A vehicle brake-by-wire system and method

Abstract

This invention provides a vehicle brake-by-wire system and method, belonging to the field of vehicle braking technology. It includes: a dynamic load monitoring module installed in the power supply circuit of a high-speed switching valve and an EPB DC motor, used to collect voltage and current fluctuation signals at the load end in real time and input these signals to a central control unit; a central control unit, used to calculate and output voltage and current adjustment commands in real time based on a preset load-output mapping model and an adaptive adjustment algorithm; and a DC / DC converter, used to dynamically adjust the output voltage and current according to the voltage adjustment commands and current compensation parameters to match the valve response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor. This ensures that the dynamic response performance meets the control requirements of the high-precision actuator.

Description

Technical Field

[0001] This invention relates to the field of vehicle braking technology, and in particular to a vehicle brake-by-wire system and method. Background Technology

[0002] In vehicle brake-by-wire systems, high-speed switching valves and EPB (electronic parking brake) DC motors are key actuators, and their stable operation directly affects the braking system's response accuracy and parking safety. The high-speed switching valve needs to complete valve opening and closing within microseconds to achieve precise brake pressure regulation, while the EPB motor needs to frequently start and stop to respond to parking / release commands. The combined load of these two components exhibits typical high-frequency transient characteristics (current change rate can reach over 50A / ms), placing stringent requirements on the dynamic response capability of the power supply system.

[0003] In existing technologies, although some solutions attempt to introduce adaptive control, none of them have achieved multi-sensor fusion processing of load signals, and they lack joint modeling of the throttling effect of high-speed valves and the electromagnetic transient process of motors, resulting in dynamic response performance that cannot meet the control requirements of high-precision actuators.

[0004] Therefore, the present invention proposes a vehicle brake-by-wire system and method. Summary of the Invention

[0005] This invention provides a vehicle brake-by-wire system and method to solve the aforementioned technical problems.

[0006] This invention provides a vehicle brake-by-wire system, comprising:

[0007] A dynamic load monitoring module is installed in the power supply circuit of the high-speed switching valve and the EPB DC motor to collect the voltage and current fluctuation signals at the load end in real time and input the fluctuation signals to the central control unit.

[0008] The central control unit is used to calculate and output voltage adjustment commands and current adjustment commands in real time based on a preset load-output mapping model and an adaptive adjustment algorithm.

[0009] A DC / DC converter is used to dynamically adjust the output voltage and current according to the voltage adjustment command and current compensation parameters to match the valve response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor.

[0010] Preferably, it also includes: integrating no less than 8 voltage monitoring channels in the power management chip, with each monitoring channel corresponding to the power supply of different subsystems of the vehicle;

[0011] Each monitoring channel independently collects the input voltage, output voltage, and ripple coefficient of the corresponding power supply and transmits them to the power management unit in real time.

[0012] The power management unit is used to trigger a fault diagnosis program when the parameters of a corresponding power supply exceed a preset safety threshold, determine the fault type, and perform fault tolerance processing. The fault tolerance processing includes isolating the faulty power supply channel, switching to a backup power supply, or issuing a fault warning signal.

[0013] Preferred options also include:

[0014] Sensors deployed in various vehicle subsystems are used to collect real-time operating status parameters of each subsystem and input them into the AI ​​algorithm module integrated in the power management chip.

[0015] The AI ​​algorithm module is used to establish a load demand prediction model by analyzing historical and real-time data, analyze the operating status parameters, and predict future load demand.

[0016] The power management chip is used to dynamically adjust the operating mode of each power supply channel based on the prediction results, and switches to a low-power mode when the load demand is low.

[0017] Preferred options also include:

[0018] An FPU floating-point arithmetic unit and a DSP digital signal processor acceleration module are integrated into the main control MCU to build a high-speed computing platform;

[0019] The acceleration module is used to optimize the PID control algorithm and the filtering algorithm. The FPU floating-point unit is responsible for high-speed floating-point operations, and the DSP digital signal processor acceleration module performs fast filtering processing on the sensor signals.

[0020] The main control MCU outputs the processed control signals to each actuator in real time.

[0021] Preferred options also include:

[0022] Load sensors and vehicle speed sensors are used to acquire vehicle load information and driving status information in real time;

[0023] The control unit of the hydraulic pump station is used to receive vehicle load information and driving status information, and dynamically adjust the speed and displacement of the hydraulic pump using an adaptive algorithm and according to the preset mapping relationship between the hydraulic pump working parameters and the vehicle status.

[0024] The pressure sensor installed on the accumulator is used to monitor the pressure changes of the accumulator in real time. When the pressure drops below the preset leakage threshold, the leakage compensation mechanism is triggered, and the hydraulic pump is controlled to replenish hydraulic oil to the accumulator.

[0025] Preferred options also include:

[0026] Four high-speed switching valves corresponding to the four control axes of the vehicle braking system are installed in the high-speed valve block;

[0027] The central control unit is used to calculate the opening time, opening angle and flow distribution ratio of each high-speed switching valve according to the braking mode requirements of slip ratio control and braking force distribution control, and to synchronously control the four high-speed switching valves.

[0028] Preferred options also include:

[0029] A pressure sensor is installed at the output end of the high-speed valve block, and a displacement sensor is installed on the valve disc to collect braking pressure signals and valve disc displacement signals in real time.

[0030] The central control unit is used to compare the brake pressure signal and the valve displacement signal with the corresponding preset target values ​​to calculate the control deviation.

[0031] The central control unit is also used to adjust the control signal of the high-speed switching valve in real time according to the control deviation using a PID control algorithm, forming a closed-loop control system.

[0032] Preferred options also include:

[0033] A temperature sensor installed in the hydraulic pump station is used to collect the hydraulic oil temperature in real time;

[0034] The central control unit is also used to correct the hydraulic pump's operating parameter adjustment strategy based on the viscosity-temperature characteristic curve of the hydraulic oil, so that the hydraulic pump can maintain optimal operating conditions under different temperature environments.

[0035] Preferably, the central control unit includes:

[0036] Equation-constructing sub-units are used to represent the combined load of the high-speed switching valve and the EPB DC motor as an equivalent time-varying impedance network, constructing the state-space equations:

[0037]

[0038] in, It is the inductor current; This refers to the output voltage. For filtering inductors; For output capacitor; The equivalent resistance of the time-varying load; This represents the real-time load current. The controller output voltage;

[0039] A model reference adaptive control architecture is adopted, and the output voltage of the reference model is defined. satisfy:

[0040]

[0041]

[0042] in, Reference temperature The inherent attenuation coefficient under these conditions; The temperature coefficient of inductance; Frequency deviation Gaussian corrected standard deviation; This represents the frequency at the k-th time point; To set the frequency; This represents the temperature at time k. This is a temperature correction term; For frequency correction; These are the reference model output voltages at time k and time (k+1), respectively.

[0043] Determine the actual model output voltage Voltage deviation from reference model And by adjusting the control parameters in real time, the deviation is made to meet the Lyapunov stability condition;

[0044] The duty cycle determination unit is used to calculate the duty cycle adjustment at time k+1 based on the real-time identified load parameters using a nonlinear predictive control algorithm. ;

[0045] in, This is the duty cycle adjustment amount at time k-1; , , These are the adjustment ratio coefficients; These are the voltage deviations at time k and time (k-1), respectively.

[0046] The instruction determination unit is used to determine voltage adjustment instructions and current adjustment instructions.

[0047]

[0048] in, Input voltage; This is the dynamic compensation coefficient for the current. This is the maximum air ratio adjustment amount; , These are the adjusted voltage and current, respectively.

[0049] This invention provides a vehicle brake-by-wire method, comprising:

[0050] Step 1: Based on the dynamic load monitoring module set in the power supply circuit of the high-speed switching valve and the EPB DC motor, the voltage and current fluctuation signals at the load end are collected in real time, and the fluctuation signals are input to the central control unit.

[0051] Step 2: Based on the central control unit and combined with the preset load-output mapping model, use the adaptive adjustment algorithm to calculate and output voltage adjustment commands and current adjustment commands in real time;

[0052] Step 3: Based on the DC / DC converter and according to the voltage adjustment command and current compensation parameters, dynamically adjust the output voltage and current to match the valve orifice response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor.

[0053] Compared with the prior art, the beneficial effects of this application are as follows:

[0054] Through a four-layer technical architecture of multi-dimensional monitoring, intelligent algorithms, hardware acceleration, and collaborative control, the dynamic response performance meets the control requirements of high-precision actuators.

[0055] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0056] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0057] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0058] Figure 1 This is a structural diagram of a vehicle brake-by-wire system according to an embodiment of the present invention;

[0059] Figure 2 This is a structural diagram of a vehicle brake-by-wire method according to an embodiment of the present invention. Detailed Implementation

[0060] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0061] This invention provides a vehicle brake-by-wire system, such as... Figure 1 As shown, it includes:

[0062] A dynamic load monitoring module is installed in the power supply circuit of the high-speed switching valve and the EPB DC motor to collect the voltage and current fluctuation signals at the load end in real time and input the fluctuation signals to the central control unit.

[0063] The central control unit is used to calculate and output voltage adjustment commands and current adjustment commands in real time based on a preset load-output mapping model and an adaptive adjustment algorithm.

[0064] A DC / DC converter is used to dynamically adjust the output voltage and current according to the voltage adjustment command and current compensation parameters to match the valve response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor.

[0065] Preferably, it also includes: integrating no less than 8 voltage monitoring channels in the power management chip, with each monitoring channel corresponding to the power supply of different subsystems of the vehicle;

[0066] Each monitoring channel independently collects the input voltage, output voltage, and ripple coefficient of the corresponding power supply and transmits them to the power management unit in real time.

[0067] The power management unit is used to trigger a fault diagnosis program when the parameters of a corresponding power supply exceed a preset safety threshold, determine the fault type, and perform fault tolerance processing. The fault tolerance processing includes isolating the faulty power supply channel, switching to a backup power supply, or issuing a fault warning signal.

[0068] Preferred options also include:

[0069] Sensors deployed in various vehicle subsystems are used to collect real-time operating status parameters of each subsystem and input them into the AI ​​algorithm module integrated in the power management chip.

[0070] The AI ​​algorithm module is used to establish a load demand prediction model by analyzing historical and real-time data, analyze the operating status parameters, and predict future load demand.

[0071] The power management chip is used to dynamically adjust the operating mode of each power supply channel based on the prediction results, and switches to a low-power mode when the load demand is low.

[0072] Preferred options also include:

[0073] An FPU floating-point arithmetic unit and a DSP digital signal processor acceleration module are integrated into the main control MCU to build a high-speed computing platform;

[0074] The acceleration module is used to optimize the PID control algorithm and the filtering algorithm. The FPU floating-point unit is responsible for high-speed floating-point operations, and the DSP digital signal processor acceleration module performs fast filtering processing on the sensor signals.

[0075] The main control MCU outputs the processed control signals to each actuator in real time.

[0076] Preferred options also include:

[0077] Load sensors and vehicle speed sensors are used to acquire vehicle load information and driving status information in real time;

[0078] The control unit of the hydraulic pump station is used to receive vehicle load information and driving status information, and dynamically adjust the speed and displacement of the hydraulic pump using an adaptive algorithm and according to the preset mapping relationship between the hydraulic pump working parameters and the vehicle status.

[0079] The pressure sensor installed on the accumulator is used to monitor the pressure changes of the accumulator in real time. When the pressure drops below the preset leakage threshold, the leakage compensation mechanism is triggered, and the hydraulic pump is controlled to replenish hydraulic oil to the accumulator.

[0080] Preferred options also include:

[0081] Four high-speed switching valves corresponding to the four control axes of the vehicle braking system are installed in the high-speed valve block;

[0082] The central control unit is used to calculate the opening time, opening angle and flow distribution ratio of each high-speed switching valve according to the braking mode requirements of slip ratio control and braking force distribution control, and to synchronously control the four high-speed switching valves.

[0083] Preferred options also include:

[0084] A pressure sensor is installed at the output end of the high-speed valve block, and a displacement sensor is installed on the valve disc to collect braking pressure signals and valve disc displacement signals in real time.

[0085] The central control unit is used to compare the brake pressure signal and the valve displacement signal with the corresponding preset target values ​​to calculate the control deviation.

[0086] The central control unit is also used to adjust the control signal of the high-speed switching valve in real time according to the control deviation using a PID control algorithm, forming a closed-loop control system.

[0087] Preferred options also include:

[0088] A temperature sensor installed in the hydraulic pump station is used to collect the hydraulic oil temperature in real time;

[0089] The central control unit is also used to correct the hydraulic pump's operating parameter adjustment strategy based on the viscosity-temperature characteristic curve of the hydraulic oil, so that the hydraulic pump can maintain optimal operating conditions under different temperature environments.

[0090] In this embodiment, the dynamic load monitoring module is integrated into the hardware unit of the power supply circuit, including a high-precision current sensor (such as a Hall effect sensor with an accuracy of ±0.5%), a voltage sampling circuit (sampling rate ≥100kHz), and a signal conditioning chip, which are used to capture the fluctuation of electrical parameters at the load end in real time.

[0091] In this embodiment, the central control unit (CCU) is the core processor of the vehicle's brake-by-wire system. It typically employs a high-performance MCU (such as the Infineon AURIX series), integrating an ARM Cortex-A core and dedicated control peripherals. It runs a load-output mapping model and adaptive algorithm, comparing it with the fixed-parameter control logic in traditional solutions, to achieve real-time calculation of dynamically adjusted parameters.

[0092] In this embodiment, the load-output mapping model is a mathematical model based on the throttling characteristics of the high-speed switching valve (valve opening-resistance curve) and the electromagnetic characteristics of the EPB motor (torque-current curve). It typically uses neural networks or state-space equations to describe the mapping relationship between load changes and power supply output.

[0093] In this embodiment, the adaptive adjustment algorithm is a composite algorithm that integrates Model Reference Adaptive Control (MRAC) and Particle Swarm Optimization (PSO) to identify load parameters (such as equivalent resistance and inductance) in real time and optimize PID control parameters.

[0094] In this embodiment, the DC / DC converter is a power conversion circuit that converts the voltage of a DC power supply into another DC voltage. This solution adopts a synchronous rectification Buck-Boost topology, with a switching frequency of over 100kHz. The output voltage (accuracy ±0.5%) and current (response time <50μs) are dynamically adjusted according to the instructions of the central control unit to match the dynamic requirements of the high-speed switching valve (response time <50μs) and the EPB motor (current change rate 50A / ms).

[0095] In this embodiment, the power management chip (PMIC) is a dedicated chip that integrates multiple power monitoring and management functions. This solution requires the integration of ≥8 independent monitoring channels (such as TI's TPS65987) to support the synchronous acquisition of parameters such as voltage, ripple, and temperature.

[0096] In this embodiment, the AI ​​algorithm module is a software module based on deep learning neural networks (such as LSTM models), deployed in the embedded processor of the power management chip, and trains the load prediction model through historical data (such as vehicle driving conditions and load current curves).

[0097] In this embodiment, the FPU (Floating Point Unit) is a hardware unit integrated into the MCU, which is dedicated to handling floating point operations (such as trigonometric functions and exponential operations in PID parameter calculation), and the operation speed can reach more than 1 GFLOPS.

[0098] In this embodiment, the DSP (Digital Signal Processor) acceleration module is a hardware module with a dedicated multiply-accumulate unit (MAC), supporting algorithms such as Fast Fourier Transform (FFT) and digital filtering, with a processing speed of up to 200 MFLOPS. It performs real-time filtering (such as Kalman filtering) on ​​sensor signals (e.g., pressure, displacement).

[0099] In this embodiment, the hydraulic pump station control unit is a distributed controller independent of the central control unit. It typically adopts an MCU + driver chip architecture to receive signals such as load and vehicle speed and control the operating parameters of the hydraulic pump (such as a gear pump or piston pump).

[0100] In this embodiment, the accumulator is a device for storing hydraulic energy, consisting of a pressure-resistant container and elastic elements (such as airbags), used to compensate for system leakage and stabilize pressure.

[0101] In this embodiment, the high-speed valve block integrates a hydraulic control unit for four high-speed switching valves. Each valve corresponds to the braking circuit of one wheel of the vehicle. The valve port response time is <50μs, and the operating frequency can reach 20kHz.

[0102] In this embodiment, the hydraulic oil temperature sensor uses a PT100 or NTC thermistor, with a measurement range of -40℃ to 125℃ and an accuracy of ±1℃, to monitor the hydraulic oil temperature in real time.

[0103] Specifically, when a vehicle is traveling at 80 km / h on a dry road, the driver suddenly presses the brake pedal, triggering the ABS anti-lock braking system to intervene.

[0104] In this embodiment, dynamic load monitoring and power supply regulation are implemented: a high-speed switching valve rapidly opens and closes (valve opening dynamically adjusts from 100% to 20% to 80%), the EPB motor synchronously starts parking assistance, and the combined load current surges from 5A to 15A within 50μs. The dynamic load monitoring module collects voltage (fluctuating from 12V to 11.5V) and current signals at a sampling rate of 100kHz and inputs them to the central control unit. The central control unit, based on a load-output mapping model (integrating the time-varying characteristics of valve resistance and the motor back EMF), calculates the duty cycle adjustment (ΔD=0.15) using an adaptive algorithm, instructing the DC / DC converter to stabilize the output voltage at 12V±0.1V with a current response time of <20μs, avoiding the problem of voltage drops exceeding 10% in traditional solutions. The power management chip's 8 monitoring channels monitor the ABS pump power supply, EPB power supply, etc., in real time. If the ABS pump power supply ripple coefficient exceeds the threshold (>5%), the faulty channel is immediately isolated and switched to the backup power supply, with a time of <200ms, mitigating the risk of system paralysis due to a single power supply failure in the background technology. The AI ​​algorithm module predicts a surge in load demand within 200ms based on sudden drops in vehicle speed and braking signal triggering, proactively maintaining a high-power supply mode to avoid power delays caused by traditional fixed threshold switching. A load sensor (measurement accuracy ±5%) detects the vehicle's full-load status, and the hydraulic pump station control unit uses an adaptive algorithm to increase the hydraulic pump speed from 2000rpm to 3000rpm, and the output pressure from 8MPa to 12MPa, matching the braking demand under heavy loads, improving energy utilization by 30% compared to traditional fixed speed control. The central control unit synchronously controls four high-speed switching valves, calculating the opening time difference (<10μs) based on the slip ratio of each wheel (left front wheel 15%, right front wheel 18%), achieving dynamic distribution of braking force and improving braking stability by 40% compared to traditional independent control. A pressure sensor (accuracy ±0.5%) provides real-time feedback on braking pressure, and the central control unit uses PID closed-loop control to correct valve opening, improving pressure control accuracy to ±1%, solving the problem of large open-loop control errors in the background technology. The hydraulic oil temperature sensor detects an oil temperature of 40℃. The central control unit adjusts the hydraulic pump displacement compensation coefficient (+5%) based on the viscosity-temperature characteristic curve to prevent leakage caused by viscosity decrease due to increased oil temperature. System pressure fluctuations are controlled within ±3%. The main control MCU's FPU accelerates floating-point calculations of PID parameters (e.g., trigonometric function calculation time is reduced from 15μs to 3μs), and the DSP module performs fast filtering of the wheel speed signal (cutoff frequency 500Hz). The overall control cycle is shortened from 100μs to 25μs, and the response speed is improved by 4 times.

[0105] The beneficial effects of the above technical solution are: through a four-layer technical architecture of multi-dimensional monitoring, intelligent algorithms, hardware acceleration, and collaborative control, the dynamic response performance meets the control requirements of high-precision actuators.

[0106] This invention provides a vehicle brake-by-wire system, wherein the central control unit includes:

[0107] Equation-constructing sub-units are used to represent the combined load of the high-speed switching valve and the EPB DC motor as an equivalent time-varying impedance network, constructing the state-space equations:

[0108]

[0109] in, It is the inductor current; This refers to the output voltage. For filtering inductors; For output capacitor; The equivalent resistance of the time-varying load; This represents the real-time load current. The controller output voltage;

[0110] A model reference adaptive control architecture is adopted, and the output voltage of the reference model is defined. satisfy:

[0111]

[0112]

[0113] in, Reference temperature The inherent attenuation coefficient under these conditions; The temperature coefficient of inductance; Frequency deviation Gaussian corrected standard deviation; This represents the frequency at the k-th time point; To set the frequency; This represents the temperature at time k. This is a temperature correction term; For frequency correction; These are the reference model output voltages at time k and time (k+1), respectively.

[0114] Determine the actual model output voltage Voltage deviation from reference model And by adjusting the control parameters in real time, the deviation is made to meet the Lyapunov stability condition;

[0115] The duty cycle determination unit is used to calculate the duty cycle adjustment at time k+1 based on the real-time identified load parameters using a nonlinear predictive control algorithm. ;

[0116] in, This is the duty cycle adjustment amount at time k-1; , , These are the adjustment ratio coefficients; These are the voltage deviations at time k and time (k-1), respectively.

[0117] The instruction determination unit is used to determine voltage adjustment instructions and current adjustment instructions.

[0118]

[0119] in, Input voltage; This is the dynamic compensation coefficient for the current. This is the maximum air ratio adjustment amount; , These are the adjusted voltage and current, respectively.

[0120] In this embodiment, for the time-varying throttling impedance of the high-speed switching valve (the dynamic change of valve opening causes the equivalent resistance to fluctuate by 30%-50%) and the transient current oscillation of the EPB motor, a state-space equation of the time-varying impedance network is innovatively constructed. The fluid characteristics of the hydraulic valve and the electromagnetic characteristics of the motor are modeled in a unified manner, which solves the core defect that the traditional fixed load model cannot describe the high-frequency transient process and improves the accuracy of the characterization of the load dynamic characteristics by 40%.

[0121] The beneficial effects of the above technical solution are: through the deep integration of physical mechanism modeling and control theory, the bottleneck of power supply control under high-frequency transient loads has been broken, providing core technical support for the high-precision and high-reliability operation of vehicle braking systems.

[0122] This invention provides a vehicle brake-by-wire method, such as... Figure 2 As shown, it includes:

[0123] Step 1: Based on the dynamic load monitoring module set in the power supply circuit of the high-speed switching valve and the EPB DC motor, the voltage and current fluctuation signals at the load end are collected in real time, and the fluctuation signals are input to the central control unit.

[0124] Step 2: Based on the central control unit and combined with the preset load-output mapping model, use the adaptive adjustment algorithm to calculate and output voltage adjustment commands and current adjustment commands in real time;

[0125] Step 3: Based on the DC / DC converter and according to the voltage adjustment command and current compensation parameters, dynamically adjust the output voltage and current to match the valve orifice response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor.

[0126] The beneficial effects of the above technical solution are: through a four-layer technical architecture of multi-dimensional monitoring, intelligent algorithms, hardware acceleration, and collaborative control, the dynamic response performance meets the control requirements of high-precision actuators.

[0127] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A vehicle brake-by-wire system, characterized in that, include: A dynamic load monitoring module is installed in the power supply circuit of the high-speed switching valve and the EPB DC motor to collect the voltage and current fluctuation signals at the load end in real time and input the fluctuation signals to the central control unit. The central control unit is used to calculate and output voltage adjustment commands and current adjustment commands in real time based on a preset load-output mapping model and an adaptive adjustment algorithm. A DC / DC converter is used to dynamically adjust the output voltage and current according to the voltage adjustment command and current compensation parameters to match the valve orifice response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor. The central control unit includes: Equation-constructing sub-units are used to represent the combined load of the high-speed switching valve and the EPB DC motor as an equivalent time-varying impedance network, constructing the state-space equations: in, It is the inductor current; This refers to the output voltage. For filtering inductors; For output capacitor; The equivalent resistance of the time-varying load; This represents the real-time load current. The controller output voltage; A model reference adaptive control architecture is adopted, and the output voltage of the reference model is defined. satisfy: in, Reference temperature The inherent attenuation coefficient under these conditions; The temperature coefficient of inductance; Frequency deviation Gaussian corrected standard deviation; This represents the frequency at the k-th time point; To set the frequency; This represents the temperature at time k. This is a temperature correction term; For frequency correction; These are the reference model output voltages at time k and time (k+1), respectively. Determine the actual model output voltage Voltage deviation from reference model And by adjusting the control parameters in real time, the deviation is made to meet the Lyapunov stability condition; The duty cycle determination unit is used to calculate the duty cycle adjustment at time k+1 based on the real-time identified load parameters using a nonlinear predictive control algorithm. ; in, This is the duty cycle adjustment amount at time k-1; , , These are the adjustment ratio coefficients; These are the voltage deviations at time k and time (k-1), respectively. The instruction determination unit is used to determine voltage adjustment instructions and current adjustment instructions. in, Input voltage; This is the dynamic compensation coefficient for the current. This is the maximum air ratio adjustment amount; , These are the adjusted voltage and current, respectively.

2. The vehicle brake-by-wire system according to claim 1, characterized in that, Also includes: The power management chip integrates no fewer than 8 voltage monitoring channels, each corresponding to the power supply of different subsystems of the vehicle. Each monitoring channel independently collects the input voltage, output voltage, and ripple coefficient of the corresponding power supply and transmits them to the power management unit in real time. The power management unit is used to trigger a fault diagnosis program when the parameters of a corresponding power supply exceed a preset safety threshold, determine the fault type, and perform fault tolerance processing. The fault tolerance processing includes isolating the faulty power supply channel, switching to a backup power supply, or issuing a fault warning signal.

3. The vehicle brake-by-wire system according to claim 1, characterized in that, Also includes: Sensors deployed in various vehicle subsystems are used to collect real-time operating status parameters of each subsystem and input them into the AI ​​algorithm module integrated in the power management chip. The AI ​​algorithm module is used to establish a load demand prediction model by analyzing historical and real-time data, analyze the operating status parameters, and predict future load demand. The power management chip is used to dynamically adjust the operating mode of each power supply channel based on the prediction results, and switches to a low-power mode when the load demand is low.

4. The vehicle brake-by-wire system according to claim 3, characterized in that, Also includes: An FPU floating-point arithmetic unit and a DSP digital signal processor acceleration module are integrated into the main control MCU to build a high-speed computing platform; The acceleration module is used to optimize the PID control algorithm and the filtering algorithm. The FPU floating-point unit is responsible for high-speed floating-point operations, and the DSP digital signal processor acceleration module performs fast filtering processing on the sensor signals. The main control MCU outputs the processed control signals to each actuator in real time.

5. The vehicle brake-by-wire system according to claim 4, characterized in that, Also includes: Load sensors and vehicle speed sensors are used to acquire vehicle load information and driving status information in real time; The control unit of the hydraulic pump station is used to receive vehicle load information and driving status information, and dynamically adjust the speed and displacement of the hydraulic pump using an adaptive algorithm and according to the preset mapping relationship between the hydraulic pump working parameters and the vehicle status. The pressure sensor installed on the accumulator is used to monitor the pressure changes of the accumulator in real time. When the pressure drops below the preset leakage threshold, the leakage compensation mechanism is triggered, and the hydraulic pump is controlled to replenish hydraulic oil to the accumulator.

6. The vehicle brake-by-wire system according to claim 5, characterized in that, Also includes: Four high-speed switching valves corresponding to the four control axes of the vehicle braking system are installed in the high-speed valve block; The central control unit is used to calculate the opening time, opening angle and flow distribution ratio of each high-speed switching valve according to the braking mode requirements of slip ratio control and braking force distribution control, and to synchronously control the four high-speed switching valves.

7. The vehicle brake-by-wire system according to claim 6, characterized in that, Also includes: A pressure sensor is installed at the output end of the high-speed valve block, and a displacement sensor is installed on the valve disc to collect braking pressure signals and valve disc displacement signals in real time. The central control unit is used to compare the brake pressure signal and the valve displacement signal with the corresponding preset target values ​​to calculate the control deviation. The central control unit is also used to adjust the control signal of the high-speed switching valve in real time according to the control deviation using a PID control algorithm, forming a closed-loop control system.

8. The vehicle brake-by-wire system according to claim 1, characterized in that, Also includes: A temperature sensor installed in the hydraulic pump station is used to collect the hydraulic oil temperature in real time; The central control unit is also used to correct the hydraulic pump's operating parameter adjustment strategy based on the viscosity-temperature characteristic curve of the hydraulic oil, so that the hydraulic pump can maintain optimal operating conditions under different temperature environments.

9. A vehicle brake-by-wire method, applied to the vehicle brake-by-wire system as described in any one of claims 1-8, characterized in that, include: Step 1: Based on the dynamic load monitoring module set in the power supply circuit of the high-speed switching valve and the EPB DC motor, the voltage and current fluctuation signals at the load end are collected in real time, and the fluctuation signals are input to the central control unit. Step 2: Based on the central control unit and combined with the preset load-output mapping model, use the adaptive adjustment algorithm to calculate and output voltage adjustment commands and current adjustment commands in real time; Step 3: Based on the DC / DC converter and according to the voltage adjustment command and current compensation parameters, dynamically adjust the output voltage and current to match the valve orifice response characteristics of the high-speed switching valve and the electromagnetic torque requirements of the EPB DC motor.

Images