Hydraulic braking decoupling method

Abstract

The embodiment of the invention relates to the field of hydraulic braking, and discloses a hydraulic braking decoupling method which comprises the following steps: providing a pedal feeling for a driver through a pedal feeling module of an EHB-HD braking loop; sensing pedal operation of a driver through a displacement sensor connected with a pedal, and analyzing the pedal operation into a target pressure signal; when a brake motor of the EHB-HD brake circuit is in a normal working state, the EHB-HD brake circuit provides pedal feeling for a driver through a pedal feeling module, obtains the target pressure signal and provides brake assistance according to the target pressure signal; when a brake motor of the EHB-HD brake circuit is in a failure state, the ESC brake circuit is connected with a brake assisting function, and the ESC brake circuit provides brake assisting power by controlling the states of valves in the EHB-HD brake circuit and the ESC brake circuit. The control method can be at least used for solving the technical problem of hydraulic decoupling type electronic hydraulic brake system control.

Description

Technical Field

[0001] The present application relates to the field of hydraulic braking, and in particular to a hydraulic braking decoupling method. Background Art

[0002] With the rapid development of intelligent driving systems, especially the gradual maturity of L3 autonomous driving technology, the automotive industry has increasingly higher requirements for vehicle safety, reliability and redundancy. L3 autonomous driving requires vehicles to have fully automated driving capabilities under certain conditions, but if the driver fails to take over the driving in time, the system must be able to ensure that the braking operation can still be completed safely in the event of a failure. Therefore, as one of the key technologies to ensure safety, the redundant braking system has become an essential feature of autonomous vehicles.

[0003] The current mainstream 2Box solutions are: ESP decoupling or mechanical decoupling solutions represented by IBooster+ESC, which have poor capacity recovery coordination. The hydraulic decoupling solution represented by IPB+RBU uses RBU as a backup pressure buildup and does not have stability redundancy capabilities. The hydraulic decoupling solution represented by DPB+ESC balances cost, performance, and redundancy capabilities and is the best choice in the current market. For example, a hydraulically decoupled electronic hydraulic braking system (application publication number CN118306361A), at least two of the main braking circuit, redundant braking circuit, and mechanical braking circuit can cooperate with each other to solve the problem of high hydraulic pressure required by the wheel-end module, and can meet the braking needs of the vehicle. However, there is currently a lack of a clear solution for how to perform brake decoupling for this hydraulically decoupled electronic hydraulic braking system. Summary of the invention

[0004] An object of the present application is to provide a hydraulic brake decoupling method, at least to solve the problem of hydraulic decoupling electronic hydraulic brake system control.

[0005] To achieve the above-mentioned purpose, some embodiments of the present application provide a hydraulic brake decoupling method, which is applied to the 2Box electronic hydraulic brake system of EHB-HD+ESC, and the method includes: providing a pedal feel to the driver through a pedal feel module of the EHB-HD brake circuit; sensing the driver's pedal operation through a displacement sensor connected to the pedal, and parsing the pedal operation into a target pressure signal; when the brake motor of the EHB-HD brake circuit is in a normal working state, the EHB-HD brake circuit provides the driver with a pedal feel and obtains the target pressure signal through the pedal feel module, and provides a brake assist according to the target pressure signal; when the brake motor of the EHB-HD brake circuit is in a failed state, the brake assist function is taken over by the ESC brake circuit, and the brake assist is provided by the ESC brake circuit by controlling the valve states in the EHB-HD brake circuit and the ESC brake circuit.

[0006] Compared with the related art, the solution provided in the embodiment of the present application realizes seamless transition when the motor fails through precise valve control in the EHB-HD brake circuit and the ESC brake circuit. When the motor fails, the ESC takes over the brake boost and maintains the normal braking effect by controlling the valve state, which will not affect the driver's braking experience. Compared with the traditional solution, it can provide a smoother braking response and a stable pedal feel, improving the driver's sense of security and comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0008] Figure 1 A schematic flow chart of a hydraulic brake decoupling method provided according to an embodiment of the present application; Figure 2 It is a structural schematic diagram of an EHB-HD+ESC 2Box electronic hydraulic brake system provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0010] The present application embodiment provides a hydraulic brake decoupling method. Applicable to the 2Box electronic hydraulic brake system of EHB-HD+ESC, the method is as follows Figure 1 The steps shown may include: S101, provides the driver with pedal feel via the pedal feel module of the EHB-HD brake circuit.

[0011] Under normal circumstances, the driver brakes by means of the brake pedal. The pedal feel module in the EHB-HD brake circuit is used to sense the driver's foot input and transmit it to the brake system. The pedal feel module is used to provide the driver with a force feedback when the driver steps on the pedal to simulate the foot feel when hydraulic pressure is generated by the mechanical pressure building module, thereby improving the driver's driving experience and comfort.

[0012] S102, sensing the driver's pedal operation through a displacement sensor connected to the pedal, and analyzing the pedal operation into a target pressure signal.

[0013] Displacement sensors are connected to the pedals to detect the driver's pedal displacement. These sensors monitor the displacement of the brake pedal in real time and convert it into an electrical signal. The control system interprets this signal as a target pressure signal, indicating the amount of braking force the driver wants to apply.

[0014] S103, when the brake motor of the EHB-HD brake circuit is in normal working state, the EHB-HD brake circuit provides the driver with a pedal feel through the pedal feel module and obtains the target pressure signal, and provides brake assist according to the target pressure signal.

[0015] When the brake motor of the EHB-HD brake circuit is in normal working condition, the system provides the required brake boost through the EHB-HD brake circuit according to the acquired target pressure signal. At this time, the brake motor of the EHB-HD brake circuit directly responds to the target pressure signal and provides hydraulic boost to the brake system through the electric pump or hydraulic module.

[0016] At the same time, the pedal feel module provides corresponding pedal feel feedback to ensure that the driver can feel stable and accurate braking force during braking. At this time, the EHB-HD braking circuit works normally and the braking process is smooth and efficient.

[0017] S104, when the brake motor of the EHB-HD brake circuit is in a failed state, the brake assist function is taken over by the ESC brake circuit, and the brake assist is provided by the ESC brake circuit by controlling the valve states in the EHB-HD brake circuit and the ESC brake circuit.

[0018] When the brake motor of the EHB-HD brake circuit fails or fails, the ESC brake circuit will automatically take over the brake assist function. At this time, the valves of the EHB-HD brake circuit and the ESC brake circuit will be reconfigured to ensure that the brake system can continue to operate without being affected by the motor failure, and can provide full braking capacity and brake feel consistent with the non-fault state.

[0019] like Figure 2 The EHB-HD+ESC 2Box electronic hydraulic brake system shown can maintain a normal powered-on system state even when the motor assist capability of the EHB-HD brake circuit is completely lost, with the CSV solenoid valve closed, the PSV solenoid valve and the SSV solenoid valve opened, to maintain a normal pedal feel; the driver's braking intention is recognized by the displacement sensor of the EHB-HD brake circuit, parsed into a corresponding target pressure signal, and sent to the ESC brake circuit via the CAN line; the EHB-HD brake circuit synchronously sends its own system state to the ESC brake circuit.

[0020] Furthermore, the EHB-HD brake circuit includes: a CSV1 solenoid valve, a CSV2 solenoid valve, a PSV1 solenoid valve, a PSV2 solenoid valve and an SSV solenoid valve; the CSV1 solenoid valve and the CSV2 solenoid valve are normally open valves; the PSV1 solenoid valve, the PSV2 solenoid valve and the SSV solenoid valve are normally closed valves.

[0021] Furthermore, the ESC brake circuit includes: an RV solenoid valve, an SV solenoid valve, an IV solenoid valve and an OV solenoid valve; the RV solenoid valve and the IV solenoid valve are normally open valves; the SV solenoid valve and the OV solenoid valve are normally closed valves.

[0022] The RV solenoid valve includes the RV1 valve and the RV2 valve; the SV solenoid valve includes the SV1 valve and the SV2 valve; the IV solenoid valve includes the IV1F valve, the IV1R valve, the IV2F valve and the IV2R valve; the OV solenoid valve includes the OV1F valve, the OV1R valve, the OV2F valve and the OV2R valve. They are connected to the first wheel group (1F and 1R) and the second wheel group (2F and 2R) respectively.

[0023] Furthermore, when the brake motor of the EHB-HD brake circuit is in normal working state: the valve states in the EHB-HD brake circuit and the ESC brake circuit are maintained according to the set valve type, and the brake motor of the EHB-HD brake circuit provides brake assist.

[0024] When the brake motor of the EHB-HD brake circuit is in normal working condition, the valves of the EHB-HD brake circuit remain normally open, that is, the CSV1 and CSV2 solenoid valves are in the open state, allowing the hydraulic fluid to flow freely. The valves of the ESC brake circuit remain in an appropriate state to prevent unnecessary hydraulic flow or system interference. The RV solenoid valve and IV solenoid valve are in the normally open state, and the SV solenoid valve and OV solenoid valve remain in the normally closed state.

[0025] In this state, the brake motor of the EHB-HD brake circuit provides the required brake assist according to the driver's target pressure signal, and controls the hydraulic pump in the hydraulic system to provide hydraulic assist for the brake circuit, thereby ensuring efficient operation of the brake system.

[0026] Furthermore, when the brake motor of the EHB-HD brake circuit is in a failed state: the valve states of the CSV1 solenoid valve, CSV2 solenoid valve, RV solenoid valve and OV solenoid valve are set to closed; the valve states of the PSV1 solenoid valve, PSV2 solenoid valve, SSV solenoid valve, SV solenoid valve and IV solenoid valve are set to open.

[0027] When the brake motor of the EHB-HD brake circuit fails or fails, the valve states of the following solenoid valves will be set to closed: CSV1 solenoid valve (normally open valve), CSV2 solenoid valve (normally open valve), RV solenoid valve (normally open valve), OV solenoid valve (normally closed valve), cutting off the hydraulic flow between the EHB-HD brake circuit and the ESC brake circuit to prevent unnecessary fluid flow in the hydraulic system from interfering with the brake operation, thereby ensuring the stability of the hydraulic circuit.

[0028] After the CSV1 and CSV2 solenoid valves are closed, the hydraulic flow originally provided by the EHB-HD brake will be cut off, avoiding the impact of motor failure on the main circuit. The closing of the RV and OV solenoid valves can further cut off the hydraulic connection between the EHB-HD circuit and the ESC circuit, ensuring that the ESC circuit works independently and avoiding unnecessary fluid flow entering the ESC system when the motor fails.

[0029] The ESC circuit can take over the brake boost function and ensure the normal operation of the brake system. The valve status of the following solenoid valves will be set to open: PSV1 solenoid valve (normally closed valve), PSV2 solenoid valve (normally closed valve), SSV solenoid valve (normally closed valve), SV solenoid valve (normally closed valve), IV solenoid valve (normally open valve). Hydraulic fluid is allowed to flow to the ESC brake circuit, so that the ESC circuit can provide brake boost through its own electric pump or hydraulic module, ensuring the stability and reliability of the brake system in the event of motor failure.

[0030] The opening of the PSV1 and PSV2 solenoid valves ensures that the pressure in the hydraulic system is stable and avoids pressure fluctuations in the hydraulic system. The opening of the SSV solenoid valve, SV solenoid valve and IV solenoid valve ensures the smooth flow of hydraulic fluid in the ESC circuit, ensuring that the ESC circuit can take over and provide the required brake assistance.

[0031] Further, the method includes: the ESC brake circuit is replenished via the one-way valve of the EHB-HD brake circuit and the replenishment hole of the pressure building chamber; the ESC brake circuit is depressurized via the pressure relief hole of the pressure building chamber of the EHB-HD brake circuit.

[0032] The ESC braking circuit learns that the HD has no power-assisting capability, and takes over to achieve closed-loop control of the wheel-end hydraulic pressure that follows the target pressure. The ESC replenishes fluid through the two one-way valves of the EHB-HD and the replenishment holes of the pressure-building chamber, and releases pressure through the pressure-releasing holes of the pressure-building chamber.

[0033] The refill hole of the pressure-building chamber in the EHB-HD brake circuit is used to connect the ESC brake circuit. The refill hole allows the hydraulic fluid to be transferred from the EHB-HD circuit to the ESC circuit to maintain the hydraulic demand of the ESC circuit and ensure that it can provide brake assistance normally. The function of the one-way valve is to ensure that the hydraulic fluid flows in only one direction, from the EHB-HD brake circuit to the ESC brake circuit. When the EHB-HD brake motor fails, the ESC circuit is refilled through the one-way valve to avoid the backflow of hydraulic fluid and ensure the stability of the hydraulic system.

[0034] When the EHB-HD motor fails, the control check valve opens, allowing the hydraulic fluid in the EHB-HD circuit to flow to the ESC circuit through the refill hole. Since the check valve only allows the hydraulic fluid to flow toward the ESC circuit, the pressure in the hydraulic system can be stabilized, ensuring that the ESC circuit can smoothly take over the brake assist function.

[0035] The pressure relief hole of the pressure-building chamber in the EHB-HD brake circuit is used to ensure that the pressure of the hydraulic system remains within a reasonable range. When the ESC brake circuit takes over and provides brake assistance, the pressure relief hole of the pressure-building chamber will be used to release excessive hydraulic pressure to avoid excessive pressure or hydraulic shock in the system. The pressure relief hole of the pressure-building chamber can actually be used as a fluid filling hole for pressure relief.

[0036] When the ESC circuit takes over the brake assist, the system will release excess hydraulic pressure through the pressure relief hole of the pressure-building chamber to prevent damage to the system caused by excessive hydraulic pressure. The opening of the pressure relief hole discharges the hydraulic fluid into a safe circuit or container, thereby maintaining the stability of the hydraulic system and the normal operation of the brake system.

[0037] When the motor of the EHB-HD brake circuit fails, the ESC brake circuit must quickly take over and work stably, and the filling and pressure relief operations ensure a smooth transition of this process. The filling provides sufficient hydraulic fluid supply through the one-way valve and the filling hole, while the pressure relief maintains the stability of the hydraulic system through the pressure relief hole to avoid functional failure caused by excessive or low system pressure. The filling operation ensures that the ESC circuit obtains sufficient hydraulic fluid to ensure that the system can provide the necessary brake assist. The function of the one-way valve is to prevent the backflow of fluid and ensure that the hydraulic fluid flows only to the ESC circuit. The pressure relief operation ensures that the pressure in the system remains within a safe range during the hydraulic replenishment process to prevent system failure due to excessive hydraulic pressure.

[0038] Through precise hydraulic replenishment and pressure relief operations, a seamless transition to the ESC braking circuit can be achieved in the event of a motor failure in the EHB-HD braking circuit, ensuring that the driver can still perceive a smooth and effective braking effect when the motor fails.

[0039] Furthermore, the method includes: determining whether the brake motor of the EHB-HD brake circuit fails by monitoring the temperature and response speed of the brake motor.

[0040] The valve switching between the EHB-HD brake circuit and the ESC brake circuit is usually dynamically adjusted by the control unit according to the working status of the motor. The system monitors the temperature, response speed and other key parameters of the motor in real time to determine whether a fault has occurred and adjust the state of the solenoid valve accordingly.

[0041] When the motor of the EHB-HD brake circuit fails, the ESC circuit automatically intervenes and achieves a smooth transition by opening / closing the corresponding solenoid valve. The control system ensures that even in the event of a motor failure, the system can continue to operate under the control of the ESC circuit without affecting the braking performance.

[0042] Furthermore, when the brake motor of the EHB-HD brake circuit is in a failed state: a brake fault light of a vehicle instrument panel is turned on, and the target curve of the brake assist is downgraded.

[0043] The control system monitors the working status of the brake motor in real time through temperature sensors, response time and other means. Once an abnormality is detected (such as overtemperature, response delay, etc.), the system will automatically start the ESC circuit to take over the braking function. Once the motor fails, the system will prompt the driver through the fault indicator light on the vehicle instrument and take measures to reduce the target curve of the brake boost to ensure safety during braking.

[0044] The step division of the above methods is only for clear description. When implemented, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this application; adding insignificant modifications to the algorithm or process or introducing insignificant designs without changing the core design of the algorithm and process are all within the scope of protection of this application.

[0045] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily mention changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims, and the above embodiments should be regarded as exemplary and non-restrictive.

Claims

1. A hydraulic brake decoupling method, applied to the 2Box electronic hydraulic brake system of EHB-HD+ESC, characterized in that: The method comprises: Providing pedal feel to the driver via the pedal feel module of the EHB-HD brake circuit; The driver's pedal operation is sensed by a displacement sensor connected to the pedal, and the pedal operation is analyzed into a target pressure signal; When the brake motor of the EHB-HD brake circuit is in a normal working state, the EHB-HD brake circuit provides a pedal feel for the driver through the pedal feel module and obtains the target pressure signal, and provides brake assistance according to the target pressure signal; When the brake motor of the EHB-HD brake circuit is in a failed state, the brake assist function is taken over by the ESC brake circuit, and the brake assist is provided by the ESC brake circuit by controlling the valve states in the EHB-HD brake circuit and the ESC brake circuit.

2. The method according to claim 1, characterized in that The EHB-HD brake circuit includes: CSV1 solenoid valve, CSV2 solenoid valve, PSV1 solenoid valve, PSV2 solenoid valve and SSV solenoid valve; The CSV1 solenoid valve and the CSV2 solenoid valve are normally open valves; the PSV1 solenoid valve, the PSV2 solenoid valve and the SSV solenoid valve are normally closed valves.

3. The method according to claim 2, characterized in that The ESC brake circuit includes: an RV solenoid valve, an SV solenoid valve, an IV solenoid valve and an OV solenoid valve; The RV solenoid valve and the IV solenoid valve are normally open valves; the SV solenoid valve and the OV solenoid valve are normally closed valves.

4. The method according to claim 3, characterized in that When the brake motor of the EHB-HD brake circuit is in normal working state: the valve states in the EHB-HD brake circuit and the ESC brake circuit are maintained according to the set valve type, and the brake motor of the EHB-HD brake circuit provides brake assist.

5. The method according to claim 4, characterized in that When the brake motor of the EHB-HD brake circuit is in a failed state: Setting the valve states of the CSV1 solenoid valve, the CSV2 solenoid valve, the RV solenoid valve and the OV solenoid valve to closed; The valve states of the PSV1 solenoid valve, the PSV2 solenoid valve, the SSV solenoid valve, the SV solenoid valve and the IV solenoid valve are set to open.

6. The method according to any one of claims 1 to 5, characterized in that: The method comprises: The ESC brake circuit is replenished via the one-way valve of the EHB-HD brake circuit and the replenishment hole of the pressure-building chamber; The ESC brake circuit releases pressure via the pressure relief hole of the pressure-building chamber of the EHB-HD brake circuit.

7. The method according to any one of claims 1 to 5, characterized in that: The method includes: determining whether the brake motor of the EHB-HD brake circuit fails by monitoring the temperature and response speed of the brake motor.

8. The method according to claim 7, characterized in that When the brake motor of the EHB-HD brake circuit is in a failed state: the brake fault light of the vehicle instrument is turned on, and the target curve of the brake boost is downgraded.

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