Control method of a hydraulic suspension system, vehicle and computer readable storage medium

Abstract

The embodiment of the application provides a kind of hydraulic suspension system control method, vehicle and computer readable storage medium, the method comprises: obtaining the target actuation force of hydraulic suspension system, actual actuation force and working state parameter;Based on target actuation force, actual actuation force and working state parameter, determine the weight distribution coefficient of feedforward control quantity and feedback control quantity in hydraulic suspension system, and the amplitude limiting threshold of feedback control quantity;Amplitude limiting threshold is based on the amplitude limiting processing of feedback control quantity, obtains the feedback control quantity after limiting amplitude;Based on weight distribution coefficient, the weighted summation of feedforward control quantity and the feedback control quantity after limiting amplitude is obtained, obtains target control quantity, and based on target control quantity, control is carried out to hydraulic suspension system.The application solves the technical problem that the control accuracy of hydraulic suspension system in the related art is low.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a control method for a hydraulic suspension system, a vehicle, and a computer-readable storage medium. Background Technology

[0002] In the field of vehicle chassis technology, hydraulic active suspension systems, by adjusting suspension damping and stiffness, can effectively isolate road impacts and suppress changes in vehicle body posture, thereby improving ride comfort, handling stability, and passenger comfort. This has become an important research direction in the development of high-end vehicle chassis. However, the control algorithms for hydraulic active suspension in related technologies suffer from low control accuracy, slow response, and susceptibility to oscillations when subjected to sudden load changes or temperature variations. Therefore, the control accuracy of hydraulic suspension systems is relatively low.

[0003] There is currently no good solution to the above problems. Summary of the Invention

[0004] This application provides a control method for a hydraulic suspension system, a vehicle, and a computer-readable storage medium to at least solve the technical problem of low control accuracy of hydraulic suspension systems in related technologies.

[0005] According to one aspect of the embodiments of this application, a control method for a hydraulic suspension system is provided, comprising: acquiring a target action force, an actual action force, and operating state parameters of the hydraulic suspension system, wherein the target action force represents the desired control force generated by the hydraulic suspension system, and the actual action force represents the actual control force generated by the hydraulic suspension system; determining, based on the target action force, the actual action force, and the operating state parameters, weight allocation coefficients for feedforward control quantities and feedback control quantities in the hydraulic suspension system, and a limiting threshold for the feedback control quantities; performing amplitude limiting processing on the feedback control quantities based on the limiting threshold to obtain a limited feedback control quantity; performing a weighted summation of the feedforward control quantities and the limited feedback control quantities based on the weight allocation coefficients to obtain a target control quantity, and controlling the hydraulic suspension system based on the target control quantity.

[0006] Furthermore, based on the target working force, actual working force, and working state parameters, the weight allocation coefficients of the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the limiting threshold of the feedback control quantity, are determined, including: determining the weight allocation coefficients based on the target working force and actual working force; and determining the limiting threshold based on the working state parameters and the maximum output limit of the feedback control quantity.

[0007] Furthermore, based on the target action force and the actual action force, the weight allocation coefficients are determined, including: determining the error signal of the hydraulic suspension system based on the target action force and the actual action force; and determining the weight allocation coefficients based on the error amplitude in the error signal.

[0008] Further, based on the error amplitude in the error signal, the weight allocation coefficient is determined, including: in response to the error amplitude being greater than a first preset threshold, determining a first weight coefficient of the feedforward control quantity as a first preset value, and determining a second weight coefficient of the feedback control quantity as a second preset value, to determine the weight allocation coefficient; in response to the error amplitude being less than or equal to the first preset threshold, and the error amplitude being greater than the second preset threshold, determining the weight allocation coefficient according to the error amplitude, the error change rate in the error signal, and the load change rate of the hydraulic suspension system; in response to the error amplitude being less than or equal to the second preset threshold, determining a first weight coefficient of the feedforward control quantity as a second preset value, and determining a second weight coefficient of the feedback control quantity as a first preset value, to determine the weight allocation coefficient.

[0009] Furthermore, the hydraulic suspension system includes a feedforward control model, which determines the limiting threshold based on the operating state parameters and the maximum output limit of the feedback control quantity. This includes: evaluating the feedforward control model based on the operating state parameters to obtain the operating reliability coefficient of the feedforward control model; and determining the limiting threshold based on the product of the operating reliability coefficient and the maximum output limit.

[0010] Furthermore, the method also includes: in response to the feedback control quantity not being within a preset threshold range, determining model correction parameters based on the average value of multiple integral terms in the feedback control quantity; and updating the model parameters of the feedforward control model based on the model correction parameters.

[0011] Furthermore, the feedforward control model is evaluated based on the working state parameters to obtain the operational reliability coefficient of the feedforward control model. This includes: determining the calibration working point that is closest to the working state parameters from multiple working points based on the oil temperature, motor speed and working pressure in the working state parameters; and determining the operational reliability coefficient based on the weighted distance between the working state parameters and the calibration working point.

[0012] Furthermore, the method also includes: determining the temperature deviation between the oil temperature and the calibrated operating point; determining the speed deviation between the motor speed and the calibrated operating point; determining the pressure deviation between the working pressure and the calibrated operating point; and, based on the temperature weight value, speed weight value, and pressure weight value, performing a weighted summation of the temperature deviation value, speed deviation value, and pressure deviation value to obtain a weighted distance.

[0013] Furthermore, based on the weighted distance between the working status parameters and the calibrated working point, the operational reliability coefficient is determined, including: in response to the weighted distance being less than a preset threshold and the working status parameters meeting preset conditions, the weighted distance is mapped based on a preset mapping function to obtain the operational reliability coefficient; in response to the weighted distance being greater than or equal to the preset threshold, or the working status parameters not meeting preset conditions, the operational reliability coefficient is determined to be a preset value.

[0014] Furthermore, the method also includes: determining the feedforward control quantity based on the target driving force and operating state parameters; and determining the feedback control quantity based on the target driving force and actual driving force.

[0015] Furthermore, the hydraulic suspension system includes a hydraulic pump and a hydraulic actuator. Based on the target actuation force and operating state parameters, feedforward control quantities are determined, including: determining the nominal output flow rate and internal leakage flow rate of the hydraulic pump based on the hydraulic pump oil temperature and motor speed in the operating state parameters; determining the target effective flow rate required for the hydraulic actuator to generate the target actuation force based on the effective area of ​​the hydraulic actuator; and determining the feedforward control quantity based on the target effective flow rate, internal leakage flow rate, nominal output flow rate, and the operating pressure of the hydraulic pump in the operating state parameters.

[0016] Furthermore, based on the target effective flow rate, internal leakage flow rate, nominal output flow rate, and the working pressure of the hydraulic pump in the operating status parameters, the feedforward control quantity is determined, including: determining the target demand flow rate of the hydraulic pump based on the target effective flow rate and internal leakage flow rate, wherein the target demand flow rate is the actual output flow rate of the hydraulic pump required to drive the hydraulic actuator to generate the target actuation force after compensating for the internal leakage flow rate; and determining the feedforward control quantity based on the target demand flow rate, nominal output flow rate, and the working pressure of the hydraulic pump in the operating status parameters.

[0017] Furthermore, based on the target demand flow rate, the nominal output flow rate, and the working pressure of the hydraulic pump in the working status parameters, the feedforward control quantity is determined, including: determining the flow deviation value between the target demand flow rate and the nominal output flow rate; determining the pressure compensation coefficient corresponding to the working pressure from multiple preset pressure compensation coefficients; and determining the feedforward control quantity based on the flow deviation value and the pressure compensation coefficient.

[0018] Furthermore, the method also includes: acquiring the vehicle body posture information corresponding to the hydraulic suspension system, or collecting road surface preview information of the road surface where the vehicle is currently located; and determining the target to act as a power source based on the vehicle body posture information or the road surface preview information.

[0019] Furthermore, controlling the hydraulic suspension system based on the target control quantity includes: analyzing the target control quantity to obtain the motor torque component; determining the target motor torque command based on the minimum motor torque and the motor torque component of the hydraulic suspension system; and controlling the hydraulic suspension system based on the target motor torque command.

[0020] According to another aspect of the embodiments of this application, a control device for a hydraulic suspension system is also provided, comprising: an acquisition module, configured to acquire a target action force, an actual action force, and working state parameters of the hydraulic suspension system, wherein the target action force represents the desired control force generated by the hydraulic suspension system, and the actual action force represents the actual control force generated by the hydraulic suspension system; a determination module, configured to determine, based on the target action force, the actual action force, and the working state parameters, a weighting coefficient for the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, and a limiting threshold for the feedback control quantity; a limiting module, configured to limit the feedback control quantity based on the limiting threshold to obtain a limited feedback control quantity; and a control module, configured to perform a weighted summation of the feedforward control quantity and the limited feedback control quantity based on the weighting coefficients to obtain a target control quantity, and to control the hydraulic suspension system based on the target control quantity.

[0021] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0022] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0023] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0024] According to another aspect of the embodiments of this application, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods in various embodiments of this application.

[0025] According to another aspect of the embodiments of this application, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of this application.

[0026] In this embodiment, the target operating force, actual operating force, and operating state parameters of the hydraulic suspension system are obtained. The target operating force represents the desired control force generated by the hydraulic suspension system, and the actual operating force represents the actual control force generated by the hydraulic suspension system. Based on the target operating force, actual operating force, and operating state parameters, the weight allocation coefficients for the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the limiting threshold for the feedback control quantity, are determined. The feedback control quantity is then limited based on the limiting threshold to obtain the limited feedback control quantity. The feedforward control quantity and the limited feedback control quantity are then weighted and summed based on the weight allocation coefficients to obtain the target control quantity, and the hydraulic suspension system is controlled based on the target control quantity. This application's embodiment employs a feedforward and feedback collaborative mechanism. By adjusting the weight allocation coefficients of the feedforward and feedback control quantities and limiting the amplitude of the feedback control quantity, it achieves feedforward compensation and error elimination for the target's dynamics. This improves the dynamic response speed and steady-state accuracy of the hydraulic system and effectively suppresses system oscillations. Thus, it achieves the technical effect of synergistic complementarity between feedforward and feedback control, enhancing the control stability of the hydraulic suspension system, and thereby solving the technical problem of low control accuracy in hydraulic suspension systems in related technologies. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0028] Figure 1 This is a flowchart of a control method for a hydraulic suspension system according to an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the system structure of a control method for a hydraulic suspension system according to an embodiment of this application;

[0030] Figure 3 This is a schematic diagram illustrating the construction and querying of a characteristic curve database for a control method of a hydraulic suspension system according to an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of an optional control method for a hydraulic suspension system according to an embodiment of this application;

[0032] Figure 5 This is a schematic diagram of an optional control method for a hydraulic suspension system according to an embodiment of this application;

[0033] Figure 6 This is a schematic diagram of a control device for a hydraulic suspension system according to an embodiment of this application. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] According to an embodiment of this application, a method for controlling a hydraulic suspension system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0037] This embodiment provides a control method for a hydraulic suspension system. Figure 1 This is a flowchart of a control method for a hydraulic suspension system according to an embodiment of this application, such as... Figure 1 As shown, the process includes the following steps:

[0038] Step S102: Obtain the target working force, actual working force, and working state parameters of the hydraulic suspension system. The target working force represents the desired control force generated by the hydraulic suspension system, and the actual working force represents the actual control force generated by the hydraulic suspension system.

[0039] The aforementioned hydraulic suspension system refers to an advanced chassis actuator that utilizes hydraulic energy as the primary power source to actively apply control forces to adjust the dynamic characteristics of the vehicle suspension. A hydraulic suspension system typically consists of an electric hydraulic pump, hydraulic actuators (hydraulic cylinders), accumulators, control valve groups, and sensors. The core function of the hydraulic suspension system is to change the flow and pressure in the hydraulic circuit according to instructions generated by the upper-level control algorithm, thereby controlling the suspension stiffness, damping, and height. The hydraulic suspension system aims to effectively isolate road vibrations, suppress changes in vehicle body posture, and improve the vehicle's ride comfort, handling stability, and passability; it is a key actuator in intelligent chassis technology. These changes in vehicle body posture can include roll, pitch, etc.

[0040] The aforementioned target action force refers to the desired control force generated by the hydraulic suspension system. The target action force is the ideal output force calculated by the suspension control algorithm based on vehicle attitude, road surface prediction information, or driving conditions. Actively applying the target action force helps suppress vehicle vibration, improve ride comfort, or enhance handling stability.

[0041] The aforementioned actual operating force refers to the actual control force generated by the hydraulic suspension system. The actual operating force is a physical quantity acquired in real time by force sensors installed on the hydraulic actuators, reflecting the resultant force actually transmitted to the sprung mass of the vehicle by the hydraulic pump, hydraulic cylinders, and piping system under the current operating condition. Due to factors such as leakage, friction, and dynamic delay, the actual operating force usually deviates from the target operating force; this deviation forms the basis for feedback control.

[0042] The aforementioned operating status parameters refer to the current operating environment and component status information of the hydraulic suspension system. These parameters include, but are not limited to, key physical quantities such as oil temperature, motor speed, and system operating pressure. These parameters directly affect the volumetric efficiency, mechanical efficiency, and flow output characteristics of the hydraulic pump, and are the fundamental data for constructing the feedforward control model. They are used to query the flow-pressure (PQ) characteristic curve database to determine the accurate control commands required to generate the target force under the current non-ideal operating conditions.

[0043] The aforementioned control force is used to represent the active interactive force applied by a hydraulic actuator (such as a hydraulic cylinder) to the sprung or unsprung mass of the vehicle under the action of a specific control algorithm, which aims to suppress vehicle body vibration or adjust vehicle body posture.

[0044] In one optional embodiment, the hydraulic suspension control system receives the target actuation force command sent from the upper suspension control strategy module via the vehicle bus interface. Furthermore, it calculates the actual actuation force by collecting piston pressure and area data inside the hydraulic actuator using sensors, and simultaneously reads the oil temperature and current motor speed data fed back from the hydraulic pump controller as operating status parameters. This ensures that all input signals are time-synchronized, providing an accurate data foundation for subsequent coordinated control.

[0045] In another alternative embodiment, the hydraulic suspension control system first filters and denoises the acquired raw signals to eliminate high-frequency noise interference. Then, it limits the target driving force to prevent exceeding the physical limits of the actuator. Furthermore, it uses a Kalman filter to fuse data from pressure and displacement sensors to estimate the actual driving force, and maps the processed operating parameters to a standardized data format, improving data quality and the robustness of the control algorithm.

[0046] This application embodiment provides a data foundation for table lookup and feedback error calculation in the feedforward model by acquiring the target working force, actual working force, and operating parameters. This application embodiment ensures that subsequent weight allocation and coordinated control are based on a reliable system state, thereby improving the overall control response speed and steady-state accuracy.

[0047] Step S104: Based on the target working force, actual working force, and working state parameters, determine the weight allocation coefficients of the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the amplitude limit threshold of the feedback control quantity.

[0048] The aforementioned feedforward control quantity refers to the theoretical control command pre-calculated based on the hydraulic pump's PQ characteristic curve model. The feedforward control quantity aims to rapidly track the target's driving force by accurately compensating for known nonlinear factors and measurable disturbances in the system. The calculation process of the feedforward control quantity relies on the mapping relationship between the operating state parameters and the target's driving force, providing the main driving energy before errors occur, thereby reducing system response lag and improving dynamic performance.

[0049] The aforementioned feedback control quantity refers to the corrective control command calculated by the proportional-integral-derivative (PID) controller based on the error signal between the target action force and the actual action force. The feedback control quantity is used to eliminate residual errors that the feedforward control model cannot cover, suppress unknown disturbances, and compensate for model parameter drift. It also adjusts the system deviation through proportional, integral, and derivative operations, ensuring that the system has high-precision tracking capability and good anti-interference robustness in steady state.

[0050] The aforementioned weighting coefficients refer to the proportional parameters of the feedforward control quantity and the feedback control quantity when they are weighted and summed. These weighting coefficients are not fixed but are adjusted according to the system's current dynamic response requirements. The weighting coefficients aim to balance the rapid response advantage of feedforward control with the steady-state accuracy advantage of feedback control, improving their synergy under different operating conditions, avoiding control conflicts or insufficient regulation, and maximizing control effectiveness.

[0051] The aforementioned limiting threshold refers to the boundary value that restricts the output range of the feedback control quantity. The limiting threshold is dynamically determined based on the reliability coefficient and operating parameters of the feedforward control model. The feedforward control model aims to prevent excessive adjustment of the feedback control quantity, which could lead to system oscillation or actuator saturation, when model uncertainty is high or operating conditions are extreme. By limiting the maximum output of the feedback control force, the safety and stability of the control system are ensured, and the feedback adjustment is guaranteed to function within the required range.

[0052] In one optional embodiment, the hydraulic suspension control system first calculates the error amplitude and rate of change between the target driving force and the actual driving force. Then, the hydraulic suspension control system determines the dynamic stage of the system based on the error magnitude. If the error is large, the weighting coefficient of the feedforward control quantity is increased to leverage its rapid response characteristics; if the error is small, the weighting coefficient of the feedback control quantity is increased to eliminate steady-state error. Furthermore, the hydraulic suspension control system dynamically sets the limiting threshold of the feedback control quantity based on the degree of matching between the feedforward model and the current operating state parameters.

[0053] In another alternative embodiment, the hydraulic suspension control system queries a PQ characteristic curve database based on the oil temperature and motor speed parameters in the operating state parameters to evaluate the reliability coefficient of the feedforward control model. If the reliability is low, the weight allocation coefficient of the feedforward control quantity is reduced and the amplitude limit threshold is increased accordingly to limit the output range of the feedback control quantity and prevent control divergence caused by model mismatch. If the reliability is high, the feedforward weight is increased and the amplitude limit is relaxed to achieve adaptive improvement of the control strategy.

[0054] This application embodiment achieves synergy between feedforward and feedback control by dynamically determining the weight allocation coefficient and the amplitude limiting threshold, which ensures both rapid response and system stability, effectively solving the problem that fixed parameter control is difficult to adapt to complex nonlinear operating conditions.

[0055] Step S106: Limit the feedback control quantity based on the limiting threshold to obtain the limited feedback control quantity.

[0056] The aforementioned amplitude limiting processing refers to a signal constraint algorithm operation. This operation forcibly restricts the value of the original feedback control quantity within a preset upper and lower limit range. If the original feedback control quantity exceeds the upper threshold, it is clamped to the upper threshold; if it falls below the lower threshold, it is clamped to the lower threshold. Within the threshold range, the original value remains unchanged. The amplitude limiting process aims to prevent the actuator from entering the saturation region or to avoid damage to the mechanical structure caused by excessive control commands, ensuring that the output signal is always within the safe and controllable operating range of the system. It is a key protective element for ensuring the reliable operation of the active suspension system. The aforementioned clamping operation refers to a nonlinear amplitude limiting mechanism.

[0057] The aforementioned limited feedback control quantity refers to the final feedback control command after correction by the limiting algorithm. The limited feedback control quantity is the result of the interaction between the original feedback control quantity and the limiting threshold, representing the maximum effective control force allowed for the PID controller to actually output under the current operating conditions. The limited feedback control quantity retains the core functions of feedback control in eliminating steady-state errors and suppressing low-frequency disturbances, while also eliminating extreme components that could lead to system instability. As one of the inputs to the weighted summation operation in the cooperative control module, the limited feedback control quantity, together with the feedforward control quantity, determines the final actuator drive command.

[0058] In one optional embodiment, the hydraulic suspension control system first reads the limiting threshold provided by the dynamic weight allocation unit. Then, the hydraulic suspension control system compares the original feedback control quantity output by the PID controller with the limiting threshold. If the absolute value of the original feedback control quantity is less than or equal to the limiting threshold, the original value is directly output as the limited feedback control quantity. If the absolute value of the original feedback control quantity is greater than the limiting threshold, the original value is replaced with the limiting threshold while retaining its sign. This achieves symmetrical or asymmetrical limiting of the positive and negative control forces, ensuring that the output signal does not exceed the system safety boundary.

[0059] In another optional embodiment, the hydraulic suspension control system employs a piecewise linear limiting strategy. In addition to the aforementioned hard limiting based on absolute values, a soft limiting characteristic is also introduced. If the original feedback control quantity is close to the limiting threshold, the output gain is smoothly compressed using a nonlinear function to avoid jitter caused by abrupt changes in the signal near the threshold. Furthermore, the slope of the limiting curve is dynamically adjusted based on the reliability evaluation results of the feedforward control quantity. A more conservative limiting curve is used when the reliability of the feedforward control model is low, and a more relaxed limiting curve is used when the reliability of the feedforward control model is high, thereby improving the smoothness and robustness of the control.

[0060] The embodiments of this application effectively prevent excessive adjustment of feedback control under model mismatch or extreme conditions through dynamic amplitude limiting processing, avoid system oscillation and actuator saturation, and improve the safety and stability of the hydraulic active suspension control process.

[0061] Step S108 involves weighting and summing the feedforward control quantity and the feedback control quantity after amplitude limiting based on the weight allocation coefficient to obtain the target control quantity, and then controlling the hydraulic suspension system based on the target control quantity.

[0062] The aforementioned target control quantity refers to the total control command generated after a weighted summation of the feedforward control quantity and the limited feedback control quantity. The target control quantity integrates the open-loop control information predicted by the model and the closed-loop correction information based on the error, and is the final control signal sent to the hydraulic actuator drive unit. The target control quantity aims to achieve accurate control of the hydraulic active suspension system by coordinating the effects of feedforward and feedback, ensuring optimal ride comfort and handling stability for the vehicle under various driving conditions. The target control quantity is the final decision result output by the control algorithm.

[0063] In one optional embodiment, the weighted summation unit in the hydraulic suspension control system first receives the feedforward weighting coefficient and the feedback weighting coefficient from the dynamic weighting allocation unit. Then, the hydraulic suspension control system multiplies the feedforward control quantity by the aforementioned weighting coefficients to obtain the feedforward weighted component, and multiplies the limited feedback control quantity by the feedback weighting coefficient to obtain the feedback weighted component. Finally, the hydraulic suspension control system algebraically adds these two weighted components to generate the target control quantity, and converts the target control quantity into a motor torque command or speed command. This command drives the hydraulic pump through the controller actuator, thereby achieving closed-loop control of the suspension system.

[0064] In another optional embodiment, before weighted summation, the hydraulic suspension control system first performs dimensional unification and polarity checks on the feedforward control quantity and the limited feedback control quantity to ensure consistency in their physical meaning and control direction. Subsequently, the hydraulic suspension control system fine-tunes the weighting coefficients according to a preset smooth transition algorithm to avoid control quantity jumps caused by abrupt weight changes. Finally, the hydraulic suspension control system performs weighted summation to obtain the target control quantity and filters it using a low-pass filter to suppress high-frequency noise. Ultimately, a smooth control command is output to drive the hydraulic suspension system, improving control smoothness. The aforementioned smooth transition algorithm refers to a mathematical processing mechanism used to adjust the rate of change of control parameters, aiming to avoid step-like abrupt changes in parameters during discrete state switching or continuous changes. Smooth transition algorithms typically employ methods such as sigmoid (S)-type functions, polynomial interpolation, or first-order hysteresis filtering. The smooth transition algorithm ensures a continuous and smooth slope change in the weighting coefficients as they transition from their initial to target values. This eliminates discontinuities or shocks in the control output caused by sudden jumps in the weighting coefficients, ensuring the continuity and stability of control commands in the hydraulic active suspension system under dynamic conditions. This improves ride comfort and protects the actuators from mechanical stress shocks. The aforementioned control parameters refer to the weighting coefficients.

[0065] The embodiments of this application achieve synergy between feedforward and feedback through weighted summation, which leverages the speed of feedforward while retaining the accuracy of feedback, thereby improving the robustness and response speed of the overall control performance of the hydraulic active suspension system under complex working conditions.

[0066] In this embodiment, the target operating force, actual operating force, and operating state parameters of the hydraulic suspension system are obtained. The target operating force represents the desired control force generated by the hydraulic suspension system, and the actual operating force represents the actual control force generated by the hydraulic suspension system. Based on the target operating force, actual operating force, and operating state parameters, the weight allocation coefficients for the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the limiting threshold for the feedback control quantity, are determined. The feedback control quantity is then limited based on the limiting threshold to obtain the limited feedback control quantity. The feedforward control quantity and the limited feedback control quantity are then weighted and summed based on the weight allocation coefficients to obtain the target control quantity, and the hydraulic suspension system is controlled based on the target control quantity. This application's embodiment employs a feedforward and feedback collaborative mechanism. By adjusting the weight allocation coefficients of the feedforward and feedback control quantities and limiting the amplitude of the feedback control quantity, it achieves feedforward compensation and error elimination for the target's dynamics. This improves the dynamic response speed and steady-state accuracy of the hydraulic system and effectively suppresses system oscillations. Thus, it achieves the technical effect of synergistic complementarity between feedforward and feedback control, enhancing the control stability of the hydraulic suspension system, and thereby solving the technical problem of low control accuracy in hydraulic suspension systems in related technologies.

[0067] Optionally, based on the target working force, actual working force, and working state parameters, the weight allocation coefficients of the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the limiting threshold of the feedback control quantity, are determined, including: determining the weight allocation coefficients based on the target working force and actual working force; and determining the limiting threshold based on the working state parameters and the maximum output limit of the feedback control quantity.

[0068] The aforementioned maximum output limit refers to the upper limit that the feedback control quantity can reach within the physically or safety-permissible range. The maximum output limit is jointly determined by the physical limits of the actuator, the stability margin of the control system, and the safety protection strategy, serving as a benchmark reference for the limiting algorithm. The maximum output limit is used to dynamically calculate the actual limiting threshold in conjunction with operating state parameters, ensuring that regardless of the system's operating condition, the output of the feedback control quantity will not exceed the actuator's capability or cause system instability.

[0069] In one optional embodiment, the hydraulic suspension control system first calculates the error amplitude and rate of change between the target driving force and the actual driving force. Then, the hydraulic suspension control system determines the dynamic stage of the system based on the error magnitude. If the error is large, the weighting coefficient of the feedforward control quantity is increased to leverage its rapid response characteristics; if the error is small, the weighting coefficient of the feedback control quantity is increased to eliminate steady-state error. Furthermore, the hydraulic suspension control system queries the PQ characteristic curve database based on the oil temperature and motor speed parameters in the operating state parameters to evaluate the reliability of the feedforward model, and dynamically sets the limiting threshold of the feedback control quantity in conjunction with the maximum output limit.

[0070] This application embodiment achieves synergy between feedforward and feedback control by dynamically determining the weight allocation coefficient and limiting threshold based on error and state parameters. This ensures both rapid response and system stability, effectively solving the problem that traditional fixed parameter control is difficult to adapt to complex nonlinear operating conditions.

[0071] Optionally, the weight allocation coefficients are determined based on the target working force and the actual working force, including: determining the error signal of the hydraulic suspension system based on the target working force and the actual working force; and determining the weight allocation coefficients based on the error amplitude in the error signal.

[0072] The aforementioned error signal refers to the vector difference between the target driving force and the actual driving force. The error signal reflects the degree of deviation between the current output capability of the hydraulic suspension system and the desired control target, and serves as the input to the feedback controller. The magnitude and polarity of the error signal determine the direction and strength of the feedback control force, guiding the PID controller or co-control module to adjust the output. The error signal is used to eliminate steady-state errors and suppress overshoot or oscillations during dynamic processes, ensuring that the system converges to the desired state.

[0073] The aforementioned error amplitude refers to the absolute value of the error signal at a specific moment or within a specific frequency band. The error amplitude scalarizes the degree to which the system deviates from the target value and is a key basis for determining the weighting coefficients of the feedforward control and feedback control. If the error amplitude is large, it indicates that the system is in the dynamic response stage, requiring an increase in the weighting coefficient of the feedforward control to quickly track the target. If the error amplitude is small, it indicates that the system is approaching steady state, requiring an increase in the weighting coefficient of the feedback control to adjust the system, thereby achieving adaptive improvement of the control strategy at different dynamic stages.

[0074] In one optional embodiment, the hydraulic suspension control system first acquires the actual actuating force of the hydraulic actuator and algebraically subtracts it from the target actuating force output by the upper-level control algorithm to obtain an instantaneous error signal. Subsequently, the hydraulic suspension control system performs absolute value calculation on the error signal to obtain the error amplitude and compares this error amplitude with a preset dynamic threshold. If the error amplitude exceeds the preset dynamic threshold, the system is determined to be in a high-dynamic condition, and the weight allocation coefficient of the feedforward control quantity is set to a higher value. If the error amplitude is lower than the preset dynamic threshold, the system is determined to be in a low-dynamic condition, and the weight allocation coefficient of the feedback control quantity is set to a higher value. The aforementioned high-dynamic condition refers to the operating mode of the hydraulic active suspension system in a state of intense response, i.e., a sudden change in road surface excitation or rapid change in vehicle posture during vehicle operation, causing the suspension system to generate a strong instantaneous control force to suppress vehicle movement. The aforementioned preset dynamic threshold refers to a set of preset error amplitude limits used to define the current dynamic response stage of the hydraulic active suspension system. The preset dynamic threshold determines the system condition by comparing the error amplitude with the preset limits.

[0075] This application embodiment achieves the ratio of feedforward control and feedback control at different dynamic stages by dynamically adjusting the weight allocation coefficient based on the error amplitude. This ensures both rapid response capability under large errors and steady-state accuracy under small errors, effectively improving the overall control performance of the hydraulic active suspension system.

[0076] Optionally, determining the weight allocation coefficient based on the error amplitude in the error signal includes: in response to the error amplitude being greater than a first preset threshold, determining a first weight coefficient of the feedforward control quantity as a first preset value and determining a second weight coefficient of the feedback control quantity as a second preset value, thereby determining the weight allocation coefficient; in response to the error amplitude being less than or equal to the first preset threshold and the error amplitude being greater than the second preset threshold, determining the weight allocation coefficient based on the error amplitude, the error change rate in the error signal, and the load change rate of the hydraulic suspension system; in response to the error amplitude being less than or equal to the second preset threshold, determining a first weight coefficient of the feedforward control quantity as a second preset value and determining a second weight coefficient of the feedback control quantity as a first preset value, thereby determining the weight allocation coefficient.

[0077] The aforementioned first preset threshold refers to the upper limit boundary of the error amplitude that divides the dynamic response stage and the transition stage of the hydraulic suspension system. If the error amplitude exceeds the first preset threshold, it indicates that the vehicle is experiencing severe road excitation or a large change in attitude. At this time, the system is in a highly dynamic condition, and the control strategy tends to maximize the rapid response capability of feedforward control to quickly suppress vehicle movement. The first preset threshold is the criterion for triggering a higher feedforward weight mode, ensuring that the model prediction accuracy is fully utilized when the error is large, and reducing the lag effect of feedback control.

[0078] The aforementioned second preset threshold refers to the lower limit boundary of the error amplitude that divides the hydraulic suspension system from the transition phase to the steady-state adjustment phase. If the error amplitude is lower than the second preset threshold, it indicates that the vehicle has entered a steady-state or slightly dynamic operating condition. At this time, the dynamic compensation requirement of feedforward control is reduced, and the control strategy tends to maximize the high-precision adjustment capability of feedback control to eliminate residual errors. The second preset threshold is the condition for triggering the high feedback weight mode, ensuring that precise control is achieved through PID feedback when the error is small, thereby improving the steady-state accuracy and anti-low-frequency interference capability of the system.

[0079] The aforementioned first weighting coefficient refers to the proportional parameter of the feedforward control component when the feedforward control quantity is weighted and summed. Under either the first or second preset threshold condition, the first weighting coefficient is set to a fixed value, aiming to forcibly allocate control weight according to the magnitude of the error amplitude. If the error amplitude is large, a larger first weighting coefficient is assigned to strengthen the effect of feedforward control; if the error amplitude is small, a smaller first weighting coefficient is assigned to weaken the feedforward effect. The setting of the first weighting coefficient can achieve a clear switch or smooth transition between the dominant roles of feedforward and feedback in different dynamic ranges.

[0080] The aforementioned second weighting coefficient refers to the proportional parameter of the feedback control component when performing a weighted summation operation on the feedback control quantity. The second weighting coefficient and the first weighting coefficient of the feedforward control quantity typically have a complementary relationship, meaning their sum is constant. Under the conditions of the first or second preset threshold, the second weighting coefficient is set to its corresponding fixed value. If the error amplitude is large, the second weighting coefficient is smaller to limit feedback intervention; if the error amplitude is small, the second weighting coefficient is larger to enhance feedback regulation. The second weighting coefficient ensures that when the error signal changes significantly, the strength of the feedback control can adaptively follow the changing trend of the feedforward control, maintaining the balance of the coordinated control.

[0081] The aforementioned error change rate refers to the instantaneous rate at which the error signal changes over time. The error change rate reflects the speed of error convergence or divergence and is a dynamic indicator for determining the weight allocation coefficients in the transition phase. If the error amplitude is between the first and second preset thresholds, the dynamic trend of the system cannot be accurately judged solely by the error amplitude. Introducing the error change rate can distinguish whether the error is rapidly decreasing or rapidly increasing, thereby more accurately adjusting the weight allocation coefficients of feedforward and feedback control. Furthermore, it can prevent overshoot caused by excessively high feedback weights when the error converges rapidly, or slow response caused by insufficient feedforward weights when the error increases rapidly.

[0082] The aforementioned load change rate refers to the rate at which the external load or internal pressure on the hydraulic suspension system changes over time. The load change rate reflects the severity of the system's dynamic state and is another important dynamic indicator for determining the weight allocation coefficients during the transition phase. A large load change rate indicates that the system is experiencing severe torque disturbances or acceleration changes. In this case, a more proactive adjustment of the weight allocation is needed to address the nonlinear coupling effect. By combining the error change rate and the load change rate, a multi-faceted evaluation of the system's dynamic characteristics can be achieved, thereby calculating a more reasonable and robust weight allocation coefficient. The aforementioned nonlinear coupling effect refers to the complex dynamic interaction phenomenon where multiple physical variables within the system influence and constrain each other, exhibiting nonlinear proportional relationships.

[0083] In one optional embodiment, the hydraulic suspension control system first compares the error amplitude with a first preset threshold and a second preset threshold. If the error amplitude is greater than the first preset threshold, the first weighting coefficient of the feedforward control quantity is directly set to a higher first preset value. Furthermore, the hydraulic suspension control system sets the second weighting coefficient of the feedback control quantity to a lower second preset value to prioritize the rapid response advantage of feedforward control. If the error amplitude is less than or equal to the second preset threshold, the first weighting coefficient of the feedforward control quantity is set to a lower second preset value, and the second weighting coefficient of the feedback control quantity is set to a higher first preset value to prioritize the steady-state adjustment advantage of feedback control.

[0084] Furthermore, if the error amplitude is between the first preset threshold and the second preset threshold, the determination of the weight allocation coefficients can adopt a multivariate weighted fusion strategy. First, the hydraulic suspension control system collects the error change rate to characterize the system's response agility and monitors the load change rate of the hydraulic suspension system to assess the severity of external disturbances. The hydraulic suspension control system maps the error change rate to a positive contribution factor to the feedback control weights and the load change rate to a positive contribution factor to the feedforward control weights. The hydraulic suspension control system calculates the relative weight ratio of the error change rate and the load change rate using a preset mapping function or fuzzy logic rule, thereby smoothly determining the dynamic allocation coefficients of the feedforward control quantity and the feedback control quantity. This allows for the increase of feedback weights to eliminate steady-state errors under conditions with high system response requirements and low load disturbances, while increasing feedforward weights to utilize their rapid compensation characteristics when severe load fluctuations lead to increased model prediction deviations, thus achieving adaptive improvement and balance of the control strategy under dynamic conditions. The aforementioned positive contribution factor refers to the increased weight allocation coefficients.

[0085] The aforementioned preset mapping function refers to a computational model used to establish the logical relationship between input parameters and output control quantities. Specifically, the preset mapping function typically uses pre-calibrated mathematical expressions, such as linear equations, polynomial curves, sigmoid functions, and two-dimensional or multi-dimensional lookup tables, to directly map input variables such as error change rate and load change rate into specific weighting coefficient values, thereby achieving deterministic and rapid calculation.

[0086] The aforementioned fuzzy logic rule is a reasoning mechanism based on expert experience. It defines a fuzzy set of input variables and pre-sets an "if-then" fuzzy rule base. After fuzzifying the input quantities, logical reasoning is performed, and finally, a defuzzification algorithm is used to convert the reasoning results into accurate weight allocation coefficients. This achieves smoother and more robust dynamic weight adjustment even when the system model has strong nonlinearity or high parameter uncertainty.

[0087] The embodiments of this application determine the weight allocation coefficients through hierarchical judgment and dynamic interpolation, thereby realizing the connection between feedforward and feedback control in different error ranges. This ensures both rapid response under large dynamic conditions and steady-state accuracy under small errors, thus improving the control smoothness and robustness of the hydraulic active suspension system.

[0088] Optionally, the hydraulic suspension system includes a feedforward control model, which determines a limiting threshold based on the operating state parameters and the maximum output limit of the feedback control quantity. This includes: evaluating the feedforward control model based on the operating state parameters to obtain the operating reliability coefficient of the feedforward control model; and determining the limiting threshold based on the product of the operating reliability coefficient and the maximum output limit.

[0089] The aforementioned feedforward control model refers to a theoretical calculation unit constructed based on the PQ characteristic curve of the hydraulic pump and the system dynamic equations. The feedforward control model pre-calculates the feedforward control quantity required to drive the hydraulic actuator by inputting target power and operating state parameters. The feedforward control model aims to compensate for known nonlinear characteristics and measurable disturbances in the system; its output accuracy depends on the consistency between the model parameters and the actual system characteristics. The feedforward control model is a fundamental component in the cooperative control architecture, providing a fast feedforward response and undertaking the main task of disturbance suppression.

[0090] The aforementioned operational reliability coefficient is a numerical indicator that quantifies the accuracy of the feedforward control model's output in the current operating state. The operational reliability coefficient typically ranges from zero to one; a higher value indicates that the current operating state is closer to the model's calibration condition, and the more reliable the model's predictions are. A lower value indicates that the current operating state is in an area not covered by the model or that there is significant uncertainty. As the basis for the feedback limiting strategy, the operational reliability coefficient determines the allowable range of feedback control intervention, balancing control performance and system safety.

[0091] In one optional embodiment, the hydraulic suspension control system first reads the current operating status parameters. These parameters include oil temperature, motor speed, and operating pressure. Then, these parameters are matched with preset calibration points of the feedforward control model to calculate the weighted distance between the current operating point and the nearest calibration point. If the weighted distance is less than a preset threshold and the operating parameters are within the calibration range, a higher operational reliability coefficient is calculated based on the mapping function; otherwise, a lower operational reliability coefficient is calculated. Subsequently, the reliability coefficient is multiplied by the maximum output limit to obtain the final limiting threshold, achieving dynamic protection of the feedback control quantity. The preset threshold refers to a pre-set distance tolerance value used to define the effective matching range between the current actual operating point and the calibration data points in the PQ characteristic curve database.

[0092] This application embodiment dynamically determines the amplitude limiting threshold based on the reliability of the feedforward control model, thereby achieving adaptive protection of feedback control under model uncertainty. This ensures high-precision adjustment when the model is reliable and prevents system oscillation when the model is mismatched, thus improving the robustness and safety of the hydraulic active suspension control algorithm.

[0093] Optionally, the method further includes: in response to the feedback control quantity not being within a preset threshold range, determining model correction parameters based on the average value of multiple integral terms in the feedback control quantity; and updating the model parameters of the feedforward control model based on the model correction parameters.

[0094] The aforementioned preset threshold range refers to the boundary set of the fluctuation range that the feedback control quantity should maintain under normal operating conditions. The preset threshold range is typically centered at zero, setting the maximum positive and negative limits allowed for the existence of the feedback control quantity. The preset threshold range aims to distinguish between a normal steady-state adjustment phase and an abnormal dynamic deviation phase. If the feedback control quantity exceeds the preset threshold range, it indicates that there is a model error in the feedforward control model or that the system characteristics have drifted, thus triggering a subsequent model adaptive correction mechanism to ensure the long-term stability and accuracy of the control system.

[0095] The integral term mentioned above refers to the component obtained by performing time integration on the error signal in the PID controller. This component reflects the cumulative effect of the error over a period of time and is mainly used to eliminate the steady-state error of the system. If the feedback control quantity is not within the preset threshold range, the magnitude of the integral term directly reflects the long-term deviation trend between the feedforward control quantity and the actual demand. By extracting the average value of multiple integral terms, instantaneous noise interference can be smoothed, and a stable signal representing the systematic error of the model can be obtained to guide the online correction of the feedforward control model parameters.

[0096] The aforementioned average value refers to the statistical result obtained by arithmetically averaging the values ​​of the integral term in the feedback control quantity over multiple past control cycles. The average value index aims to filter out high-frequency fluctuations and random noise in the integral term during transient processes, extracting the DC component that reflects the long-term deviation trend of the feedforward model. By calculating the average value, the hydraulic suspension control system can accurately assess the overall offset of the feedforward control model under the current operating conditions, avoiding misjudgments caused by single sampling. The average value can provide stable and reliable input data for model correction parameters, ensuring the smoothness and effectiveness of model updates.

[0097] The aforementioned model correction parameters refer to incremental variables used to adjust the internal structure or coefficients of the feedforward control model. These parameters can be calculated based on the average value of the integral term in the feedback control quantity, aiming to compensate for hydraulic system characteristic drift caused by factors such as oil temperature changes, component wear, or manufacturing tolerances. By applying the model correction parameters to the flow or pressure mapping relationship of the feedforward control model, the output of the feedforward control model can be updated, making it closer to the physical characteristics of the actual system. This improves the predictive accuracy of the feedforward control and reduces the adjustment required for subsequent feedback control.

[0098] The aforementioned model parameters refer to the mathematical variables or lookup table data used in the feedforward control model to describe the physical characteristics of the hydraulic system. Model parameters include the volumetric efficiency coefficient, mechanical efficiency coefficient, leakage coefficient, or key node data on the PQ characteristic curve of the hydraulic pump. These parameters determine the mapping relationship from the target force to the control command. By updating these model parameters online based on the model correction parameters, the feedforward control model can acquire adaptive capabilities, enabling it to follow changes in the hydraulic system over time. Online updates of these model parameters based on the model correction parameters also maintain long-term stable control performance and avoid a decrease in control accuracy due to model mismatch.

[0099] In one optional embodiment, the hydraulic suspension control system first monitors the value of the feedback control quantity to determine whether it exceeds a preset threshold range. If the feedback control quantity exceeds the preset threshold range, it extracts the integral term data from the past several control cycles and calculates the average value. This average value is then multiplied by a preset adaptive learning rate to obtain the model correction parameters. Subsequently, the hydraulic suspension control system adds the correction parameters to the corresponding flow mapping coefficient in the feedforward control model and checks whether the corrected parameters are within a physically reasonable range. If they exceed the reasonable range, amplitude limiting is performed. Finally, the updated model parameters are stored in non-volatile memory for use in subsequent control cycles. The aforementioned adaptive learning rate refers to a dynamic gain coefficient used to adjust the model parameter update step size during the online correction process of the feedforward control model, aiming to balance the convergence speed and stability of the model correction.

[0100] This application embodiment achieves adaptive tracking of hydraulic system characteristic drift by the control model through an online correction mechanism driven by the average value of the integral term. This improves the accuracy and robustness of feedforward control in long-term operation, reduces the burden of feedback control, and enhances the overall control performance of the system.

[0101] Optionally, the feedforward control model is evaluated based on the operating state parameters to obtain the operating reliability coefficient of the feedforward control model, including: determining the calibration operating point that is closest to the operating state parameters from multiple operating points based on the oil temperature, motor speed and operating pressure in the operating state parameters; and determining the operating reliability coefficient based on the weighted distance between the operating state parameters and the calibration operating point.

[0102] The oil temperature mentioned above represents the thermodynamic state parameter of the working medium inside the hydraulic system. The oil temperature affects the viscosity characteristics of the hydraulic oil, which in turn relates to the internal leakage and flow resistance of the hydraulic pump and valves. Oil temperature is a key environmental factor for evaluating the energy efficiency of hydraulic systems and the accuracy of feedforward control models.

[0103] The motor speed mentioned above represents the rotational speed of the DC brushless motor or AC asynchronous motor driving the electric hydraulic pump. The value of the motor speed determines the nominal theoretical output flow rate of the hydraulic pump. The motor speed is the independent variable used to construct the PQ characteristic curve of the hydraulic pump and to calculate the target flow demand in the feedforward control.

[0104] The aforementioned working pressure represents the static pressure of the fluid in the hydraulic system circuit. The value of the working pressure reflects the current load on the suspension system and the state of the accumulator, and is a key indicator of the leakage caused by changes in volumetric efficiency in the actual output flow of the hydraulic pump. Working pressure is an important performance indicator for evaluating the reliability of the feedforward control model under current load conditions.

[0105] The aforementioned operating points represent a series of representative discrete state combinations covering the entire operating range, pre-selected and recorded through bench tests during the hydraulic pump performance calibration process. Each operating point is determined by specific parameters in three dimensions: oil temperature, motor speed, and system operating pressure, forming the basic sample set for constructing the hydraulic pump PQ characteristic curve database. These operating points serve as reference benchmarks during real-time control. By calculating the distance between the current actual operating state parameters and the calibrated operating points, the applicability and reliability of the feedforward control model under the current operating condition are evaluated.

[0106] The aforementioned calibration operating points refer to a set of standard operating conditions pre-calibrated through bench tests, possessing known PQ characteristic curve data. Each calibration operating point consists of a specific combination of oil temperature, motor speed, and operating pressure, and stores the corresponding actual output flow and leakage data of the hydraulic pump. These calibration operating points form the basic framework of the feedforward control model database, used to cover the expected operating range of the system. If the operating state parameters have a high degree of matching with a certain calibration operating point, it indicates that the model prediction under the current operating condition has high reliability. Therefore, the calibration operating points are the benchmark reference for calculating the weighted distance and confidence coefficient.

[0107] The weighted distance mentioned above refers to a comprehensive measure of the difference between the operating state parameters and the most recently calibrated operating point in the multidimensional parameter space. The weighted distance is not a simple Euclidean distance, but rather a weighted calculation result that considers the different physical dimensions and importance differences of oil temperature, motor speed, and operating pressure. By introducing weighting coefficients, parameters that have a significant impact on the accuracy of feedforward control can be highlighted. A smaller weighted distance indicates that the current operating condition is closer to the model's calibration condition, and the smaller the model's extrapolation error; conversely, a larger weighted distance indicates a larger deviation from the operating condition, and a decrease in model reliability. The weighted distance is a key quantitative indicator for evaluating the applicability of the model. The parameters with a significant impact mentioned above can be pressure or temperature, etc.

[0108] In one optional embodiment, the hydraulic suspension control system first constructs a multi-dimensional vector database containing calibration operating points. Then, the hydraulic suspension control system calculates the weighted Euclidean distance between the state vector composed of currently collected oil temperature, motor speed, and working pressure and the vector of each calibration operating point in the database. The weighting coefficient is determined based on the sensitivity to control accuracy in historical calibration data, and the minimum calculated distance is selected as the distance to the nearest calibration operating point. Subsequently, the hydraulic suspension control system inputs the weighted distance into a preset mapping function, obtaining an operational reliability coefficient through a monotonically decreasing mapping relationship. The smaller the distance, the closer the operational reliability coefficient is to one; the larger the distance, the closer the operational reliability coefficient is to zero.

[0109] This application embodiment determines the operational reliability coefficient based on weighted distance, thereby achieving a quantitative assessment of the applicability of the feedforward control model. This enables the system to adaptively adjust the intervention intensity of feedback control according to the degree of deviation from the operating conditions, effectively solving the control instability problem caused by model extrapolation error and improving the control robustness of the hydraulic active suspension across the entire operating range.

[0110] Optionally, the method further includes: determining the temperature deviation between the oil temperature and the calibrated operating point; determining the speed deviation between the motor speed and the calibrated operating point; determining the pressure deviation between the working pressure and the calibrated operating point; and weighting and summing the temperature deviation, speed deviation, and pressure deviation based on the temperature weight value, speed weight value, and pressure weight value to obtain a weighted distance.

[0111] The temperature deviation value mentioned above refers to the algebraic difference between the oil temperature currently collected by the hydraulic system and the preset standard oil temperature in the most recently matched calibration point. The temperature deviation value quantifies the degree to which the thermodynamic state deviates from the reference. Since oil viscosity has a significant impact on the volumetric efficiency and internal leakage characteristics of the hydraulic pump, the temperature deviation directly reflects the degree of mismatch in the thermodynamic dimension of the feedforward control model. Temperature deviation is the fundamental data for evaluating the reliability of the feedforward control model in the temperature dimension.

[0112] The aforementioned speed deviation value refers to the algebraic difference between the current actual speed of the motor driving the hydraulic pump and the preset standard motor speed in the most recently matched calibration operating point. The speed deviation value quantifies the degree to which the mechanical motion state deviates from the baseline. The motor speed determines the geometric displacement flow rate of the hydraulic pump, and the speed deviation reflects the applicability of the model in the kinematic dimension. Since changes in speed affect fluid dynamics and mechanical friction characteristics, the speed deviation value is also a key parameter for evaluating the predictive accuracy of the feedforward control model in the speed dimension.

[0113] The aforementioned pressure deviation value refers to the algebraic difference between the currently measured working pressure of the hydraulic system and the preset standard working pressure at the most recently matched calibration point. The pressure deviation quantifies the degree to which the hydraulic load state deviates from the baseline; the working pressure directly affects the leakage and effective output flow of the hydraulic pump. The pressure deviation reflects the mismatch of the feedforward control model in the mechanical dimension. Because pressure changes have a significant nonlinear impact on the PQ characteristics, this pressure deviation value is an important input variable for evaluating the reliability of the feedforward control model in the pressure dimension.

[0114] The aforementioned temperature weighting value refers to a proportional coefficient used in the calculation of the weighted distance to measure the importance of oil temperature deviation on the reliability of the feedforward control model. The temperature weighting value reflects the sensitivity of temperature parameters to changes in hydraulic system characteristics and is typically determined based on historical calibration data or system dynamics analysis. A larger temperature weighting value indicates a greater negative impact of temperature deviation on the accuracy of the feedforward control model, and a higher proportion in the weighted distance calculation. This makes the impact of temperature deviation on the final reliability coefficient more significant, reflecting differentiated treatment in multivariate evaluation.

[0115] The aforementioned speed weight value refers to the proportional coefficient used in calculating the weighted distance to measure the importance of motor speed deviation on the reliability of the feedforward control model. The speed weight value reflects the sensitivity of the speed parameter to changes in hydraulic system characteristics. The magnitude of the speed weight value determines the contribution ratio of speed deviation in the overall evaluation. A higher speed weight value means the system is more sensitive to speed changes, requiring more precise speed matching to ensure the accuracy of feedforward control. By adjusting the speed weight value, the evaluation accuracy of the model under different mechanical operating conditions can be improved.

[0116] The aforementioned pressure weight value refers to the proportional coefficient used in calculating the weighted distance to measure the importance of the working pressure deviation on the reliability of the feedforward control model. The pressure weight value reflects the sensitivity of pressure parameters to changes in hydraulic system characteristics. The magnitude of the pressure weight value determines the contribution ratio of the pressure deviation in the comprehensive evaluation. Since pressure typically has a significant impact on hydraulic pump leakage and efficiency, the pressure weight value is often large. Through weighted summation, it can reflect the comprehensive impact of the deviations of each physical quantity on the overall reliability of the feedforward control model.

[0117] In one optional embodiment, the hydraulic suspension control system calculates the differences between the current oil temperature, motor speed, and operating pressure and the corresponding standard values ​​of the most recently calibrated operating point. This obtains the deviation values ​​for the three dimensions: oil temperature, motor speed, and operating pressure. Subsequently, the hydraulic suspension control system reads the temperature weight value, speed weight value, and pressure weight value. The system multiplies the temperature deviation value by the temperature weight value, the speed deviation value by the speed weight value, and the pressure deviation value by the pressure weight value to obtain three weighted deviation components. Finally, the three weighted deviation components are algebraically summed to obtain the final weighted distance, achieving a comprehensive quantitative evaluation of the deviations of multiple parameters.

[0118] This application embodiment determines the weighted distance by weighted summation of multi-dimensional deviations, which realizes accurate quantification of the applicability of the feedforward control model. It can sensitively capture the degree of deviation of the system state from the calibration condition, providing a reliable basis for the accurate calculation of the subsequent reliability coefficient, and effectively improving the adaptability of the control algorithm to complex nonlinear conditions.

[0119] Optionally, the operation reliability coefficient is determined based on the weighted distance between the working status parameters and the calibration working point, including: in response to the weighted distance being less than a preset threshold and the working status parameters meeting preset conditions, mapping the weighted distance based on a preset mapping function to obtain the operation reliability coefficient; in response to the weighted distance being greater than or equal to the preset threshold, or the working status parameters not meeting preset conditions, determining the operation reliability coefficient as a preset value.

[0120] The aforementioned preset threshold refers to the boundary value used to determine whether the current operating state of the feedforward control model is in a high-confidence region. The preset threshold is set based on the error tolerance or system stability requirements calibrated by bench testing. If the weighted distance is less than the preset threshold, it indicates that the real-time operating state parameters are sufficiently close to the calibrated operating point, and the interpolation error of the feedforward control model is within the allowable range; in this case, the model output can be trusted. If the weighted distance is greater than or equal to the preset threshold, it indicates a significant deviation from the operating condition, the feedforward control model is in the extrapolation region, the prediction results have low confidence, and protective measures are required. The feedforward control model serves as the dividing line between the reliable and unreliable regions of the model.

[0121] The aforementioned preset conditions refer to a set of logical rules for verifying the physical rationality or safety of operating parameters. These preset conditions include whether the oil temperature, motor speed, and operating pressure are within the safe operating envelope of the hydraulic pump or control system. If these parameters meet the preset conditions, the system is considered to be in a normal, operable state; otherwise, even if the weighted distance is small, the confidence level needs to be reduced to prevent system failures due to physical limits. For example, whether the temperature is within the anti-freezing or anti-overheating range, whether the speed is within the anti-cavitation or overload range, and whether the pressure is within the tolerance range of the seals.

[0122] The aforementioned pre-defined mapping function refers to a mathematical formula that non-linearly converts the weighted distance into a running confidence coefficient. The pre-defined mapping function typically exhibits a monotonically decreasing characteristic; that is, the smaller the weighted distance, the closer the mapped running confidence coefficient is to its maximum value, indicating a more reliable model. Conversely, the larger the weighted distance, the closer the mapped coefficient is to its minimum value, indicating a lower model confidence. The pre-defined mapping function transforms the geometric indicator of distance into a probability or confidence index that intuitively reflects the model's reliability, achieving a smooth transition from distance to confidence. The maximum value can be 1.0, and the minimum value can be 0.0.

[0123] The aforementioned preset values ​​refer to fixed values ​​that are forcibly assigned to the operational reliability coefficient if the feedforward control model has low reliability or the system state is abnormal. These preset values ​​are typically set at a low level to ensure that the system automatically switches to a safer mode that prioritizes feedback control or reduces the aggressiveness of control when the model fails or boundary conditions are not met. By setting preset values, dangerous control command outputs due to erroneous high reliability assessments under extreme operating conditions are avoided. Setting preset values ​​also ensures the basic safety of the hydraulic active suspension system under non-standard braking or fault conditions. The aforementioned low level can be zero or a minimum permissible value close to zero.

[0124] In one optional embodiment, the hydraulic suspension control system compares the calculated weighted distance with a preset threshold and checks whether the oil temperature, motor speed, and operating pressure are within the calibrated safe operating window. If the weighted distance is less than the preset threshold and the operating state parameters meet the preset conditions, a preset nonlinear mapping function is invoked, using the weighted distance as an input variable to calculate the corresponding operational reliability coefficient. The operational reliability coefficient increases smoothly as the distance decreases, thereby ensuring that the model is within the effective interpolation region while providing a high reliability assessment, supporting the full utilization of feedforward control. The aforementioned preset nonlinear mapping function can be an sigmoid function.

[0125] This application embodiment determines the operational reliability coefficient by distinguishing operating condition regions and using a strategy that combines mapping functions with preset values. This achieves accurate hierarchical evaluation of the reliability of the feedforward model, which not only utilizes the high precision advantage of the model in the calibration region, but also provides safety protection in the non-calibration region, thereby improving the robustness and safety of the hydraulic active suspension control algorithm.

[0126] Optionally, the method further includes: determining a feedforward control quantity based on the target driving force and operating state parameters; and determining a feedback control quantity based on the target driving force and actual driving force.

[0127] In one optional embodiment, the hydraulic suspension control system first acquires operating status parameters such as current oil temperature, motor speed, and working pressure. The hydraulic suspension control system inputs the target working power and the aforementioned operating status parameters to the PQ characteristic curve feedforward controller. Using a multi-dimensional interpolation algorithm, it queries and calculates the target hydraulic pump flow rate and the corresponding target motor torque required to achieve the target working power from the PQ characteristic curve database. Finally, a feedforward control quantity is generated. Furthermore, the actual working power signal is acquired, and the actual working power signal is subtracted from the target working power to obtain an error signal, which is input to the PID feedback controller for calculation to generate a feedback control quantity, thereby realizing parallel calculation of open-loop feedforward and closed-loop feedback.

[0128] This application embodiment achieves an organic combination of open-loop prediction and closed-loop correction by determining the feedforward control quantity and feedback control quantity in parallel. The feedforward control provides a basis for fast response, and the feedback control eliminates residual errors. The synergistic effect of the two improves the control accuracy, response speed and robustness of the hydraulic active suspension system.

[0129] Optionally, the hydraulic suspension system includes a hydraulic pump and a hydraulic actuator. Based on the target actuation force and operating state parameters, a feedforward control quantity is determined, including: determining the nominal output flow rate and internal leakage flow rate of the hydraulic pump based on the hydraulic pump oil temperature and motor speed in the operating state parameters; determining the target effective flow rate required for the hydraulic actuator to generate the target actuation force based on the effective area of ​​the hydraulic actuator; and determining the feedforward control quantity based on the target effective flow rate, internal leakage flow rate, nominal output flow rate, and the operating pressure of the hydraulic pump in the operating state parameters.

[0130] The aforementioned hydraulic pump refers to an energy conversion device that converts the mechanical energy input from an electric motor into hydraulic energy. Electric variable displacement pumps are commonly used in active suspension systems. The function of a hydraulic pump is to output hydraulic oil with specific pressure and flow rate according to control commands to drive the actuator. The performance parameters of a hydraulic pump are directly affected by oil temperature, motor speed, and operating pressure, and it is the fundamental actuator for constructing a feedforward model of the PQ characteristic curve. The performance parameters of the aforementioned hydraulic pump can be indicative of flow rate and internal leakage.

[0131] The aforementioned hydraulic actuator refers to an actuator that converts hydraulic energy into mechanical energy to generate active control force, typically consisting of a hydraulic cylinder and its piston. By receiving high-pressure hydraulic fluid from a hydraulic pump, it utilizes the effective working area to convert the fluid pressure into linear thrust or tension, directly acting on the vehicle's suspension arms or body. The actual acting force generated is closely related to the input flow rate, system pressure, and load resistance, and is the direct output for measuring the final control effect of the suspension system.

[0132] The nominal output flow rate mentioned above refers to the ideal output flow rate of the hydraulic pump calculated based on the theoretical geometric displacement under specific oil temperature and motor speed. The nominal output flow rate reflects the maximum fluid delivery capacity of the hydraulic pump under leak-free conditions. It serves as the fundamental benchmark for evaluating hydraulic pump performance. The nominal output flow rate is obtained by querying a pre-calibrated PQ characteristic curve database. It depends only on speed and temperature, and is unaffected by operating pressure. It characterizes the intrinsic transport characteristics of the hydraulic pump under current operating conditions, providing a theoretical reference benchmark for subsequent calculations of the actual required flow rate.

[0133] The aforementioned internal leakage flow rate refers to the volume of fluid leaking from the high-pressure side to the low-pressure side of a hydraulic pump under specific operating pressure, oil temperature, and motor speed conditions due to a pressure difference existing within the pump's internal clearances. The internal leakage flow rate is positively correlated with the operating pressure, increasing with rising pressure, reflecting the volumetric efficiency loss of the hydraulic pump. The internal leakage flow rate is a key deduction item for determining the actual effective output flow rate of the hydraulic pump. It is obtained from leakage characteristic curves in the PQ characteristic curve database and used to compensate for insufficient flow caused by internal leakage, improving the accuracy of feedforward control. The aforementioned internal clearances can be between the plunger and cylinder, or between the distributor plate and cylinder, etc.

[0134] The aforementioned effective area refers to the equivalent force-bearing area of ​​a hydraulic actuator piston or plunger when it generates thrust under pressure. The effective area is a key geometric constant that converts fluid pressure in a hydraulic system into mechanical force. For double-acting hydraulic cylinders, it is necessary to distinguish the effective areas of the rodless chamber and the rod chamber. The effective area is a conversion parameter connecting the hydraulic power end and the mechanical actuation end, directly affecting the transmission efficiency.

[0135] The aforementioned target effective flow rate refers to the flow rate required by the hydraulic actuator to generate the target working force and meet specific motion speed requirements. The target effective flow rate is the direct fluid demand driving the hydraulic actuator, calculated using the effective area of ​​the hydraulic actuator and the desired motion characteristics. The target effective flow rate reflects the system's immediate work demand on external loads and is the minimum flow rate benchmark that must be met in feedforward control calculations to ensure that the hydraulic pump can provide sufficient power to support the achievement of the target force.

[0136] In one optional embodiment, the hydraulic suspension control system first queries the PQ characteristic curve database for the corresponding nominal output flow rate curve and internal leakage flow rate curve based on the oil temperature and motor speed parameters in the current operating state. Then, the hydraulic suspension control system obtains the nominal output flow rate value and the corresponding internal leakage flow rate value under the current operating condition through interpolation. Next, it calculates the target effective flow rate based on the target actuation force and the effective area of ​​the hydraulic actuator, combined with the dynamic pressure change rate. Finally, it adds the target effective flow rate to the internal leakage flow rate to obtain the total required flow rate of the hydraulic pump, and then compares it with the nominal output flow rate. The corresponding target motor speed or torque command is calculated using a lookup table or analytical formula as the feedforward control quantity.

[0137] This application embodiment constructs a physical mechanism feedforward model based on PQ characteristics by decomposing nominal flow rate, internal leakage flow rate and target effective flow rate. This improves the mapping accuracy from target force to actuator drive command, effectively compensates for the nonlinear leakage characteristics of the hydraulic system, and enhances the dynamic response speed and steady-state control accuracy of the active suspension.

[0138] Optionally, based on the target effective flow rate, internal leakage flow rate, nominal output flow rate, and the working pressure of the hydraulic pump in the operating status parameters, the feedforward control quantity is determined, including: determining the target demand flow rate of the hydraulic pump based on the target effective flow rate and internal leakage flow rate, wherein the target demand flow rate is the actual output flow rate of the hydraulic pump required to drive the hydraulic actuator to generate the target actuation force after compensating for the internal leakage flow rate; and determining the feedforward control quantity based on the target demand flow rate, nominal output flow rate, and the working pressure of the hydraulic pump in the operating status parameters.

[0139] The target required flow rate mentioned above refers to the actual volumetric flow rate of fluid that the hydraulic pump must output under current operating conditions. The target required flow rate is the sum of the target effective flow rate and the internal leakage flow rate. The target required flow rate aims to compensate for fluid backflow losses caused by pressure differences within the pump's internal clearances, ensuring that the flow rate ultimately reaching the hydraulic actuator is sufficient to generate the target actuation force. The target required flow rate is a key intermediate variable connecting the actuator's demand and the pump's output, reflecting the net flow reserve required by the system after overcoming internal leakage losses.

[0140] The operating pressure of the hydraulic pump mentioned above refers to the static pressure of the fluid at the outlet or load side of the hydraulic system. The operating pressure of the hydraulic pump determines the amount of internal leakage and its volumetric efficiency. As the load changes, fluctuations in operating pressure cause changes in leakage, which in turn affects the pump's actual output flow. By monitoring the operating pressure of the hydraulic pump, the control algorithm can dynamically adjust the feedforward commands to compensate for flow losses caused by pressure fluctuations, ensuring that the hydraulic actuator can respond to the target force under different loads and maintaining the stability of the system control.

[0141] In one optional embodiment, the hydraulic suspension control system first adds the target effective flow rate to the internal leakage flow rate obtained from the current operating pressure to obtain the target required flow rate of the hydraulic pump. Then, it reads the nominal output flow rate corresponding to the current motor speed from the PQ characteristic curve database and calculates the flow deviation value between the target required flow rate and the nominal output flow rate. Next, it selects the corresponding coefficient from a preset pressure compensation coefficient table based on the current operating pressure. Finally, it multiplies the flow deviation value by the pressure compensation coefficient to obtain the feedforward control quantity used to correct the motor speed or torque, achieving accurate feedforward calculation based on flow balance and pressure compensation. The aforementioned preset pressure compensation coefficient table refers to a pre-calibrated lookup table stored in the controller, which establishes a mapping relationship between the hydraulic pump operating pressure, flow rate, and pressure characteristic deviation correction coefficient.

[0142] This application embodiment calculates the target required flow rate and determines the feedforward quantity by combining the nominal flow rate and pressure. This effectively compensates for the nonlinear leakage characteristics of the hydraulic pump, improves the accuracy and response speed of the feedforward control, and ensures high-performance control of the hydraulic active suspension under complex load conditions.

[0143] Optionally, based on the target demand flow rate, the nominal output flow rate, and the working pressure of the hydraulic pump in the working status parameters, the feedforward control quantity is determined, including: determining the flow deviation value between the target demand flow rate and the nominal output flow rate; determining the pressure compensation coefficient corresponding to the working pressure from multiple preset pressure compensation coefficients; and determining the feedforward control quantity based on the flow deviation value and the pressure compensation coefficient.

[0144] The aforementioned flow deviation value refers to the algebraic difference between the actual required output flow rate of the hydraulic pump under current operating conditions and the theoretical nominal output flow rate. The flow deviation value reflects the flow loss caused by factors such as internal leakage, volumetric efficiency loss, or mechanical friction. A positive deviation indicates that the actual required flow rate is greater than the nominal flow rate, requiring an increase in motor speed or torque to improve output. A negative deviation indicates that the actual required flow rate is less than the nominal flow rate, requiring a decrease in motor speed or torque to improve output. By quantifying the flow deviation value, the control algorithm can calculate the additional drive energy required to compensate for the system's nonlinear losses, providing fundamental data for achieving high-precision feedforward control.

[0145] The aforementioned preset pressure compensation coefficient refers to a set of dimensionless coefficients pre-calibrated in the PQ characteristic curve database to correct the impact of pressure on hydraulic pump performance. The preset pressure compensation coefficient reflects the nonlinear characteristics of the hydraulic pump's volumetric efficiency and mechanical efficiency as a function of pressure under different operating pressures. If the operating pressure increases, internal leakage and frictional losses increase, and the pressure compensation coefficient is adjusted accordingly to compensate for these effects. By finding the preset pressure compensation coefficient corresponding to the current operating pressure, the flow deviation value can be mapped to an accurate increment of motor control commands, ensuring that the feedforward control quantity can adapt to the dynamic changes in system load pressure.

[0146] The aforementioned pressure compensation coefficient refers to a specific coefficient value obtained by matching or interpolating from a preset pressure compensation coefficient table based on the currently collected real-time hydraulic pump operating pressure. The pressure compensation coefficient makes the feedforward control variable not a fixed linear gain, but an adaptive variable that dynamically changes with the load pressure. By selecting a coefficient that matches the current pressure, the actual performance state of the hydraulic pump at the aforementioned pressure point can be reflected, thereby eliminating feedforward control errors caused by pressure fluctuations and improving the system's control accuracy under varying load conditions.

[0147] In one optional embodiment, the hydraulic suspension control system first calculates the difference between the target required flow rate and the nominal output flow rate to obtain a flow rate deviation value. Then, based on a preset pressure compensation coefficient table, it determines the corresponding pressure compensation coefficient using linear interpolation according to the current operating pressure. If the current pressure is between two calibrated pressure points, proportional interpolation is used to obtain a more accurate coefficient value. Finally, the flow rate deviation value is multiplied by the pressure compensation coefficient to obtain the feedforward control quantity used to adjust the motor speed.

[0148] This application embodiment achieves feedforward compensation for the nonlinear characteristics of the hydraulic pump by combining flow deviation and pressure compensation coefficient. This embodiment effectively eliminates control errors caused by load pressure variations, improving the dynamic response speed and steady-state control accuracy of the hydraulic active suspension system.

[0149] Optionally, the method further includes: acquiring the vehicle body posture information corresponding to the hydraulic suspension system, or collecting road surface preview information of the road surface where the vehicle is currently located; and determining the target to act as a power source based on the vehicle body posture information or the road surface preview information.

[0150] The aforementioned vehicle attitude information refers to a set of physical parameters reflecting the real-time motion of the vehicle's sprung mass in three-dimensional space. Vehicle attitude information includes variables such as vertical displacement, vertical acceleration, roll angle, pitch angle, and roll rate. These parameters characterize the dynamic response characteristics of the vehicle during driving and are indicators for evaluating vehicle ride comfort and handling stability. Vehicle attitude information is used to feed back the actual motion state of the vehicle to the suspension control system, enabling the generation of corresponding control commands to suppress undesirable vehicle movements.

[0151] The aforementioned road surface preview information refers to the geometric shape and texture features of the road surface ahead of the vehicle, detected in advance by front-mounted sensors. Road surface preview information includes, but is not limited to, the position, height, width, and shape of obstacles such as road bumps, depressions, potholes, and slope changes. This information can predict the excitation input that the vehicle suspension will encounter, serving as a crucial input source for feedforward control. By identifying road surface unevenness and converting it into equivalent displacement or force spectrum signals, it provides a control basis for the active suspension system. Simultaneously, it allows hydraulic actuators to respond in advance before the wheels contact the road surface excitation, effectively isolating the transmission of road vibrations to the vehicle body. The aforementioned front-mounted sensors can be cameras, LiDAR, or ultrasonic sensors, etc.

[0152] In one optional embodiment, the hydraulic suspension control system first constructs a vehicle state vector by collecting data on the vehicle's vertical acceleration, roll angle, and pitch angle. Then, the vehicle state vector is input into a preset vehicle dynamics state observer to calculate the target action power required for each wheel suspension, minimizing vehicle vibration energy and satisfying tire contact force constraints. The aforementioned preset vehicle dynamics state observer is a software module that estimates key dynamic state variables of the vehicle that cannot be directly measured, based on a vehicle mathematical model and sensor measurement data, using algorithms such as Kalman filtering, sliding mode observers, or high-gain observers. These key dynamic state variables that cannot be directly measured may include the center of gravity sideslip angle, tire sideslip stiffness, and road surface adhesion coefficient.

[0153] This application embodiment integrates vehicle posture feedback and road surface preview feedforward information to determine the target for dynamic control, achieving an organic combination of responsive and predictive control. This application embodiment improves the hydraulic active suspension's ability to suppress dynamic disturbances and its proactive adaptation to road surface stimuli.

[0154] Optionally, controlling the hydraulic suspension system based on the target control quantity includes: analyzing the target control quantity to obtain the motor torque component; determining the target motor torque command based on the minimum motor torque and the motor torque component of the hydraulic suspension system; and controlling the hydraulic suspension system based on the target motor torque command.

[0155] The aforementioned motor torque component refers to the portion of motor torque extracted or separated from the target control quantity, specifically used to overcome the load resistance of the hydraulic system and generate the required hydraulic power. The motor torque component directly corresponds to the mechanical input torque required by the hydraulic pump under the current operating pressure and flow rate demands. It does not include the additional torque required for system inertia compensation or dynamic acceleration, but rather represents the steady-state or quasi-steady-state torque demand calculated based on the hydraulic pump's operating pressure, displacement, and efficiency model. The motor torque component reflects the main portion of the hydraulic system's consumption of the motor's mechanical energy and is a fundamental core element in determining the final motor drive command, ensuring that the motor can provide sufficient continuous power to maintain the achievement of the target control quantity.

[0156] The aforementioned minimum motor torque refers to the minimum torque threshold required for the electro-hydraulic pump in the hydraulic suspension frame to maintain normal operation, overcome internal mechanical friction, and maintain the system's basic pressure. The minimum motor torque is determined by the hydraulic pump's mechanical efficiency, friction characteristics, and system static pressure, and is used to prevent the motor from losing synchronization, stopping, or failing to build sufficient oil pressure under low load or reverse operating conditions. The minimum motor torque ensures that the hydraulic system maintains basic functional integrity under control commands. As a safe lower limit for control commands, the minimum motor torque prevents hydraulic pump failure due to excessively low target torque, thereby guaranteeing the basic support capacity and safety of the suspension system.

[0157] The aforementioned target motor torque command refers to the actual torque command, after minimum torque limitation, ultimately sent to the electric hydraulic pump drive motor. The target motor torque command is the direct basis for the motor controller. It combines the load torque component with safety lower limit protection, ensuring that the motor output torque meets both the dynamic requirements of the hydraulic system and the boundary conditions for safe mechanical operation. Precise tracking of this command is achieved through pulse width modulation (PWM) or current loop control, driving the hydraulic pump to generate the corresponding speed and pressure, thereby driving the hydraulic actuator to produce the target operating force.

[0158] In one optional embodiment, the hydraulic suspension control system first inputs the target control quantity to the torque calculation unit and calculates the steady-state load torque required to maintain this operating condition, which is the motor torque component, based on the current hydraulic pump's working pressure and efficiency curve. Subsequently, the hydraulic suspension control system compares this motor torque component with a preset minimum motor torque. If the motor torque component is less than the minimum motor torque, the target motor torque command is set to the minimum motor torque to maintain basic system operation. If the motor torque component is greater than the minimum motor torque, the target motor torque command is set as the motor torque component, thereby outputting the final drive signal.

[0159] This application embodiment achieves safe and accurate processing of hydraulic pump drive commands by analyzing the target control quantity and introducing a minimum motor torque limit. This ensures stable operation of the motor under low load conditions and accurate power output under high load conditions, effectively improving the reliability and dynamic response performance of hydraulic active suspension control.

[0160] This application provides a hydraulic active suspension coordinated control algorithm based on PQ curve feedforward and PID feedback, including the following scheme: construction of PQ curve feedforward controller, construction of PID feedback controller, coordinated control mechanism of feedforward and feedback, and output and execution of control commands.

[0161] In the construction phase of the PQ curve feedforward controller, the flow and pressure characteristic curves of the electro-hydraulic pump in the hydraulic active suspension system are first acquired across the entire operating range, including the PQ characteristics and pump leakage characteristics under different oil temperatures and motor speeds. A PQ characteristic curve database is established. Based on the target working power output by the suspension control algorithm, and combined with the current system working pressure, oil temperature, and motor speed information, the target hydraulic pump flow rate, the corresponding target motor speed, and the target torque required to achieve the target working power are calculated by querying the PQ characteristic curve database and performing interpolation calculations, thus forming the feedforward control quantity.

[0162] During the construction phase of the PID feedback controller, the actual output force signal of the hydraulic active suspension system or vehicle attitude information (such as vehicle vertical acceleration, suspension dynamic deflection, etc.) is collected. The deviation between the target action force and the measured actual action force is used as the input of the PID controller. After proportional, integral, and derivative operations, the PID feedback control quantity is generated to eliminate the residual error of the feedforward control and suppress unknown disturbances.

[0163] In the collaborative control mechanism of feedforward and feedback, a collaborative improvement strategy for the feedforward control quantity and the PID feedback control quantity is established. Specifically, this includes: dynamic weight allocation, which adjusts the weight coefficients of the feedforward and feedback control quantities in the total control output according to the system's operating state to achieve dynamic coordination of their control effects; feedforward correction, which uses the integral output or error accumulation information of the PID feedback controller as a correction signal for the feedforward control model, periodically or based on event triggering to update the model parameters in the PQ characteristic curve database, enabling the feedforward control model to adaptively track changes in the hydraulic system characteristics; feedback limiting protection, which dynamically limits the output range of the PID feedback control quantity based on the confidence interval of the feedforward control quantity to prevent excessive adjustment of the feedback control quantity from causing system oscillations; and the output and execution of control commands, which converts the collaboratively improved total control quantity, i.e., the weighted sum of the feedforward and feedback control quantities, into a drive command (motor torque command or speed command) for the electric hydraulic pump, driving the hydraulic pump to output the corresponding flow and pressure, thus enabling the hydraulic actuator to generate the target working force.

[0164] In related technologies, feedforward control is mostly based on ideal hydraulic models or simplified dynamic models. However, the embodiments of this application use the actual PQ characteristic curve of the hydraulic pump as the basis for feedforward control and establish an accurate feedforward model covering all working conditions.

[0165] In related technologies, feedforward control and PID feedback control are mostly designed independently and simply superimposed, while the embodiments of this application establish a collaborative working mechanism that includes dynamic weight allocation, feedforward correction and feedback limiting.

[0166] In related technologies, the accuracy of the conversion from target force to pump control parameters is insufficient. However, the embodiments of this application achieve accurate mapping from target force value to motor torque and speed through the PQ characteristic curve database.

[0167] This application's embodiments improve the accuracy of feedforward control. Instead of using an idealized hydraulic model, this embodiment uses the actual PQ characteristic curve of the hydraulic pump under all operating conditions as the core of the feedforward control, thus accurately reflecting the pump's actual flow output capacity under different operating pressures and oil temperatures. The feedforward control based on the PQ characteristic curve in this application's embodiments can reduce the steady-state deviation between the target force value and the actual output force by more than 60%, effectively solving the compensation deviation problem caused by model simplification in related technologies.

[0168] This application's embodiments achieve complementarity between feedforward and feedback control. Through a dynamic weight allocation mechanism, the feedforward control undertakes the primary task of compensating for measurable disturbances, while the PID feedback control focuses on suppressing residual errors and unknown disturbances. The collaborative work of these two systems ensures both rapid response characteristics and steady-state accuracy and robustness, overcoming the control conflicts or deficiencies caused by independent design and simple superposition of these two technologies in related technologies.

[0169] This application's embodiments enhance the control algorithm's adaptability to the nonlinearity of hydraulic systems. Through a feedforward correction stage, the embodiments utilize error information from the PID feedback controller to periodically update the PQ characteristic curve model parameters, enabling the feedforward control model to adaptively track hydraulic system characteristic drift caused by factors such as oil temperature changes and component wear. Compared to fixed-parameter feedforward and PID control, this application's embodiments maintain good control performance even with large variations in the system's operating point, significantly improving control robustness.

[0170] This application's embodiments improve the conversion accuracy and response speed from target force values ​​to pump control parameters. Through a pre-calibrated PQ characteristic curve database, this application's embodiments achieve rapid table lookup and interpolation calculations from target force to motor torque and speed commands. Compared to related technologies that rely on empirical formulas or offline simulations, this application's embodiments offer higher conversion accuracy and faster response speed, better meeting the real-time requirements of hydraulic active suspension.

[0171] The embodiments of this application reduce the engineering implementation difficulty of the control algorithm. The PQ characteristic curves of the embodiments of this application can be pre-calibrated through bench testing, and once the database is established, it can be used offline in the vehicle controller. The online computation is small, and the hardware requirements of the controller are low.

[0172] Figure 2 This is a schematic diagram of the system structure of a control method for a hydraulic suspension system according to an embodiment of this application, as shown below. Figure 2 As shown, this application also provides a hydraulic active suspension cooperative control algorithm based on flow and pressure curve feedforward and proportional, integral and derivative feedback. The above control system mainly includes: a target power input module, a flow and pressure curve feedforward controller and a proportional, integral and derivative feedback controller, a cooperative control module, a flow and pressure characteristic curve database, a signal acquisition module, and a hydraulic actuation system.

[0173] The output of the target power input module is connected to the input of the flow and pressure curve feedforward controller and the first input of the proportional, integral, and derivative feedback controller. The first input of the flow and pressure curve feedforward controller is connected to the target power input module, the second input is connected to the flow and pressure characteristic curve database, and the output is connected to the first input of the cooperative control module. The first input of the proportional, integral, and derivative feedback controller is connected to the target power input module, the second input is connected to the output of the signal acquisition module, and the output is connected to the second input of the cooperative control module. The cooperative control module includes a dynamic weight allocation unit, a feedforward correction unit, and a feedback limiting unit. The output of the cooperative control module is connected to the input of the hydraulic actuation system. The hydraulic actuation system includes an electric hydraulic pump, a hydraulic actuator, and an accumulator. The output of the hydraulic actuation system acts on the controlled object (i.e., the sprung mass of the vehicle). The input of the signal acquisition module is connected to the hydraulic actuation system to acquire the actual output force signal, system operating pressure, oil temperature, and motor speed information.

[0174] The target operating power input module provides the target operating power to the flow and pressure curve feedforward controller and the proportional, integral, and derivative (PI) feedback controller. The signal acquisition module collects the actual output force, working pressure, oil temperature, and motor speed from the hydraulic actuator and feeds these signals back to the PI feedback controller. The flow and pressure curve feedforward controller combines the target operating power with data from the flow and pressure characteristic curve database to generate a feedforward control quantity. The PI feedback controller generates a PID feedback control quantity based on the deviation between the target operating power and the actual output force. The collaborative control module receives the feedforward control quantity and the PID feedback control quantity, processes them through an internal dynamic weight allocation unit, a feedforward correction unit, and a feedback limiting unit, and then generates a total control quantity. This control quantity drives the hydraulic actuator system, causing its output to act as a target force on the sprung mass of the vehicle.

[0175] Figure 3 This is a schematic diagram illustrating the construction and querying of a characteristic curve database for a control method of a hydraulic suspension system according to an embodiment of this application, as shown below. Figure 3 As shown, the flow rate and pressure characteristic curve database was obtained through bench testing.

[0176] First, during the test platform setup phase, the electric hydraulic pump was installed on a hydraulic pump performance test bench. The test bench included a drive motor, torque sensor, flow meter, pressure sensor, temperature control device, and adjustable load valve. The drive motor powers the electric hydraulic pump, the torque sensor measures the input torque, the flow meter is installed at the pump's outlet to measure the actual output flow rate Q, the pressure sensor is installed at the pump's outlet to measure the working pressure P, and the temperature control device maintains the oil temperature at a set value. .

[0177] During the calibration phase of the flow and pressure characteristic curves under all operating conditions, the oil temperature... Under these conditions, the motor speed is set to... At each set speed, the system operating pressure P is gradually increased by adjusting the load valve. The actual output flow rate Q at each pressure point is recorded, and the flow rate versus pressure characteristic curves at that speed and temperature are plotted to construct a database of flow rate versus pressure characteristic curves under all operating conditions. Furthermore, with the pump outlet closed (i.e., output flow rate Q=0), the internal leakage of the pump is measured at different pressures P. Leakage characteristic curves were plotted, and a leakage characteristic curve library was constructed. Based on the full-condition flow and pressure characteristic curve database and the leakage characteristic curve library, a final multidimensional interpolation lookup table database was built.

[0178] In the database storage and interpolation model, calibration data is stored in a flow and pressure characteristic curve database, which is organized in the form of a three-dimensional lookup table. The first dimension is the current oil temperature T, the second dimension is the current motor speed n, and the third dimension is the current working pressure P. The corresponding outputs are the actual output flow rate Q and the leakage rate. For operating points that are not directly calibrated, multidimensional linear interpolation methods can be used for calculation.

[0179] Ultimately, the target flow rate and target motor speed can be obtained based on the current oil temperature, current motor speed, and current working pressure.

[0180] For example, the above oil temperature , i=1,2,…,n, n≥5, temperature range is Every A calibration temperature point can be set. The motor speed mentioned above... j=1, 2, ..., m, m≥8, the speed range is ,from A calibration speed point can be set every 500 rpm initially. The system operating pressure P is gradually increased from 0 to the maximum operating pressure of 150 bar, with the pressure step size set to 5 bar.

[0181] This application provides a collaborative control module, which includes a dynamic weight allocation unit, a feedforward correction unit, and a feedback limiting unit, used to achieve a collaborative improvement in the ratio of feedforward control quantity and PID feedback control quantity.

[0182] During the dynamic weight allocation phase, the dynamic weight allocation unit calculates the dynamic weight coefficients of the feedforward control quantity based on the current operating state of the system. Dynamic weighting coefficients of PID feedback control quantity The above and satisfy .

[0183] First, the dynamic weight allocation unit obtains the current operating status parameters of the system from the signal acquisition module. These operating status parameters include the error amplitude. Error change rate and load change rate If the error magnitude Greater than the first preset threshold When this occurs, it indicates that the system is in the dynamic response phase, at which point the rapid response advantage of feedforward control should be fully utilized. The dynamic weight allocation unit assigns weight coefficients to the feedforward control quantity. Set to a larger value. Adjust the weighting coefficient of the PID feedback control quantity. Set to a smaller value. If the error amplitude... Less than the second preset threshold And the rate of change of error Less than the third threshold When this occurs, it indicates that the system is in a steady-state phase, at which point the high-precision steady-state regulation advantage of PID feedback control should be fully utilized. The dynamic weight allocation unit assigns weight coefficients to the feedforward control quantity. Set to a smaller value, and adjust the weighting coefficient of the PID feedback control quantity. Set to a larger value. If the error amplitude is within the first preset threshold... With the second preset threshold When the time interval is between these two points, it indicates that the system is in a transition phase.

[0184] The above Setting it to a larger value can be The above. Smaller values ​​can be The above. Smaller values ​​can be The above. Larger values ​​can be The dynamic weight allocation unit smoothly adjusts the weighting coefficients based on the error change rate and load change rate. and An S-shaped curve can be used for the transition to avoid system jitter caused by abrupt changes in weights. Specifically, and The calculation formula is as follows:

[0185] ;

[0186] ;

[0187] in, The error magnitude, It is the hyperbolic tangent function. The first preset threshold, The second preset threshold is then set. Subsequently, the dynamic weight allocation unit assigns the weighted coefficients... and Output to the weighted summation unit.

[0188] During the feedforward correction stage, the input of the feedforward correction unit is connected to the integral output or error accumulation information of the PID feedback controller, which is used to correct the model parameters in the PQ characteristic curve database online.

[0189] First, the feedforward correction unit continuously monitors the integral term output of the PID feedback controller. If the integral term output remains positive and exceeds a set threshold... This indicates that the feedforward control input is consistently too small, requiring positive correction of the flow parameters in the PQ curve database. Conversely, if the integral term output is consistently negative and lower than... This indicates that the feedforward control input is consistently too large and requires negative correction.

[0190] The above correction amount The calculation uses a cumulative error proportional adjustment method, and the calculation formula is as follows:

[0191] ;

[0192] in, This is the average value of the integral term over the past N control cycles. This is an adaptive correction factor. The corrected flow rate value. The calculation formula is as follows:

[0193] ;

[0194] in, This is the nominal flow rate value obtained from the PQ characteristic curve database. The corrected parameters are stored in the corrected parameter field of the PQ characteristic curve database for subsequent feedforward control queries. To prevent over-correction, the correction amount can be adjusted. A limiting effect is applied. For example, the limiting value for the above limiting effect can be ±5% of the nominal flow rate.

[0195] During the feedback limiting calculation stage, the input of the feedback limiting unit is connected to the reliability evaluation signal of the feedforward control quantity, which is used to dynamically limit the output range of the PID feedback control quantity according to the reliability interval of the feedforward control quantity.

[0196] First, the feedback limiting unit evaluates the reliability of the feedforward control quantity. The reliability assessment is based on the distance between the current operating point and the nearest calibrated operating point (the closer the distance, the higher the reliability), whether the current oil temperature is within the calibrated temperature range, and whether the current speed is within the calibrated speed range. Taking all these factors into account, the reliability coefficient of the feedforward control quantity is calculated. The above credibility coefficient The range can be .

[0197] Secondly, based on the credibility coefficient Determine the amplitude limit of the PID feedback control quantity :

[0198] ;

[0199] in, This is the maximum permissible output value of the PID feedback control quantity. Further feedback limiting unit controls the output of the PID feedback controller. The amplitude limiting process is calculated using the following formula:

[0200] ;

[0201] PID feedback control quantity after amplitude limiting Output to the weighted summation unit.

[0202] Finally, in the stage of weighted summation and output of the total control quantity, the weighted summation unit receives the feedforward control quantity. PID feedback control quantity after amplitude limiting and weighting coefficients and Perform a weighted summation to determine the total control quantity. The calculation formula is as follows:

[0203] ;

[0204] Among them, total control quantity The electric hydraulic pump, which outputs motor torque commands to the hydraulic actuator system, drives the hydraulic pump to operate at the target speed and target torque, outputting the corresponding flow rate and pressure, so that the hydraulic actuator generates the target working force.

[0205] This application also provides a control method for a hydraulic suspension system, the steps of which are as follows:

[0206] First, the target force input module acquires the target action force output by the hydraulic suspension control algorithm. The suspension control algorithm can calculate the target dynamics based on vehicle attitude information, or it can calculate them in advance using road surface preview information. The aforementioned vehicle attitude information can include vertical acceleration, roll angle, pitch angle, etc.

[0207] The signal acquisition module collects information on the current system's operating pressure P, oil temperature T, and motor speed n, and transmits this information to the PQ curve feedforward controller and the collaborative control module. The PQ curve feedforward controller queries the PQ characteristic curve database and performs multi-dimensional interpolation calculations to calculate the power required to achieve the target. Required hydraulic pump target flow rate and the corresponding target motor speed and target torque Generate feedforward control quantity The signal acquisition module acquires the actual output force signal of the hydraulic active suspension system. The PID feedback controller uses the target as the driving force. Compared with the measured output force The deviation e between the two is taken as input, and after proportional, integral, and derivative operations, a PID feedback control quantity is generated. .

[0208] The dynamic weight allocation unit calculates the dynamic weighting coefficients of the feedforward control quantity in real time based on the system's operating status (load change rate, error amplitude, etc.). Dynamic weighting coefficients of PID feedback control quantity .

[0209] The feedforward correction unit uses the integral output or error accumulation information of the PID feedback controller as the feedforward correction signal to update the model parameters in the PQ characteristic curve database.

[0210] The feedback limiting unit dynamically limits the output range of the PID feedback control quantity based on the reliability interval of the feedforward control quantity, thus obtaining... .

[0211] The weighted summation unit will feed forward control input. The total control quantity is obtained by weighted summation of the control quantity and the PID feedback control quantity after amplitude limiting. .

[0212] Finally, the collaborative control module will control the total amount of data. The drive command is converted into a motor torque command for the electric hydraulic pump. This command drives the motor through the controller's PWM output module, causing the hydraulic pump to operate at the target speed and torque, outputting the corresponding flow and pressure. This drives the hydraulic actuator to generate the target driving force, thereby achieving active suspension control of the controlled object.

[0213] Figure 4This is a schematic diagram of an optional control method for a hydraulic suspension system according to an embodiment of this application, as shown below. Figure 4 As shown, the sensor first collects the current working pressure, oil temperature, and motor speed to query the flow-pressure curve. The acquired target force is then input to the flow-pressure curve query module to generate a feedforward control quantity. Simultaneously, the actual output force is collected to calculate the deviation from the target force, thereby generating a feedback control quantity. Dynamic weighting is applied to the feedforward and feedback control quantities. Subsequently, feedforward correction is performed based on the deviation to update the flow-pressure curve, and feedback limiting is applied based on the reliability of the feedforward model. Finally, the feedforward control quantity and the limited feedback control quantity are weighted and summed to convert into a drive command, which drives the hydraulic pump to output the target force.

[0214] This application proposes a feedforward control method based on the PQ characteristic curve of a hydraulic pump. By using the actual flow and pressure characteristic curves of the hydraulic pump under all operating conditions as the basis for feedforward control, an accurate mapping model from the target working power to the hydraulic pump control parameters is established, overcoming the problem of insufficient compensation accuracy caused by feedforward control based on an ideal hydraulic model in related technologies.

[0215] This application proposes a dynamic collaborative mechanism for feedforward control and PID feedback control. The embodiments of this application include a three-layer collaborative architecture comprising dynamic weight allocation, feedforward correction, and feedback limiting, achieving an improved balance and deep coupling between feedforward and feedback control.

[0216] This application establishes an adaptive correction strategy for the PQ curve based on error feedback. By utilizing the error accumulation information of the PID feedback controller, the parameters of the PQ characteristic curve model are corrected online, enabling the feedforward control model to adaptively track changes in hydraulic system characteristics with factors such as temperature and wear, thus enhancing the environmental adaptability and long-term stability of the control algorithm.

[0217] This application embodiment constructs a PQ characteristic curve database covering all operating conditions and a fast interpolation algorithm. PQ and leakage characteristic curves at different temperatures and speeds are pre-calibrated through bench tests to establish a relatively complete database. Combined with an efficient interpolation algorithm, a fast and accurate conversion from target force values ​​to motor torque or speed is achieved.

[0218] This application proposes the concept of a confidence interval for the feedforward control quantity and a feedback limiting protection strategy. This application can assess the confidence interval of the feedforward control quantity based on the uncertainty of the feedforward control model, and accordingly dynamically limit the output range of the PID feedback control quantity, effectively preventing system oscillations caused by over-adjustment while ensuring system response speed.

[0219] The feedforward control based on the PQ characteristic curve in this application embodiment can complete the conversion calculation from the target force value to the motor torque command in a short time, and the response speed is significantly improved.

[0220] The dynamic coordination mechanism of feedforward control and PID feedback control in this embodiment enables the overshoot of the system under step input to be controlled within 5% and the settling time to be less than 50ms, while the overshoot of simple superposition of feedforward and PID control is usually more than 15% and the settling time is greater than 100ms.

[0221] The online adaptive capability of the feedforward correction unit in this application embodiment enables the system to maintain a steady-state control accuracy within ±3% over the entire temperature range of oil temperature, from -20℃ to +100℃, while the steady-state error of uncorrected conventional control can reach more than ±15% under extreme temperatures.

[0222] The protection mechanism of the feedback limiting unit in this embodiment effectively prevents system oscillation caused by excessive control input under extreme operating conditions not covered by the PQ curve database, thus ensuring the safety and reliability of the control system.

[0223] Figure 5 This is a schematic diagram of an optional control method for a hydraulic suspension system according to an embodiment of this application, as shown below. Figure 5 As shown, it includes the following steps:

[0224] Step S502: Obtain the target working force, actual working force, and working status parameters of the hydraulic suspension system.

[0225] Step S504: Determine the weight allocation coefficient based on the target working force and the actual working force; determine the amplitude limit threshold based on the working state parameters and the maximum output limit of the feedback control quantity.

[0226] Step S506: Limit the feedback control quantity based on the limiting threshold to obtain the limited feedback control quantity.

[0227] Step S508: The feedforward control quantity and the feedback control quantity after amplitude limiting are weighted and summed based on the weight allocation coefficient to obtain the target control quantity, and the hydraulic suspension system is controlled based on the target control quantity.

[0228] According to an embodiment of this application, an apparatus embodiment for a control method of a hydraulic suspension system is provided. It should be noted that the apparatus can be used to execute the above-described control method of the hydraulic suspension system. Figure 6 This is a schematic diagram of a control device for a hydraulic suspension system according to an embodiment of this application, as shown below. Figure 6 As shown, the device includes: an acquisition module 602, a determination module 604, a limiting module 606, and a control module 608.

[0229] The acquisition module 602 is used to acquire the target action force, actual action force, and working state parameters of the hydraulic suspension system. The target action force refers to the desired control force generated by the hydraulic suspension system, and the actual action force refers to the actual control force generated by the hydraulic suspension system. The determination module 604 is used to determine the weighting coefficients of the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the limiting threshold of the feedback control quantity, based on the target action force, actual action force, and working state parameters. The limiting module 606 is used to limit the feedback control quantity based on the limiting threshold to obtain the limited feedback control quantity. The control module 608 is used to perform a weighted summation of the feedforward control quantity and the limited feedback control quantity based on the weighting coefficients to obtain the target control quantity, and then controls the hydraulic suspension system based on the target control quantity.

[0230] The determination module is also used to determine the weight allocation coefficient based on the target working force and the actual working force; and to determine the amplitude limit threshold based on the working state parameters and the maximum output limit of the feedback control quantity.

[0231] The determination module is also used to determine the error signal of the hydraulic suspension system based on the target driving force and the actual driving force; and to determine the weight allocation coefficient based on the error amplitude in the error signal.

[0232] The determining module is further configured to: determine a first weighting coefficient of the feedforward control quantity as a first preset value and a second weighting coefficient of the feedback control quantity as a second preset value in response to an error amplitude greater than a first preset threshold, thereby determining a weight allocation coefficient; determine a weight allocation coefficient based on the error amplitude, the error change rate in the error signal, and the load change rate of the hydraulic suspension system in response to an error amplitude less than or equal to a second preset threshold; and determine a first weighting coefficient of the feedforward control quantity as a second preset value and a second weighting coefficient of the feedback control quantity as a first preset value in response to an error amplitude less than or equal to a second preset threshold, thereby determining a weight allocation coefficient.

[0233] The hydraulic suspension system includes a feedforward control model and a determination module. It is also used to determine the limiting threshold based on the operating state parameters and the maximum output limit of the feedback control quantity. This includes: evaluating the feedforward control model based on the operating state parameters to obtain the operating reliability coefficient of the feedforward control model; and determining the limiting threshold based on the product of the operating reliability coefficient and the maximum output limit.

[0234] The device is also used to determine model correction parameters based on the average value of multiple integral terms in the feedback control quantity in response to the feedback control quantity not being in the preset threshold range; and to update the model parameters of the feedforward control model based on the model correction parameters.

[0235] The determination module is also used to determine the calibration working point that is closest to the working state parameters from multiple working points based on the oil temperature, motor speed and working pressure in the working state parameters; and to determine the operation reliability coefficient based on the weighted distance between the working state parameters and the calibration working point.

[0236] The device is also used to determine the temperature deviation between the oil temperature and the calibrated operating point; to determine the speed deviation between the motor speed and the calibrated operating point; to determine the pressure deviation between the working pressure and the calibrated operating point; and to obtain the weighted distance by weighting the temperature deviation, speed deviation, and pressure deviation based on the temperature weight value, speed weight value, and pressure weight value.

[0237] The determination module is further configured to, in response to a weighted distance less than a preset threshold and working status parameters meeting preset conditions, map the weighted distance based on a preset mapping function to obtain an operational reliability coefficient; and in response to a weighted distance greater than or equal to a preset threshold, or working status parameters not meeting preset conditions, determine the operational reliability coefficient as a preset value.

[0238] The device is also used to determine the feedforward control quantity based on the target driving force and working state parameters, and to determine the feedback control quantity based on the target driving force and actual driving force.

[0239] The hydraulic suspension system includes a hydraulic pump and a hydraulic actuator. This device is also used to determine the nominal output flow and internal leakage flow of the hydraulic pump based on the hydraulic pump oil temperature and motor speed in the working state parameters; to determine the target effective flow required for the hydraulic actuator to generate the target actuation force based on the effective area of ​​the hydraulic actuator; and to determine the feedforward control quantity based on the target effective flow, internal leakage flow, nominal output flow, and the working pressure of the hydraulic pump in the working state parameters.

[0240] The device is also used to determine the target required flow rate of the hydraulic pump based on the target effective flow rate and the internal leakage flow rate. The target required flow rate is the actual output flow rate of the hydraulic pump required to drive the hydraulic actuator to generate the target working power after compensating for the internal leakage flow rate. Based on the target required flow rate, the nominal output flow rate and the working pressure of the hydraulic pump in the working state parameters, the feedforward control quantity is determined.

[0241] The device is also used to determine the flow deviation between the target required flow rate and the nominal output flow rate; to determine the pressure compensation coefficient corresponding to the working pressure from multiple preset pressure compensation coefficients; and to determine the feedforward control quantity based on the flow deviation and the pressure compensation coefficient.

[0242] The device is also used to acquire the vehicle body posture information corresponding to the hydraulic suspension system, or to collect road surface preview information of the current road surface where the vehicle is located; based on the vehicle body posture information or road surface preview information, the target is determined for power.

[0243] The control module is also used to analyze the target control quantity to obtain the motor torque component; determine the target motor torque command based on the minimum motor torque and motor torque component of the hydraulic suspension system; and control the hydraulic suspension system based on the target motor torque command.

[0244] Embodiments of this application also provide a vehicle, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods described in various embodiments of this application when it runs.

[0245] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0246] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0247] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program that, when executed by a processor, implements the methods in various embodiments of this application.

[0248] Embodiments of this application also provide a computer program that, when executed by a processor, implements the methods described in the various embodiments of this application.

[0249] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0250] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0251] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0252] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0253] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0254] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A control method for a hydraulic suspension system, characterized in that, include: The target working force, actual working force, and working state parameters of the hydraulic suspension system are obtained, wherein the target working force is used to represent the control force expected to be generated by the hydraulic suspension system, and the actual working force is used to represent the control force actually generated by the hydraulic suspension system. Based on the target working force, the actual working force, and the working state parameters, determine the weight allocation coefficients of the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the amplitude limit threshold of the feedback control quantity; The feedback control quantity is limited based on the limiting threshold to obtain the limited feedback control quantity. The feedforward control quantity and the limited feedback control quantity are weighted and summed based on the weight allocation coefficient to obtain the target control quantity, and the hydraulic suspension system is controlled based on the target control quantity. Specifically, based on the target working force, the actual working force, and the working state parameters, the weight allocation coefficients for the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the amplitude limiting threshold of the feedback control quantity, are determined, including: The weight allocation coefficients are determined based on the target action force and the actual action force. The amplitude limiting threshold is determined based on the operating state parameters and the maximum output limit of the feedback control quantity; The hydraulic suspension system includes a feedforward control model, which determines the limiting threshold based on the operating state parameters and the maximum output limit of the feedback control quantity, including: The feedforward control model is evaluated based on the operating state parameters to obtain the operational reliability coefficient of the feedforward control model. The amplitude limiting threshold is determined based on the product of the operational reliability coefficient and the maximum output limit.

2. The method according to claim 1, characterized in that, Based on the target action force and the actual action force, the weight allocation coefficients are determined, including: Based on the target force and the actual force, the error signal of the hydraulic suspension system is determined; The weight allocation coefficients are determined based on the error amplitude in the error signal.

3. The method according to claim 2, characterized in that, Determining the weight allocation coefficients based on the error amplitude in the error signal includes: In response to the error amplitude being greater than a first preset threshold, a first weighting coefficient of the feedforward control quantity is determined as a first preset value, and a second weighting coefficient of the feedback control quantity is determined as a second preset value, so as to determine the weight allocation coefficient; In response to the error amplitude being less than or equal to the first preset threshold and the error amplitude being greater than the second preset threshold, the weight allocation coefficient is determined based on the error amplitude, the error change rate in the error signal, and the load change rate of the hydraulic suspension system. In response to the error amplitude being less than or equal to the second preset threshold, the first weighting coefficient of the feedforward control quantity is determined to be the second preset value, and the second weighting coefficient of the feedback control quantity is determined to be the first preset value, so as to determine the weight allocation coefficient.

4. The method according to claim 1, characterized in that, The method further includes: In response to the feedback control quantity not being within a preset threshold range, model correction parameters are determined based on the average value of multiple integral terms in the feedback control quantity; The model parameters of the feedforward control model are updated based on the model correction parameters.

5. The method according to claim 4, characterized in that, The feedforward control model is evaluated based on the operating state parameters to obtain the operational reliability coefficient of the feedforward control model, including: Based on the oil temperature, motor speed and working pressure in the working status parameters, the calibration working point that is closest to the working status parameters is determined from multiple working points; The operational reliability coefficient is determined based on the weighted distance between the working status parameters and the calibrated working point.

6. The method according to claim 5, characterized in that, The method further includes: Determine the temperature deviation between the oil temperature and the calibrated operating point; Determine the deviation value between the motor speed and the speed at the calibration operating point; Determine the pressure deviation between the working pressure and the calibrated operating point; The weighted distance is obtained by weighting the temperature deviation, the speed deviation, and the pressure deviation based on the temperature weight value, the speed deviation value, and the pressure deviation value.

7. The method according to claim 5, characterized in that, The operational reliability coefficient is determined based on the weighted distance between the operating status parameters and the calibrated operating points, including: In response to the weighted distance being less than a preset threshold and the working state parameters meeting preset conditions, the weighted distance is mapped based on a preset mapping function to obtain the running reliability coefficient; In response to the weighted distance being greater than or equal to the preset threshold, or the working status parameter not meeting the preset condition, the operating reliability coefficient is determined to be a preset value.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: Based on the target driving force and the working state parameters, the feedforward control quantity is determined; The feedback control quantity is determined based on the target driving force and the actual driving force.

9. The method according to claim 8, characterized in that, The hydraulic suspension system includes a hydraulic pump and a hydraulic actuator. Based on the target actuation force and the operating state parameters, the feedforward control quantity is determined, including: Based on the hydraulic pump's oil temperature and motor speed in the operating parameters, the nominal output flow rate and internal leakage flow rate of the hydraulic pump are determined. Based on the effective area of ​​the hydraulic actuator, determine the target effective flow rate required for the hydraulic actuator to generate the target actuating force; The feedforward control quantity is determined based on the target effective flow rate, the internal leakage flow rate, the nominal output flow rate, and the working pressure of the hydraulic pump in the working status parameters.

10. The method according to claim 9, characterized in that, Based on the target effective flow rate, the internal leakage flow rate, the nominal output flow rate, and the working pressure of the hydraulic pump in the operating status parameters, the feedforward control quantity is determined, including: Based on the target effective flow rate and the internal leakage flow rate, the target required flow rate of the hydraulic pump is determined, wherein the target required flow rate is the actual output flow rate of the hydraulic pump required to drive the hydraulic actuator to generate the target working power after compensating for the internal leakage flow rate; The feedforward control quantity is determined based on the target required flow rate, the nominal output flow rate, and the working pressure of the hydraulic pump in the working status parameters.

11. The method according to claim 10, characterized in that, Based on the target required flow rate, the nominal output flow rate, and the working pressure of the hydraulic pump in the operating status parameters, the feedforward control quantity is determined, including: Determine the flow deviation value between the target required flow rate and the nominal output flow rate; The pressure compensation coefficient corresponding to the working pressure is determined from a plurality of preset pressure compensation coefficients; The feedforward control quantity is determined based on the flow deviation value and the pressure compensation coefficient.

12. The method according to any one of claims 1 to 7, characterized in that, The method further includes: Obtain the vehicle body posture information corresponding to the hydraulic suspension system, or collect the road surface preview information of the road surface where the vehicle is currently located; Based on the vehicle posture information or the road surface pre-aiming information, the target is determined to act as a driving force.

13. The method according to any one of claims 1 to 7, characterized in that, Controlling the hydraulic suspension system based on the target control quantity includes: The target control quantity is analyzed to obtain the motor torque component; The target motor torque command is determined based on the minimum motor torque of the hydraulic suspension system and the motor torque component. The hydraulic suspension system is controlled based on the target motor torque command.

14. A control device for a hydraulic suspension system, characterized in that, include: The acquisition module is used to acquire the target working force, actual working force, and working state parameters of the hydraulic suspension system, wherein the target working force is used to represent the control force expected to be generated by the hydraulic suspension system, and the actual working force is used to represent the control force actually generated by the hydraulic suspension system. The determination module is used to determine the weight allocation coefficients of the feedforward control quantity and the feedback control quantity in the hydraulic suspension system, as well as the amplitude limit threshold of the feedback control quantity, based on the target working force, the actual working force and the working state parameters. A limiting module is used to limit the feedback control quantity based on the limiting threshold to obtain the limited feedback control quantity. The control module is used to perform a weighted summation of the feedforward control quantity and the limited feedback control quantity based on the weight allocation coefficient to obtain the target control quantity, and to control the hydraulic suspension system based on the target control quantity. The determining module is further configured to: determine the weight allocation coefficient based on the target action force and the actual action force; determine the limiting threshold based on the operating state parameters and the maximum output limit of the feedback control quantity; determine the weight allocation coefficient based on the target action force and the actual action force; evaluate the feedforward control model based on the operating state parameters to obtain the operating reliability coefficient of the feedforward control model; and determine the limiting threshold based on the product of the operating reliability coefficient and the maximum output limit.

15. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 13.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the method according to any one of claims 1 to 13.

Images