Method and system for automatically adjusting damping strength of new energy automobile shock absorber

Abstract

The invention discloses an automatic adjusting method and system for damping strength of a new energy automobile shock absorber, and relates to the field of damping adjustment. A feedforward estimation mechanism of an energy recovery torque signal is introduced, a disturbance trend is predicted in combination with a torque change rate, and damping of a front suspension and damping of a rear suspension are actively adjusted by using a feedforward control law; pre-compensation is formed before actual occurrence of pitching disturbance. Meanwhile, by fusing feedforward and feedback control, residual disturbance is further eliminated on the basis of suppressing initial impact. Besides, a fusion strategy of system space energy function modeling and feature space dynamic reconstruction optimizes the synergistic effect of feedforward, feedback and reference damping, control signal conflicts are avoided, and response speed and control precision are both considered. According to the scheme, the torque look-ahead information of the energy recovery system and the vehicle body posture feedback data are fully utilized, pitching disturbance is rapidly restrained, and the driving comfort is improved.

Description

Technical Field

[0001] The present application relates to the field of damping adjustment, and more specifically, to a method and system for automatically adjusting the damping strength of a shock absorber for a new energy vehicle. Background Art

[0002] With the popularization of new energy vehicles, energy recovery technology has become the key to improving endurance and energy efficiency. However, during relatively strong regenerative braking, the forward braking torque generated between the wheels and the ground is transmitted to the vehicle body, which can cause the vehicle to nod or experience pitching motion with a dragging feeling. Especially under frequent start-stop or complex working conditions, this instantaneous and significant pitching disturbance will greatly reduce the ride comfort and become one of the main reasons for poor user experience. Therefore, effectively suppressing or reducing the pitching disturbance during the energy recovery process and improving the ride comfort are important challenges in the current field of automotive suspension control.

[0003] In order to improve the ride comfort and handling stability of vehicles, various adaptive or active suspension systems have been widely applied in the prior art, which adjust the damping characteristics of shock absorbers to adapt to different road conditions and driving states. These systems usually rely on collecting signals such as vehicle body acceleration, wheel bounce, and even some vehicle dynamic parameters, and in a feedback control manner, adjust the damping force of the shock absorber in real time according to the actual vehicle motion state. However, for the pitching disturbance caused by the unique energy recovery process of new energy vehicles, pure feedback control often has a certain lag. The system needs to first sense that the vehicle body has experienced pitching motion (such as changes in pitching angular velocity or longitudinal acceleration), and then can calculate and apply the corresponding damping adjustment. This makes it possible that when the energy recovery starts or changes suddenly, the initial pitching impact may not be suppressed in a timely and effective manner, and passengers may still feel an obvious nodding sensation. At the same time, traditional suspension control strategies usually do not make full use of the forward-looking torque information provided by the energy recovery system of new energy vehicles itself to predict and respond in advance to the upcoming pitching disturbance. This limits the response speed and optimization degree of the system to such specific dynamic disturbances.

[0004] Therefore, the existing methods still have the defects of insufficiently rapid response and incomplete suppression when dealing with the pitching disturbance problem caused by the energy recovery of new energy vehicles, and it is difficult to fully meet the higher demands of users for comfort. Summary of the Invention

[0005] In order to solve the above technical problems, the present application is proposed.

[0006] According to one aspect of the present application, there is provided a method for automatically adjusting the damping strength of a shock absorber for a new energy vehicle, which includes: Obtaining a real-time energy recovery torque signal and a vehicle body attitude sensor signal; Performing signal analysis on the real-time energy recovery torque signal to obtain an effective energy recovery torque; Perform pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index; Perform damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector; Perform signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and perform attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector; Fuse the feedforward damping adjustment vector, the feedback damping adjustment vector, and a reference damping vector to obtain a shock absorber control signal.

[0007] According to another aspect of the present application, there is provided a new energy vehicle shock absorber damping strength automatic adjustment system, which includes: A signal acquisition module, configured to acquire a real-time energy recovery torque signal and a vehicle body attitude sensor signal; An energy recovery torque analysis module, configured to perform signal analysis on the real-time energy recovery torque signal to obtain an effective energy recovery torque; A pitch disturbance feedforward estimation module, configured to perform pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index; A feedforward damping adjustment module, configured to perform damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector; A feedback damping adjustment module, configured to perform signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and perform attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector; A shock absorber control signal generation module, configured to fuse the feedforward damping adjustment vector, the feedback damping adjustment vector, and a reference damping vector to obtain a shock absorber control signal.

[0008] Compared with the prior art, a method and system for automatically adjusting the damping strength of a shock absorber of a new energy vehicle provided by the present application introduce a feedforward estimation mechanism for the energy recovery torque signal, calculate in advance the equivalent longitudinal force and the target pitching moment generated by energy recovery, and combine the torque change rate to predict the disturbance trend. The front and rear suspension damping is actively adjusted using a feedforward control law (such as differentially adjusting the compression / tension damping according to the direction of the feedforward pitching moment), forming a pre-compensation before the pitching disturbance actually occurs, significantly shortening the system response delay. At the same time, by integrating feedforward and feedback control (dynamically adjusting the PID integral gain based on the filtered longitudinal acceleration and driving the closed-loop correction with the pitching angular velocity error), on the basis of suppressing the initial impact, the residual disturbance is further eliminated to ensure attitude stability. In addition, the fusion strategy of system space energy function modeling and feature space dynamic reconstruction optimizes the synergistic effect of feedforward, feedback, and reference damping, avoids control signal conflicts, and balances the response speed and control accuracy. This solution makes full use of the torque preview information of the energy recovery system and the body attitude feedback data, realizes the rapid suppression of pitching disturbances, and improves the riding comfort. Description of the Drawings

[0009] The above and other objects, features, and advantages of the present application will become more apparent by describing the embodiments of the present application in more detail with reference to the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0010] Figure 1 It is a flowchart of a method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to an embodiment of the present application.

[0011] Figure 2 It is a flowchart of step S3 in the method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to an embodiment of the present application.

[0012] Figure 3 It is a flowchart of step S5 in the method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to an embodiment of the present application.

[0013] Figure 4 It is a block diagram of a system for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to an embodiment of the present application. Detailed Embodiments

[0014] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure.

[0015] In view of the problems in the above background art, in the technical solution of this application, a method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle is proposed. Figure 1 The flowchart of the method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to an embodiment of this application. As Figure 1 shown, the method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to an embodiment of this application includes: S1, obtaining a real-time energy recovery torque signal and a vehicle body attitude sensor signal; S2, performing signal analysis on the real-time energy recovery torque signal to obtain an effective energy recovery torque; S3, performing pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index; S4, performing damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector; S5, performing signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and performing attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector; S6, fusing the feedforward damping adjustment vector, the feedback damping adjustment vector, and a reference damping vector to obtain a shock absorber control signal.

[0016] In step S1, a real-time energy recovery torque signal and a vehicle body attitude sensor signal are acquired. It should be understood that the purpose of acquiring the real-time energy recovery torque signal is to capture the original excitation source information that causes vehicle pitch disturbance, that is, the braking torque generated by energy recovery. This signal is directly output or controlled by the vehicle's powertrain and has better foresight and predictability compared to the vehicle body attitude change. It can provide a basis for the feedforward control path, thereby predicting the trend and intensity of the pitch movement before it fully develops or occurs, and achieving faster and more proactive intervention. At the same time, the purpose of acquiring the real-time vehicle body attitude sensor signal (for example, including longitudinal acceleration and pitch angular velocity information) is to monitor the current actual motion state of the vehicle in real time, especially the dynamic response related to pitch. This signal provides a basis for the feedback control path, enabling the system to correct the damping setting according to the actual vehicle body motion deviation, compensate for the disturbances that cannot be completely suppressed by the feedforward control, or respond to the attitude changes caused by other unknown disturbances, thereby ensuring the stability and comfort of the vehicle attitude. By simultaneously acquiring and comprehensively using the feedforward information of energy recovery torque and the feedback information of vehicle body attitude, this method can construct a control strategy that combines the advantages of feedforward and feedback, aiming to more effectively and timely suppress the pitch disturbance during the energy recovery process and overcome the lag defect of the existing pure feedback control.

[0017] Specifically, step S1 can be implemented in the following way: The real-time energy recovery torque signal comes from the power control unit (PCU) or the motor controller of a new energy vehicle. These controllers are responsible for managing the operating mode of the motor, including the torque output during energy recovery. This torque signal, as a real-time state parameter, is periodically broadcast through the vehicle's internal high-speed communication network, such as the controller area network (CAN) bus, or obtained by the shock absorber controller subscribing. The control unit responsible for performing shock absorber damping adjustment (such as the suspension controller or the integrated chassis controller) listens to or reads the data frame corresponding to the energy recovery torque signal identifier on the CAN bus through its built-in CAN communication interface hardware and the corresponding communication protocol software. After receiving the data frame, the software layer will parse the original data, extract the current real-time energy recovery torque value, and perform necessary unit conversion or calibration processing to obtain the effective energy recovery torque that can be directly used for subsequent calculations. The cycle frequency of acquiring this signal needs to be high enough to capture the rapid changes in torque. For example, it can be set from dozens of hertz to hundreds of hertz to ensure the real-time requirement of the control system.

[0018] The acquisition of the vehicle body attitude sensor signals depends on the attitude sensor unit installed on the vehicle, such as an Inertial Measurement Unit (IMU), which integrates sensor components such as accelerometers and gyroscopes inside. These sensors measure the acceleration and angular velocity of the vehicle in all directions in real time, including the longitudinal acceleration of the vehicle and the pitch angular velocity around the transverse axis. The IMU unit will perform preliminary processing on the measured raw data and send the processed attitude information to the shock absorber control unit in real time through the vehicle's CAN bus or other suitable communication interfaces. The shock absorber control unit also receives and parses the data frames from the attitude sensors through its communication interface, and extracts the current real-time longitudinal acceleration value and pitch angular velocity value. These sensor signals are also transmitted and collected at a relatively high frequency, such as equivalent to or higher than the acquisition frequency of the energy recovery torque signal, to accurately reflect the dynamic response of the vehicle body.

[0019] In step S2, signal parsing is performed on the real-time energy recovery torque signal to obtain the effective energy recovery torque. Correspondingly, considering that the raw real-time energy recovery torque signal obtained from the vehicle communication network or sensors may contain noise, interference, or its value does not directly correspond to the braking force generated by the drive wheels on the ground that can cause vehicle body pitch. There may be factors such as internal system losses, non-linearity of control strategies, and errors of the sensors themselves in the actual generation and transmission process of the energy recovery torque. Therefore, it is necessary to perform necessary parsing processing on the raw signal to accurately extract the effective energy recovery torque component that actually acts on the wheels and is converted into the ground longitudinal force, thereby causing vehicle body pitch, ensuring that the subsequent feedforward pitch disturbance estimation based on this torque is more accurate and reliable, so as to provide high-quality input data for the precise feedforward damping compensation of the shock absorber and improve the performance of the entire control system and the suppression effect of pitch disturbance.

[0020] Specifically, step S2 can be implemented in the following way: The real-time energy recovery torque signal is generated by the vehicle's Power Control Unit (PCU) or motor controller and broadcast through the vehicle's internal CAN communication network. The shock absorber control unit (or the integrated controller responsible for this function) receives the CAN message containing the energy recovery torque information through its CAN communication hardware interface. These messages are encapsulated in accordance with the predetermined vehicle communication protocol format, and the specific data fields store the raw energy recovery torque data, which may be represented in integer, floating-point or other formats. The first step of signal parsing is to identify and read these specific CAN messages and extract the fields containing the raw torque data. For example, according to the vehicle's CAN communication matrix specification, the energy recovery torque information is stored in a specific data segment (such as bytes 4-5) of a specific CAN ID (such as 0x123). The controller software will read the corresponding byte data according to these specifications.

[0021] The extracted raw data are digital values that have been quantified or represented proportionally, and they need to be converted into engineering units with physical meaning, namely Newton meters (Nm). This conversion process relies on the calibration data of the vehicle, including the scale factor (Scale) and offset (Offset) between the raw data and the actual physical torque. For example, the calibration data shows that the raw data is a 16-bit unsigned integer representing a torque value scaled by a certain ratio, and the unit conversion relationship is: Effective energy recovery torque (Nm) = (Raw data value * Scale) + Offset. Scale and Offset are constants determined in advance during the vehicle development and calibration phases and are stored in the non-volatile memory of the control unit. For example, Scale is set to 0.1 Nm / count and Offset is set to 0 Nm. If the raw torque data value extracted from the CAN message is 3000, then the effective energy recovery torque obtained after parsing and conversion is (3000 * 0.1 Nm / count) + 0 Nm = 300 Nm. In addition, the parsing process also includes filtering the extracted data, such as using a low-pass filter, to filter out the glitches caused by communication noise or high-frequency vibrations of the sensor, ensuring that the output effective energy recovery torque signal is smooth and stable, more truly reflecting the actual output of the power system, and thus improving the accuracy of subsequent feedforward estimation. This series of data reading, format parsing, unit conversion, and filtering processes constitute the complete implementation process of converting the raw real-time energy recovery torque signal into the effective energy recovery torque for control calculation.

[0022] In step S3, a pitch disturbance feedforward estimation is performed on the effective energy recovery torque to obtain the estimated feedforward pitch moment and the pitch disturbance trend index. It should be understood that the energy recovery torque is the direct external excitation source causing the pitch motion of the new energy vehicle. By monitoring and estimating this excitation source in real time, the magnitude of the pitch moment and its change speed (trend) generated by this excitation source can be predicted before the vehicle body actually undergoes obvious pitch attitude changes. This forward-looking estimation based on the cause enables the control system to know in advance the characteristics of the upcoming disturbance. Compared with relying on the feedback control of the vehicle body attitude sensor signal (whose response occurs after the disturbance has caused an attitude change), the feedforward estimation uses the prediction ability of the disturbance source signal to calculate the required damping adjustment amount earlier, so as to apply an inhibitory effect at the beginning or in the initial stage of the pitch motion, significantly reducing the response lag of the control system and improving the inhibitory effect on the transient pitch impact caused by energy recovery, thereby greatly enhancing the ride comfort.

[0023] Figure 2 It is a flowchart of step S3 in the method for automatically adjusting the damping strength of the shock absorber of a new energy vehicle according to an embodiment of the present application. Specifically, in the embodiment of the present application, as Figure 2As shown, in step S3, a pitch disturbance feedforward estimation is performed on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index, including: S31, calculating an equivalent longitudinal force generated by energy recovery based on the effective energy recovery torque and the tire radius; S32, calculating a target pitch force generated by the equivalent longitudinal force and the center of gravity height as the estimated feedforward pitch moment; S33, calculating a change rate of the effective energy recovery torque as the pitch disturbance trend index.

[0024] It should be understood that the energy recovery torque is the rotational effect acting on the wheel axle, and what directly causes the pitching motion of the vehicle body is the longitudinal force (braking force) converted from this torque through the interaction between the wheel and the ground. It is this longitudinal force that acts on the ground contact point of the wheel and generates a moment arm relative to the vehicle's center of gravity, thus forming a pitch moment that causes the vehicle to nod or lift its tail. Therefore, converting the energy recovery torque into an equivalent longitudinal force is the key physical quantity conversion process connecting the output of the power system and the dynamic response of the vehicle attitude.

[0025] Specifically, step S31 can be implemented in the following way: First, obtain the real-time effective energy recovery torque obtained through parsing in the previous step. This torque represents the actual braking torque generated by the current energy recovery system on the drive wheel axle. At the same time, the tire radius of the vehicle needs to be obtained. The tire radius is an inherent parameter of the vehicle, referring to the effective working radius of the vehicle tire, such as the wheel radius under static load or the dynamic radius considering the influence of speed. For the sake of simplicity and to ensure real-time performance, a preset nominal tire radius value is adopted here, which can be determined according to the tire specifications and models of the vehicle, through actual measurement or by referring to the vehicle design parameters. For example, for a common passenger car, its tire radius can be set to about 0.3 meters. The process of calculating the equivalent longitudinal force is based on basic mechanical principles: the torque acting on a rotating object is equal to the product of the tangential force and the acting radius. Therefore, by dividing the effective energy recovery torque by the tire radius, the equivalent longitudinal force generated by energy recovery at the ground contact point of the wheel can be obtained. The magnitude of this longitudinal force is the direct excitation force causing the vehicle to pitch. For example, if the currently measured effective energy recovery torque is 300 N·m and the preset tire radius is 0.3 meters, the calculated equivalent longitudinal force generated by energy recovery is 300 N·m / 0.3 m = 1000 Newtons. This calculation process is performed in real time in the software of the shock absorber control unit to ensure obtaining the latest equivalent longitudinal force value and providing real-time input for the subsequent pitch moment estimation.

[0026] Accordingly, while the equivalent longitudinal force is the direct cause of vehicle pitch, the physical quantity that actually causes the vehicle body to rotate about its transverse axis (i.e., pitch motion) is a torque. The longitudinal force acts at the contact point between the wheels and the ground, while the vehicle's pitch motion occurs about the vehicle's center of gravity. Therefore, it is necessary to calculate the torque of the longitudinal force acting on the ground relative to the vehicle's center of gravity. The vehicle's center of gravity height is a key parameter in determining this torque, as it represents the vertical distance from the longitudinal force's line of action (along the ground) to the horizontal line of the vehicle's center of gravity, effectively forming the effective moment arm that generates the pitch moment. This calculation converts the effect of the longitudinal ground force into a torque input in the vehicle's pitch direction. This torque directly represents the intensity and direction of the regenerative energy disturbance to the vehicle's pitch attitude, providing a direct prediction of the disturbance magnitude for subsequent feedforward control, enabling the controller to perform targeted damping compensation.

[0027] Specifically, step S32 can be implemented as follows: First, the equivalent longitudinal force generated by the regenerative energy calculated in real time in the previous step is obtained. Simultaneously, the vehicle's center of gravity height must be obtained. The vehicle's center of gravity height is an inherent parameter that characterizes the vehicle's mass distribution and is determined during the vehicle design phase through theoretical calculations or actual measurements. In the suspension control system, the center of gravity height is stored as a preset constant parameter in the control unit's memory. For example, for a certain model of new energy vehicle, its center of gravity height can be set to 0.6 meters. Based on the physical principle that torque equals force multiplied by the lever arm, the equivalent longitudinal force obtained in the previous step is multiplied by the center of gravity height to calculate the pitching moment generated by this longitudinal force. Specifically, if the equivalent longitudinal force is F and the center of gravity height is h, the estimated feedforward pitching moment M = F * h. For example, if the calculated equivalent longitudinal force is 1000 Newtons and the vehicle's center of gravity height is set to 0.6 meters, the estimated feedforward pitching moment is 1000 Newtons * 0.6 meters = 600 Newton-meters. This calculation is performed in real time within the shock absorber control unit's processor, leveraging the latest equivalent longitudinal force values and stored center of gravity height parameters to quickly and accurately calculate the current or impending estimated pitching moment. The calculated target pitching force (i.e., the estimated feedforward pitching moment) is then used in the damping compensation feedforward calculation, guiding the system's proactive adjustment of shock absorber damping to counteract this predicted pitching disturbance.

[0028] It should be understood that merely knowing the current equivalent longitudinal force (or the estimated feedforward pitching moment) provides information about the magnitude of the disturbance, but is not sufficient to fully characterize the dynamics of the disturbance and its potential impact on the vehicle's attitude. The rate of change of the energy recovery torque, i.e., its derivative, reflects the abruptness or smoothness of the energy recovery process. For example, a rapidly increasing energy recovery torque will cause a more intense and sudden pitching impact than an equivalent final magnitude but slowly increasing torque. Therefore, taking the rate of change of torque as an independent index can provide additional forward-looking information about the pitching disturbance trend and dynamic intensity. This trend index enables the control system to not only predict the magnitude of the pitching moment to be generated, but also predict whether this moment will appear abruptly or accumulate slowly, thereby guiding the feedforward control to make finer and more timely damping adjustments according to the dynamic characteristics of the disturbance. Especially when dealing with sudden energy recovery braking, it helps to more effectively suppress the initial nodding impact and further enhance the ride comfort.

[0029] Specifically, step S33 can be implemented in the following way: Calculating the change rate of the effective energy recovery torque in real time requires tracking the change of this torque over time. This is achieved by numerically differentiating the continuously acquired samples of the effective energy recovery torque. Inside the shock absorber control unit, a register or buffer is maintained to store the most recent or several effective energy recovery torque values. When the system obtains the current real-time effective energy recovery torque value T_current in each control cycle (for example, the cycle is Delta_T, ranging from a few milliseconds to dozens of milliseconds, specifically depending on the system processing capacity and control requirements, such as set to 10 milliseconds), the change rate can be calculated using the effective energy recovery torque value T_previous obtained in the previous control cycle. The formula for the change rate can be approximated as the difference between the current torque value and the torque value at the previous moment divided by the time interval between two sampling moments (i.e., the control cycle). Specifically, the change rate of the energy recovery torque = (T_current - T_previous) / Delta_T. For example, if the effective energy recovery torque value obtained in the previous control cycle is 250 N·m, the value obtained in the current control cycle is 300 N·m, and the control cycle is 10 milliseconds (i.e., 0.01 seconds), then the calculated change rate of the energy recovery torque is (300 N·m - 250 N·m) / 0.01 s = 50 N·m / 0.01 s = 5000 N·m / s. To improve robustness, especially in the case of noisy signals, the linear fitting slope within a sliding window or a low-pass filter can also be used to smooth the differential result, but the core idea is to quantify the change amplitude of the torque per unit time. This calculated change rate value is used as the pitch perturbation trend indicator, which, together with the previously calculated estimated feedforward pitch moment, is fed as input into the look-up table based on the control law to jointly determine the magnitude and direction of the feedforward damping adjustment vector. After the calculation is completed, the current T_current value is stored and used as the T_previous value for the next control cycle.

[0030] In step S4, based on the estimated feedforward pitch moment and the pitch disturbance trend index, a damping compensation feedforward calculation is performed to obtain a feedforward damping adjustment vector. Correspondingly, the previous step has prospectively estimated the magnitude of the pitch moment caused by energy recovery and the trend of the development of this disturbance. This step precisely utilizes these predicted values and, based on a preset control strategy or model, calculates the pre-compensation damping adjustment amount that needs to be applied to the shock absorber, that is, the feedforward damping adjustment vector. This vector represents how the system should actively adjust the shock absorber damping in advance to counteract the predicted pitch disturbance before actually perceiving the change in the vehicle body attitude. Through this calculation, the system can generate a part of the control signal in advance, enabling the shock absorber to respond at the beginning of the occurrence or rapid development of the pitch motion, thereby achieving fast and active disturbance suppression, making up for the response delay of pure feedback control, and significantly improving the ride comfort during the energy recovery process.

[0031] Specifically, in the embodiment of the present application, performing a damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector includes: obtaining the current vehicle speed; inputting the current vehicle speed, the estimated feedforward pitch moment, and the pitch disturbance trend index into a look-up table based on a control law to obtain the feedforward damping adjustment vector.

[0032] It should be understood that the driving speed of the vehicle is a key operating parameter that affects the vehicle dynamics characteristics and the working state of the suspension system. When the vehicle speed is different, the response characteristics of the vehicle to external excitations (including the pitch moment generated by energy recovery) will also change accordingly. For example, when driving at high speed, the pitch inertia effect, the longitudinal tire force characteristics, and the aerodynamic effect of the vehicle are significantly different from those in the low-speed or stationary state. Therefore, in order for the feedforward control strategy to provide the most appropriate and effective damping compensation for the current actual working conditions, the vehicle speed needs to be used as an important input variable for determining the feedforward damping adjustment vector.

[0033] Specifically, the current vehicle speed can be obtained in the following way: The current vehicle speed depends on the existing sensor system on the vehicle. The most common way is to use the wheel speed sensors of the vehicle. These sensors (electromagnetic or Hall sensors installed near each wheel) measure the rotational speed or angular position of the wheels in real time and send these signals to the vehicle's anti-lock braking system (ABS), electronic stability control system (ESC), or vehicle controller. The shock absorber control unit obtains the data of these wheel speed sensors through the vehicle's internal communication network, such as the CAN bus. To obtain the overall driving speed of the vehicle, the control unit processes the signals from multiple wheels, uses an algorithm to calculate the linear speed of each wheel (by multiplying the wheel speed by the preset or estimated effective rolling radius of the tire), and then synthesizes multiple wheel speed signals (for example, taking the average of the wheel speeds of the wheels that do not have obvious slip) to calculate the reference driving speed of the vehicle. For example, if the angular velocity of a certain wheel is 100 radians per second and the effective rolling radius of the tire is set to 0.3 meters (this radius value can be determined and stored during the vehicle calibration phase), then the linear speed of this wheel is 100 * 0.3 = 30 meters per second, which is approximately 108 kilometers per hour. By performing similar calculations and averaging on multiple wheel speeds, the real-time vehicle driving speed can be obtained. In particular, the frequency of obtaining the vehicle speed signal is the same as or higher than the sampling frequency of the control system to ensure that the vehicle speed information on which the feedforward calculation is based is real-time and accurate.

[0034] Correspondingly, in the previous step, the magnitude of the pitch disturbance caused by energy recovery (estimated feedforward pitch moment) and its dynamic characteristics (pitch disturbance trend index) have been prospectively estimated, and at the same time, the key parameter vehicle speed reflecting the current operating state of the vehicle has been obtained. To effectively suppress this predicted disturbance, it is necessary to determine the precise feedforward damping adjustment amount that the shock absorber should apply based on this information. Therefore, in this application, the current vehicle speed, the estimated feedforward pitch moment, and the pitch disturbance trend index are input into a look-up table based on a control law to obtain the feedforward damping adjustment vector. Feeding these inputs into the look-up table based on a control law is an effective method to map multi-dimensional inputs to an optimal or predetermined output (i.e., the feedforward damping adjustment vector). It is worth mentioning that the look-up table stores the optimal shock absorber feedforward damping adjustment strategies corresponding to different working conditions (combined by vehicle speed, disturbance magnitude, and trend) determined based on offline optimization or experience. Through fast look-up or interpolation, the system can obtain the specific damping adjustment instructions required for the current predicted disturbance and vehicle state in real time and efficiently, avoid complex real-time model calculations, ensure the fast response ability of the control system, and thus achieve precise and timely feedforward suppression of the pitch disturbance caused by energy recovery.

[0035] More specifically, in the embodiments of the present application, inputting the current vehicle speed, the estimated feedforward pitching moment, and the pitching disturbance trend index into a lookup table based on a control law to obtain the feedforward damping adjustment vector includes: when the estimated feedforward pitching moment is greater than zero, increasing the compression damping of the front suspension and increasing the extension damping of the rear suspension; when the estimated feedforward pitching moment is less than zero, increasing the extension damping of the front suspension and increasing the compression damping of the rear suspension.

[0036] It should be understood that an estimated feedforward pitching moment greater than zero means that regenerative braking is currently or about to cause the vehicle to experience a nose-down pitching motion. When the vehicle noses down, the front of the vehicle moves downward, causing the front suspension to be compressed; at the same time, the rear of the vehicle moves upward, causing the rear suspension to be extended. To effectively suppress this specific pitching trend, it is necessary to apply damping forces to the suspension to counteract these motions. Increasing the compression damping of the front suspension can resist the compression speed of the front suspension when the front of the vehicle sinks, thereby slowing down the downward movement of the front part; increasing the extension damping of the rear suspension can resist the extension speed of the rear suspension when the rear of the vehicle rises, thereby suppressing the upward movement of the rear part. By simultaneously enhancing the damping forces of the front and rear suspensions corresponding to their motion directions (front compression, rear extension), a moment opposite to the pitching motion trend can be generated, thereby actively attenuating or canceling the pitching vibration caused by regenerative braking and improving the ride comfort and stability of the vehicle during braking.

[0037] Similarly, an estimated feedforward pitching moment less than zero means that the vehicle is currently or about to experience a nose-up or rear-sitting pitching motion trend. Although nose-down is more common during regenerative braking, in some transitional conditions or specific vehicle designs, a negative pitching moment may exist. When the vehicle experiences a nose-up or rear-sitting motion, the front of the vehicle moves upward, causing the front suspension to be extended; at the same time, the rear of the vehicle moves downward, causing the rear suspension to be compressed. To effectively suppress this motion, it is necessary to specifically enhance the damping against these motion directions. Increasing the extension damping of the front suspension can resist the extension speed of the front suspension when the front of the vehicle rises, thereby slowing down the upward movement of the front part; increasing the compression damping of the rear suspension can resist the compression speed of the rear suspension when the rear of the vehicle sinks, thereby suppressing the downward movement of the rear part. By simultaneously enhancing the damping forces of the front and rear suspensions corresponding to their motion directions (front extension, rear compression), a moment opposite to this pitching motion trend can be generated, thereby actively attenuating or canceling potential negative pitching vibrations and improving the ride comfort and stability of the vehicle under these conditions.

[0038] Specifically, when the estimated feedforward pitching moment is greater than zero, increasing the compression damping of the front suspension and increasing the extension damping of the rear suspension, and when the estimated feedforward pitching moment is less than zero, increasing the extension damping of the front suspension and increasing the compression damping of the rear suspension, these two steps are specific rules or mechanisms for calculating or determining the feedforward damping adjustment vector.

[0039] Specifically, inputting the current vehicle speed, the estimated feedforward pitching moment, and the pitching disturbance trend index into the lookup table based on the control law to obtain the feedforward damping adjustment vector can be achieved in the following way: First, real-time input data needs to be acquired: the current vehicle speed value (obtained through the vehicle bus, such as from the vehicle speed sensor signal), the estimated feedforward pitching moment value (obtained through the calculation of the previous step, including the sign), and the pitching disturbance trend index value (obtained through the calculation of the previous step). These input values are the basis for implementing feedforward control, providing information about the current motion state of the vehicle and the characteristics (direction, magnitude, trend) of the upcoming pitching disturbance.

[0040] There is a multi-dimensional lookup table pre-stored inside the electronic control unit. This lookup table is created and optimized during the vehicle design and development and control system calibration phases. It is a collection of offline calculation results based on the control law, associating various combinations of input parameters (vehicle speed, estimated feedforward pitching moment, pitching disturbance trend index) with the corresponding optimal feedforward damping adjustment amounts (i.e., the feedforward damping adjustment vector). For example, when in a simulation or test, a working condition with a vehicle speed of 70 km / h, an estimated feedforward pitching moment of +700 Newton-meters (corresponding to accelerating and pitching up), and a high pitching disturbance trend index occurs, according to the control law, at this time, the compression damping of the front suspension and the extension damping of the rear suspension should be increased. After optimization calculations, it is determined that the compression damping of the front suspension (left / right) needs to be increased by +180 Ns / m, the extension damping of the rear suspension (left / right) needs to be increased by +150 Ns / m, while the adjustment amounts of the extension damping of the front suspension and the compression damping of the rear suspension are 0 or small values. This set of values (e.g., +180, 0, +180, 0, 0, +150, 0, +150) is used as the feedforward damping adjustment vector and is stored in the unit of the lookup table corresponding to the input combination (vehicle speed = 70 km / h, estimated moment = +700 Nm, trend index = high). The content of this lookup table directly reflects the required control strategy, including determining the main damping adjustment direction according to the sign of the estimated feedforward pitching moment. For example, during the calibration phase, when simulating or testing the vehicle in a working condition with a positive estimated feedforward pitching moment (such as accelerating and pitching up), the engineer will calculate and determine that the compression damping of the front suspension and the extension damping of the rear suspension should be increased according to the desired control effect, and store these increased amounts as the corresponding component values of the feedforward damping adjustment vector in the position corresponding to this working condition input in the lookup table. Similarly, when encountering a working condition with a negative estimated feedforward pitching moment (such as energy recovery and pitching down), the adjustment amounts of increasing the extension damping of the front suspension and the compression damping of the rear suspension will be stored as vector components in the position corresponding to this working condition in the lookup table. The magnitudes of these adjustment amounts not only depend on the direction of the moment but also on the amplitude of the moment, the current vehicle speed, and the pitching disturbance trend index, and these relationships are pre-fixed in the data of the lookup table.

[0041] During the actual operation of the vehicle, within each control cycle, the shock absorber control unit uses the currently obtained real-time vehicle speed, the estimated feedforward pitching moment, and the numerical value of the pitching disturbance trend index as multi-dimensional indices to query this preset look-up table. Since the real-time input values are unlikely to exactly match all the discrete calibration points in the look-up table, the system will execute a multi-dimensional interpolation algorithm (for example, trilinear interpolation is usually adopted for a three-dimensional look-up table). The interpolation process calculates a smoothly transitional output value based on the relative positions of the real-time input values between their nearest look-up table data points and the stored data at these points. For example, if the real-time vehicle speed is 55 km / h, the estimated moment is -450 Nm, and the trend index is 0.7, the system will find the discrete points closest to these values and calculate the corresponding output according to the interpolation algorithm. The result of the interpolation calculation is a vector containing multiple components, where each component value represents the damping adjustment amount (for example, in Newton-seconds per meter) that the feedforward control part recommends to apply to a specific working mode (compression or extension) of a specific shock absorber (for example, front left, front right, rear left, rear right) under the current predicted working conditions. This vector obtained by querying the look-up table and interpolation is the aforementioned feedforward damping adjustment vector, which contains the specific damping adjustment instructions required for feedforward compensation for predictive pitching disturbances. For example, it may contain component values such as a front left extension damping adjustment amount of +110 Ns / m and a rear right compression damping adjustment amount of +85 Ns / m, while other components may be 0 or smaller values.

[0042] In step S5, the body attitude sensor signals are signal-analyzed to obtain the filtered longitudinal acceleration and the filtered pitching angular velocity, and the filtered longitudinal acceleration and the filtered pitching angular velocity are subjected to attitude feedback and damping correction to obtain a feedback damping adjustment vector. It should be understood that although feedforward control is introduced to cope with the predictive disturbances brought about by energy recovery, feedback control remains an important part of ensuring the vehicle attitude stability. Body attitude sensors (such as accelerometers and gyroscopes) can measure the actual motion state of the vehicle in real time, including the longitudinal acceleration and the pitching angular velocity. These signals directly reflect whether the current pitching motion of the vehicle occurs and its degree. Therefore, through signal analysis and filtering processing, accurate and smooth attitude information can be extracted from the original sensor data. Based on these actually measured attitude information, the feedback control algorithm can calculate the damping correction amount required to suppress the currently occurring pitching motion. This feedback mechanism can respond to various unknown disturbances or residual disturbances that cannot be completely cancelled by the feedforward control, forming a closed-loop control loop, continuously adjusting the shock absorber damping, and ensuring that the vehicle can maintain the desired attitude stability under various working conditions, thus improving the overall ride comfort and handling performance.

[0043] Specifically, signal parsing of the vehicle body attitude sensor signals is performed to obtain the filtered longitudinal acceleration and the filtered pitch angular velocity, which can be achieved through the following steps: First, the vehicle body attitude sensor signals are converted from analog to digital signals (ADC) by a sensor module or a dedicated control unit. These digital signals are then transmitted via the in-vehicle communication network (such as the CAN bus) to the control unit responsible for shock absorber control. After the control unit receives these digitized sensor signals, the signal parsing process is carried out. This involves converting the original digital values into physical meaningful units. For example, the output of the acceleration sensor is converted into the longitudinal acceleration expressed in meters per second squared (m / s²), and the output of the gyroscope is converted into the pitch angular velocity expressed in radians per second (rad / s). This conversion requires parameters such as the scale factor and offset determined during the calibration phase of the sensor. For example, the digital output value of an accelerometer is multiplied by a preset sensitivity coefficient (such as 0.01 m / s² / bit) and added with a preset zero offset (such as 0.05 m / s²) to obtain the raw value of the current longitudinal acceleration.

[0044] Next, filtering is performed on the parsed raw longitudinal acceleration and pitch angular velocity signals. Sensor signals are often accompanied by high-frequency noise or vibration interference, and direct use may cause misoperation or performance degradation of the control system. Therefore, a digital filter (such as a low-pass filter) is applied to attenuate or remove these unwanted high-frequency components, thereby obtaining signals that smoothly and accurately reflect the actual trend of the vehicle body. The specific type of the filter (such as Butterworth filter, Kalman filter, etc.) and parameters (such as the cut-off frequency) need to be determined in advance according to the vehicle characteristics and noise characteristics during the system development and calibration phases and stored in the control unit. For example, a second-order low-pass filter with a cut-off frequency set to 10 Hz can be applied to filter the parsed longitudinal acceleration signal to obtain the filtered longitudinal acceleration; at the same time, the parsed pitch angular velocity signal is filtered to obtain the filtered pitch angular velocity. The finally output signals are the filtered longitudinal acceleration and the filtered pitch angular velocity signals that have undergone parsing and filtering and are used for subsequent attitude feedback control.

[0045] Figure 3 It is a flowchart of step S5 in the method for automatically adjusting the damping strength of the shock absorber of a new energy vehicle according to an embodiment of the present application. Specifically, in the embodiment of the present application, as Figure 3As shown, in step S5, the signals of the vehicle body attitude sensor are parsed to obtain the filtered longitudinal acceleration and the filtered pitch angular velocity, and attitude feedback and damping correction are performed on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector, including: S51, adjusting the integral gain in the PID controller based on the filtered longitudinal acceleration to obtain a fine-tuned PID controller; S52, calculating the error between the filtered pitch angular velocity and the target pitch angular velocity; S53, inputting the error into the fine-tuned PID controller to obtain the feedback damping adjustment vector.

[0046] Correspondingly, when a standard PID controller processes a system with time-varying dynamic characteristics, its fixed parameters may not achieve optimal performance under all working conditions. Especially the integral term, although it can eliminate the steady-state error, during the severe pitch transient process caused by large acceleration and deceleration of the vehicle, an excessive integral gain may lead to a lag in the response of the control system, serious overshoot, or even oscillation, reducing the ride comfort. By dynamically adjusting the integral gain of the PID controller according to the real-time longitudinal acceleration, the system can make the controller more adaptable to the current longitudinal motion state, appropriately reducing the integral effect during large acceleration and deceleration to enhance the transient response and stability, and increasing the integral effect under steady or small acceleration and deceleration conditions to ensure accurate tracking of the pitch angular velocity error and elimination of the steady-state error.

[0047] Specifically, step S51 can be implemented in the following way: First, receive the value of the filtered longitudinal acceleration (for example, in meters per second squared). This value is a real-time scalar input representing the magnitude of the current longitudinal acceleration or deceleration of the vehicle. Inside the control unit, there is a pre-determined longitudinal acceleration-integral gain mapping relationship based on the control law during the vehicle development and calibration phase. This mapping relationship exists in the form of a look-up table, storing the PID integral gain values (or an adjustment coefficient relative to the basic integral gain) corresponding to different discrete points of the longitudinal acceleration. This look-up table is optimized and calibrated through a large number of vehicle dynamics simulations and actual road tests, with the aim of determining the integral gain that can achieve the best pitch control effect of the vehicle under various acceleration and deceleration conditions.

[0048] During each control cycle, the control unit uses the current filtered longitudinal acceleration value as an index to query this preset lookup table. For example, the lookup table defines discrete points such as the base integral gain value Kibase for a longitudinal acceleration of 0 m / s², 0.7*Kibase for a longitudinal acceleration of +4 m / s² (acceleration), and 0.6*K_i_base for a longitudinal acceleration of -5 m / s² (deceleration). If the real-time longitudinal acceleration value does not exactly match any discrete point in the lookup table (for example, if the real-time acceleration is -3.2 m / s²), the control unit performs interpolation (e.g., linear interpolation) to calculate the corresponding integral gain value based on the relative position of -3.2 m / s² between the two adjacent calibration points of -5 m / s² and 0 m / s². For example, the interpolated integral gain for this acceleration is 0.72*K_i_base. This calculated value is the PID controller integral gain adjusted for the current longitudinal acceleration.

[0049] It should be understood that the basic principle of a feedback control system is to compare the system's actual output state (here, the filtered pitch angular velocity) with the desired target state and use this difference (i.e., error) to drive the controller to produce an adjustment action to reduce or eliminate this error. In particular, in this application, the target pitch angular velocity is 0 rad / s, which directly reflects the suspension control system's control objective for the vehicle's pitch attitude during energy recovery: to minimize or prevent dynamic pitch rotation of the vehicle body, that is, to keep the vehicle's pitch angular velocity close to zero, thereby maintaining vehicle stability, reducing the nodding or head-raising shock felt by passengers, and improving driving comfort.

[0050] Specifically, step S52 can be implemented as follows: the error is calculated by performing a subtraction operation, subtracting the filtered actual pitch velocity from the target pitch velocity. That is, error = 0 - filtered pitch velocity, meaning the error is equal to the negative value of the filtered pitch velocity. For example, if the filtered pitch velocity measurement is positive 0.1 radians / second (indicating the vehicle nose is pitching upward), the calculated error is 0 - 0.1 = -0.1 radians / second. If the filtered pitch velocity is negative 0.05 radians / second (indicating the vehicle nose is pitching downward), the calculated error is 0 - (-0.05) = 0.05 radians / second.

[0051] Accordingly, the core of feedback control is to generate control commands based on the deviation between the current actual motion state and the desired state of the vehicle. The pitch angular velocity error calculated in real time is input into the PID controller, enabling the controller to comprehensively evaluate the deviation degree, duration, and change trend of the current pitch motion by utilizing the proportional, integral, and derivative information of the error. Based on this information, the PID controller can calculate the required feedback control output quantity, which is subsequently converted into a damping adjustment command for the shock absorber.

[0052] Specifically, step S53 can be implemented in the following manner: The filtered pitch angular velocity error value (e.g., in radians per second) calculated in the previous step is input into the PID control algorithm module implemented in the control unit. This PID controller is a fine-tuned PID controller with the integral gain (Ki) adjusted in the previous steps. Its proportional gain (Kp), integral gain (Ki, dynamically determined according to the longitudinal acceleration), and derivative gain (Kd) are pre-calibrated and set through simulation or experiment. The controller calculates three control components in real time based on the input error value: the proportional term (proportional to the current error), the integral term (proportional to the cumulative value of the error over time, with its gain being the dynamically adjusted Ki), and the derivative term (proportional to the rate of change of the error). For example, if the current error is E, the cumulative value of the integral error is ∫Edt, and the rate of change of the error is dE / dt, the original output of the PID controller can be conceptually represented in the form of Kp*E + Ki*(longitudinal acceleration)*∫Edt + Kd*dE / dt (note that Ki(longitudinal acceleration) indicates that the integral gain is a function of the longitudinal acceleration). After these components are weighted and summed, a feedback control signal is formed. This feedback control signal is then mapped or converted into a feedback damping adjustment vector. This vector contains the specific damping adjustment amounts for each adjustable shock absorber of the vehicle (e.g., front left, front right, rear left, rear right) and their different motion directions (compression, extension). The mapping relationship is pre-set. For example, the positive or negative sign and magnitude of the PID output determine how much the compression / extension damping of the front / rear suspension needs to be increased or decreased. For example, a positive PID output indicates that the front suspension compression damping and the rear suspension extension damping need to be increased, and the increase amount is related to the magnitude of the PID output. The finally output feedback damping adjustment vector, each of its components represents the correction amount recommended by the feedback control part for the damping of each shock absorber to correct the current pitch angular velocity error. For example, the front left compression damping adjustment is +50 Newton-seconds per meter, and the rear right extension damping adjustment is +30 Newton-seconds per meter, etc.

[0053] In step S6, the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector are fused to obtain a shock absorber control signal. Correspondingly, the reference damping vector represents the preset basic damping characteristics of the vehicle in the normal driving state, which is used to maintain the basic driving stability and comfort. The feedforward damping adjustment vector uses the energy recovery information to predict and cancel potential pitching disturbances in advance, and has the advantage of fast response. The feedback damping adjustment vector is corrected in real time according to the actual attitude error of the vehicle to compensate for the feedforward deficiency or cope with unexpected disturbances, providing robustness. By fusing these three, the respective advantages can be comprehensively utilized to generate a comprehensive shock absorber control signal, enabling the suspension system to not only quickly respond to the pitching impact caused by energy recovery but also continuously stabilize the vehicle attitude, thereby maximizing the ride comfort and stability of new energy vehicles under energy recovery conditions and overcoming the lag problem of pure feedback control in the prior art.

[0054] Specifically, in the embodiment of the present application, fusing the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain a shock absorber control signal includes: adding the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain a target damping command; performing a clipping process on the target damping command and then performing signal conversion on it to obtain the shock absorber control signal.

[0055] Specifically, the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector are added to obtain a target damping command. It should be understood that adding these three is a direct method for constructing a comprehensive control strategy. Doing so can ensure that the final target damping of the shock absorber simultaneously reflects the basic performance requirements, the advance response to predicted disturbances, and the timely correction of actual errors, thereby forming a more perfect, robust, and responsive control command, maximizing the ride comfort and stability of new energy vehicles during energy recovery.

[0056] Specifically, adding the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain the target damping command can be achieved by performing a vector addition operation on the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector. Each vector contains values corresponding to different control modes of each adjustable shock absorber of the vehicle (e.g., front left compression damping, front left extension damping, front right compression damping, and so on, up to the rear right extension damping). The control unit performs a position-wise (or "component-wise") addition of these three vectors. For example, the first component of the final target damping command vector (representing the target value of the front left compression damping) is equal to the sum of the first component of the reference damping vector, the first component of the feedforward damping adjustment vector, and the first component of the feedback damping adjustment vector. This process is performed in parallel or sequentially for all components to obtain the target damping command vector as the target damping command.

[0057] Preferably, in another example, adding the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain the target damping command can be achieved as follows: It should be understood that, different from directly adding the reference damping amount to the feedforward damping adjustment amount and the feedback damping adjustment amount, by performing an addition process on the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector, the damping feedforward adjustment characteristics and the damping feedback adjustment characteristics in the real-time energy recovery torque signal and the vehicle body attitude sensor signal can be more effectively correlated, thereby improving the control accuracy of the shock absorber control signal.

[0058] Based on this, in the embodiment of the present application, adding the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain the target damping command includes: performing a correlation modeling on the feedforward damping adjustment vector and the feedback damping adjustment vector through a system space energy function to obtain a correlation reference state representation vector; using the correlation reference state representation vector as an adaptive gain state, and performing a homomorphic projection mapping on the feedforward damping adjustment vector and the feedback damping adjustment vector respectively to obtain a feedforward damping mapping adjustment vector and a feedback damping mapping adjustment vector; using the reference damping vector as a chain state prior, performing a feature space dynamic reconstruction on the feedforward damping mapping adjustment vector and the feedback damping mapping adjustment vector to obtain a corrected feedforward damping adjustment vector and a corrected feedback damping adjustment vector; performing a position-wise addition of the corrected feedforward damping adjustment vector, the corrected feedback damping adjustment vector, and the reference damping vector to obtain a target damping command vector as the target damping command.

[0059] That is, considering the energy feature representation of the feedforward damping adjustment vector corresponding to the real-time energy recovery torque signal and the spatial feature representation of the feedback damping adjustment vector corresponding to the vehicle body attitude sensor signal, the correlation between the feedforward damping adjustment vector and the feedback damping adjustment vector is first modeled through the system spatial energy function as: ; where is the transpose operation, is the vector multiplication, is the feedforward damping adjustment vector, is the feedback damping adjustment vector, and and are both row vectors, is the correlation reference state representation vector. That is, taking the energy features of different states (i.e., kinetic energy - potential energy state) as the conjugate momentum of the energy - space correlation, the function self - balance correlation of different energy states in energy - space is carried out.

[0060] Then, taking the above - mentioned correlation reference state representation vector as the adaptive gain state, the homomorphic projection mapping is respectively carried out with the feedforward damping adjustment vector and the feedback damping adjustment vector: ; where is the element - by - element multiplication, is the feedforward damping mapping adjustment vector, is the feedback damping mapping adjustment vector; Then, taking the reference damping vector, for example, expressed as as the chain - state prior, the feature space dynamic reconstruction is carried out as: ; where is the element - by - element subtraction, is the reference damping vector, is to calculate the reciprocal of each eigenvalue in is the corrected feedforward damping adjustment vector, is the corrected feedback damping adjustment vector; In this way, then adding the corrected feedforward damping adjustment vector , the feedback damping adjustment vector and the reference damping vector element - by - element, the dynamic reconstruction (correlation - preserving reconstruction) of the feature space can be realized through the spatial adaptive homomorphic projection under different characteristic energy states, so as to realize the correlation - preserving addition of the feedforward damping adjustment vector, the feedback damping adjustment vector and the reference damping vector, and improve the control accuracy of the shock absorber control signal.

[0061] Specifically, after performing a clipping process on the target damping command, a signal conversion is carried out on it to obtain the shock absorber control signal. Correspondingly, the damping coefficient or damping force of the shock absorber has physical minimum and maximum limits. If the target damping command obtained by summation is directly sent to the actuator, and if this command exceeds these physical limits, not only can the desired damping effect not be achieved, it may lead to control failure, and in severe cases, it may even damage the shock absorber or affect vehicle stability. The clipping process ensures that the output command value always falls within the effective range achievable by the shock absorber. The subsequent signal conversion is necessary because the target damping command output by the control algorithm is in physical units (such as Newton-seconds per meter or Newtons), while actuators such as the solenoid valve or motor of the shock absorber need to receive specific forms of electrical signals (such as current, voltage, or pulse-width modulation PWM signals) to adjust the damping. This conversion transforms the theoretical target damping value into an actual control signal that the actuator can understand and execute, thereby achieving precise adjustment of the shock absorber damping.

[0062] Specifically, the signal conversion to obtain the shock absorber control signal after performing a clipping process on the target damping command can be achieved in the following way: First, a clipping process is performed on the target damping command (target damping command vector) obtained by summation in the previous step, which contains multiple components. Each component of this vector represents the target damping value that each shock absorber of the vehicle expects to achieve in the compression or extension direction. For each component in the vector, the system compares it with the pre-determined minimum damping limit value and maximum damping limit value for the corresponding working mode of the shock absorber. These limit values are determined based on the physical characteristics of the shock absorber itself (such as valve structure, motor capacity, etc.) and the vehicle dynamics calibration results (the upper and lower bounds set to ensure comfort, handling, and safety), and are stored in the control unit. If the value of a certain component is less than its corresponding minimum limit value, it is set to the minimum value; if it is greater than the maximum limit value, it is set to the maximum value; if it is between the minimum and maximum limit values, it remains unchanged. For example, the damping range of a certain shock absorber in the compression mode is from 100 Ns / m to 800 Ns / m. If the target compression damping command obtained by summation is 50 Ns / m, it will become 100 Ns / m after clipping; if it is 900 Ns / m, it will become 800 Ns / m after clipping; if it is 450 Ns / m, it will remain 450 Ns / m.

[0063] What is obtained after the clipping process is a clipped target damping command vector, and the values therein still represent physical quantities of damping. Next, signal conversion is performed. The control unit converts the clipped target damping value into a corresponding electrical signal according to the type and characteristics of the shock absorber actuator. This is achieved through a Lookup Table or a mathematical model. This Lookup Table or model describes the non-linear correspondence between the shock absorber damping value and the control signal (such as current), and this relationship has been determined during the factory production of the shock absorber or the vehicle calibration phase. For example, the Lookup Table stipulates that when the target damping value is 100 Ns / m, it corresponds to a current of 0.1 ampere; when the target damping value is 450 Ns / m, it corresponds to a current of 0.4 ampere; when the target damping value is 800 Ns / m, it corresponds to a current of 0.7 ampere. The control unit looks up or calculates the electrical signal value corresponding to the clipped target damping value (linear interpolation is required). What is finally output is a shock absorber control signal vector, and each component therein is a specific electrical signal value used to drive the corresponding shock absorber actuator (for example, in amperes or as a percentage representing the PWM duty cycle). These signals are then sent to each shock absorber through a drive circuit to achieve precise damping adjustment.

[0064] In summary, the automatic adjustment method for the damping strength of the shock absorbers of new energy vehicles based on the embodiments of the present application is elucidated. By introducing a feedforward estimation mechanism for the energy recovery torque signal, it calculates in advance the equivalent longitudinal force and the target pitching moment generated by energy recovery, combines the torque change rate to predict the disturbance trend, and actively adjusts the front and rear suspension damping using the feedforward control law (such as differentially adjusting the compression / tension damping according to the direction of the feedforward pitching moment), forming a pre-compensation before the pitching disturbance actually occurs, significantly shortening the system response delay. At the same time, by integrating feedforward and feedback control (dynamically adjusting the PID integral gain based on the filtered longitudinal acceleration and driving the closed-loop correction with the pitching angular velocity error), it further eliminates the residual disturbance on the basis of suppressing the initial impact, ensuring attitude stability. In addition, the fusion strategy of system space energy function modeling and feature space dynamic reconstruction optimizes the synergistic effect of feedforward, feedback, and reference damping, avoids control signal conflicts, and takes into account both the response speed and control accuracy. This solution makes full use of the torque preview information of the energy recovery system and the body attitude feedback data, realizes the rapid suppression of pitching disturbances, and improves the ride comfort.

[0065] Figure 4 It is a block diagram of an automatic adjustment system for the damping strength of the shock absorbers of new energy vehicles according to the embodiments of the present application. As Figure 4As shown, the automatic damping strength adjustment system 100 of a new energy vehicle shock absorber according to an embodiment of the present application includes: a signal acquisition module 110, configured to acquire a real-time energy recovery torque signal and a vehicle body attitude sensor signal; an energy recovery torque analysis module 120, configured to perform signal analysis on the real-time energy recovery torque signal to obtain an effective energy recovery torque; a pitch disturbance feedforward estimation module 130, configured to perform pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index; a feedforward damping adjustment module 140, configured to perform damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector; a feedback damping adjustment module 150, configured to perform signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and perform attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector; and a shock absorber control signal generation module 160, configured to fuse the feedforward damping adjustment vector, the feedback damping adjustment vector, and a reference damping vector to obtain a shock absorber control signal.

[0066] Here, those skilled in the art can understand that the specific operations of each step in the above automatic damping strength adjustment system of the new energy vehicle shock absorber have been described in detail in the description of the new energy vehicle shock absorber damping strength automatic adjustment method referred to above, and thus, the repeated description thereof will be omitted. Figures 1 to 3 ​

Claims

1. An automatic adjustment method for the damping strength of a shock absorber of a new energy vehicle, characterized in that, Including: Obtain a real-time energy recovery torque signal and a vehicle body attitude sensor signal; Perform signal analysis on the real-time energy recovery torque signal to obtain an effective energy recovery torque; Perform pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index; Perform damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector; Perform signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and perform attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector; Fuse the feedforward damping adjustment vector, the feedback damping adjustment vector, and a reference damping vector to obtain a shock absorber control signal.

2. The method for automatically adjusting the damping strength of a shock absorber for a new energy vehicle according to claim 1, wherein, Performing pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index, including: Calculate an equivalent longitudinal force generated by energy recovery based on the effective energy recovery torque and the tire radius; Calculate a target pitch force generated by the equivalent longitudinal force based on the equivalent longitudinal force and the center of gravity height as the estimated feedforward pitch moment; Calculate the change rate of the effective energy recovery torque as the pitch disturbance trend index.

3. The automatic adjustment method for the damping strength of a shock absorber of a new energy vehicle according to claim 2, wherein, Performing damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector, including: Obtain the current vehicle speed; Input the current vehicle speed, the estimated feedforward pitch moment, and the pitch disturbance trend index into a look-up table based on a control law to obtain the feedforward damping adjustment vector.

4. The method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to claim 3, characterized in that, Inputting the current vehicle speed, the estimated feedforward pitch moment, and the pitch disturbance trend index into a look-up table based on a control law to obtain the feedforward damping adjustment vector, including: When the estimated feedforward pitch moment is greater than zero, increase the compression damping of the front suspension and increase the extension damping of the rear suspension; When the estimated feedforward pitch moment is less than zero, increase the extension damping of the front suspension and increase the compression damping of the rear suspension.

5. The method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to claim 1, characterized in that: Performing signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and performing attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector, including: Adjust the integral gain in the PID controller based on the filtered longitudinal acceleration to obtain a fine-tuned PID controller; Calculate the error between the filtered pitch angular velocity and the target pitch angular velocity; Input the error into the fine-tuned PID controller to obtain the feedback damping adjustment vector.

6. The method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to claim 5, characterized in that, The target pitch angular velocity is 0 rad / s.

7. The method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to claim 1, characterized in that: Fusing the feedforward damping adjustment vector, the feedback damping adjustment vector, and a reference damping vector to obtain a shock absorber control signal, including: Sum the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain a target damping command; After performing amplitude limiting processing on the target damping command, signal conversion is carried out on it to obtain the shock absorber control signal.

8. The method for automatically adjusting the damping strength of a shock absorber of a new energy vehicle according to claim 7, wherein, Adding the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain the target damping command includes: Carrying out correlation modeling on the feedforward damping adjustment vector and the feedback damping adjustment vector through the system space energy function to obtain a correlation reference state representation vector; Taking the correlation reference state representation vector as the adaptive gain state, and performing homomorphic projection mapping with the feedforward damping adjustment vector and the feedback damping adjustment vector respectively to obtain a feedforward damping mapping adjustment vector and a feedback damping mapping adjustment vector; Using the reference damping vector as the chain state prior, performing feature space dynamic reconstruction on the feedforward damping mapping adjustment vector and the feedback damping mapping adjustment vector to obtain a corrected feedforward damping adjustment vector and a corrected feedback damping adjustment vector; Performing position-wise addition on the corrected feedforward damping adjustment vector, the corrected feedback damping adjustment vector, and the reference damping vector to obtain a target damping command vector as the target damping command.

9. An automatic damping strength adjustment system for a shock absorber of a new energy vehicle, characterized in that, Including: A signal acquisition module for acquiring a real-time energy recovery torque signal and a vehicle body attitude sensor signal; An energy recovery torque analysis module for performing signal analysis on the real-time energy recovery torque signal to obtain an effective energy recovery torque; A pitch disturbance feedforward estimation module for performing pitch disturbance feedforward estimation on the effective energy recovery torque to obtain an estimated feedforward pitch moment and a pitch disturbance trend index; A feedforward damping adjustment module for performing damping compensation feedforward calculation based on the estimated feedforward pitch moment and the pitch disturbance trend index to obtain a feedforward damping adjustment vector; A feedback damping adjustment module for performing signal analysis on the vehicle body attitude sensor signal to obtain a filtered longitudinal acceleration and a filtered pitch angular velocity, and performing attitude feedback and damping correction on the filtered longitudinal acceleration and the filtered pitch angular velocity to obtain a feedback damping adjustment vector; A shock absorber control signal generation module for fusing the feedforward damping adjustment vector, the feedback damping adjustment vector, and the reference damping vector to obtain a shock absorber control signal.

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