Esos-based vehicle longitudinal control and disturbance compensation system

Abstract

The present application relates to the technical field of vehicle control, and discloses a vehicle longitudinal control and disturbance compensation system based on ESO, which comprises an acceleration estimation end, a disturbance compensation end, a parameter correction end and an auxiliary function end; the disturbance compensation end is used to estimate the comprehensive disturbance, including ramp resistance, air resistance and rolling resistance, in the process of vehicle driving in real time by using an extended state observer, and the estimated total disturbance value is compensated to the acceleration control instruction in a feedforward manner to offset the influence of external disturbance on the vehicle longitudinal dynamics and improve the suppression ability of the system to external disturbance; the acceleration estimation end is used to collect the wheel speed signal of the vehicle in real time, and the longitudinal acceleration of the vehicle is estimated based on the extended state observer, so that the real-time output longitudinal acceleration estimation value can inhibit the wheel speed signal differential noise of the vehicle longitudinal control instruction and ensure the smoothness and accuracy of the acceleration estimation.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, specifically to a vehicle longitudinal control and disturbance compensation system based on ESO. Background Technology

[0002] Currently, with the development of intelligent connected vehicles, the automotive industry is conducting in-depth research on key technologies for autonomous vehicles. Among them, the motion control system is a crucial component for realizing autonomous driving functions. Vehicle motion control includes the control of the vehicle's longitudinal and lateral motion states. The motion control system directly controls the vehicle's motion state, and the performance of the motion control directly affects the subjective driving experience of the passengers.

[0003] Currently, existing methods for estimating vehicle longitudinal acceleration rely on direct differential of wheel speed signals, which easily introduces differential noise and makes it difficult to meet the requirements of high-precision control. At the same time, there is a lack of effective real-time estimation and compensation mechanisms for external disturbances such as slope resistance, air resistance and rolling resistance encountered by vehicles during driving, which makes the control system's anti-interference capability insufficient under complex operating conditions. In addition, traditional extended state observers (ESOs) usually use fixed parameters, which are difficult to adapt to changes in vehicle dynamic characteristics under different loads and road conditions, resulting in limited system robustness and difficulty in maintaining stable and reliable control performance under all operating conditions.

[0004] Therefore, an ESO-based vehicle longitudinal control and disturbance compensation system is proposed to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a vehicle longitudinal control and disturbance compensation system based on ESO, which solves the problem mentioned in the background art of difficulty in maintaining stable and reliable control performance under all operating conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a vehicle longitudinal control and disturbance compensation system based on ESO, the system comprising an acceleration estimation terminal, a disturbance compensation terminal, a parameter correction terminal, and an auxiliary function terminal; The acceleration estimation terminal is used to estimate the longitudinal acceleration of the vehicle by acquiring the vehicle wheel speed signal in real time and based on the extended state observer. The longitudinal acceleration estimation value is output in real time to suppress the longitudinal control command of the vehicle from the differential noise of the wheel speed signal. The disturbance compensation end is used to estimate the comprehensive disturbances experienced by the vehicle during driving in real time through the extended state observer, including slope resistance, air resistance and rolling resistance, and to compensate the estimated total disturbance value to the acceleration control command in a feedforward manner to offset the influence of external disturbances on the longitudinal dynamics of the vehicle. The parameter correction terminal is used to perform online correction of the core parameters of the extended state observer according to the actual operating state of the vehicle, so as to adapt to the dynamic characteristics of the vehicle under different loads and road conditions and reduce the system's dependence on the accuracy of model parameter calibration. The auxiliary function terminal is used to integrate the auxiliary function modules required by the system.

[0007] Preferably, the acceleration estimation terminal includes a signal acquisition module, an observer construction module, and an acceleration calculation module; The signal acquisition module includes a wheel speed sensing unit and a period setting unit; The wheel speed sensing unit is used to collect the wheel speed pulse signals of the four wheels in real time through the vehicle CAN bus at a preset sampling period, and convert them into angular velocity signals. The period setting unit is used to set the value of the sampling period, which is the same as the vehicle CAN bus message update period.

[0008] Preferably, the observer construction module is used to construct a vehicle longitudinal dynamics model based on a linear extended state observer, specifically including a state equation establishment unit and an observation bandwidth setting unit; The state equation establishment unit is used to treat the longitudinal acceleration of the vehicle as a state variable and expand the lumped disturbance experienced by the vehicle into a new state variable, thereby establishing the state equation of the second-order linear extended state observer. The observation bandwidth setting unit is used to set the observation bandwidth parameter of the extended state observer. The range of the observation bandwidth determines the observer's response speed to state changes and its noise suppression capability. Its typical value range is determined according to the response frequency range of vehicle dynamics.

[0009] Preferably, the acceleration calculation module includes a state prediction unit and an estimation output unit; The state prediction unit is used to predict the vehicle state at the current moment in real time based on the state estimate value of the previous moment and the system input, using the discretized extended state observer equation. The vehicle state includes the vehicle's longitudinal acceleration and lumped disturbance. The estimation output unit is used to output the predicted longitudinal acceleration as a corrected estimated value. Compared with the acceleration value obtained by directly calculating the differential of the wheel speed signal, the estimated value has a reduced noise amplitude and improved time-domain smoothness.

[0010] Preferably, the disturbance compensation terminal includes a disturbance estimation module and a feedforward compensation module; The disturbance estimation module includes a disturbance extraction unit and a disturbance identification unit; The disturbance extraction unit is used to extract the lumped disturbance estimate expanded into state variables from the expanded state observer in real time. The lumped disturbance includes the sum of all unmodeled dynamics and external disturbances, including ramp drag, air drag, and rolling drag. The disturbance identification unit is used to decompose the extracted lumped disturbance estimate into air resistance components related to vehicle speed, slope resistance components related to road gradient, and rolling resistance components related to tire characteristics based on the vehicle dynamics equation, so as to facilitate subsequent targeted compensation.

[0011] Preferably, the feedforward compensation module includes a compensation amount calculation unit and an instruction correction unit; The compensation calculation unit is used to calculate an equivalent feedforward compensation torque to offset the total disturbance based on each disturbance component output by the disturbance identification unit. The instruction correction unit is used to superimpose the calculated feedforward compensation amount with the expected driving torque corresponding to the target acceleration instruction issued by the upper controller to form the corrected final execution instruction, which drives the braking system to generate the corresponding torque and actively feedforward compensates for the disturbance.

[0012] Preferably, the parameter correction terminal includes a performance monitoring module and a gain adjustment module; The performance monitoring module includes a residual calculation unit and an index evaluation unit; The residual calculation unit is used to calculate the residual between the actual measured wheel speed signal and the wheel speed signal predicted by the extended state observer in real time. The index evaluation unit is used to evaluate the estimation accuracy and convergence status of the current observer based on the statistical characteristics of the calculated residuals, and to determine whether the parameter correction process needs to be initiated.

[0013] Preferably, the gain adjustment module includes a bandwidth adaptive unit and a gain mapping unit; The bandwidth adaptive unit is used to dynamically adjust the observation bandwidth parameters of the extended state observer according to the evaluation indicators output by the performance monitoring module. When the system is in transient condition, the observation bandwidth needs to be increased to improve the response speed; when the system is in steady state condition, the observation bandwidth needs to be decreased to enhance the noise suppression capability. The gain mapping unit is used to store the mapping relationship between the observation bandwidth parameter and other gain coefficients of the extended state observer. Based on the adjusted observation bandwidth, the updated observer gain matrix is ​​obtained by looking up the table and the original gain is replaced in real time.

[0014] Preferably, the auxiliary function terminal includes a working condition discrimination unit and a verification and recording unit, wherein the working condition discrimination unit includes a road surface identification subunit and a load estimation subunit; The road surface recognition subunit is used to identify the type of road surface the vehicle is currently traveling on by analyzing the spectral characteristics of the wheel speed signal and the fluctuation amplitude of the acceleration estimate. This includes flat roads and bumpy roads. Under bumpy road conditions, an additional filtering algorithm is enabled to smooth the acceleration estimate in order to suppress high-frequency noise introduced by road excitation. The load estimation subunit is used to deduce the approximate current load state of the vehicle by using the long-term statistical mean of the lumped disturbance under steady-state conditions from the extended state observer, and sends this information to the parameter correction terminal as the basis for parameter initialization.

[0015] Preferably, the verification and recording unit includes an error statistics subunit and an effect evaluation subunit; The error statistics subunit is used to calculate the root mean square error between the acceleration estimate and the high-precision reference value under specific test conditions, and compare it with the error of the acceleration estimation scheme based on the traditional wheel speed difference method, and quantitatively record the accuracy improvement ratio of this system. The performance evaluation subunit is used to compare the control tracking error of the recorded vehicle speed and the change in acceleration estimation accuracy when the overall vehicle mass deviates, under both perturbation-compensated and non-perturbation-compensated modes, in order to comprehensively evaluate the robustness of the system to parameter perturbations and external disturbances, and store the evaluation results in the log for analysis.

[0016] Compared with the prior art, the present invention provides a vehicle longitudinal control and disturbance compensation system based on ESO, which has the following beneficial effects: 1. In this invention, when estimating the longitudinal acceleration of a vehicle, the vehicle wheel speed signal is collected in real time through the acceleration estimation terminal, and the longitudinal acceleration of the vehicle is estimated based on the extended state observer. The longitudinal acceleration estimation value is output in real time, which suppresses the longitudinal control command of the vehicle from the differential noise of the wheel speed signal and ensures the smoothness and accuracy of the acceleration estimation.

[0017] 2. In this invention, when performing longitudinal dynamics control of the vehicle, the comprehensive disturbances experienced by the vehicle during driving are estimated in real time by using an extended state observer through the disturbance compensation end. These disturbances include slope resistance, air resistance, and rolling resistance. The estimated total disturbance value is then compensated to the acceleration control command in a feedforward manner to offset the influence of external disturbances on the longitudinal dynamics of the vehicle and improve the system's ability to suppress external disturbances.

[0018] 3. In this invention, when tuning the parameters of the extended state observer, the core parameters of the extended state observer are calibrated online according to the actual operating state of the vehicle through the parameter calibration terminal to adapt to the dynamic characteristics changes of the vehicle under different loads and road conditions, reduce the system's dependence on the accuracy of model parameter calibration, and further optimize the system's adaptability through the road identification subunit and load estimation subunit in the auxiliary function terminal to ensure the robustness of the system under different working conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the vehicle longitudinal control and disturbance compensation system based on ESO of the present invention. Figure 2 This is a module architecture diagram of the acceleration estimation end in this invention; Figure 3 This is a flowchart illustrating the operational steps of the vehicle longitudinal control and disturbance compensation system based on ESO according to the present invention. Detailed Implementation

[0020] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] For specific implementation examples, please refer to: Figures 1-3 The vehicle longitudinal control and disturbance compensation system based on ESO includes an acceleration estimation end, a disturbance compensation end, a parameter correction end, and an auxiliary function end. The acceleration estimation end is used to estimate the longitudinal acceleration of the vehicle by acquiring the vehicle wheel speed signal in real time and based on the extended state observer. The real-time output of the longitudinal acceleration estimate value suppresses the vehicle longitudinal control command from the differential noise of the wheel speed signal. The disturbance compensation end is used to estimate the comprehensive disturbances experienced by the vehicle during driving in real time through the extended state observer, including slope resistance, air resistance and rolling resistance, and to compensate the estimated total disturbance value to the acceleration control command in a feedforward manner to offset the influence of external disturbances on the longitudinal dynamics of the vehicle. The parameter calibration terminal is used to perform online calibration of the core parameters of the extended state observer according to the actual operating state of the vehicle, so as to adapt to the dynamic characteristics of the vehicle under different loads and road conditions and reduce the system's dependence on the accuracy of model parameter calibration. The auxiliary function terminal is used to integrate the auxiliary function modules required by the system.

[0022] The acceleration estimation module includes a signal acquisition module, an observer construction module, and an acceleration calculation module. The signal acquisition module includes a wheel speed sensing unit and a period setting unit; The wheel speed sensing unit is used to collect the wheel speed pulse signals of the four wheels in real time through the vehicle's CAN bus at a preset sampling period and convert them into angular velocity signals. The specific formula for converting to angular velocity signal is as follows: ; in, For the first The angular velocity of each wheel For the first The number of pulses collected per wheel within one sampling period. The number of pulses generated per revolution of the wheel. The sampling period; The period setting unit is used to set the value of the sampling period, which is the same as the vehicle CAN bus message update period.

[0023] The observer building module is used to build a vehicle longitudinal dynamics model based on a linear extended state observer, specifically including a state equation establishment unit and an observation bandwidth setting unit; The state equation establishment unit is used to treat the longitudinal acceleration of the vehicle as a state variable and expand the lumped disturbances experienced by the vehicle into a new state variable, thereby establishing the state equation of the second-order linear extended state observer. The specific steps for establishing the state equation of a second-order linear extended state observer are as follows: First, the vehicle's longitudinal velocity is selected as the first state variable, incorporating the combination of the vehicle's longitudinal acceleration and lumped disturbances into the system dynamics. Next, the sum of all unmodeled dynamics and external disturbances experienced by the vehicle during its movement is expanded into a second state variable, considered as a new unknown state. Based on this, the state equation for a second-order linear extended state observer is established as follows: ; in, For the longitudinal speed of the vehicle, The longitudinal acceleration corresponding to the system control input. The expanded state represents the lumped disturbance. Let be the rate of change of the lumped disturbance; The observation bandwidth setting unit is used to set the observation bandwidth parameter of the extended state observer. The range of the observation bandwidth determines the observer's response speed to state changes and its noise suppression capability. Its typical value range is determined according to the response frequency range of vehicle dynamics.

[0024] The acceleration calculation module includes a state prediction unit and an estimation output unit; The state prediction unit is used to predict the vehicle state at the current moment in real time based on the state estimate of the previous moment and the system input, using the discretized extended state observer equation. The vehicle state includes the vehicle's longitudinal acceleration and lumped disturbance. The specific formula for the discretized extended state observer equation is as follows: ; ; in, This is the estimated longitudinal velocity at the current moment. This is the estimated value of the lumped disturbance at the current moment. The sampling period is To control the approximate value of the input gain, This is the estimated longitudinal velocity value from the previous moment. This is the estimated value of the lumped disturbance from the previous moment. This is the estimated longitudinal acceleration value from the previous moment. This is the system control input from the previous moment. This is the measured wheel speed signal from the previous moment. The wheel speed signal predicted by the extended state observer at the previous moment. , is the observer gain coefficient.

[0025] The estimation output unit is used to output the predicted longitudinal acceleration as a corrected estimate, which has a reduced noise amplitude and improved time-domain smoothness compared to the acceleration value obtained by directly differentially calculating the wheel speed signal. The acceleration value obtained by directly calculating the difference between the wheel speed signals is given by the following formula: ; in, This is the longitudinal acceleration value calculated using the finite difference method at the current moment. This is the wheel speed signal actually measured at the current moment. This is the wheel speed signal actually measured at the previous moment. The sampling period.

[0026] The disturbance compensation module includes a disturbance estimation module and a feedforward compensation module; The disturbance estimation module includes a disturbance extraction unit and a disturbance identification unit; The disturbance extraction unit is used to extract in real time the lumped disturbance estimate expanded into state variables from the expanded state observer. The lumped disturbance includes the sum of all unmodeled dynamics and external disturbances, including ramp drag, air drag, and rolling drag. The disturbance identification unit is used to decompose the extracted lumped disturbance estimate into air resistance components related to vehicle speed, slope resistance components related to road gradient, and rolling resistance components related to tire characteristics based on the vehicle dynamics equations, so as to facilitate subsequent targeted compensation.

[0027] The feedforward compensation module includes a compensation amount calculation unit and an instruction correction unit; The compensation calculation unit is used to calculate an equivalent feedforward compensation torque to offset the total disturbance based on each disturbance component output by the disturbance identification unit. The specific formula for calculating the equivalent feedforward compensation torque used to offset the total disturbance is as follows: ; in, For equivalent feedforward compensation torque, The radius of the wheel's rolling motion. For air resistance components, For the slope resistance component, This is the rolling resistance component; The command correction unit is used to superimpose the calculated feedforward compensation amount with the expected driving torque corresponding to the target acceleration command issued by the upper controller to form the corrected final execution command, which drives the braking system to generate the corresponding torque and actively feedforward compensates for the disturbance. The specific formula for superimposing the calculated feedforward compensation amount with the desired driving torque corresponding to the target acceleration command issued by the upper-level controller is as follows: ; in, The driving torque corresponding to the final executed command after correction. The desired driving torque corresponding to the target acceleration command. This is the equivalent feedforward compensation torque.

[0028] The parameter calibration module includes a performance monitoring module and a gain adjustment module; The performance monitoring module includes a residual calculation unit and an index evaluation unit; The residual calculation unit is used to calculate the residual between the actual measured wheel speed signal and the wheel speed signal predicted by the extended state observer in real time. The specific formula for calculating the residual between the actual measured wheel speed signal and the wheel speed signal predicted by the extended state observer is as follows: ; in, The residual at the current moment, This is the wheel speed signal actually measured at the current moment. The wheel speed signal predicted by the extended state observer at the current moment; The indicator evaluation unit is used to evaluate the estimation accuracy and convergence status of the current observer based on the statistical characteristics of the calculated residuals, and to determine whether the parameter correction process needs to be initiated. The specific steps for determining whether to initiate the parameter calibration process are as follows: First, calculate the root mean square value of the residual sequence over a period of time; then, compare this statistical indicator with a preset threshold; if the statistical indicator continuously exceeds the preset threshold, it is determined that the current observer estimation accuracy has decreased or has not converged, and the parameter correction process needs to be initiated; otherwise, the current parameters remain unchanged.

[0029] The gain adjustment module includes a bandwidth adaptive unit and a gain mapping unit; The bandwidth adaptive unit is used to dynamically adjust the observation bandwidth parameters of the extended state observer based on the evaluation indicators output by the performance monitoring module. When the system is in transient condition, the observation bandwidth needs to be increased to improve the response speed; when the system is in steady condition, the observation bandwidth needs to be decreased to enhance the noise suppression capability. The gain mapping unit is used to store the mapping relationship between the observation bandwidth parameter and other gain coefficients of the extended state observer. Based on the adjusted observation bandwidth, the updated observer gain matrix is ​​obtained by looking up the table and the original gain is replaced in real time.

[0030] The auxiliary function unit includes a working condition discrimination unit and a verification and recording unit. The working condition discrimination unit includes a road surface identification subunit and a load estimation subunit. The road surface recognition subunit is used to identify the type of road surface the vehicle is currently traveling on by analyzing the spectral characteristics of the wheel speed signal and the fluctuation amplitude of the acceleration estimate. This includes flat roads and bumpy roads. Under bumpy road conditions, an additional filtering algorithm is enabled to smooth the acceleration estimate in order to suppress high-frequency noise introduced by road excitation. The specific formula for using additional filtering algorithms to smooth the acceleration estimates is as follows: ; in, This is the smoothed estimate of the longitudinal acceleration at the current moment. This is the raw, unsmoothed estimate of the longitudinal acceleration at the current moment. This is the estimated longitudinal acceleration value after smoothing from the previous moment. These are the filter coefficients; The load estimation subunit is used to deduce the approximate current load state of the vehicle by using the long-term statistical mean of the lumped disturbance under steady-state conditions from the extended state observer, and sends this information to the parameter correction terminal as the basis for parameter initialization.

[0031] The verification and recording unit includes an error statistics subunit and an effect evaluation subunit; The error statistics subunit is used to calculate the root mean square error between the estimated acceleration value and the high-precision reference value under specific test conditions, and compare it with the error of the acceleration estimation scheme based on the traditional wheel speed difference method, and quantitatively record the accuracy improvement ratio of this system. The specific formula for calculating the root mean square error between the estimated acceleration value and the high-precision reference value is as follows: ; in, The root mean square error, The total number of sampling points. For the first Estimated longitudinal acceleration values ​​for each sampling point For the first High-precision reference longitudinal acceleration values ​​for each sampling point; The performance evaluation subunit is used to compare the control tracking error of the recorded vehicle speed and the change in acceleration estimation accuracy when the overall vehicle mass deviates, under both perturbation-compensated and non-perturbation-compensated modes, in order to comprehensively evaluate the robustness of the system to parameter perturbations and external disturbances, and store the evaluation results in the log for analysis.

[0032] The operation steps of the ESO-based vehicle longitudinal control and disturbance compensation system are as follows: Step 1: Acquire wheel speed signals at the acceleration estimation end and estimate longitudinal acceleration based on the extended state observer. The signal acquisition module collects wheel speed pulse signals at a preset sampling period and converts them into angular velocity signals. The observer construction module establishes the state equation of a second-order linear extended state observer, taking longitudinal acceleration and lumped disturbance as state variables. The acceleration calculation module uses the discretized observer equation to predict and output the longitudinal acceleration in real time. This estimate has reduced noise amplitude and improved time-domain smoothness.

[0033] Step 2: The disturbance compensation end estimates the combined disturbance and compensates it to the acceleration control command using a feedforward method. The disturbance estimation module extracts the lumped disturbance estimate from the extended state observer. This estimate includes the sum of ramp drag, air drag, and rolling drag, and is decomposed into individual drag components by the disturbance identification unit. The feedforward compensation module calculates the equivalent feedforward compensation torque based on each component, and superimposes it with the expected driving torque corresponding to the target acceleration command to form the final execution command, which drives the braking system to actively compensate for the disturbance.

[0034] Step 3: The parameter calibration terminal calibrates the core parameters of the observer online based on the actual operating status of the vehicle. The performance monitoring module calculates the residual between the measured wheel speed signal and the observer's predicted value, evaluates the estimation accuracy based on the statistical characteristics of the residual, and determines whether to initiate correction. The gain adjustment module dynamically adjusts the observation bandwidth parameter according to the evaluation index. In transient conditions, the bandwidth is increased to improve the response speed, while in steady-state conditions, the bandwidth is decreased to enhance noise suppression capability. The observer gain matrix is ​​updated by looking up a table.

[0035] Step 4: Integrate auxiliary function modules for working condition judgment and verification recording. The operating condition discrimination unit identifies flat or bumpy road surfaces by analyzing the wheel speed signal spectrum and acceleration fluctuation amplitude. For bumpy road surfaces, additional filtering is used to smooth the estimated acceleration value, and the vehicle load is back-calculated using the mean of lumped disturbances under stable operating conditions as the basis for parameter initialization. The verification and recording unit compares the acceleration estimation error of this system with that of the traditional differential method, evaluates the control tracking error and quality deviation impact when there is disturbance compensation, and stores it in the log for analysis.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vehicle longitudinal control and disturbance compensation system based on ESO, characterized in that: The system includes an acceleration estimation terminal, a disturbance compensation terminal, a parameter correction terminal, and an auxiliary function terminal; The acceleration estimation terminal is used to estimate the longitudinal acceleration of the vehicle by acquiring the vehicle wheel speed signal in real time and based on the extended state observer. The longitudinal acceleration estimation value is output in real time to suppress the longitudinal control command of the vehicle from the differential noise of the wheel speed signal. The disturbance compensation end is used to estimate the comprehensive disturbances experienced by the vehicle during driving in real time through the extended state observer, including slope resistance, air resistance and rolling resistance, and to compensate the estimated total disturbance value to the acceleration control command in a feedforward manner to offset the influence of external disturbances on the longitudinal dynamics of the vehicle. The parameter correction terminal is used to perform online correction of the core parameters of the extended state observer according to the actual operating state of the vehicle, so as to adapt to the dynamic characteristics of the vehicle under different loads and road conditions and reduce the system's dependence on the accuracy of model parameter calibration. The auxiliary function terminal is used to integrate the auxiliary function modules required by the system.

2. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 1, characterized in that: The acceleration estimation module includes a signal acquisition module, an observer construction module, and an acceleration calculation module. The signal acquisition module includes a wheel speed sensing unit and a period setting unit; The wheel speed sensing unit is used to collect the wheel speed pulse signals of the four wheels in real time through the vehicle CAN bus at a preset sampling period, and convert them into angular velocity signals. The period setting unit is used to set the value of the sampling period, which is the same as the vehicle CAN bus message update period.

3. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 2, characterized in that: The observer construction module is used to construct a vehicle longitudinal dynamics model based on a linear extended state observer, specifically including a state equation establishment unit and an observation bandwidth setting unit; The state equation establishment unit is used to treat the longitudinal acceleration of the vehicle as a state variable and expand the lumped disturbance experienced by the vehicle into a new state variable, thereby establishing the state equation of the second-order linear extended state observer. The observation bandwidth setting unit is used to set the observation bandwidth parameter of the extended state observer. The range of the observation bandwidth determines the observer's response speed to state changes and its noise suppression capability. Its typical value range is determined according to the response frequency range of vehicle dynamics.

4. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 2, characterized in that: The acceleration calculation module includes a state prediction unit and an estimation output unit; The state prediction unit is used to predict the vehicle state at the current moment in real time based on the state estimate value of the previous moment and the system input, using the discretized extended state observer equation. The vehicle state includes the vehicle's longitudinal acceleration and lumped disturbance. The estimation output unit is used to output the predicted longitudinal acceleration as a corrected estimated value. Compared with the acceleration value obtained by directly calculating the differential of the wheel speed signal, the estimated value has a reduced noise amplitude and improved time-domain smoothness.

5. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 1, characterized in that: The disturbance compensation module includes a disturbance estimation module and a feedforward compensation module; The disturbance estimation module includes a disturbance extraction unit and a disturbance identification unit; The disturbance extraction unit is used to extract in real time the lumped disturbance estimate expanded into state variables from the expanded state observer. The lumped disturbance includes the sum of all unmodeled dynamics and external disturbances, including ramp drag, air drag, and rolling drag. The disturbance identification unit is used to decompose the extracted lumped disturbance estimate into air resistance components related to vehicle speed, slope resistance components related to road gradient, and rolling resistance components related to tire characteristics based on the vehicle dynamics equation, so as to facilitate subsequent targeted compensation.

6. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 5, characterized in that: The feedforward compensation module includes a compensation amount calculation unit and an instruction correction unit; The compensation calculation unit is used to calculate an equivalent feedforward compensation torque to offset the total disturbance based on each disturbance component output by the disturbance identification unit. The instruction correction unit is used to superimpose the calculated feedforward compensation amount with the expected driving torque corresponding to the target acceleration instruction issued by the upper controller to form the corrected final execution instruction, which drives the braking system to generate the corresponding torque and actively feedforward compensates for the disturbance.

7. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 1, characterized in that: The parameter calibration terminal includes a performance monitoring module and a gain adjustment module; The performance monitoring module includes a residual calculation unit and an index evaluation unit; The residual calculation unit is used to calculate the residual between the actual measured wheel speed signal and the wheel speed signal predicted by the extended state observer in real time. The index evaluation unit is used to evaluate the estimation accuracy and convergence status of the current observer based on the statistical characteristics of the calculated residuals, and to determine whether the parameter correction process needs to be initiated.

8. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 7, characterized in that: The gain adjustment module includes a bandwidth adaptive unit and a gain mapping unit; The bandwidth adaptive unit is used to dynamically adjust the observation bandwidth parameters of the extended state observer according to the evaluation indicators output by the performance monitoring module. When the system is in transient condition, the observation bandwidth needs to be increased to improve the response speed; when the system is in steady state condition, the observation bandwidth needs to be decreased to enhance the noise suppression capability. The gain mapping unit is used to store the mapping relationship between the observation bandwidth parameter and other gain coefficients of the extended state observer. Based on the adjusted observation bandwidth, the updated observer gain matrix is ​​obtained by looking up the table and the original gain is replaced in real time.

9. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 1, characterized in that: The auxiliary function terminal includes a working condition discrimination unit and a verification and recording unit. The working condition discrimination unit includes a road surface identification subunit and a load estimation subunit. The road surface recognition subunit is used to identify the type of road surface the vehicle is currently traveling on by analyzing the spectral characteristics of the wheel speed signal and the fluctuation amplitude of the acceleration estimate. This includes flat roads and bumpy roads. Under bumpy road conditions, an additional filtering algorithm is enabled to smooth the acceleration estimate in order to suppress high-frequency noise introduced by road excitation. The load estimation subunit is used to deduce the approximate current load state of the vehicle by using the long-term statistical mean of the lumped disturbance under steady-state conditions from the extended state observer, and sends this information to the parameter correction terminal as the basis for parameter initialization.

10. The vehicle longitudinal control and disturbance compensation system based on ESO according to claim 9, characterized in that: The verification and recording unit includes an error statistics subunit and an effect evaluation subunit; The error statistics subunit is used to calculate the root mean square error between the acceleration estimate and the high-precision reference value under specific test conditions, and compare it with the error of the acceleration estimation scheme based on the traditional wheel speed difference method, and quantitatively record the accuracy improvement ratio of this system. The performance evaluation subunit is used to compare the control tracking error of the recorded vehicle speed and the change in acceleration estimation accuracy when the overall vehicle mass deviates, under both perturbation-compensated and non-perturbation-compensated modes, in order to comprehensively evaluate the robustness of the system to parameter perturbations and external disturbances, and store the evaluation results in the log for analysis.

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