Electro-hydraulic braking force coordination control method, device, electronic equipment and system

Abstract

This invention relates to a method, device, electronic device, and system for coordinated electro-hydraulic braking force control, belonging to the field of vehicle braking control technology. The method includes: acquiring braking operation signals and vehicle status signals; determining a target braking torque based on the braking operation signals and vehicle status signals; calling an electro-hydraulic braking dynamic response time-domain model based on the vehicle status signals and performing prediction using a model predictive control algorithm to obtain a hydraulic pressure build-up hysteresis; pre-allocating braking force based on the hydraulic pressure build-up hysteresis and the vehicle status signals to obtain a pre-allocated electric braking force, and determining an initial hydraulic braking force based on the pre-allocated electric braking force; and outputting power commands corresponding to the pre-allocated electric braking force and the initial hydraulic braking force to the corresponding actuators to complete the coordinated electro-hydraulic braking force control. This invention enables seamless and smooth transition of electro-hydraulic braking force, improving the accuracy of coordinated control and driving comfort.

Description

Technical Field

[0001] This invention relates to the field of vehicle braking control technology, and in particular to an electro-hydraulic braking force coordination control method, device, electronic equipment and system. Background Technology

[0002] In new energy vehicles, electro-hydraulic hybrid braking systems are the mainstream configuration. Their core is to coordinate the braking torque of electric motor braking and hydraulic braking, prioritizing the use of electric braking force for energy recovery, with the remaining energy supplemented by hydraulic braking force, thus balancing braking safety and range. Existing coordinated control strategies mainly include parallel, series, and adaptive types, with the parallel type being the most widely used due to its high energy recovery efficiency. Some strategies employ fuzzy PID control to correct the electric braking force, or control the electric braking force to follow a pure hydraulic braking model. Simultaneously, the braking intention can be analyzed through pedal signals, and a lookup table method can be used to complete the initial distribution of braking force.

[0003] However, while existing technologies can achieve basic braking force distribution, they fail to address core pain points, resulting in poor control performance and an inability to meet the requirements for smoothness, precision, and stability in vehicle braking. Specifically, this manifests as: lag in hydraulic pressure build-up and jerky switching; hydraulic braking inherently has a response delay, with braking force build-up slower than electric motor braking, causing torque fluctuations during mode switching and affecting driving comfort; lack of prediction and pre-distribution, leading to disjointed transitions; for example, using "post-event remediation" control fails to predict electro-hydraulic response time differences and lacks active pre-distribution strategies, exacerbating jerkyness when braking intensity changes; low control precision and weak anti-interference capabilities; for example, the lack of a complete closed-loop feedback or adjustment of only a single parameter fails to correct torque deviations caused by interference and parameter drift in real time, affecting braking safety and energy recovery efficiency; and poor model adaptability; for example, the absence of a precise electro-hydraulic braking dynamic response model makes it impossible to describe lag patterns and response differences, resulting in a lack of reliable support for control optimization and insufficient adaptability. Summary of the Invention

[0004] In view of this, it is necessary to provide an electro-hydraulic braking force coordination control method, device, electronic device and system to solve the problems of switching jerks, inability to cancel response time differences, insufficient control accuracy and poor model adaptability in the existing electro-hydraulic braking force coordination control.

[0005] To address the aforementioned problems, in a first aspect, the present invention provides an electro-hydraulic braking force coordination control method, comprising: Acquire braking operation signals and vehicle status signals; The target braking torque is determined based on the braking operation signal and the vehicle status signal; Based on the vehicle state signal, the time-domain model of the electro-hydraulic braking dynamic response is invoked and the hydraulic pressure build-up hysteresis is obtained through model predictive control algorithm. Braking force is pre-allocated based on the hydraulic pressure build-up hysteresis and the vehicle status signal to obtain the pre-allocated electric braking force, and the initial hydraulic braking force is determined based on the pre-allocated electric braking force. The power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force are output to the corresponding actuators to complete the coordinated control of electro-hydraulic braking force.

[0006] In one possible implementation, determining the target braking torque based on the braking operation signal and the vehicle state signal includes: Based on the braking operation signal, the brake pedal travel and pedal speed are obtained, and the total braking force required by the driver is obtained by mapping the brake pedal travel and pedal speed using a lookup table method. The reference braking torque is calculated by combining the wheel radius and the total braking force. Based on the vehicle state signal, the battery state of charge and the road adhesion coefficient are obtained, and the reference braking torque is corrected based on the battery state of charge and the road adhesion coefficient to obtain the target braking torque.

[0007] In one possible implementation, the step of calling the electro-hydraulic braking dynamic response time-domain model based on the vehicle state signal and predicting it using a model predictive control algorithm to obtain the hydraulic pressure build-up hysteresis includes: The electro-hydraulic braking dynamic response time-domain model is invoked; the electro-hydraulic braking dynamic response time-domain model includes an electric motor braking dynamic model and a hydraulic braking dynamic model. The electric motor braking dynamic model is used to describe the dynamic response characteristics of the electric motor's power, and the hydraulic braking dynamic model is used to describe the pressure build-up hysteresis dynamic response characteristics of the hydraulic braking system. Based on the vehicle state signal, the electric motor braking dynamic model and the hydraulic braking dynamic model are used as the prediction basis. The hydraulic braking force response curve in multiple future control cycles is predicted by the model predictive control algorithm. The time required for the hydraulic braking force to build up from the start to the target value is determined based on the hydraulic braking force response curve, and is used as the hydraulic pressure build-up hysteresis.

[0008] In one possible implementation, the method further includes: Within each control cycle, the system output for multiple future control cycles is predicted using a discretized state-space model based on the current system state vector. With the goal of minimizing the deviation between the target braking torque and the predicted braking torque, and with the constraint that the electric motor braking force and the hydraulic braking force do not exceed their respective maximum output capabilities, the control command sequence for multiple future control cycles is obtained by solving the problem. After executing the first optimal control command in the control command sequence of the current control cycle, the system enters the next control cycle to re-predict and optimize in order to update the hydraulic braking force response curve.

[0009] In one possible implementation, the step of pre-distributing braking force based on the hydraulic pressure build-up hysteresis and the vehicle state signal to obtain a pre-distributed electric braking force, and determining the initial hydraulic braking force based on the pre-distributed electric braking force, includes: The pre-allocated electric braking force is calculated based on the hydraulic pressure build-up hysteresis and the battery state of charge, motor temperature and road adhesion coefficient obtained based on the vehicle state signal through a pre-allocation algorithm. The hydraulic pressure build-up hysteresis is positively correlated with the pre-allocated electric braking force. When the battery state of charge is higher than a preset threshold or the motor temperature exceeds a preset safety range, the pre-allocated electric braking force is reduced. The difference between the target braking torque and the pre-allocated electric braking force is used as the initial hydraulic braking force, wherein the pre-allocated electric braking force does not exceed the maximum braking force of the motor, and the initial hydraulic braking force does not exceed the maximum hydraulic braking force.

[0010] In one possible implementation, the method further includes: The actual electric braking force and the actual hydraulic braking force are collected in real time, and the actual total braking torque is determined based on the actual electric braking force and the actual hydraulic braking force. Calculate the deviation between the actual total braking torque and the target braking torque; When the deviation exceeds the preset allowable range, the correction amount is calculated through a closed-loop feedback adjustment algorithm. Based on the correction amount, the distribution of electric braking force and hydraulic braking force is dynamically adjusted, and the braking force commands corresponding to the corrected electric braking force and the corrected hydraulic braking force are output to the corresponding actuators.

[0011] In one possible implementation, the dynamic adjustment of the distribution of electric braking force and hydraulic braking force based on the correction amount includes: Based on the braking force correction amount and the preset first and second allocation coefficients, the electric braking force correction component and the hydraulic braking force correction component are calculated respectively. The current electric braking force is corrected according to the electric braking force correction component to obtain the corrected electric braking force; The current hydraulic braking force is corrected based on the hydraulic braking force correction component to obtain the corrected hydraulic braking force.

[0012] Secondly, the present invention also provides an electro-hydraulic braking force coordination control device, comprising: The signal acquisition module is used to acquire braking operation signals and vehicle status signals; A braking torque determination module is used to determine the target braking torque based on the braking operation signal and the vehicle status signal; The model prediction module is used to call the electro-hydraulic braking dynamic response time-domain model based on the vehicle state signal and make predictions through the model prediction control algorithm to obtain the hydraulic pressure build-up hysteresis. The braking force pre-distribution module is used to pre-distribute the braking force according to the hydraulic pressure build-up hysteresis and the vehicle status signal to obtain the pre-distributed electric braking force, and to determine the initial hydraulic braking force according to the pre-distributed electric braking force. The command output module is used to output the power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force to the corresponding actuators to complete the coordinated control of electro-hydraulic braking force.

[0013] Thirdly, the present invention also provides an electronic device, including a data acquisition unit, a memory, and a processor, wherein the data acquisition unit is used to acquire braking operation signals and vehicle status signals; The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the electro-hydraulic braking force coordination control method described in any of the above implementations.

[0014] Fourthly, the present invention also provides an electro-hydraulic braking force coordination control system, which includes an electronic device, a data acquisition device, and a result output device as described above. The data acquisition device and the result output device are respectively connected to the electronic device. The data acquisition device is used to acquire braking operation signals and vehicle status signals, and the result output device is used to output and execute electro-hydraulic braking force coordination control.

[0015] The beneficial effects of this invention are as follows: The electro-hydraulic braking force coordination control method provided by this invention acquires braking operation signals and vehicle status signals, and determines the target braking torque based on these signals, providing an accurate benchmark for subsequent braking force distribution. Furthermore, based on the vehicle status signals, it calls the electro-hydraulic braking dynamic response time-domain model and uses a model predictive control algorithm to predict the hydraulic pressure build-up lag. This step utilizes the forward-looking advantage of model predictive control, accurately predicting the pressure build-up delay time of the hydraulic braking system through the dynamic response model, realizing a shift from post-event remediation to pre-event prediction. On this basis, braking force is pre-distributed based on the hydraulic pressure build-up lag and vehicle status signals to obtain the pre-distributed electric braking force, and the initial hydraulic braking force is determined based on the pre-distributed electric braking force. This step actively adjusts the output timing and amplitude of the electric braking force using the predicted lag, so that the early output of the electric braking force offsets the hydraulic pressure build-up lag, achieving a seamless transition of electro-hydraulic torque. Finally, the power commands corresponding to the pre-distributed electric braking force and the initial hydraulic braking force are output to the corresponding actuators to complete the electro-hydraulic braking force coordination control. This successfully solved the technical problem of jerky switching of electro-hydraulic braking force and the inability to offset response time difference caused by hydraulic pressure build-up lag in the existing technology, and achieved smooth and seamless coordinated control of electro-hydraulic braking force, significantly improving driving comfort and braking safety. Attached Figure Description

[0016] Figure 1 A flowchart illustrating an embodiment of the electro-hydraulic braking force coordination control method provided by the present invention; Figure 2 A schematic diagram of the electro-hydraulic braking force coordination control system architecture of an embodiment of the electro-hydraulic braking force coordination control method provided by the present invention; Figure 3 A schematic diagram of the overall algorithm collaborative working logic of an embodiment of the electro-hydraulic braking force coordination control method provided by the present invention; Figure 4 A functional block diagram of an electro-hydraulic braking force coordination control device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the description of the embodiments of the present invention, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0019] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] Before demonstrating the embodiments, the following terms will be explained.

[0022] MPC: Model Predictive Control (MPC) is a forward-looking control algorithm based on a system dynamic model. It predicts the system output over multiple control cycles to optimize the objective function and solve for the optimal control sequence, thus achieving rolling optimization control.

[0023] PID control: Proportional-Integral-Derivative (PID) is a classic closed-loop feedback control algorithm that adjusts system deviation through three components: proportional, integral, and derivative. It is widely used in industrial process control.

[0024] SOC: State of Charge (SOC) refers to the ratio of the battery's current remaining charge to its rated capacity, and is used to characterize the battery's charge and discharge state.

[0025] Electro-hydraulic hybrid braking system: A vehicle braking system that combines electric motor braking and hydraulic braking functions. The electric motor braking is used for energy recovery, and the hydraulic braking is used to supplement insufficient braking force.

[0026] This invention provides an electro-hydraulic braking force coordination control method, device, electronic device, and system, which are described below.

[0027] Figure 1This is a schematic flowchart of an embodiment of the electro-hydraulic braking force coordination control method provided by the present invention. The executing entity of the electro-hydraulic braking force coordination control method can be a computer, a portable smart device, or a cloud server, etc. The specific executing entity is the storage medium in the computer, and this embodiment does not limit it.

[0028] like Figure 1 As shown, the electro-hydraulic braking force coordination control method includes: S101. Obtain braking operation signals and vehicle status signals.

[0029] It should be noted that braking operation signals include signals reflecting the driver's braking intention, such as brake pedal travel and pedal speed. Vehicle status signals include signals reflecting the vehicle's current operating status, such as wheel speeds, real-time wheel cylinder pressure, motor speed, motor power, motor temperature, battery SOC value, and road surface adhesion coefficient. These signals are collected in real time by various sensors in the perception layer and transmitted to the decision control layer for processing.

[0030] In some embodiments, before activating the vehicle braking control system, system initialization is required. The parameters of each module initialized include the prediction time domain Np and control time domain Nc of the MPC prediction model, the proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd of the PID feedback regulator, the electro-hydraulic braking force distribution coefficients k1 and k2, the allowable range of hydraulic pressure build-up hysteresis Δt_max, the allowable range of torque deviation [ΔT_min, ΔT_max], and vehicle inherent parameters such as wheel radius r, maximum motor braking force T_reg_max, and maximum hydraulic braking force T_hyd_max.

[0031] Furthermore, refer to Figure 2 As shown, Figure 2 This is a system architecture diagram of an embodiment of the electro-hydraulic braking force coordination control method provided by the present invention. Figure 2 As shown, the seamless coordinated control system for electro-hydraulic braking force of this invention adopts a layered architecture design, which is divided into a perception layer, a decision control layer, and an execution layer. The perception layer collects signals in real time, such as brake pedal travel, pedal speed, wheel speed, wheel cylinder real-time pressure, motor speed, motor power, motor temperature, battery SOC value, and road adhesion coefficient, through various sensors, and transmits these signals to the decision control layer. The decision control layer includes a braking intent recognition module, an MPC prediction model module, a braking force pre-distribution module, and a closed-loop feedback adjustment module. These modules work together to achieve seamless coordinated control of braking force. The execution layer includes an electric motor brake actuator and a hydraulic brake actuator, used to receive and execute braking force commands issued by the decision control layer.

[0032] It should be understood that this invention achieves coordinated control of electro-hydraulic braking force through the coordinated operation of the MPC prediction algorithm, the PID feedback regulation algorithm, and the braking force pre-distribution algorithm. Specifically, please refer to... Figure 3 As shown, Figure 3 The collaborative working logic of the MPC prediction algorithm, PID feedback control algorithm, and braking force pre-allocation algorithm is demonstrated. The MPC prediction algorithm predicts the hydraulic pressure build-up hysteresis based on the time-domain model of the electro-hydraulic braking dynamic response and outputs the prediction result to the braking force pre-allocation algorithm. The braking force pre-allocation algorithm calculates the pre-allocated electric braking force and the initial hydraulic braking force based on the hydraulic pressure build-up hysteresis and multi-condition parameters, and outputs them to the execution layer. At the same time, the closed-loop feedback control module collects the actual braking force in real time, calculates the deviation, and corrects it through the PID algorithm. The correction result is fed back to the braking force allocation stage to form a complete closed-loop control logic.

[0033] S102. Determine the target braking torque based on the braking operation signal and the vehicle status signal.

[0034] In this embodiment, the target braking torque is determined based on the braking operation signal and the vehicle status signal. This means that the system receives information about the travel and speed of the brake pedal applied by the driver, as well as parameters reflecting the vehicle's current operating status such as wheel speed, road adhesion coefficient, and battery state of charge. Based on a preset mapping relationship or calculation logic, the system directly derives the overall braking torque value required by the vehicle at that moment. This process does not rely on subsequent electro-hydraulic distribution or feedback correction; it only relies on the input braking operation signal and vehicle status signal to complete the initial calculation of the target braking torque, providing a clear control target for subsequent braking force execution.

[0035] In some embodiments, step S102 includes: obtaining the brake pedal travel and pedal speed based on the braking operation signal, and mapping the total braking force required by the driver based on the brake pedal travel and pedal speed using a lookup table method; calculating a reference braking torque by combining the wheel radius and the total braking force; obtaining the battery state of charge and road adhesion coefficient based on the vehicle state signal, and correcting the reference braking torque based on the battery state of charge and road adhesion coefficient to obtain the target braking torque.

[0036] Specifically, the braking intention recognition module uses the collected pedal travel and pedal speed to map the total braking force F_total required by the driver using a 1-D Lookup Table. Then, based on the wheel radius r, it calculates the reference braking torque T_c = F_total × r. At the same time, it combines the road adhesion coefficient μ and the battery SOC state to make a safety correction to T_c, ensuring that the target braking torque T_total after correction does not exceed the road adhesion limit and the maximum output capacity of the motor and hydraulic system.

[0037] S103. Based on the vehicle state signal, the electro-hydraulic braking dynamic response time-domain model is invoked and predicted using the model predictive control algorithm to obtain the hydraulic pressure build-up hysteresis.

[0038] In this embodiment, model predictive control is introduced to establish a time-domain model of the dynamic response of the electro-hydraulic braking system. This model is used to accurately describe the dynamic characteristics of the electro-hydraulic braking system and predict the hydraulic pressure build-up hysteresis. The model consists of two parts: a dynamic model of the electric motor braking system and a dynamic model of the hydraulic system, which are integrated into a unified time-domain model.

[0039] In some embodiments, step S103 includes: invoking the electro-hydraulic braking dynamic response time-domain model; the electro-hydraulic braking dynamic response time-domain model includes an electric motor braking dynamic model and a hydraulic braking dynamic model, the electric motor braking dynamic sub-model is used to describe the dynamic response characteristics of the electric motor braking force, and the hydraulic braking dynamic sub-model is used to describe the pressure build-up hysteresis dynamic response characteristics of the hydraulic braking system; based on the vehicle state signal, using the electric motor braking dynamic sub-model and the hydraulic braking dynamic sub-model as the prediction basis, the hydraulic braking force response curve within multiple future control cycles is predicted through a model predictive control algorithm; the time required for the hydraulic braking force to reach the target value from the start of pressure build-up is determined according to the hydraulic braking force response curve, as the hydraulic pressure build-up hysteresis.

[0040] Specifically, the dynamic model of electric motor braking: The response speed of electric motor power is relatively fast, and its dynamic characteristics can be described using a first-order inertial model, as shown in the following formula:

[0041] in, for Actual electric braking force at all times (N·m). for Immediate electric braking force command (N·m). The time constant (s) of the motor braking system is determined by the characteristics of components such as the motor controller and inverter, and is obtained through experimental identification.

[0042] Hydraulic Braking Dynamic Model: The hydraulic braking system exhibits significant pressure build-up hysteresis. Considering the operating characteristics of the high-pressure accumulator, electromagnetic proportional valve, and wheel cylinders, its dynamic response is described by a second-order linear differential equation, as shown in the following formula:

[0043] in, for Real-time cylinder pressure (Pa). for Constant cylinder pressure command (Pa). For the damping ratio of the hydraulic system, The natural frequency of the hydraulic system (rad / s) was obtained through experimental testing and system identification.

[0044] The relationship between hydraulic braking force and wheel cylinder pressure is as follows:

[0045] in, The effective area of ​​the wheel cylinder (m²) The radius of the wheel is (m).

[0046] Unified Time-Domain Model for Electro-Hydraulic Braking: By integrating the two sub-models mentioned above, a unified time-domain model of the dynamic response of electro-hydraulic braking is obtained.

[0047] Furthermore, the core of the MPC prediction algorithm is "prediction + optimization". Through the aforementioned electro-hydraulic braking dynamic response time-domain model, it predicts the electro-hydraulic braking force output within the next Np control cycles, thereby predicting the hydraulic pressure build-up hysteresis. The specific implementation is as follows: State vector definition: Selecting the system state vector:

[0048] Where k is the current control period, Let k be the rate of change of electric braking force. Let k be the rate of change of cylinder pressure.

[0049] Control vector definition: Control vector:

[0050] That is, the electric braking force command and the wheel cylinder pressure command of the current control cycle.

[0051] Discretization: The continuous-time model is discretized into a state-space model to facilitate the implementation of the MPC algorithm. The discretized model is as follows:

[0052]

[0053] Where A is the system matrix, B is the input matrix, and C is the output matrix, which are obtained by discretization using the zero-order preservation method; This is the system output vector.

[0054] Prediction and Optimization: In each control cycle, based on the current state x(k), the system output y(k+1), y(k+2), ..., y(k+Np) for the next Np control cycles is predicted using a discrete state-space model. The optimization objective is to minimize the deviation between the target braking torque and the predicted braking torque. The constraints are that the electric motor power and hydraulic braking force do not exceed their respective maximum output capabilities, and the battery SOC and motor temperature are within safe ranges. The optimal control sequence u(k), u(k+1), ..., u(k+Nc-1) for the next Nc control cycles is obtained by solving the problem. Only the optimal control command u(k) for the first control cycle is executed. After entering the next control cycle, prediction and optimization are repeated to achieve rolling optimization.

[0055] Hydraulic pressure build-up lag prediction: The time required for the hydraulic braking force to reach the target value T_hyd_init from the start of pressure build-up is obtained through MPC prediction, which is the hydraulic pressure build-up lag Δt. The calculation formula is as follows:

[0056] in, 0.95 is the error tolerance coefficient to ensure the accuracy of the lag prediction.

[0057] S104. Based on the hydraulic pressure build-up hysteresis and the vehicle status signal, pre-allocate the braking force to obtain the pre-allocated electric braking force, and determine the initial hydraulic braking force based on the pre-allocated electric braking force.

[0058] In this embodiment, the pre-allocation of braking force based on the hydraulic pressure build-up lag and vehicle status signals means that, based on the time delay required for the hydraulic braking system to build up the target pressure from startup, combined with signals reflecting vehicle operating conditions (such as battery SOC, motor temperature, road surface adhesion coefficient, etc.), the braking force that should be output by the electric motor braking system in advance is actively calculated to compensate for the response delay of the hydraulic system. On this basis, by subtracting the pre-allocated electric braking force from the target total braking force, the initial braking force value that the hydraulic braking system needs to output is determined. Thus, before the hydraulic system has fully built up pressure, the electric motor braking system takes on part of the braking force demand, thereby achieving active control of the timing of braking force output.

[0059] In some embodiments, step S104 includes: calculating a pre-allocated electric braking force based on the hydraulic pressure build-up hysteresis and in combination with the battery state of charge, motor temperature, and road adhesion coefficient obtained based on the vehicle state signal using a pre-allocation algorithm, wherein the hydraulic pressure build-up hysteresis is positively correlated with the pre-allocated electric braking force, and the pre-allocated electric braking force is reduced when the battery state of charge is higher than a preset threshold or the motor temperature exceeds a preset safety range; and using the difference between the target braking torque and the pre-allocated electric braking force as the initial hydraulic braking force, wherein the pre-allocated electric braking force does not exceed the maximum braking force of the motor, and the initial hydraulic braking force does not exceed the maximum hydraulic braking force.

[0060] Specifically, the calculation of the electric braking force pre-distribution T_reg_pre needs to comprehensively consider the hydraulic pressure build-up hysteresis Δt, battery SOC, motor temperature T_motor, and road adhesion coefficient μ. The algorithm formula is as follows:

[0061] in, This is the lag correction factor. , The larger, The closer to 1, The larger the value, the better it can offset the lag.

[0062] Battery SOC correction factor for:

[0063] To avoid overcharging or over-discharging the battery.

[0064] Motor temperature correction factor for:

[0065] in, This is the maximum allowable temperature for the motor to prevent overheating and damage. Vehicle mass (kg). The acceleration due to gravity is 9.8 m / s². The maximum braking torque corresponding to the road surface adhesion limit is used as a 10% margin (multiplied by 0.9) to ensure braking safety.

[0066] S105. Output the power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force to the corresponding actuators to complete the coordinated control of electro-hydraulic braking force.

[0067] In this embodiment, the system directly transmits the pre-calculated electro-braking force command and the initial hydraulic braking force command to the motor brake actuator and the hydraulic brake actuator. The actuators then output the corresponding braking torque according to the command, thereby completing the coordinated control of the electro-hydraulic braking force.

[0068] In some embodiments, the method further includes: acquiring actual electric braking force and actual hydraulic braking force in real time, and determining actual total braking torque based on the actual electric braking force and the actual hydraulic braking force; calculating the deviation between the actual total braking torque and the target braking torque; calculating a correction amount through a closed-loop feedback adjustment algorithm when the deviation exceeds a preset allowable range; dynamically adjusting the distribution of electric braking force and hydraulic braking force based on the correction amount, and outputting braking force commands corresponding to the corrected electric braking force and the corrected hydraulic braking force to the corresponding actuators.

[0069] It should be noted that the perception layer collects the actual electric braking force T_reg_actual and the actual hydraulic braking force T_hyd_actual in real time and transmits them to the closed-loop feedback adjustment module; this module calculates the deviation between the actual total braking torque and the target braking torque. ΔT=T_total-(T_reg_actual+T_hyd_actual) If ΔT exceeds the allowable range, the correction amount ΔT_corr is calculated using the PID algorithm, and the electro-hydraulic braking force distribution ratio is dynamically adjusted to obtain the corrected electro-braking force T_reg_new and hydraulic braking force T_hyd_new, ensuring that the actual braking torque always approaches the target value.

[0070] Specifically, a PID algorithm is used to implement closed-loop feedback regulation, correct torque distribution deviation in real time, and improve control accuracy. The PID regulation formula is as follows:

[0071] in, for Braking force correction amount (N·m) at any given time. This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... for Torque deviation at any moment for Torque deviation at any moment For control period (s).

[0072] In some embodiments, the dynamic adjustment of the distribution of electric braking force and hydraulic braking force based on the correction amount includes: calculating the electric braking force correction component and the hydraulic braking force correction component based on the braking force correction amount combined with a preset first distribution coefficient and a second distribution coefficient; correcting the current electric braking force according to the electric braking force correction component to obtain the corrected electric braking force; and correcting the current hydraulic braking force according to the hydraulic braking force correction component to obtain the corrected hydraulic braking force.

[0073] The revised formula for calculating electro-hydraulic braking force is as follows:

[0074]

[0075] in, , The braking force correction distribution coefficient, namely the first distribution coefficient and the second distribution coefficient mentioned above, satisfies... It can be dynamically adjusted according to the response speed of the electro-hydraulic system.

[0076] This implementation acquires braking operation signals and vehicle status signals, and determines the target braking torque based on these signals, providing an accurate benchmark for subsequent braking force distribution. Furthermore, based on the vehicle status signals, it invokes the electro-hydraulic braking dynamic response time-domain model and uses a model predictive control algorithm to predict the hydraulic pressure build-up lag. This step leverages the forward-looking advantage of model predictive control, accurately predicting the pressure build-up delay time of the hydraulic braking system through the dynamic response model, achieving a shift from reactive remediation to proactive prediction. On this basis, braking force is pre-distributed based on the hydraulic pressure build-up lag and vehicle status signals to obtain the pre-distributed electric braking force. The initial hydraulic braking force is then determined based on the pre-distributed electric braking force. This step proactively adjusts the output timing and amplitude of the electric braking force using the predicted lag, allowing the early output of the electric braking force to offset the hydraulic pressure build-up lag and achieve a seamless transition of the electro-hydraulic torque. Finally, the power commands corresponding to the pre-distributed electric braking force and the initial hydraulic braking force are output to the corresponding actuators to complete the coordinated control of the electro-hydraulic braking force. This successfully solved the technical problem of jerky switching of electro-hydraulic braking force and inability to offset response time difference caused by hydraulic pressure build-up lag in the existing technology, and achieved smooth and seamless coordinated control of electro-hydraulic braking force, significantly improving driving comfort and braking safety.

[0077] Based on the same idea as the electro-hydraulic braking force coordination control method in the above embodiments, this application also provides an electro-hydraulic braking force coordination control device 400, which can be used to execute the above-described electro-hydraulic braking force coordination control method. For example... Figure 4As shown, the electro-hydraulic braking force coordination control device 400 includes: a signal acquisition module 401, a braking torque determination module 402, a model prediction module 403, a braking force pre-allocation module 404, and a command output module 405, used to output the power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force to the corresponding actuators to complete the electro-hydraulic braking force coordination control. In some embodiments, the above modules can be programmable software instructions stored in a memory and executable by a processor. It is understood that in other embodiments, the above modules can also be program instructions or firmware embedded in a processor.

[0078] The signal acquisition module 401 is used to acquire braking operation signals and vehicle status signals; Braking torque determination module 402 is used to determine the target braking torque based on the braking operation signal and the vehicle status signal; Model prediction module 403 is used to call the electro-hydraulic braking dynamic response time-domain model based on the vehicle state signal and predict it through the model prediction control algorithm to obtain the hydraulic pressure build-up hysteresis. The braking force pre-distribution module 404 is used to pre-distribute the braking force according to the hydraulic pressure build-up hysteresis and the vehicle status signal to obtain the pre-distributed electric braking force, and to determine the initial hydraulic braking force according to the pre-distributed electric braking force. The instruction output module 405 is used to output the power commands corresponding to the pre-allocated electric braking force and the initial hydraulic braking force to the corresponding actuators to complete the coordinated control of the electro-hydraulic braking force.

[0079] Please refer to Figure 5 , Figure 5 This is a schematic diagram of an embodiment of the electronic device of this application. In this embodiment of the invention, the electronic device 500 includes a processor 501, a memory 502, a display 503, and a data acquisition device 504. Figure 5 Only some components of the electronic device 500 are shown, but it should be understood that it is not required to implement all the components shown, and more or fewer components may be implemented instead.

[0080] In some embodiments, processor 501 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 502 or process data, such as the electro-hydraulic braking force coordination control method of the present invention.

[0081] In some embodiments, display 503 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 503 is used to display information from electronic device 500 and to display visual user applications. Components 501-503 of electronic device 500 communicate with each other via a system bus.

[0082] In one embodiment, when the processor 501 executes the electro-hydraulic braking force coordination control program in the memory 502, the following steps can be implemented: Acquire braking operation signals and vehicle status signals; The target braking torque is determined based on the braking operation signal and the vehicle status signal; Based on the vehicle state signal, the time-domain model of the electro-hydraulic braking dynamic response is invoked and the hydraulic pressure build-up hysteresis is obtained through model predictive control algorithm. Braking force is pre-allocated based on the hydraulic pressure build-up hysteresis and the vehicle status signal to obtain the pre-allocated electric braking force, and the initial hydraulic braking force is determined based on the pre-allocated electric braking force. The power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force are output to the corresponding actuators to complete the coordinated control of electro-hydraulic braking force.

[0083] It should be understood that when the processor 501 executes the aero-optical effect sequence image restoration program in the memory 502, in addition to the functions mentioned above, it can also perform other functions, as can be found in the description of the corresponding method embodiments above.

[0084] Furthermore, this embodiment of the invention does not specifically limit the type of electronic device 500 mentioned. Electronic device 500 can be a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, laptop computer, or other portable electronic device. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic device can also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the invention, electronic device 500 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0085] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0086] The electro-hydraulic braking force coordination control method, device, electronic device and system provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for coordinated control of electro-hydraulic braking force, characterized in that, include: Acquire braking operation signals and vehicle status signals; The target braking torque is determined based on the braking operation signal and the vehicle status signal; Based on the vehicle state signal, the time-domain model of the electro-hydraulic braking dynamic response is invoked and the hydraulic pressure build-up hysteresis is obtained through model predictive control algorithm. Braking force is pre-allocated based on the hydraulic pressure build-up hysteresis and the vehicle status signal to obtain the pre-allocated electric braking force, and the initial hydraulic braking force is determined based on the pre-allocated electric braking force. The power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force are output to the corresponding actuators to complete the coordinated control of electro-hydraulic braking force.

2. The electro-hydraulic braking force coordination control method according to claim 1, characterized in that, Determining the target braking torque based on the braking operation signal and the vehicle status signal includes: Based on the braking operation signal, the brake pedal travel and pedal speed are obtained, and the total braking force required by the driver is obtained by mapping the brake pedal travel and pedal speed using a lookup table method. The reference braking torque is calculated by combining the wheel radius and the total braking force. Based on the vehicle state signal, the battery state of charge and the road adhesion coefficient are obtained, and the reference braking torque is corrected based on the battery state of charge and the road adhesion coefficient to obtain the target braking torque.

3. The electro-hydraulic braking force coordination control method according to claim 1, characterized in that, The process of calling the electro-hydraulic braking dynamic response time-domain model based on the vehicle state signal and predicting it using a model predictive control algorithm to obtain the hydraulic pressure build-up hysteresis includes: The electro-hydraulic braking dynamic response time-domain model is invoked; the electro-hydraulic braking dynamic response time-domain model includes an electric motor braking dynamic model and a hydraulic braking dynamic model. The electric motor braking dynamic sub-model is used to describe the dynamic response characteristics of the electric motor's power, and the hydraulic braking dynamic sub-model is used to describe the pressure build-up hysteresis dynamic response characteristics of the hydraulic braking system. Based on the vehicle state signal, the electric motor braking dynamic sub-model and the hydraulic braking dynamic sub-model are used as the prediction basis. The hydraulic braking force response curve in multiple future control cycles is predicted by the model predictive control algorithm. The time required for the hydraulic braking force to build up from the start to the target value is determined based on the hydraulic braking force response curve, and is used as the hydraulic pressure build-up hysteresis.

4. The electro-hydraulic braking force coordination control method according to claim 3, characterized in that, The method further includes: Within each control cycle, the system output for multiple future control cycles is predicted using a discretized state-space model based on the current system state vector. With the goal of minimizing the deviation between the target braking torque and the predicted braking torque, and with the constraint that the electric motor braking force and the hydraulic braking force do not exceed their respective maximum output capabilities, the control command sequence for multiple future control cycles is obtained by solving the problem. After executing the first optimal control command in the control command sequence of the current control cycle, the system enters the next control cycle to re-predict and optimize in order to update the hydraulic braking force response curve.

5. The electro-hydraulic braking force coordination control method according to claim 1, characterized in that, The step of pre-distributing braking force based on the hydraulic pressure build-up hysteresis and the vehicle state signal to obtain the pre-distributed electric braking force, and determining the initial hydraulic braking force based on the pre-distributed electric braking force, includes: The pre-allocated electric braking force is calculated based on the hydraulic pressure build-up hysteresis and the battery state of charge, motor temperature and road adhesion coefficient obtained based on the vehicle state signal through a pre-allocation algorithm. The hydraulic pressure build-up hysteresis is positively correlated with the pre-allocated electric braking force. When the battery state of charge is higher than a preset threshold or the motor temperature exceeds a preset safety range, the pre-allocated electric braking force is reduced. The difference between the target braking torque and the pre-allocated electric braking force is used as the initial hydraulic braking force, wherein the pre-allocated electric braking force does not exceed the maximum braking force of the motor, and the initial hydraulic braking force does not exceed the maximum hydraulic braking force.

6. The electro-hydraulic braking force coordination control method according to claim 1, characterized in that, The method further includes: The actual electric braking force and the actual hydraulic braking force are collected in real time, and the actual total braking torque is determined based on the actual electric braking force and the actual hydraulic braking force. Calculate the deviation between the actual total braking torque and the target braking torque; When the deviation exceeds the preset allowable range, the correction amount is calculated through a closed-loop feedback adjustment algorithm. The distribution of electric braking force and hydraulic braking force is dynamically adjusted based on the correction amount, and the braking force commands corresponding to the corrected electric braking force and the corrected hydraulic braking force are output to the corresponding actuators.

7. The electro-hydraulic braking force coordination control method according to claim 6, characterized in that, The dynamic adjustment of the distribution of electric braking force and hydraulic force based on the correction amount includes: Based on the braking force correction amount and the preset first and second allocation coefficients, the electric braking force correction component and the hydraulic braking force correction component are calculated respectively. The current electric braking force is corrected according to the electric braking force correction component to obtain the corrected electric braking force; The current hydraulic braking force is corrected based on the hydraulic braking force correction component to obtain the corrected hydraulic braking force.

8. An electro-hydraulic braking force coordination control device, characterized in that, include: The signal acquisition module is used to acquire braking operation signals and vehicle status signals; A braking torque determination module is used to determine the target braking torque based on the braking operation signal and the vehicle status signal; The model prediction module is used to call the electro-hydraulic braking dynamic response time-domain model based on the vehicle state signal and make predictions through the model prediction control algorithm to obtain the hydraulic pressure build-up hysteresis. The braking force pre-distribution module is used to pre-distribute the braking force according to the hydraulic pressure build-up hysteresis and the vehicle status signal to obtain the pre-distributed electric braking force, and to determine the initial hydraulic braking force according to the pre-distributed electric braking force. The command output module is used to output the power commands corresponding to the pre-allocated electro-hydraulic braking force and the initial hydraulic braking force to the corresponding actuators to complete the coordinated control of electro-hydraulic braking force.

9. An electronic device, characterized in that, It includes a data acquisition unit, a memory, and a processor, wherein the data acquisition unit is used to acquire braking operation signals and vehicle status signals; The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the electro-hydraulic braking force coordination control method according to any one of claims 1 to 7.

10. An electro-hydraulic braking force coordination control system, characterized in that, The electro-hydraulic braking force coordination control system includes the electronic device, data acquisition device, and result output device as described in claim 9. The data acquisition device and the result output device are respectively connected to the electronic device. The data acquisition device is used to acquire braking operation signals and vehicle status signals. The result output device is used to output and execute electro-hydraulic braking force coordination control.

Images