylinder 520, a servo cylinder circuit isolation valve 522, a servo cylinder pressure sensor 524, a servo cylinder body 526, a servo cylinder piston 528, a ball screw transmission mechanism 530, and a servo motor 532.

[0118] Controller 502 is configured to detect whether the brake-by-wire system is powered on normally; if the brake-by-wire system is not powered on normally, enter the first mechanical backup braking mode; if the brake-by-wire system is powered on normally, detect whether the brake-by-wire system is faulty; if the brake-by-wire system is faulty, enter the first mechanical backup braking mode; if the brake-by-wire system is not faulty, detect the mechanical zero point of the servo cylinder piston in the brake-by-wire system; and,

[0119] Determine whether the mechanical zero point of the servo cylinder piston is detected; if the mechanical zero point of the servo cylinder piston is not detected, enter the second mechanical backup braking mode, and in the second mechanical backup braking mode, continue to detect the mechanical zero point of the servo cylinder piston; if the mechanical zero point of the servo cylinder piston is detected, detect whether the wire control brake system is allowed to enter the pedal power-on braking mode; if the wire control brake system is not allowed to enter the pedal power-on braking mode, enter the normal wire control brake mode; if the wire control brake system is allowed to enter the pedal power-on braking mode, enter the pedal power-on braking mode; in the pedal power-on braking mode, control the analog cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain in the closed state, control the manual cylinder circuit isolation valve to change from the open state to the closed state after power is applied, and determine the first target pressure according to the stroke of the mechanical push rod; determine the second target pressure according to the pressure detected by the manual cylinder pressure sensor, select the larger value of the first target pressure and the second target pressure as the target braking pressure, and output the braking pressure; and,

[0120] Check whether the brake-by-wire system is powered off; if it is detected that the brake-by-wire system is not powered off, return to the step of checking whether the brake-by-wire system is faulty; if it is detected that the brake-by-wire system is powered off, the process ends.

[0121] Optionally, the controller 502 is also used to detect whether the wire control brake system meets the preset exit condition in the pedal-on electric braking mode. If it is detected that the wire control brake system meets the preset exit condition, the normal wire control brake mode is entered; if it is detected that the wire control brake system does not meet the preset exit condition, the normal wire control brake mode is continued to remain in the pedal-on electric braking mode.

[0122] Optionally, the controller 502 detects whether the brake-by-wire system meets a preset exit condition by performing the following steps:

[0123] Detect whether the stroke of the mechanical push rod is less than the preset stroke value;

[0124] If the stroke of the mechanical push rod is less than the preset stroke value, it is determined that the brake-by-wire system meets the preset exit condition;

[0125] If the stroke of the mechanical push rod is greater than or equal to the preset stroke value, it is determined that the brake-by-wire system does not meet the preset exit condition; or,

[0126] Check whether the pressure of the manual cylinder is less than the preset pressure value;

[0127] If the pressure of the manual cylinder is less than the preset pressure value, it is determined that the brake-by-wire system meets the preset exit condition;

[0128] If the pressure of the manual cylinder is greater than or equal to the preset pressure value, it is determined that the brake-by-wire system does not meet the preset exit condition.

[0129] Optionally, the controller 502 detects whether the brake-by-wire system is allowed to enter the pedal-on electric braking mode through the following steps, including:

[0130] Determine whether the brake pedal is pressed at the moment the change is completed and whether the brake pedal has not been fully released after the change is completed;

[0131] If the brake pedal is detected to be depressed at the moment when the change is completed, and the brake pedal has not been fully released after the change is completed, a flag that allows the brake-by-wire system to enter the pedal-on power-on braking mode is set to true;

[0132] When the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is true, if it is detected that the brake pedal has been fully released, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false; or if it is detected that the brake pedal is not depressed at the moment when the change is completed, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false;

[0133] When the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is true, the brake-by-wire system enters the pedal-on power-on braking mode; when the flag allowing the brake-by-wire system to enter the pedal-on power-on braking mode is false, the brake-by-wire system enters the normal brake-by-wire mode.

[0134] Optionally, the controller 502 is also used to control the manual cylinder circuit isolation valve to remain open and control the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain closed after entering the first mechanical backup braking mode, so that the two piston chambers of the manual cylinder are connected to the electronic stability control system and the wheel-side braking circuit. When the brake pedal is stepped on to build up pressure, the connected braking circuit pressure is established normally, and the pressure is greater than 0. The circuit pressure from the simulation cylinder circuit isolation valve to the simulation cylinder is 0, and the pressure before the servo cylinder circuit isolation valve and in the servo cylinder is also 0.

[0135] Optionally, the controller is also used to control the manual cylinder circuit isolation valve to change from an open state to a closed state, and control the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve to change from a closed state to an open state after entering the normal wire control braking mode, and measure the pressure in the manual cylinder and the simulation cylinder through the manual cylinder pressure sensor, and measure the pressure in the servo cylinder body, the hydraulic circuits before and after the servo cylinder circuit isolation valve, the electronic stability control system and the wheel side through the servo cylinder pressure sensor.

[0136] The specific details of each module or unit in the above system have been described in detail in the corresponding method, so they will not be repeated here.

[0137] It should be noted that, although several modules or units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiment of the application, the features and functions of two or more modules or units described above can be concretized in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.

[0138] In an embodiment of the present application, a computer-readable storage medium is further provided, on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned wire control braking method is implemented.

[0139] It should be noted that the computer-readable storage medium shown in this application can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination thereof. More specific examples of computer-readable storage media can 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 thereof. In this application, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, device or device. The program code contained on the computer-readable storage medium can be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, radio frequency, etc., or any suitable combination thereof.

[0140] In an embodiment of the present application, a computer program product is further provided. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned wire control braking method.

[0141] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0142] The foregoing description is intended only to provide specific embodiments of the present application, which will enable those skilled in the art to understand and implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments described herein, but is intended to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A fully decoupled wire control brake method, characterized in that: include: Check whether the brake-by-wire system is powered on normally; If the wire control brake system is not powered on normally, entering the first mechanical backup braking mode; If the brake-by-wire system is powered on normally, detecting whether the brake-by-wire system has a fault; If there is a fault in the brake-by-wire system, entering a first mechanical backup braking mode; If there is no fault in the brake-by-wire system, detecting a mechanical zero point of a servo cylinder piston in the brake-by-wire system; Determining whether the mechanical zero point of the servo cylinder piston is detected; If the mechanical zero point of the servo cylinder piston is not detected, the second mechanical backup braking mode is entered, and in the second mechanical backup braking mode, the detection of the mechanical zero point of the servo cylinder piston is continued; If the mechanical zero point of the servo cylinder piston has been detected, detecting whether the wire control brake system is allowed to enter the pedal-operated power-on braking mode; If the brake-by-wire system is not allowed to enter the pedal-on-brake mode, entering the normal brake-by-wire mode; If the brake-by-wire system is allowed to enter the pedal-on-electric braking mode, entering the pedal-on-electric braking mode; In the pedal-powered braking mode, the analog cylinder circuit isolation valve and the servo cylinder circuit isolation valve are controlled to remain in a closed state, and the manual cylinder circuit isolation valve is controlled to change from an open state to a closed state after power is applied. A first target pressure is determined according to the stroke of the mechanical push rod; a second target pressure is determined according to the pressure detected by the manual cylinder pressure sensor, and the larger value of the first target pressure and the second target pressure is selected as the target braking pressure, and the braking pressure is output; detecting whether the brake-by-wire system is powered off; If it is detected that the brake-by-wire system is not powered off, returning to the step of detecting whether the brake-by-wire system has a fault; If it is detected that the brake-by-wire system is powered off, the process ends.

2. The method according to claim 1, characterized in that The method further comprises: In the pedal-operated electric braking mode, detecting whether the brake-by-wire system meets a preset exit condition, and if it is detected that the brake-by-wire system meets the preset exit condition, entering the normal brake-by-wire mode; If it is detected that the brake-by-wire system does not meet the preset exit condition, the brake-by-wire system continues to be in the pedal-on electric braking mode.

3. The method according to claim 2, characterized in that The detecting whether the brake-by-wire system satisfies a preset exit condition includes: Detect whether the stroke of the mechanical push rod is less than the preset stroke value; If the stroke of the mechanical push rod is less than the preset stroke value, it is determined that the wire control brake system meets the preset exit condition; If the stroke of the mechanical push rod is greater than or equal to the preset stroke value, it is determined that the wire control brake system does not meet the preset exit condition; or, Check whether the pressure of the manual cylinder is less than the preset pressure value; If the pressure of the manual cylinder is less than a preset pressure value, it is determined that the brake-by-wire system meets a preset exit condition; If the pressure of the manual cylinder is greater than or equal to the preset pressure value, it is determined that the brake-by-wire system does not meet the preset exit condition.

4. The method according to claim 1, wherein The detecting whether the brake-by-wire system is allowed to enter the pedal-on-power braking mode includes: Determine whether the brake pedal is pressed at the moment the change is completed and whether the brake pedal has not been fully released after the change is completed; If the brake pedal is detected to be depressed at the moment when the change is completed, and the brake pedal has not been fully released after the change is completed, a flag that allows the brake-by-wire system to enter the pedal-on power-on braking mode is set to true; When the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is true, if it is detected that the brake pedal has been completely released, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false; or if it is detected that the brake pedal is not depressed at the moment when the change is completed, the flag for allowing the brake-by-wire system to enter the pedal-on electric braking mode is set to false; When the flag allowing the wire control brake system to enter the pedal-on power-on braking mode is true, the wire control brake system enters the pedal-on power-on braking mode; when the flag allowing the wire control brake system to enter the pedal-on power-on braking mode is false, the wire control brake system enters the normal wire control brake mode.

5. The method according to claim 1, wherein After entering the first mechanical backup braking mode, the method further includes: Control the manual cylinder circuit isolation valve to remain in the open state, and control the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain in the closed state, so that the two piston chambers of the manual cylinder are connected to the electronic stability control system and the wheel-side brake circuit. When the brake pedal is stepped on to build up pressure, the connected brake circuit pressure is built up normally, and the pressure is greater than 0. The circuit pressure from the simulation cylinder circuit isolation valve to the simulation cylinder is 0, and the pressure before the servo cylinder circuit isolation valve and in the servo cylinder is also 0.

6. The method according to claim 1, characterized in that After entering the normal brake-by-wire mode, the method further includes: The manual cylinder circuit isolation valve is controlled to change from an open state to a closed state, and the simulation cylinder circuit isolation valve and the servo cylinder circuit isolation valve are controlled to change from a closed state to an open state. The pressure in the manual cylinder and the simulation cylinder is measured by the manual cylinder pressure sensor, and the pressure in the servo cylinder body, the hydraulic circuits before and after the servo cylinder circuit isolation valve, the electronic stability control system and the wheel side are measured by the servo cylinder pressure sensor.

7. A fully decoupled brake-by-wire system, characterized in that: include: Controller, brake pedal, mechanical push rod, travel sensor, fluid reservoir, manual cylinder including piston and spring, manual cylinder pressure sensor, manual cylinder circuit isolation valve, simulation cylinder circuit isolation valve, simulation cylinder, servo cylinder circuit isolation valve, servo cylinder pressure sensor, servo cylinder body, servo cylinder piston, ball screw transmission mechanism and servo motor; The controller is configured to detect whether the brake-by-wire system is normally powered on; if the brake-by-wire system is not normally powered on, enter a first mechanical backup braking mode; if the brake-by-wire system is normally powered on, detect whether the brake-by-wire system is faulty; If the brake-by-wire system has a fault, entering a first mechanical backup braking mode; if the brake-by-wire system has no fault, detecting a mechanical zero point of a servo cylinder piston in the brake-by-wire system; and, Determine whether the mechanical zero point of the servo cylinder piston has been detected; if the mechanical zero point of the servo cylinder piston has not been detected, enter the second mechanical backup braking mode, and continue to detect the mechanical zero point of the servo cylinder piston in the second mechanical backup braking mode; if the mechanical zero point of the servo cylinder piston has been detected, detect whether the wire control brake system is allowed to enter the pedal-operated braking mode; if the wire control brake system is not allowed to enter the pedal-operated braking mode, enter the normal wire control brake mode; if the wire control brake system is allowed to enter the pedal-operated braking mode, enter the pedal-operated braking mode; in the pedal-operated braking mode, control the analog cylinder circuit isolation valve and the servo cylinder circuit isolation valve to remain in a closed state, control the manual cylinder circuit isolation valve to change from an open state to a closed state after power is applied, and determine the first target pressure according to the stroke of the mechanical push rod; determine the second target pressure according to the pressure detected by the manual cylinder pressure sensor, select the larger value of the first target pressure and the second target pressure as the target braking pressure, and output the braking pressure; as well as, Detect whether the brake-by-wire system is powered off; if it is detected that the brake-by-wire system is not powered off, return to the step of detecting whether the brake-by-wire system is faulty; if it is detected that the brake-by-wire system is powered off, the process ends.

8. The system according to claim 7, characterized in that The controller is further configured to detect whether the brake-by-wire system satisfies a preset exit condition in the pedal-on electric braking mode, and enter a normal brake-by-wire mode if it is detected that the brake-by-wire system satisfies the preset exit condition; and continue to remain in the pedal-on electric braking mode if it is detected that the brake-by-wire system does not satisfy the preset exit condition.

9. The system according to claim 8, characterized in that The controller detects whether the brake-by-wire system meets a preset exit condition by performing the following steps: Detect whether the stroke of the mechanical push rod is less than the preset stroke value; If the stroke of the mechanical push rod is less than the preset stroke value, it is determined that the wire control brake system meets the preset exit condition; If the stroke of the mechanical push rod is greater than or equal to the preset stroke value, it is determined that the brake-by-wire system does not meet the preset exit condition; or, Check whether the pressure of the manual cylinder is less than the preset pressure value; If the pressure of the manual cylinder is less than a preset pressure value, it is determined that the brake-by-wire system meets a preset exit condition; If the pressure of the manual cylinder is greater than or equal to the preset pressure value, it is determined that the brake-by-wire system does not meet the preset exit condition.

10. The system according to claim 7, wherein: The controller detects whether the brake-by-wire system is allowed to enter the pedal-on-brake mode by performing the following steps: Determine whether the brake pedal is pressed at the moment the change is completed and whether the brake pedal has not been fully released after the change is completed; If the brake pedal is detected to be depressed at the moment when the change is completed, and the brake pedal has not been fully released after the change is completed, a flag that allows the brake-by-wire system to enter the pedal-on power-on braking mode is set to true; When the flag for allowing the brake-by-wire system to enter the pedal-down electric braking mode is true, if it is detected that the brake pedal has been fully released, the flag for allowing the brake-by-wire system to enter the pedal-down electric braking mode is set to false; Alternatively, if it is detected that the brake pedal is not depressed at the moment when the change is completed, the flag for allowing the brake-by-wire system to enter the pedal-depressed electric braking mode is set to false; When the flag allowing the wire control brake system to enter the pedal-on power-on braking mode is true, the wire control brake system enters the pedal-on power-on braking mode; when the flag allowing the wire control brake system to enter the pedal-on power-on braking mode is false, the wire control brake system enters the normal wire control brake mode.

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