CN-121989883-A - Vehicle brake control system regulated by proportional valve

CN121989883ACN 121989883 ACN121989883 ACN 121989883ACN-121989883-A

Abstract

The invention discloses a vehicle brake control system regulated by a proportional valve, which relates to the technical field of vehicle brake control and comprises an input processing module, a control generating module, a valve control module, a model analysis module and a closed-loop supervision module. The system calculates a target brake pressure by receiving a brake request and a vehicle condition and generates an initial control signal for the proportional valve based thereon. The valve control module drives the proportional valve and monitors actual pressure change, and the model analysis module adaptively corrects the opening control strategy of the valve according to the comparison result of the pressure change data and the pre-stored model so as to improve pressure tracking accuracy and system robustness. The closed-loop monitoring module synchronously collects wheel speed and vehicle dynamic parameters, monitors and compensates the pressure regulating process, and realizes cooperative optimization of braking control and vehicle stability control. The invention improves the adaptability of brake pressure control and the running safety of the vehicle.

Inventors

CHEN QIUSHENG
SANG YIMIN

Assignees

温州庆瓯碟刹有限公司

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. A vehicle brake control system utilizing proportional valve modulation, comprising: The input processing module is used for receiving a vehicle braking request instruction and acquiring current vehicle running state data, and calculating target braking pressure based on the vehicle braking request instruction and the vehicle running state data; the control generation module is used for generating an initial proportional valve opening control signal according to the difference value between the target braking pressure and the current actual braking pressure; the valve control module is used for driving a proportional valve in the brake loop according to the initial proportional valve opening control signal to adjust the opening degree and monitoring actual brake pressure change data caused by opening degree change; The model analysis module is used for comparing the actual brake pressure change data with a pre-stored pressure-flow-valve opening relation model, correcting an opening control strategy of the proportional valve based on the comparison result, and updating a control signal to enable the actual brake pressure to change along with the target brake pressure; And the closed-loop monitoring module is used for continuously collecting wheel speed signals and vehicle dynamic parameters in the braking pressure regulating process and carrying out closed-loop monitoring and compensation on the braking pressure regulating process by utilizing the signals and the parameters.
2. The vehicle brake control system using proportional valve adjustment according to claim 1, wherein the acquiring current vehicle running state data specifically includes: Acquiring a vehicle speed signal, a longitudinal acceleration signal, a steering wheel corner signal and a yaw rate signal through a vehicle-mounted sensor network; Reading a state zone bit of the electronic stability program system and an activation state of the anti-lock brake system; Acquiring real-time wheel speed pulse signals of all wheels, and calculating slip rate instantaneous values of all the wheels; And integrating the vehicle speed signal, the longitudinal acceleration signal, the steering wheel corner signal, the yaw rate signal, the state flag bit, the activation state, the real-time wheel speed pulse signal and the slip rate instantaneous value to form the vehicle running state data.
3. The vehicle brake control system using proportional valve adjustment according to claim 1, characterized in that the calculation of the target brake pressure based on the vehicle brake request command and the vehicle running state data specifically includes: Analyzing the vehicle braking request instruction to obtain the braking strength required by a driver or the deceleration value required by an advanced driving assistance system; Inquiring a preset brake pressure reference mapping table by combining the current vehicle speed and the vehicle load information in the vehicle running state data to obtain a basic brake pressure requirement; Judging the steering state of the vehicle according to the steering wheel angle and the yaw rate in the vehicle running state data, and carrying out steering working condition correction on the basic brake pressure requirement; According to the activation state of the electronic stability program system or the anti-lock braking system in the vehicle running state data, adding additional braking pressure required by dynamic stability control or pressure modulation components required by anti-lock regulation; And integrating the basic brake pressure requirement, the steering working condition correction quantity and the additional brake pressure or pressure modulation component, and calculating to obtain the target brake pressure finally applied to each wheel.
4. The vehicle brake control system using proportional valve adjustment according to claim 1, wherein the generating an initial proportional valve opening control signal according to a difference between the target brake pressure and a current actual brake pressure specifically includes: Acquiring the current actual braking pressure of each braking wheel cylinder in real time through a pressure sensor in a braking pipeline; calculating, for each wheel, a pressure difference between the target brake pressure and the current actual brake pressure thereof; Determining the adjusting direction and the adjusting strength reference value of the proportional valve according to the positive and negative values and the magnitude of the pressure difference value; According to a preset proportional valve opening-pressure change rate characteristic curve, converting the regulating intensity reference value into a corresponding pulse width modulation duty ratio or a current instruction initial value; and packaging the pulse width modulation duty ratio or the current instruction initial value into the initial proportional valve opening control signal, wherein the signal comprises a target proportional valve identifier and a corresponding control quantity.
5. A vehicle brake control system using proportional valve adjustment according to claim 1, characterized in that the driving of the proportional valve in the brake circuit to adjust the opening degree in accordance with the initial proportional valve opening degree control signal specifically comprises: sending the initial proportional valve opening control signal to a corresponding proportional valve driver; The proportional valve driver outputs corresponding driving current to an electromagnetic coil of the target proportional valve according to the received control signal; The electromagnetic coil generates electromagnetic force under the action of the driving current, and the valve core of the driving proportional valve overcomes the pretightening force of the spring to displace; The displacement of the valve core changes the flow area of an orifice in the proportional valve, so that the opening degree of the proportional valve is adjusted; the opening degree adjustment directly changes the flow resistance of the brake fluid from the master cylinder to the wheel cylinder or from the wheel cylinder to the reservoir tank.
6. A vehicle brake control system using proportional valve regulation according to claim 1, wherein the monitoring of actual brake pressure change data caused by opening degree change specifically comprises: after the opening degree of the proportional valve is adjusted, collecting a pressure sensor signal of a brake cylinder at a frequency higher than a conventional sampling rate; recording the time-varying sequence of the pressure sensor signals to obtain an original curve of pressure rise or pressure drop; performing digital filtering processing on the original curve, and eliminating high-frequency noise interference to obtain a smooth pressure change curve; Extracting key features from the smoothed pressure change curve, including an initial response time of the pressure change, a rise time to reach a steady value, a rate of pressure change, and a final steady pressure value; And storing the key features, the corresponding time stamp, the proportional valve identifier and the initial control signal in a correlated manner to form the actual brake pressure change data.
7. The vehicle brake control system using proportional valve adjustment according to claim 1, wherein the comparison and analysis of the actual brake pressure change data with a pre-stored pressure-flow-valve opening degree relation model specifically includes: Reading the pressure change rate and the final stable pressure value under the current control signal from the actual brake pressure change data; inquiring a theoretical pressure change rate and a theoretical stable pressure value under the same environment temperature and brake fluid characteristic conditions from the pre-stored pressure-flow-valve opening relation model; calculating the deviation of the pressure change rate and the theoretical pressure change rate, and calculating the deviation of the final stable pressure value and the theoretical stable pressure value; And analyzing whether the deviation exceeds a preset allowable range, and judging the reason tendency of the deviation, namely that the response characteristic of the proportional valve drifts, the brake pipeline leaks or the brake fluid contains gas.
8. The vehicle brake control system using proportional valve adjustment according to claim 7, characterized in that the correction of the opening degree control strategy of the proportional valve based on the comparison analysis result specifically includes: If the deviation is in the allowable range, maintaining the current opening control strategy, and performing fine adjustment updating on model parameters only; if the deviation exceeds the allowable range and the response characteristic of the proportional valve is judged to drift, reversely adjusting the mapping relation of the pulse width modulation duty ratio or the current instruction value in the proportional valve opening control signal according to the magnitude and the direction of the deviation; if the deviation exceeds the allowable range and the slow leakage is judged to exist, a compensation component for maintaining the opening degree is overlapped in the generated control signal so as to offset the pressure holding deficiency caused by the leakage; If the deviation exceeds the allowable range and the brake fluid is judged to contain gas, generating a correction strategy containing a small-amplitude oscillation opening signal with specific frequency so as to promote the discharge of bubbles; And integrating the adjustment and compensation rules adopted for different deviation reasons to form a corrected pulse width modulation duty ratio-target pressure relation or current-pressure relation as a new opening control strategy.
9. A vehicle brake control system using proportional valve regulation according to claim 1, wherein said closed-loop supervision and compensation of the brake pressure regulation process using said signals and parameters comprises in particular: in the braking pressure following adjustment process, calculating the slip rate of each wheel based on the wheel speed signal in real time; Comparing the slip rate with an optimal slip rate range, and generating an anti-lock intervention signal aiming at the wheel proportional valve if the slip rate of a certain wheel is close to or exceeds a critical value; meanwhile, the yaw rate and the lateral acceleration in the dynamic parameters of the vehicle are analyzed, and if the deviation between the yaw rate and the lateral acceleration is too large from an expected value based on the steering wheel angle, an electronic stability program intervention signal is generated; The anti-lock intervention signal or the electronic stability program intervention signal is used as a superposition instruction with higher priority to temporarily cover or modify the current proportional valve opening control signal; and continuously monitoring related parameters during the period of effective intervention signals, and recovering the proportional valve opening control based on the target brake pressure after the condition is released.
10. The vehicle brake control system using proportional valve adjustment according to claim 7, wherein the pre-stored pressure-flow-valve opening relation model is constructed in a manner specifically including: In a hydraulic bench test environment of a vehicle braking system, installing a target proportional valve in a simulated braking loop; Inputting a group of known and accurate pulse width modulation duty ratio or current command values covering the working range of the electromagnetic coil of the proportional valve, and recording the corresponding valve core displacement as the actual opening; Under each stable opening degree, measuring the steady-state flow rate of the brake fluid flowing through the proportional valve under different inlet pressures through the flowmeter to generate a plurality of groups of opening degree-pressure-flow data points; In the environment test cabin, changing the environment temperature and changing the brake fluid of different types, repeatedly executing the following measurement operations, namely inputting a group of known and accurate pulse width modulation duty ratio or current command values covering the working range of the electromagnetic coil of the proportional valve, and recording the corresponding valve core displacement as the actual opening; Based on the data point set, a mathematical model which takes the ambient temperature, the viscosity parameter of the brake fluid and the target pressure change rate as input and the theoretical opening degree or the theoretical control current of the needed proportional valve as output is established through curve fitting or neural network training, and the mathematical model is stored as the pressure-flow-valve opening degree relation model.

Description

Vehicle brake control system regulated by proportional valve Technical Field The invention belongs to the technical field of vehicle brake control, and particularly relates to a vehicle brake control system regulated by a proportional valve. Background In vehicle brake systems, in particular brake-by-wire systems, it is common practice to use proportional valves for brake pressure regulation. The prior art solutions generally rely on classical control algorithms, which directly calculate and output the valve opening control signal via a proportional-integral-derivative controller. The control logic of this method is fixed, and its parameters are often set based on ideal conditions or specific calibration conditions. When the brake system is in actual operation and faces complex nonlinear factors such as the characteristic of oil liquid along with temperature change, abrasion or manufacturing tolerance of a valve, pipeline pressure fluctuation and the like, the fixed control parameters are difficult to realize accurate, quick and stable pressure following, and pressure overshoot, response delay or steady state error increase can be caused. The brake control of modern vehicles is closely related to vehicle stability control. In the prior art architecture, the foundation brake pressure adjusting module and the dynamic control modules of the vehicle such as an anti-lock brake system, an electronic vehicle body stabilizing system and the like usually work in layers or relatively independently. The foundation brake module is responsible for executing the pressure request, while the advanced stability control module overrides or intervenes in the foundation brake request when wheel slip or body instability is monitored. The discrete or loose coupling mode may cause delay or conflict of control instructions at the generation, transmission and execution levels, and under extreme working conditions such as emergency braking or low adhesion road surface, the optimal coordination between the braking pressure adjustment and the dynamic state of the vehicle cannot be realized, so that the braking efficiency and the driving safety are affected. There is a need for an integrated solution that overcomes the nonlinear effects of the braking system itself, enables high-precision pressure adaptive control, and integrates foundation brake regulation with the overall dynamic supervision depth of the vehicle. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the invention proposes a vehicle brake control system regulated with a proportional valve, comprising: The input processing module is used for receiving a vehicle braking request instruction and acquiring current vehicle running state data, and calculating target braking pressure based on the vehicle braking request instruction and the vehicle running state data; the control generation module is used for generating an initial proportional valve opening control signal according to the difference value between the target braking pressure and the current actual braking pressure; the valve control module is used for driving a proportional valve in the brake loop according to the initial proportional valve opening control signal to adjust the opening degree and monitoring actual brake pressure change data caused by opening degree change; The model analysis module is used for comparing the actual brake pressure change data with a pre-stored pressure-flow-valve opening relation model, correcting an opening control strategy of the proportional valve based on the comparison result, and updating a control signal to enable the actual brake pressure to change along with the target brake pressure; And the closed-loop monitoring module is used for continuously collecting wheel speed signals and vehicle dynamic parameters in the braking pressure regulating process and carrying out closed-loop monitoring and compensation on the braking pressure regulating process by utilizing the signals and the parameters. Further, the acquiring the current vehicle running state data specifically includes: Acquiring a vehicle speed signal, a longitudinal acceleration signal, a steering wheel corner signal and a yaw rate signal through a vehicle-mounted sensor network; Reading a state zone bit of the electronic stability program system and an activation state of the anti-lock brake system; Acquiring real-time wheel speed pulse signals of all wheels, and calculating slip rate instantaneous values of all the wheels; And integrating the vehicle speed signal, the longitudinal acceleration signal, the steering wheel corner signal, the yaw rate signal, the state flag bit, the activation state, the real-time wheel speed pulse signal and the slip rate instantaneous value to form the vehicle running state data. Further, the calculating the target brake pressure based on the vehicle brake request command and the vehicle running st