Redundant vehicle dynamic control method, controller and electronic hydraulic brake system

Abstract

The present application provides a redundant vehicle dynamic control method, controller and electronic hydraulic brake system, the method comprising: an ECU control module monitors the dynamic parameters of the vehicle in real time under the driving state, the dynamic parameters including: the steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle; analyzes the dynamic parameters and determines whether the activation conditions of the VDC system are met; when the activation conditions are met, the ECU control module determines the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusts the braking of the target wheel through the VDC system, and the steering condition includes oversteering and understeering. The present application provides an effective solution for the two working conditions of oversteering and understeering. During the vehicle dynamic control process, the braking force of the wheel is precisely controlled to adjust the braking force in real time in a closed loop. In this way, the system can respond quickly to dynamic changes in the vehicle, adjust the braking force in time, and ensure the stability of the vehicle during driving.

Description

Technical Field

[0001] The present application relates to the technical field of wire-controlled braking, and in particular to a redundant vehicle dynamic control method, a controller and an electronic hydraulic braking system. Background Art

[0002] Vehicle Dynamics Control (VDC) is an advanced vehicle safety technology. Its core function is to identify the vehicle's driving status, monitor and adjust the vehicle's braking, steering and power output in real time, and provide the driver with vehicle stability and controllability support.

[0003] This function of the VDC system is mainly achieved by the Electronic Stability Control (ESC). The ESC system uses complex algorithms and precise sensor data to determine the dynamic state of the vehicle and actively boost the vehicle's braking system when necessary, thereby adjusting the vehicle's driving trajectory.

[0004] When the vehicle is performing vehicle dynamic control, if the vehicle understeers or oversteers, the vehicle needs to be braked immediately to correct the understeer or oversteer. Increasing the vehicle's yaw by applying additional braking to the inner rear wheels of the vehicle so that the front of the vehicle swings inwards towards the bend is an effective dynamic control strategy. However, during the vehicle dynamic control process, if the ESC system's pressure buildup response is slow, it means that it takes longer to build up the brake pressure, which will result in a delay in the braking effect and an inability to correct the vehicle's trajectory in time, which may increase the risk of the vehicle losing control. At the same time, low control accuracy when ESC is actively boosting will also cause fluctuations in the braking effect, affecting the vehicle's dynamic performance. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present application provides a redundant vehicle dynamic control method, a controller and an electronic hydraulic brake system, aiming to solve the problems existing in the prior art.

[0006] In order to achieve the above purpose and other advantages, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present application provides a redundant vehicle dynamic control method, comprising:

[0008] The ECU control module monitors the dynamic parameters of the vehicle in real time, including the steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle;

[0009] Analyze the dynamic parameters and determine whether the activation conditions of the VDC system are met;

[0010] When the activation condition is met, the ECU control module determines the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusts the braking of the target wheel through the VDC system, wherein the steering condition includes oversteering and understeering.

[0011] According to a redundant vehicle dynamic control method provided by the present application, the steering condition is an oversteering condition and no brake pedal displacement signal is detected;

[0012] The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises:

[0013] In response to an oversteering steering condition, when no large slip of the vehicle is detected, selecting at least one outer wheel away from the steering center as a target wheel for applying braking force;

[0014] Calculating a first yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters;

[0015] Calculating a braking force applied to a target wheel according to a relationship between the first yaw moment and the adhesion between the tire and the ground;

[0016] The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies a corresponding braking force to the target wheel.

[0017] According to a redundant vehicle dynamic control method provided by the present application, the steering condition is an oversteering condition and a brake pedal displacement signal is detected;

[0018] The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises:

[0019] In response to an oversteering steering condition, when no vehicle slip rate is detected, an outer front wheel away from a steering center and an opposite rear wheel close to the steering center are selected as target wheels for applying braking force and releasing braking force respectively;

[0020] Calculating a second yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters;

[0021] According to the relationship between the two yaw moments and the adhesion between the tire and the ground, respectively calculating a first braking force applied to the outer front wheel and a second braking force that needs to be released by the opposite rear wheel;

[0022] The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies the first braking force to the outer front wheel while releasing the second braking force to the opposite rear wheel.

[0023] According to a redundant vehicle dynamic control method provided by the present application, the steering condition is an understeering condition and no brake pedal displacement signal is detected;

[0024] The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises:

[0025] In response to an understeering steering condition, when no large slip of the vehicle is detected, at least one inner wheel close to the steering center is selected as a target wheel for applying braking force;

[0026] Calculating a third yaw moment in the same direction as the vehicle yaw rate required to correct understeering according to the dynamic parameters;

[0027] Calculating the braking force applied to the target wheel according to the third yaw moment and the relationship between the tire and the ground adhesion;

[0028] The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies a corresponding braking force to the target wheel.

[0029] According to a redundant vehicle dynamic control method provided by the present application, the steering condition is an understeering condition and a brake pedal displacement signal is detected;

[0030] The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises:

[0031] In response to an oversteering steering condition, when no vehicle slip rate is detected, an inner rear wheel close to a steering center and an opposite front wheel far from the steering center are selected as target wheels for applying braking force and releasing braking force, respectively;

[0032] Calculating a fourth yaw moment in the same direction as the vehicle yaw rate required to correct oversteering according to the dynamic parameters;

[0033] According to the relationship between the four yaw moments and the adhesion between the tire and the ground, respectively calculating a third braking force applied to the inner rear wheel and a fourth braking force to be released by the opposite front wheel;

[0034] The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies the third braking force to the inner rear wheel while releasing the fourth braking force to the opposite front wheel.

[0035] According to a redundant vehicle dynamic control method provided by the present application, the step of adjusting the braking of the target wheel by the VDC system includes:

[0036] When the VDC system is activated, the VDC system establishes a braking force applied to a target wheel end;

[0037] According to the first control instruction issued by the VDC system, the pressure building module of the electronic hydraulic brake starts to build pressure. After the pressure is built up, the PSV solenoid valve and the RV solenoid valve are powered on and opened, and the ESC module opens the boost valve of the wheel end corresponding to the power to be adjusted, and closes the boost valves of other wheel ends at the same time, and the brake fluid enters the wheel end from the opened boost valve to adjust the braking force;

[0038] In the dynamic control of the VDC system, when the braking force of the wheel end needs to be reduced, the VDC system establishes a target wheel end braking force release, opens the pressure relief valve corresponding to the wheel end to release the pressure, and releases the brake fluid into the accumulator of the ESC module.

[0039] According to a redundant vehicle dynamic control method provided by the present application, after the step of discharging brake fluid into an accumulator of an ESC module, the method includes:

[0040] determining whether the brake fluid in the accumulator exceeds a set brake fluid threshold;

[0041] In response to the brake fluid in the accumulator exceeding the brake fluid threshold, according to the second control instruction issued by the VDC system, the motor of the ESC module is controlled to operate, the SV solenoid valve is powered on and closed, the plunger pump draws the brake fluid from the accumulator, and the fluid flows back into the pressure building chamber through the RV solenoid valve and the PSV solenoid valve, and the brake fluid pushes the piston in the pressure building chamber back until the fluid pressure of the ESC module is the same as the fluid pressure in the pressure building chamber.

[0042] According to a redundant vehicle dynamic control method provided by the present application, in the VDC system dynamic control, when it is necessary to reduce the braking force of the wheel end, the step of opening the pressure relief valve corresponding to the wheel end to release pressure also includes:

[0043] Determining whether the braking force applied to the target wheel end is greater than a set braking force threshold;

[0044] In response to the braking force applied to the target wheel end being greater than the set braking force threshold, according to the third control instruction issued by the VDC system, the pressure relief valve is opened to release pressure, and the plunger pump of the ESC module is controlled to cooperate with the pressure relief valve to release pressure, so that the brake fluid at the wheel end directly flows back to the pressure building chamber.

[0045] In a second aspect, the present application provides a controller comprising a processor and a memory, wherein the memory stores a computer program that can be executed by the processor, and the processor can execute the computer program to implement the redundant vehicle dynamic control method as described in the first aspect.

[0046] In a third aspect, the present application provides an electronic hydraulic braking system, comprising a controller as described in the first aspect.

[0047] The present application provides a redundant vehicle dynamic control method, controller and electronic hydraulic brake system, the method includes: the ECU control module monitors the dynamic parameters of the vehicle in real time under the driving state, the dynamic parameters include: the steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle; analyzes the dynamic parameters and determines whether the activation conditions of the VDC system are met; when the activation conditions are met, the ECU control module determines the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusts the braking of the target wheel through the VDC system, and the steering condition includes oversteering and understeering. The present application provides an effective solution for the two working conditions of oversteering and understeering. During the dynamic control of the vehicle, the braking force of the wheel is accurately controlled and the braking force is adjusted in real time in a closed loop. In this way, the system can quickly respond to the dynamic changes of the vehicle, adjust the braking force in time, ensure the stability of the vehicle during driving, and through real-time closed-loop adjustment, the system can accurately control the application and release of the braking force to avoid unnecessary braking operations to cause wear and damage to the braking system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other implementation methods can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 is a flow chart of a redundant vehicle dynamic control method provided in an embodiment of the present application;

[0050] Figure 2 is a logic diagram of single-wheel active boost control of a wire-controlled brake system provided in an embodiment of the present application;

[0051] Figure 3is a logic diagram of dual-wheel active boost control of a wire-controlled brake system provided in an embodiment of the present application;

[0052] Figure 4 It is a schematic diagram of the structure of a controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specifically cites the preferred embodiments and describes them in detail with the accompanying drawings.

[0054] It should be noted that it is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict. Unless otherwise defined, the technical terms or scientific terms involved in this application should be the usual meanings understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation and may represent the singular or plural. The terms "including", "comprising", "having" and any of their variations involved in this application are intended to cover non-exclusive inclusions; the terms "first", "second", "third", etc. involved in this application are merely to distinguish similar objects and do not represent a specific ordering of objects.

[0055] The Electronic Control Unit (ECU) receives sensor data, processes information, and sends instructions to precisely control and manage the various electronic systems of the vehicle, ensuring safe and reliable operation of the vehicle. Figure 1 As shown, an embodiment of the present application provides a redundant vehicle dynamic control method, including:

[0056] Step S1: The ECU control module monitors the dynamic parameters of the vehicle in real time under the driving state, and the dynamic parameters include: the steering angle, vehicle speed, yaw angular velocity and lateral acceleration of the vehicle.

[0057] Step S2: Analyze the dynamic parameters and determine whether the activation conditions of the VDC system are met.

[0058] Specifically, the sensor monitors the dynamic parameters of the vehicle in real time. For example, the steering angle sensor is installed on the steering system to monitor the steering wheel rotation angle in real time. The vehicle speed sensor is usually installed on the gearbox or wheel. It calculates the vehicle speed by measuring the wheel speed and transmits the vehicle speed signal to the ECU control module. The yaw rate and lateral acceleration can be measured by an inertial measurement unit (IMU) or a dedicated yaw rate and lateral acceleration sensor. The ECU control module calculates and analyzes the received dynamic parameter signals in real time according to the preset algorithms and models to determine the driving status of the vehicle.

[0059] The activation conditions of the VDC system are usually based on the ECU's judgment of the vehicle's driving status. When it is detected that the vehicle is in an unstable or dangerous state, such as abnormal yaw rate (detecting that the yaw rate exceeds the normal range may mean that the vehicle is oversteering or understeering), excessive lateral acceleration (detecting that the vehicle's lateral acceleration exceeds the preset threshold may mean that the vehicle is skidding or losing control), wheel slippage (determining whether the wheel is slipping through comprehensive analysis of multiple sensor data), etc., the vehicle dynamic control system automatically intervenes to maintain the stability and safety of the vehicle.

[0060] Step S3: When the activation conditions are met, the ECU control module determines the braking force required for the target wheel controlled by the VDC system based on the vehicle's steering conditions, and then adjusts the braking of the target wheel through the VDC system. The steering conditions include oversteering and understeering.

[0061] In this embodiment, the steering condition is an oversteering condition and no brake pedal displacement signal is detected, step S3 specifically includes:

[0062] Step SA301: In response to an oversteering steering condition, when no large slip of the vehicle is detected, selecting at least one outer wheel away from the steering center as a target wheel for applying braking force;

[0063] Step SA302: Calculate the first yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters;

[0064] Step SA303: Calculate the braking force applied to the target wheel according to the first yaw moment and the relationship between the tire and the ground adhesion;

[0065] Step SA304: The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies corresponding braking force to the target wheel.

[0066] Specifically, when the system determines that the vehicle has a tendency to oversteer, the VDC system will immediately intervene and start responding. The VDC system also evaluates the slip state between the tires and the ground, and does not detect a large slip of the vehicle, that is, the system determines that the slip rate between the tires and the ground is low and does not reach the level of "large slip". Since the dynamic behavior of the vehicle is still within the controllable range, no brake pedal displacement signal is detected (that is, the pedal displacement sensor does not detect the displacement of the brake pedal), which means that the vehicle's driving trajectory has changed slightly, such as a slight curve or avoiding an obstacle, but this change is not enough to cause the vehicle to lose control or require the driver to brake urgently. At this time, the system selects at least one outer wheel away from the steering center as the target wheel for applying braking force. This is because in the case of oversteering, applying braking force to the outer wheel can generate an inward yaw moment, which helps to correct the tendency of oversteering. This braking force is applied accurately and briefly, aiming to quickly correct the steering state of the vehicle, rather than reducing the speed or stopping the vehicle. To dynamically balance the outward yaw moment generated by oversteering during vehicle driving.

[0067] The ECU control module determines the direction in which oversteering needs to be corrected based on the vehicle's steering angle and yaw rate, which is the opposite direction to the vehicle's current yaw rate. Based on the vehicle's mass, center of mass position, vehicle speed and other parameters, as well as the required direction and degree of correction, the ECU control module calculates the first yaw moment required to correct oversteering. Based on the relationship between the first yaw moment and the adhesion between the tire and the ground, the ECU calculates the braking force that needs to be applied to the target wheel. This braking force must be large enough to generate the required first yaw moment, but it must not exceed the adhesion limit between the tire and the ground, otherwise it will cause the wheel to slip.

[0068] The ECU control module sends the calculated braking force signal to the VDC system, and the VDC system generates the corresponding control instructions. The ESC module executes the corresponding control instructions and applies the corresponding braking force to the target wheels (two outer wheels, i.e., the outer front wheel and the outer rear wheel) by controlling the actuator of the brake actuator (such as a solenoid valve, etc.). This braking force will generate a yaw moment in the opposite direction of the vehicle's yaw rate, which helps to correct oversteering. For this oversteering condition and the scenario where the driver does not need to brake urgently, the yaw moment of the vehicle is balanced by braking the two outer wheels of the steering wheel through the VDC system to ensure the comfort of the vehicle's stable steering.

[0069] When there is a slight oversteer tendency, i.e. at low speeds and with good road adhesion, the vehicle's yaw moment can also be corrected by braking one of the outside wheels (usually the outside front wheel).

[0070] In this embodiment, the steering condition is an oversteering condition and a brake pedal displacement signal is detected, step S3 specifically includes:

[0071] Step SB301: In response to an oversteering steering condition, when no vehicle slip rate is detected, selecting an outer front wheel away from the steering center and an opposite rear wheel close to the steering center as target wheels for applying braking force and releasing braking force respectively;

[0072] Step SB302: Calculate the second yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters;

[0073] Step SB303: Calculate the first braking force applied to the outer front wheel and the second braking force to be released by the opposite rear wheel according to the relationship between the second yaw moment and the adhesion between the tire and the ground;

[0074] Step SB304: The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies a first braking force to the outer front wheel while releasing a second braking force to the opposite rear wheel.

[0075] Specifically, when the system determines that the vehicle has a tendency to oversteer, the VDC system will immediately intervene and begin to respond. When the driver realizes that the vehicle is oversteering and begins to step on the brake pedal, the vehicle's braking system begins to work, trying to reduce the speed of the vehicle by reducing the wheel speed. The system will first determine whether the vehicle has a slip rate (that is, the degree of sliding of the wheel relative to the ground). If the vehicle slip rate is not detected, it means that the friction between the wheel and the ground is still sufficient and the vehicle has not yet entered a serious out-of-control state. At this time, the system will select the outer front wheel away from the steering center and the opposite rear wheel close to the steering center as the target wheels. The outer front wheel is used to apply braking force to help reduce the steering angle; the opposite rear wheel releases the braking force to help the vehicle return to a normal driving trajectory.

[0076] The ECU control module calculates the yaw torque required to correct oversteering based on the vehicle's dynamic parameters. During the calculation process, the adhesion relationship between the tire and the ground is also taken into account to ensure that the braking force does not exceed the tire's grip ability, thereby preventing the wheels from slipping. The VDC system controls the actuator of the brake actuator to apply the first braking force to the outer front wheel for boosting, while releasing the second braking force to the opposite rear wheel for depressurization to ensure the vehicle's steering ability. The application and release of wheel-end braking force needs to be fast and accurate to ensure that the vehicle can regain stability in a timely manner.

[0077] When the driver realizes that the vehicle is oversteering and begins to step on the brake pedal, relying solely on braking may not be able to quickly and effectively control the vehicle's driving trajectory. At this time, the VDC system will intelligently adjust the braking force distribution of each wheel based on the evaluation results. By precisely controlling the distribution of braking force, additional braking force is applied to the outer front wheel to help reduce the steering angle, while releasing or reducing the braking force on the opposite rear wheel to assist the vehicle in returning to a normal driving trajectory. Therefore, the VDC system can quickly intervene and correct oversteering in situations where the driver may not be able to react in a timely or accurate manner, ensuring that the vehicle has stable steering capabilities while maintaining a stable driving state, thereby enhancing driving safety.

[0078] In this embodiment, the steering condition is an understeering condition and no brake pedal displacement signal is detected, step S3 specifically includes:

[0079] Step SC301: In response to an understeering steering condition, when no large slip of the vehicle is detected, selecting at least one inner wheel close to the steering center as a target wheel to which braking force is applied;

[0080] Step SC302: Calculate the third yaw moment in the same direction as the vehicle yaw rate required to correct understeering according to the dynamic parameters;

[0081] Step SC303: Calculate the braking force applied to the target wheel according to the third yaw moment and the relationship between the tire and the ground adhesion;

[0082] Step SC304: the ECU control module sends the calculated braking force to the VDC system, and the VDC system applies corresponding braking force to the target wheel.

[0083] Specifically, when the system determines that the vehicle has a tendency to understeer, the VDC system will immediately intervene and start responding. In response to the steering condition of understeer and no brake pedal displacement signal is detected, it means that the dynamic behavior of the vehicle is still within the controllable range. At this time, if no large slip of the vehicle is detected, the system will select at least one inner wheel close to the steering center as the target wheel for applying braking force according to the preset algorithm. By applying braking force to the inner rear wheel, a yaw moment in the same direction as the vehicle's yaw angular velocity can be generated to help the vehicle restore a normal steering trajectory. The system calculates the braking force applied to the target wheel based on the third yaw moment and the adhesion relationship between the tire and the ground. The adhesion relationship is usually obtained through a tire model or experimental data, which describes the adhesion between the tire and the ground under different vehicle speeds, tire pressures and road conditions. Ensure that the applied braking force does not exceed the adhesion limit between the tire and the ground to avoid wheel locking or slipping. The ECU control module sends the calculated braking force to the VDC system, and after receiving the command, the VDC system applies the corresponding braking force to the target wheel.

[0084] The ECU control module sends the calculated braking force signal to the VDC system, and the VDC system generates the corresponding control instructions. The ESC module executes the corresponding control instructions and applies the corresponding braking force to the target wheels (two inner wheels, i.e., the inner front wheel and the inner rear wheel) by controlling the actuator of the brake actuator (such as a solenoid valve, etc.). This braking force will generate a yaw moment in the same direction as the vehicle's yaw rate, which helps correct understeer. For this understeer condition and the scenario where the driver does not need to brake urgently, the yaw moment of the vehicle is balanced for the two inner wheels that are turned by braking with the VDC system to ensure the comfort of stable steering of the vehicle.

[0085] When there is a slight understeer tendency, i.e. at low speeds and with good road adhesion, the vehicle's yaw moment can also be corrected by braking an inside wheel (usually the inside rear wheel).

[0086] In this embodiment, the steering condition is an understeering condition and a brake pedal displacement signal is detected, step S3 specifically includes:

[0087] Step SD301: In response to an oversteering steering condition, when no vehicle slip rate is detected, an inner rear wheel close to the steering center and an opposite front wheel far from the steering center are selected as target wheels for applying braking force and releasing braking force respectively;

[0088] Step SD302: Calculate the fourth yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters;

[0089] Step SD303: Calculate the third braking force applied to the inner rear wheel and the fourth braking force to be released by the opposite front wheel according to the relationship between the four yaw moments and the adhesion between the tire and the ground;

[0090] Step SD304: The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies the third braking force to the inner rear wheel while releasing the fourth braking force to the opposite front wheel.

[0091] Specifically, when it is detected that the vehicle is in understeering and there is a displacement signal from the brake pedal, the VDC system will immediately intervene and begin to respond. If the system does not detect the vehicle's slip rate, it means that the friction between the wheels and the ground is still sufficient and the vehicle has not yet entered a serious out-of-control state. Analyze the dynamic state of the vehicle, select the inner rear wheel close to the steering center as the wheel to apply additional braking force, and select the opposite front wheel away from the steering center as the wheel that needs to release the braking force. Based on the steering dynamics principle of the vehicle, increasing the braking force of the inner rear wheel can help the vehicle rotate more closely around the steering center, while reducing the braking force of the opposite front wheel helps reduce the steering resistance of the wheel and promote the vehicle to turn in the desired direction. Adjust the vehicle's steering response through differential braking to correct the understeering trend.

[0092] Based on the dynamic parameters of the vehicle, the system calculates the fourth yaw moment in the same direction as the vehicle's current yaw rate required to correct understeer. This moment is intended to help the vehicle reach the desired steering trajectory faster. During the calculation process, combined with the adhesion relationship between the tire and the ground, the system calculates the third braking force that needs to be applied to the inner rear wheel and the fourth braking force that needs to be released from the opposite front wheel. The VDC system controls the actuator of the brake actuator to apply the third braking force to the inner rear wheel for boosting, and releases the fourth braking force to the opposite front wheel for decompression to ensure the vehicle's steering ability. The application and release of wheel-end braking force needs to be fast and accurate to ensure that the vehicle can regain stability in a timely manner.

[0093] Therefore, especially when emergency braking is required for emergency obstacle avoidance or high-speed turning, relying solely on braking may not be able to quickly and effectively control the vehicle's driving trajectory. At this time, VDC quickly intervenes and quickly corrects the vehicle's understeer by accurately controlling the braking force of specific wheels, thereby improving the vehicle's driving stability and safety.

[0094] In this embodiment, in step S3, the step of adjusting the braking of the target wheel by the VDC system includes:

[0095] When the VDC system is activated, the VDC system establishes a braking force applied to the target wheel end;

[0096] According to the first control command issued by the VDC system, the pressure building module of the electronic hydraulic brake starts to build pressure. After the pressure is built up, the PSV solenoid valve and the RV solenoid valve are energized and opened. The ESC module opens the booster valve at the wheel end corresponding to the power to be adjusted, and closes the booster valves at other wheel ends at the same time. The brake fluid enters the wheel end from the opened booster valve to adjust the braking force.

[0097] In the dynamic control of the VDC system, when the braking force of the wheel end needs to be reduced, the VDC system establishes the braking force to release the target wheel end, opens the pressure relief valve corresponding to the wheel end to release the pressure, and releases the brake fluid into the accumulator of the ESC module.

[0098] Specifically, when the brake-by-wire module is not performing brake pressure building, the solenoid valve in the brake-by-wire system is in an initial state, such as Figure 2 The figure shows the hydraulic control principle diagram of the Twobox wire control brake system. The upper dotted box in the figure contains components such as the oil pot, master cylinder, electric cylinder, displacement sensor, CSV solenoid valve, PSV solenoid valve, and pressure sensor. These components together constitute the main control module of the hydraulic system, which is responsible for the establishment and control of hydraulic pressure. The lower dotted box contains multiple solenoid valves, ESC motors, plunger pumps, accumulators, pressure sensors and other components. This part is mainly a hydraulic execution module, which is used to realize the distribution of hydraulic pressure and perform specific braking actions. Among them, the CSV1 and CSV2 solenoid valves are responsible for the on-off of the master cylinder to the wheel cylinder brake circuit, and are powered on and closed. The SSV solenoid valve is used for the on-off of the backup path for mechanical backup, and is powered on and opened. The PSV1 and PSV2 solenoid valves are responsible for the on-off of the electric cylinder to the wheel cylinder brake circuit, and are powered on and opened. The RV1 and RV2 solenoid valves are pressure regulating valves, which are responsible for adjusting the hydraulic pressure in the brake system circuit and are powered off and opened. The SV1 and SV2 solenoid valves are fluid replenishment valves, which are responsible for replenishing brake fluid from the oil pot to the brake system and are powered off and closed. IV1F, IV1R, IV2F, and IV2R are the boost valves at the four wheel ends respectively, which are responsible for controlling the oil inlet passage of each wheel-end brake and will be opened when the power is cut off; OV1F, OV1R, OV2F, and OV2R are the pressure relief valves at the four wheel ends respectively, which are responsible for controlling the oil outlet passage of each wheel-end brake and will be closed when the power is cut off.

[0099] In response to the steering condition of oversteering to the left and no brake pedal displacement signal is detected, the VDC system is activated. According to the determination that the target wheel is the right front wheel and the calculated braking force to be applied, the pressure building module starts to work according to the first control instruction issued by the VDC system to provide the required hydraulic pressure to the brake system. The PSV solenoid valve and the RV solenoid valve are energized to open, allowing high-pressure brake fluid to enter the brake system. Figure 2As shown, the IV1R solenoid valve remains in the open state with power off, the IV1F, IV2F, and IV2R solenoid valves are powered on and closed, and the OV1F, OV1R, OV2F, and OV2R solenoid valves remain in the closed state with power off. Since only the boost valve of the right front wheel is opened for boosting, the boost valves at the other wheel ends are closed at the same time. As the brake fluid flows in, the brakes of the right front wheel begin to work, generating a torque opposite to the vehicle's oversteering, helping the vehicle stabilize. The VDC system continuously monitors the dynamic parameters of the vehicle and adjusts the braking force applied to the right front wheel in real time to ensure that the vehicle can travel stably as the driver intends. In this vehicle dynamic process, the VDC system accurately controls the opening and closing states of each solenoid valve and regulates the braking force precisely to each wheel, thereby achieving precise control of the vehicle's dynamic performance. If the target wheels under this condition are the right front wheel and the right rear wheel, such as Figure 3 As shown, the IV1R and IV2R solenoid valves need to be kept in the open state with power off, and the IV1F and IV2F solenoid valves need to be powered on and closed. At this time, the VDC system performs real-time braking force control on the two outer wheels of the steering wheel to meet the precise control of the VDC system.

[0100] In response to the steering condition of left oversteering and the detection of the brake pedal displacement signal, the VDC system is activated to intervene. According to the determination that the target wheels are the right front wheel and the left rear wheel and the calculated first braking force to be applied to the right front wheel and the second braking force to be released by the left rear wheel, at this time, the IV1R solenoid valve remains in the de-energized open state, the IV1F, IV2F, and IV2R solenoid valves are powered on and closed, and the right front wheel is pressurized through the opened boost valve. The OV2R solenoid valve is powered on and opened, and the OV1F, OV1R, and OV2F solenoid valves remain de-energized and closed, and the left rear wheel is depressurized through the opened pressure relief valve. With the inflow of brake fluid, the brake of the right front wheel begins to work, generating a torque opposite to the vehicle oversteering. At the same time, the wheel-end braking force of the left rear wheel is depressurized, and the brake fluid is discharged into the accumulator A2. In the process of vehicle dynamic control, the real-time closed-loop adjustment of the braking force is realized, so as to achieve the purpose of rapid intervention and timely correction of oversteering.

[0101] In this embodiment, after the step of discharging the brake fluid into the accumulator of the ESC module, the following steps are included:

[0102] Determine whether the brake fluid in the accumulator exceeds a set brake fluid threshold;

[0103] In response to the brake fluid in the accumulator exceeding the brake fluid threshold, the motor of the ESC module is controlled to operate according to the second control instruction issued by the VDC system, the SV solenoid valve is energized and closed, the plunger pump draws the brake fluid from the accumulator, and the fluid flows back into the pressure building chamber through the RV solenoid valve and the PSV solenoid valve. The brake fluid pushes the piston in the pressure building chamber back until the fluid pressure of the ESC module is the same as the fluid pressure in the pressure building chamber.

[0104] Specifically, in the hydraulic brake system, the accumulator (A1, A2) is used to store brake fluid, and when necessary, the wheel-end braking force is discharged, and the brake fluid is returned to the main control module of the hydraulic system. When the vehicle is in the VDC working condition for a long time, the brake fluid will be frequently delivered to the wheel end to provide the necessary braking force. At the same time, the wheel-end braking force will also be frequently fed back and enter the accumulator. The accumulator is filled, resulting in the wheel-end brake fluid cannot be discharged. In order to adjust the amount of brake fluid in the accumulator, a pressure sensor or a liquid level sensor is set in the accumulator to monitor whether the brake fluid in the accumulator exceeds the set brake fluid threshold. When the amount of brake fluid in the accumulator exceeds the set brake fluid threshold, the VDC system controls the ESC motor M2 to work. For accumulator A1, the SV1 solenoid valve is closed, the RV1 solenoid valve is opened, and the plunger pump B1 draws the brake fluid from the accumulator A1 and enters the pressure building chamber through the RV1 solenoid valve and the PSV1 solenoid valve. For accumulator A2, close the SV2 solenoid valve, open the RV2 solenoid valve, and the plunger pump B2 draws the brake fluid from the accumulator A2 and enters the pressure-building chamber through the RV2 solenoid valve and the PSV2 solenoid valve. Since the increased braking force of a specific wheel will increase the hydraulic pressure in the ESC module, at this time the hydraulic pressure of the ESC module is greater than the hydraulic pressure in the pressure-building chamber, the brake fluid will push the piston back to absorb the excess hydraulic pressure, so that the hydraulic pressure in the entire hydraulic circuit is equal to the braking target value, ensuring that the VDC system can obtain stable and accurate braking pressure when working, thereby ensuring the safety and stability of the vehicle.

[0105] In this embodiment, in the dynamic control of the VDC system, when the braking force of the wheel end needs to be reduced, the step of opening the pressure relief valve corresponding to the wheel end to release pressure also includes:

[0106] Determining whether the braking force applied to the target wheel end is greater than a set braking force threshold;

[0107] In response to the braking force applied to the target wheel end being greater than the set braking force threshold, according to the third control instruction issued by the VDC system, the pressure relief valve is opened to release pressure, and at the same time, the plunger pump of the ESC module is controlled to cooperate with the pressure relief valve to release pressure, so that the brake fluid at the wheel end directly flows back to the pressure building chamber.

[0108] Specifically, the braking force applied to the target wheel end needs to be released after acting on the wheel end. Under normal circumstances, when the system pressure increases, the accumulator will absorb excess hydraulic energy and release the stored hydraulic energy when necessary. Under certain working conditions, such as when the system needs to intervene in the control of vehicle stability in a timely manner after emergency braking, the braking force of the wheel end needs to be quickly reduced. At this time, if the pressure is released through the accumulator, it may be necessary to add additional control logic and sensors to monitor the state and pressure of the accumulator. The response speed of the accumulator may not meet the needs of rapid pressure release, so a more direct pressure release method is needed. In order to quickly release the braking force, the system first determines whether the braking force applied to the target wheel end is greater than the set braking force threshold. When the braking force is greater than the set braking force threshold, the system will choose to directly open the wheel end pressure relief solenoid valve. At the same time, the system starts the ESC motor M2, and the plunger pump (B1, B2) starts working under the drive of the ESC motor M2 to directly pump the brake fluid of the wheel end back to the pressure building chamber without passing through the accumulator. This pressure relief method can reduce the braking force on the wheel end more quickly and relieve the storage pressure of the accumulator at the same time.

[0109] Those skilled in the art will appreciate that, in the above method of specific implementation, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0110] Based on the same inventive concept as the above redundant vehicle dynamic control method, an embodiment of the present invention also provides a controller. Figure 4 An example of a physical structure diagram of a controller is shown below: Figure 4 As shown, the controller may include: a processor 310, a communication interface 320, a memory 330 and a communication bus 340, wherein the processor 310, the communication interface 320 and the memory 330 communicate with each other via the communication bus 340. The processor 310 may call a computer program in the memory 330 to execute the redundant vehicle dynamic control method provided in the above embodiment.

[0111] The electronic hydraulic braking system can be an integrated electronic hydraulic braking system, and can be a braking system for transportation vehicles such as electric vehicles and hybrid vehicles. On low-adhesion roads (such as icy and snowy roads), the electronic hydraulic braking system accurately controls the braking force and driving force of each wheel to prevent the vehicle from skidding and losing control. When avoiding obstacles in an emergency, the electronic hydraulic braking system helps the driver keep the vehicle stable by coordinating wheel braking and steering control. When turning at high speed, the electronic hydraulic braking system adjusts the vehicle's yaw rate and lateral acceleration by coordinating wheel braking to prevent the vehicle from understeering or oversteering.

[0112] The electronic hydraulic braking system can also provide redundant control strategies. Under normal circumstances, the VDC system intervenes to adjust the brake pressure of each wheel to help the vehicle maintain a stable driving trajectory. When the motor of the wire control brake module fails, the ESC module can be started for pressurization. Or when the pressure building capacity of the wire control brake module is insufficient, the ESC module can be used for fluid replenishment and pressurization. Or when multiple wheels are controlled at the same time for pressure increase or decrease, the motor M1 of the wire control brake module and the ESC motor M2 can work synchronously. By precisely controlling the output of the two motors, the system can quickly adjust the brake pressure of each wheel to achieve faster and smoother braking effects. This synchronous working capability not only improves the response speed of the braking system, but also enhances the stability and safety of the vehicle in emergency situations.

[0113] In summary, the embodiments of the present application provide a redundant vehicle dynamic control method, controller and electronic hydraulic brake system, the method includes: the ECU control module monitors the dynamic parameters of the vehicle in real time under the driving state, the dynamic parameters include: the steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle; analyze the dynamic parameters and determine whether the activation conditions of the VDC system are met; when the activation conditions are met, the ECU control module determines the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusts the braking of the target wheel through the VDC system, and the steering condition includes oversteering and understeering. The present application provides an effective solution for the two working conditions of oversteering and understeering. During the dynamic control of the vehicle, the braking force of the wheel is accurately controlled and the braking force is adjusted in real time in a closed loop. In this way, the system can quickly respond to the dynamic changes of the vehicle, adjust the braking force in time, ensure the stability of the vehicle during driving, and through real-time closed-loop adjustment, the system can accurately control the application and release of the braking force to avoid unnecessary braking operations to cause wear and damage to the braking system.

[0114] The flow chart or block diagram in the accompanying drawings shows the possible architecture, function and operation of the equipment, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated system for hardware that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0115] 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 redundant vehicle dynamic control method, characterized in that: include: The ECU control module monitors the dynamic parameters of the vehicle in real time, including the steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle; Analyzing the dynamic parameters and determining whether the activation conditions of the VDC system are met specifically includes: The ECU control module calculates and analyzes the received dynamic parameter signals in real time according to the preset algorithms and models to obtain the vehicle driving state, and determines whether the vehicle driving state meets the activation conditions of the VDC system; When the activation condition is met, the ECU control module determines the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusts the braking of the target wheel through the VDC system, wherein the steering condition includes oversteering and understeering; When the VDC system intervenes to adjust the brake pressure of each wheel, when the motor of the wire control brake module fails, the ESC module is activated to increase the pressure, or when the pressure building capacity of the wire control brake module is insufficient, the ESC module is used to increase the pressure, so as to provide a redundant control strategy; In the dynamic control of the VDC system, when it is necessary to reduce the braking force of the wheel end, the VDC system establishes a braking force release target wheel end, opens the pressure relief valve corresponding to the wheel end to release the pressure, and releases the brake fluid into the accumulator of the ESC module; Following the procedure for bleeding brake fluid into the ESC module's accumulator, include: determining whether the brake fluid in the accumulator exceeds a set brake fluid threshold; In response to the brake fluid in the accumulator exceeding the brake fluid threshold, according to the second control instruction issued by the VDC system, the motor of the ESC module is controlled to operate, the SV solenoid valve is powered on and closed, the plunger pump draws the brake fluid from the accumulator, and the fluid flows back into the pressure building chamber through the RV solenoid valve and the PSV solenoid valve. The brake fluid pushes the piston in the pressure building chamber back until the fluid pressure of the ESC module is the same as the fluid pressure in the pressure building chamber, so as to realize real-time closed-loop adjustment of the braking force during the vehicle dynamic control process.

2. The redundant vehicle dynamic control method according to claim 1, characterized in that: The steering condition is an oversteering condition and no brake pedal displacement signal is detected; The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises: In response to an oversteering steering condition, when no large slip of the vehicle is detected, selecting at least one outer wheel away from the steering center as a target wheel for applying braking force; Calculating a first yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters; Calculating a braking force applied to a target wheel according to a relationship between the first yaw moment and the adhesion between the tire and the ground; The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies a corresponding braking force to the target wheel.

3. The redundant vehicle dynamic control method according to claim 1, characterized in that: The steering condition is an oversteering condition and a brake pedal displacement signal is detected; The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises: In response to an oversteering steering condition, when no vehicle slip rate is detected, an outer front wheel away from a steering center and an opposite rear wheel close to the steering center are selected as target wheels for applying braking force and releasing braking force respectively; Calculating a second yaw moment in the opposite direction of the vehicle yaw rate required to correct oversteering according to the dynamic parameters; According to the relationship between the two yaw moments and the adhesion between the tire and the ground, respectively calculating a first braking force applied to the outer front wheel and a second braking force that needs to be released by the opposite rear wheel; The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies the first braking force to the outer front wheel while releasing the second braking force to the opposite rear wheel.

4. The redundant vehicle dynamic control method according to claim 1, characterized in that: The steering condition is an understeering condition and no brake pedal displacement signal is detected; The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises: In response to an understeering steering condition, when no large slip of the vehicle is detected, at least one inner wheel close to the steering center is selected as a target wheel for applying braking force; Calculating a third yaw moment in the same direction as the vehicle yaw rate required to correct understeering according to the dynamic parameters; Calculating the braking force applied to the target wheel according to the third yaw moment and the relationship between the tire and the ground adhesion; The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies a corresponding braking force to the target wheel.

5. The redundant vehicle dynamic control method according to claim 1, characterized in that: The steering condition is an understeering condition and a brake pedal displacement signal is detected; The step of, when the activation condition is met, the ECU control module determining the braking force required for the target wheel controlled by the VDC system based on the steering condition of the vehicle, and then adjusting the braking of the target wheel through the VDC system, comprises: In response to an oversteering steering condition, when no vehicle slip rate is detected, an inner rear wheel close to a steering center and an opposite front wheel far from the steering center are selected as target wheels for applying braking force and releasing braking force, respectively; Calculating a fourth yaw moment in the same direction as the vehicle yaw rate required to correct oversteering according to the dynamic parameters; According to the relationship between the four yaw moments and the adhesion between the tire and the ground, respectively calculating a third braking force applied to the inner rear wheel and a fourth braking force to be released by the opposite front wheel; The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies the third braking force to the inner rear wheel while releasing the fourth braking force to the opposite front wheel.

6. The redundant vehicle dynamic control method according to claim 1, characterized in that: The step of adjusting the braking of the target wheel by the VDC system comprises: When the VDC system is activated, the VDC system establishes a braking force applied to a target wheel end; According to the first control instruction issued by the VDC system, the pressure building module of the electronic hydraulic brake starts to build pressure. After the pressure is built up, the PSV solenoid valve and the RV solenoid valve are energized and opened. The ESC module opens the boost valve at the wheel end corresponding to the wheel end that needs to adjust the control power, and closes the boost valves at other wheel ends at the same time. The brake fluid enters the wheel end from the opened boost valve to adjust the braking force.

7. The redundant vehicle dynamic control method according to claim 1, characterized in that: In the VDC system dynamic control, when the braking force of the wheel end needs to be reduced, the step of opening the pressure relief valve corresponding to the wheel end to release pressure also includes: Determining whether the braking force applied to the target wheel end is greater than a set braking force threshold; In response to the braking force applied to the target wheel end being greater than the set braking force threshold, according to the third control instruction issued by the VDC system, the pressure relief valve is opened to release pressure, and the plunger pump of the ESC module is controlled to cooperate with the pressure relief valve to release pressure, so that the brake fluid at the wheel end directly flows back to the pressure building chamber.

8. A controller, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a computer program executable by the processor, and the processor can execute the computer program to implement the redundant vehicle dynamic control method according to any one of claims 1 to 7.

9. An electronic hydraulic brake system, characterized in that: Comprising a controller as claimed in claim 8.

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