Continuous control method, system and control unit for damping of a semi-active suspension system of a vehicle

Abstract

The application relates to a continuous control method, system and control unit of damping of a semi-active suspension system of an automobile, and the method comprises the following steps: acquiring motion state information of an automobile body and a suspension system and whole vehicle working condition information; based on the motion state information of the automobile body and the suspension system and a preset global skyhook damping control strategy, calculating corresponding required damping forces of each suspension; based on the corresponding required damping forces of each suspension, an external characteristic of a damper of the automobile, road excitation frequency identification information and a preset skyhook damping control rule, calculating a vertical control current of the automobile; based on a lateral working condition, a longitudinal working condition and an expert database, determining a lateral control current and a longitudinal control current of the automobile; based on a control mode, the vertical control current, the lateral control current and the longitudinal control current, determining a target control current, and controlling the posture of the automobile body according to the target control current. The application has the effect of simultaneously optimizing vertical comfort and lateral / longitudinal handling and stability performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile semi-active suspension control, and particularly relates to a damping continuous control method, system and control unit of an automobile semi-active suspension system. BACKGROUND

[0002] With the rapid development of automobile technology and the continuous improvement of consumer requirements for driving experience, the automobile suspension system, as a key component directly affecting the vehicle ride comfort and handling stability, has received extensive attention and research. In recent years, the maturity of the active suspension technology and the acceleration of the process of domestication of parts have enabled advanced technologies such as the damping continuous adjustable semi-active suspension system (CDC system) and the air spring (ECAS system) to be applied in medium and low-end vehicles, further promoting the development of automobile suspension systems.

[0003] Then, the traditional semi-active suspension control method often regards the whole vehicle suspension system as four independent subsystems and controls them respectively. This independent control strategy ignores the coupling relationship between the body roll, pitch motion and the vertical motion of each tire in the actual whole vehicle suspension system, resulting in unsatisfactory control effect in some high coupling conditions, and at the same time, it cannot be compatible with the air spring, and the hardware cost is also high.

[0004] Therefore, there is an urgent need for a damping continuous control method of an automobile semi-active suspension system that can be compatible with the air spring, has low cost and can simultaneously optimize the vertical comfort and lateral / longitudinal handling stability performance. SUMMARY

[0005] The technical problem solved by the present application is to provide a damping continuous control method, system and control unit of an automobile semi-active suspension system, aiming to solve at least one of the above technical problems.

[0006] The technical solution of the present application to solve the above technical problems is as follows:

[0007] In a first aspect, the present application provides a damping continuous control method of an automobile semi-active suspension system, which adopts the following technical solution:

[0008] A damping continuous control method of an automobile semi-active suspension system, comprising:

[0009] acquire body motion state information, suspension system motion state information and vehicle working condition information of the vehicle, wherein the body motion state information comprises vertical vibration speed, roll angle speed and pitch angle speed, the suspension system motion state information comprises shock absorber speed, road roughness and road excitation frequency identification information, the working condition information comprises lateral working condition information and longitudinal working condition information, the lateral working condition information represents a working condition corresponding to a steering operation in a driving process of the vehicle, and the longitudinal working condition information represents a working condition corresponding to an acceleration operation or a deceleration operation in the driving process of the vehicle;

[0010] calculate a required damping force corresponding to each suspension based on the body motion state information, the suspension system motion state information and a preset global skyhook damping control strategy, wherein the preset global skyhook damping control strategy is a correlation between a body posture of the vehicle as a whole and the damping force of each suspension;

[0011] calculate a vertical control current of the vehicle based on the required damping force corresponding to each suspension, an external characteristic of a shock absorber of the vehicle, the road excitation frequency identification information and a preset skyhook damping control rule, wherein the vertical control current is a current for controlling body and wheel vibration of the vehicle caused by road vertical excitation;

[0012] determine a lateral control current of the vehicle based on the lateral working condition information and a first expert database containing expert evaluation data, wherein the first expert database comprises a relationship between different lateral working condition information and corresponding lateral control currents, and the lateral control current is a current for controlling a body posture change of the vehicle caused by a steering operation;

[0013] determine a longitudinal control current of the vehicle based on the longitudinal working condition information and a second expert database containing expert evaluation data, wherein the second expert database comprises a relationship between different longitudinal working condition information and corresponding longitudinal control currents, and the longitudinal control current is a current for controlling a body posture change of the vehicle caused by an acceleration or deceleration operation;

[0014] acquire a control mode of a semi-active suspension of the vehicle, calculate a target control current based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and adjust the damping of the suspension of the vehicle according to the target control current.

[0015] The beneficial effects of the present application are: by the preset global skyhook damping strategy, the correlation between the overall vehicle body posture and the damping force of each suspension can be established, and the whole vehicle coupling control is realized; the vertical comfort control method links the four suspensions together from the perspective of whole vehicle coupling, focuses on the vertical vibration of the vehicle and the roll and pitch motion of the vehicle, and strives to obtain better vehicle ride comfort. At the same time, combined with the identification results of road roughness and road excitation frequency, the control parameters can be adjusted to ensure that the vehicle can still maintain a stable driving posture under complex road conditions. In addition, the determination method of the lateral and longitudinal control currents based on the expert database can identify the driving intention of the driver and distinguish different driving conditions, realize targeted control, and further enhance the handling and stability performance of the vehicle. Finally, the vertical / lateral / longitudinal control currents are comprehensively arbitrated and output to the shock absorber to achieve better comfort and handling and stability control effect. On the basis of the above technical scheme, the present application can also be improved as follows.

[0016] Further, the body motion state information, suspension system motion state information and vehicle working condition information of the vehicle are obtained, comprising:

[0017] The motion state signals of the vehicle body are collected by the 6-axis IMU sensor, and based on the motion state signals, the running state data of each body measuring point of the vehicle is calculated to obtain the body motion state information, and the plurality of body measuring points are respectively the body mass center position, the body left front suspension position, the body right front suspension position, the body left rear suspension position and the body right rear suspension position.

[0018] The height sensor signals on the respective corresponding suspension swing arms are collected by the height sensors on the respective suspension swing arms, and based on the height sensor signals, the velocities of the respective corresponding shock absorbers of the respective suspension swing arms are calculated; and based on the height sensor signals, the road roughness and road excitation frequency of the current road are identified to obtain the road roughness and road excitation frequency identification information of the current road.

[0019] CAN message data of the vehicle is obtained, and the working condition identification is performed on the CAN message data to obtain the working condition information, the CAN message data includes the steering wheel angle, the steering wheel angular velocity, the longitudinal acceleration or longitudinal deceleration of the vehicle, the throttle change amount and the brake pedal change amount, the longitudinal acceleration is the acceleration in the same direction as the vehicle traveling direction, the longitudinal deceleration is the deceleration in the same direction as the vehicle traveling direction, the lateral working condition includes any one of the straight line driving working condition, the first steering working condition and the second steering working condition, and the longitudinal working condition information includes any one of the uniform speed driving working condition, the first acceleration driving working condition, the second acceleration driving working condition, the first deceleration driving working condition and the second deceleration driving working condition.

[0020] The straight driving condition represents a condition in which the steering wheel angle is less than a preset angle threshold, the first steering condition represents a condition in which the steering wheel angle is not less than a preset angle threshold and the steering wheel angular velocity is less than a preset angular velocity threshold, and the second steering condition represents a condition in which the steering wheel angle is not less than a preset angle threshold and the steering wheel angular velocity is not less than a preset angular velocity threshold; the uniform speed driving condition represents a condition in which the longitudinal acceleration is less than a preset acceleration threshold or the longitudinal deceleration is less than a preset deceleration threshold, the accelerator change amount is less than a preset first change threshold, and the brake pedal displacement change amount is less than a preset second change threshold; the first acceleration driving condition represents a condition in which the accelerator change amount is not less than a preset first change threshold; the second acceleration driving condition represents a condition in which the longitudinal acceleration is greater than a preset acceleration threshold and the accelerator change amount is less than a preset first change threshold; the first deceleration driving condition represents a condition in which the brake pedal displacement change amount is not less than a preset second change threshold; and the second deceleration driving condition represents a condition in which the longitudinal deceleration is greater than a preset threshold and the brake pedal displacement change amount is less than a preset second change threshold.

[0021] The beneficial effect of the further scheme is that a 6-axis IMU + 4 height sensor system sensor scheme is adopted, the 6-axis IMU sensor is integrated on the control unit, and the two ends of the four height sensors are respectively mounted on the respective shock absorber outer cylinder and suspension swing arm, which effectively reduces the hardware cost while being compatible with the air spring, and facilitates the later addition of the air spring.

[0022] Through the 6-axis IMU sensor and the height sensor on the suspension swing arm, the motion state data of the vehicle body and the suspension system can be collected in real time and accurately. These data provide an important basis for performance analysis, fault diagnosis and control system optimization of the vehicle. Through the analysis of CAN message data and the identification of working conditions, different driving conditions such as straight driving, steering, acceleration and deceleration can be accurately distinguished, and the driving intention of the driver can be identified.

[0023] Further, the global skyhook damping strategy includes a pre-established calculation formula of the damping force corresponding to each suspension, and the demand damping force corresponding to each suspension is calculated based on the vehicle body motion state information, the suspension system motion state information and the preset global skyhook damping control strategy, including:

[0024] The skyhook damping coefficient is calibrated based on the identification result of the road roughness and the road excitation frequency, and the upper limit value and the lower limit value of the damping force are determined;

[0025] calculating a reference damping force of each suspension of the vehicle based on the skyhook damping coefficient, a vertical vibration speed of the vehicle body, a pitch angular velocity, a roll angular velocity of the vehicle body, and a pre-established calculation formula of the damping force corresponding to each suspension;

[0026] determining a required damping force corresponding to each suspension based on the shock absorber speed, the vertical vibration speed, and the reference damping force of each suspension;

[0027] wherein the pre-established calculation formula of the damping force corresponding to each suspension is:

[0028]

[0029] wherein

[0030] F d =[F lf F rf F lr F rr ] T ;c z =4c sky ;c θ =t 2 c sky ;

[0031] wherein F d is the reference damping force of each suspension, c z is an equivalent skyhook damping coefficient of the vertical vibration, c θ is an equivalent skyhook damping coefficient of the roll vibration, is an equivalent skyhook damping coefficient of the pitch vibration; is the vertical vibration speed, is the pitch angular velocity, is the roll angular velocity; a s is a distance from a front axle of the vehicle to the center of mass, b s is a distance from a rear axle of the vehicle to the center of mass, t is a wheelbase of the vehicle, and c sky is the skyhook damping coefficient based on the identification result of the road roughness and the road excitation frequency.

[0032] The beneficial effects of the above further scheme are: through the global skyhook damping control strategy, the correlation between the overall vehicle body posture and the damping force of each suspension is considered, and the coupling control between the vehicle body and each suspension can be realized to achieve better control effect. By introducing the equivalent skyhook damping coefficient, the method can dynamically adjust the size of the damping force according to different vibration degrees of freedom (vertical, roll, and pitch) of the vehicle body and different driving conditions to adapt to different road conditions and driving requirements. And each equivalent damping coefficient cz 、c θ 、 And the parameter matrix A can be calculated offline, reducing the amount of online calculation.

[0033] Further, the establishment process of the calculation formula of the damping force corresponding to each suspension includes:

[0034] Based on the vertical vibration speed of the vehicle body, the calibrated skyhook damping coefficient, the front and rear wheel track of the vehicle, the distance from the front axle of the vehicle to the center of mass, and the distance from the rear axle of the vehicle to the center of mass, the first skyhook damping force when the vehicle is vertically vibrating, the second skyhook damping force when the vehicle is rolling, and the third skyhook damping force when the vehicle is pitching are calculated respectively.

[0035] Based on the first skyhook damping force, the first equivalent skyhook damping coefficient of the whole vehicle when vertically vibrating is determined, based on the second skyhook damping force, the second equivalent skyhook damping coefficient of the whole vehicle when rolling is determined, and based on the third skyhook damping force, the third equivalent skyhook damping coefficient of the whole vehicle when pitching is determined.

[0036] Based on the first equivalent skyhook damping coefficient, the second equivalent skyhook damping coefficient, the third equivalent skyhook damping coefficient, and the preset parameter matrix, the calculation formula of the damping force corresponding to each suspension is established.

[0037] The beneficial effects of the above further scheme are: by defining the equivalent skyhook damping coefficients of the whole vehicle when vertically vibrating, rolling and pitching, the complex damping control problem is simplified to the adjustment of the equivalent damping coefficients, making the control strategy more intuitive and easy to implement.

[0038] Further, the determination of the demand damping force corresponding to each suspension based on the shock absorber speed, the vertical vibration speed and the reference damping force of each suspension includes:

[0039] When the shock absorber speed and the vertical vibration speed are in the same direction, the demand damping force corresponding to each suspension is the reference damping force;

[0040] When the shock absorber speed and the vertical vibration speed are in opposite directions, the demand damping force corresponding to each suspension is the minimum value in the preset damping force range.

[0041] The beneficial effect of the above further scheme is that when the shock absorber speed and the vertical vibration speed of the corresponding measuring point of the vehicle body are opposite, the damping force of each suspension is set to the minimum value in the preset damping force range, which helps to reduce the direct impact of the vehicle on the road, thereby reducing the impact of vibration on the people in the vehicle. When the shock absorber speed and the vertical vibration speed are in the same direction, the required damping force of each suspension is the reference damping force, which can realize accurate control and distribution of the damping force. This helps to reduce the change of the vehicle body posture and ensures good ride comfort under various driving conditions.

[0042] Further, the vertical control current of the vehicle is calculated based on the required damping force of each suspension, the damping external characteristic of the vehicle shock absorber, the road excitation frequency identification information, and a preset skyhook damping control rule, comprising:

[0043] Based on the required damping force of each suspension, the damping external characteristic of the vehicle shock absorber, and a preset damping characteristic table, the vertical skyhook control current of each suspension is determined.

[0044] If the road excitation frequency is in a preset wheel resonance frequency range, the vertical control current of the vehicle is calculated based on the vertical skyhook control current and a preset skyhook control algorithm.

[0045] The lateral control current of the vehicle is determined based on the lateral working condition information and a first expert database containing expert evaluation data established in advance, comprising:

[0046] When the lateral working condition of the vehicle is a first steering working condition, the lateral control current of the vehicle is determined based on the vehicle lateral acceleration and the first expert database.

[0047] When the lateral working condition of the vehicle is a second steering working condition, the lateral control current of the vehicle is determined based on the steering wheel angular velocity and the first expert database.

[0048] The longitudinal control current of the vehicle is determined based on the longitudinal working condition information and a second expert database containing expert evaluation data established in advance, comprising:

[0049] When the longitudinal working condition of the vehicle is a first acceleration driving working condition, the longitudinal control current of the vehicle is determined based on the throttle change amount and the second expert database.

[0050] When the longitudinal working condition of the vehicle is a second acceleration driving working condition, the longitudinal control current of the vehicle is determined based on the longitudinal acceleration of the vehicle and the second expert database.

[0051] When the longitudinal working condition of the automobile is the first deceleration driving working condition, the longitudinal control current of the automobile is determined based on the brake pedal change amount and the second expert database;

[0052] When the longitudinal working condition of the automobile is the second deceleration driving working condition, the longitudinal control current of the automobile is determined based on the longitudinal deceleration of the vehicle and the second expert database.

[0053] The beneficial effects of the further scheme are: by setting the upper limit value and the lower limit value of the damping force based on the road roughness, it can be ensured that the damping force is adjusted within a reasonable range, neither too large to affect the comfort of the vehicle, nor too small to cause poor damping effect; by the road excitation frequency, it is determined whether to use the ground shelf control, avoiding the adverse effects of the use of ground shelf control on comfort outside the wheel resonance frequency range, and when the road excitation frequency is in the wheel resonance frequency range, the resonance phenomenon can be further suppressed by combining the ground shelf control algorithm to ensure driving stability and safety.

[0054] According to the lateral working condition information, the lateral control current is determined in combination with the expert database, so that the vehicle is more stable when turning or changing lanes, and the handling performance is improved. According to the longitudinal working condition information, the longitudinal control current is determined in combination with the expert database, so that the vehicle is more stable when accelerating or decelerating, and the handling performance is improved. The system can adapt to different driving conditions and adjust the control current to adapt to different driving requirements, and has strong adaptability.

[0055] Further, the control mode of the semi-active suspension is a first mode or a second mode, the first mode represents a mode meeting the comfort demand, and the second mode represents a mode meeting the handling demand;

[0056] The target control current is determined based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, comprising:

[0057] When the control mode is the first mode, a lateral weighting coefficient is determined based on the lateral working condition information of the automobile;

[0058] A longitudinal weighting coefficient is determined based on the longitudinal working condition information;

[0059] A vertical weighting coefficient is determined based on the lateral weighting coefficient and the longitudinal weighting coefficient;

[0060] The vertical control current, the lateral control current and the longitudinal control current are weighted and summed according to the respective weighting coefficients to obtain the target control current;

[0061] When the control mode is the second mode, the maximum current is selected from the vertical control current, the lateral control current and the longitudinal control current as the target control current.

[0062] The beneficial effect of adopting the above further scheme is that by setting two control modes, the vehicle can be flexibly switched according to the needs of the driver or the driving conditions, so as to realize the optimization of ride comfort and handling in different scenarios. In the first mode, by calculating the lateral weighting coefficient, the longitudinal weighting coefficient and the vertical weighting coefficient, the vertical, lateral and longitudinal control currents can be accurately weighted and summed to obtain a target control current that comprehensively considers multiple control factors, which has certain handling and stability performance under the premise of ensuring comfort. In the second mode, the maximum value of the three control currents is directly selected as the target control current, which ensures that the shock absorber is always in a larger damping state under complex working conditions, so that the handling and stability performance is at a relatively optimal level at any time. By adopting different comprehensive arbitration strategies for different driving modes, the comfort and handling and stability performance requirements are switched according to different needs.

[0063] In a second aspect, the application provides a continuous damping control system for a semi-active suspension system of an automobile, adopting the following technical scheme:

[0064] A continuous damping control system for a semi-active suspension system of an automobile, comprising:

[0065] A data acquisition module for acquiring body motion state information, suspension system motion state information and vehicle working condition information of the automobile, wherein the body motion state information includes body vertical vibration speed, roll angle speed and pitch angle speed, the suspension system motion state information includes shock absorber speed, road roughness and road excitation frequency identification information, the working condition information includes lateral working condition information and longitudinal working condition information, the lateral working condition information represents the working condition corresponding to the steering operation of the automobile during driving, and the longitudinal working condition information represents the working condition corresponding to the acceleration operation or deceleration operation of the automobile during driving;

[0066] A damping force calculation module for calculating the required damping force of each suspension based on the body motion state information, the suspension system motion state information and a preset global skyhook damping control strategy, wherein the preset global skyhook damping control strategy is the correlation between the body posture of the automobile as a whole and the damping force of each suspension;

[0067] A vertical control current calculation module for calculating the vertical control current of the automobile based on the required damping force of each suspension, the damping external characteristic of the automobile shock absorber, the road excitation frequency identification information and a preset skyhook damping control rule, wherein the vertical control current is the current for controlling the body and wheel vibration of the automobile caused by road vertical excitation;

[0068] a lateral control current calculation module configured to determine a lateral control current of the vehicle based on the lateral working condition information and a first expert database comprising expert evaluation data, the first expert database comprising relationships between different lateral working condition information and corresponding lateral control currents, the lateral control current being a current for controlling a body posture change of the vehicle caused by a steering operation;

[0069] a longitudinal control current calculation module configured to determine a longitudinal control current of the vehicle based on the longitudinal working condition information and a second expert database comprising expert evaluation data, the second expert database comprising relationships between different longitudinal working condition information and corresponding longitudinal control currents, the longitudinal control current being a current for controlling a body posture change of the vehicle caused by an acceleration or deceleration operation or a deceleration operation;

[0070] an arbitration scheme output module configured to obtain a control mode of the semi-active suspension of the vehicle, calculate a target control current based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and adjust a damping of the suspension of the vehicle according to the target control current.

[0071] In a third aspect, the present application provides a control unit, which adopts the following technical scheme:

[0072] An electronic device comprising a memory and a processor, the memory storing a computer program capable of being loaded and executed by the processor to implement the continuous control method of the damping of the semi-active suspension system of the vehicle according to any one of the first aspect.

[0073] In a fourth aspect, the present application provides a computer readable storage medium, which adopts the following technical scheme:

[0074] A computer readable storage medium storing a computer program capable of being loaded and executed by a processor to implement the continuous control method of the damping of the semi-active suspension system of the vehicle according to any one of the first aspect.

[0075] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0076] Figure 1 A structural block diagram of a semi-active suspension system of a vehicle according to an embodiment of the present application;

[0077] Figure 2 A flowchart of a continuous control method of a semi-active suspension system of a vehicle according to an embodiment of the present application;

[0078] Figure 3This is a schematic diagram of global ceiling control for comprehensive vehicle body posture control according to an embodiment of the present invention;

[0079] Figure 4 A global ceiling-controlled vehicle body vibration model provided in one embodiment of the present invention;

[0080] Figure 5 A structural block diagram of a continuous damping control system for a semi-active suspension system of an automobile is provided in one embodiment of the present invention;

[0081] Figure 6 This is a schematic diagram of the structure of a control unit provided in one embodiment of the present invention. Detailed Implementation

[0082] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0083] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0084] This application provides a method for continuous damping control of a semi-active suspension system for automobiles. This method is applicable to any application scenario requiring control of the semi-active suspension. The solution provided in this embodiment can be executed by an electronic device with data processing capabilities, such as a control unit with data processing capabilities installed on the semi-active suspension system of an automobile.

[0085] like Figure 1 As shown, this control method is applied to a semi-active suspension system for automobiles. The semi-active suspension system includes a control unit, a 6-axis IMU sensor, and four height sensors. The 6-axis IMU sensor is integrated into the control unit, and the two ends of the four height sensors are respectively mounted on their respective body and suspension arms.

[0086] The control unit stores the designed bottom layer driver and application layer control program, and when the program is executed, the designed continuous damping control method can be realized. The control unit can also obtain the respective height signals transmitted by each height sensor, and accept the vehicle CAN message signal of the vehicle, and output the required target control current to the four shock absorbers respectively to control the damping force of the shock absorbers. The system sensor scheme of one 6-axis IMU + four height sensors can make the system compatible with air springs while effectively reducing the hardware cost, facilitating the addition of air springs later.

[0087] It should be noted that the shock absorber can also be an internal valve shock absorber or a magneto-rheological / electro-rheological shock absorber or an active hydraulic shock absorber and other structural forms of active or semi-active shock absorbers.

[0088] As shown in Figure 2 A continuous damping control method for a semi-active suspension system of an automobile, comprising:

[0089] Step S1, obtaining the vehicle body motion state information, suspension system motion state information and vehicle working condition information, wherein the vehicle body motion state information includes vehicle body vertical vibration speed, roll angle speed and pitch angle speed, the suspension system motion state information includes shock absorber speed, road roughness and road excitation frequency identification information, the working condition information includes lateral working condition information and longitudinal working condition information, the lateral working condition information represents the working condition corresponding to the steering operation of the automobile during driving, and the longitudinal working condition information represents the working condition corresponding to the acceleration operation or deceleration operation of the automobile during driving;

[0090] In the embodiment of the application, the automobile has five vehicle body measurement points, which are the vehicle mass center position, the vehicle left front suspension position, the vehicle right front suspension position, the vehicle left rear suspension position or the vehicle right rear suspension position.

[0091] Step S1 specifically comprises the following sub-steps:

[0092] Step S11, acquiring the motion state signal of the vehicle body through the 6-axis IMU sensor, and calculating the running state data of each vehicle body measurement point of the automobile based on the motion state signal to obtain the vehicle body motion state information;

[0093] Step S12, acquiring the height sensor signal on each corresponding suspension swing arm through the height sensor on each suspension swing arm, calculating the shock absorber speed of each corresponding suspension swing arm based on each height sensor signal, and identifying the road roughness and road excitation frequency of the current road based on each height sensor signal to obtain the road roughness and road excitation frequency identification information of the current road;

[0094] In step S13, CAN message data of the vehicle is acquired, and working condition recognition is performed on the CAN message data to obtain working condition information. The CAN message data includes a steering wheel angle, a steering wheel angular velocity, a longitudinal acceleration or a longitudinal deceleration of the vehicle, a throttle variation, and a brake pedal variation. The longitudinal acceleration is an acceleration in the same direction as the vehicle travels, and the longitudinal deceleration is a deceleration in the same direction as the vehicle travels. The lateral working condition includes any one of a straight-line driving working condition, a first steering working condition (i.e., a steady-state slow steering working condition), and a second steering working condition (i.e., a transient-state sharp steering working condition). The longitudinal working condition information includes any one of a constant-speed driving working condition, a first accelerating driving working condition (i.e., a transient-state sharp accelerating working condition), a second accelerating driving working condition (i.e., a steady-state slow accelerating working condition), a first decelerating driving working condition (i.e., a transient-state sharp decelerating working condition), and a second decelerating driving working condition (i.e., a steady-state slow decelerating working condition).

[0095] The straight-line driving working condition represents a working condition in which the steering wheel angle is less than a preset angle threshold. The first steering working condition represents a working condition in which the steering wheel angle is not less than a preset angle threshold and the steering wheel angular velocity is less than a preset angular velocity threshold. The second steering working condition represents a working condition in which the steering wheel angle is not less than a preset angle threshold and the steering wheel angular velocity is not less than a preset angular velocity threshold. The constant-speed driving working condition represents a working condition in which the longitudinal acceleration is less than a preset acceleration threshold or the longitudinal deceleration is less than a preset deceleration threshold, the throttle variation is less than a preset first variation threshold, and the brake pedal displacement variation is less than a preset second variation threshold. The first accelerating driving working condition represents a working condition in which the throttle variation is not less than a preset first variation threshold. The second accelerating driving working condition represents a working condition in which the longitudinal acceleration is greater than a preset acceleration threshold and the throttle variation is less than a preset first variation threshold. The first decelerating driving working condition represents a working condition in which the brake pedal displacement variation is not less than a preset second variation threshold. The second decelerating driving working condition represents a working condition in which the longitudinal deceleration is greater than a preset threshold and the brake pedal displacement variation is less than a preset second variation threshold.

[0096] It should be noted that all the thresholds involved in the above description are calibration values and are related to the vehicle speed.

[0097] In the above embodiment, in step S11, the vehicle running state data of each body measuring point of the vehicle is calculated based on the IMU signal, and specifically includes:

[0098] First, the IMU signal is filtered, unit-converted, integrated, and differentiated to obtain a body roll angle, a pitch angle, a roll angular velocity, a pitch angular velocity, a roll angular acceleration, a pitch angular acceleration, an acceleration in the X-axis direction, an acceleration in the Y-axis direction, and an acceleration in the Z-axis direction of the vehicle.

[0099] Then, based on the body roll angle, the pitch angle, the acceleration in the X-axis direction, the acceleration in the Y-axis direction, the acceleration in the Z-axis direction, and the Euler formula, the vertical acceleration of the body after removing the gravity effect, which is the vertical acceleration at the IMU mounting point, is calculated, and the vertical acceleration after removing the gravity effect is taken as the first vertical acceleration;

[0100] The XYZ-direction acceleration values after removing the gravity effect can be expressed as:

[0101] Acc ZN = Acc Z -g*cos(θ)*cos(ψ);

[0102] Acc XN = Acc X -g*cos(θ)*sin(ψ);

[0103] Acc YN = Acc Y -g*sin(θ);

[0104] wherein, Acc XN , Acc YN , Acc ZN are the X, Y, Z-direction acceleration values after removing the gravity acceleration component, Acc X , Acc Y , Acc Z are the X, Y, Z-direction acceleration values read by the IMU, and θ, ψ are the roll angle and the pitch angle, respectively.

[0105] Then, based on the body roll angle, the pitch angle, the roll angular velocity, the pitch angular velocity, the roll angular acceleration, the pitch angular acceleration, the first vertical acceleration, and the body geometric parameters, the vertical acceleration of each of the body measuring points is calculated, and the vertical acceleration of the body measuring points is taken as the second vertical acceleration.

[0106] The calculation formula of the vertical acceleration of the body measuring points is:

[0107]

[0108] In the formula, a are the vertical accelerations of the front left, the front right, the rear left, the rear right, and the center of mass of the body, respectively; a f , a r , a CG are the longitudinal projection distances of the IMU mounting point from the front axle, the rear axle, and the center of mass, respectively; t L , t R , t CGThe lateral projection distance of the IMU mounting point from the left side, the right side, and the center of mass, respectively.

[0109] It should be noted that the IMU mounting position is in front of the center of mass by default in the above formula. If the relationship between the IMU position and the center of mass position changes, the calculation The symbols in the formula should be changed accordingly.

[0110] Finally, based on the second vertical acceleration corresponding to each vehicle body measurement point and the preset linear Kalman filtering algorithm, the running state data of each vehicle body measurement point of the vehicle is calculated.

[0111] The preset linear Kalman filtering algorithm is:

[0112]

[0113] where X k is the system state at time k; Z k is the measurement at time k; U k is the system control quantity at time k; W k is the process noise, with covariance Q; V k is the measurement noise, with covariance R; A and B are system parameters S; and H is the measurement system parameter.

[0114] By using the Euler formula and Kalman filtering, the speed and acceleration signals obtained after processing the signals of the IMU have good accuracy and less high-frequency interference.

[0115] In the embodiments of the present application, in step S12, based on each of the height sensor signals, the speed of the corresponding shock absorber of each suspension swing arm is calculated; and based on each of the height sensor signals, the road roughness and road excitation frequency of the current road surface are identified to obtain road roughness and road excitation frequency identification information of the current road surface, specifically including:

[0116] First, based on each of the height sensor signals, filtering and differential processing are performed to obtain the speed of each shock absorber and the filtered stroke information;

[0117] Then, based on the vehicle speed, the stroke information of each suspension, and the driving time of the vehicle within a preset distance, the preset evaluation index is calculated to obtain the road roughness of the current road surface. The road roughness is an index that describes the degree of road surface undulation and concave-convex.

[0118] The evaluation index is: the integral value of the suspension stroke with respect to the driving distance within a certain distance is calculated, and the road roughness is classified according to the value. The integral formula is:

[0119]

[0120] Wherein: S n+1 -S n = S = v * Δt, v is the vehicle speed, and Δt is the time required for the vehicle to travel a distance S.

[0121] Finally, the vibration frequency of the shock absorber is calculated by using the preset zero-crossing method, and then the road excitation frequency is estimated, so as to obtain the road excitation frequency, which is the frequency of the reciprocating vibration of the shock absorber due to the uneven road during the driving of the vehicle.

[0122] Wherein, the preset zero-crossing method is:

[0123]

[0124] In the formula, v n is the suspension speed of the previous sampling point before the nth zero-crossing; v n+1 is the suspension speed of the next sampling point after the nth zero-crossing; T sample is the sampling period; f is the estimated frequency; N is the number of samples from the first sampling point after the nth zero-crossing to the previous sampling point before the (n+2)th zero-crossing; T n and T n+2 are the time intervals between the zero-crossing and the next sampling point after the nth zero-crossing and the (n+2)th zero-crossing, respectively.

[0125] By using the signal of the height sensor to estimate the road unevenness and the road excitation frequency, the corresponding parameters can be adjusted for different road conditions to obtain better control effect.

[0126] Step S2, based on the vehicle body motion state information, the suspension system motion state information and the preset global skyhook damping control strategy, the demand damping force corresponding to each suspension is calculated, and the preset global skyhook damping control strategy is the correlation between the overall vehicle body posture and the damping force of each suspension;

[0127] In the embodiments of the present application, the global skyhook damping strategy includes a pre-established calculation formula of the damping force corresponding to each suspension, and step S2 specifically includes the following sub-steps:

[0128] Step S21, based on the identification result of the road unevenness and the road excitation frequency, the skyhook damping coefficient is calibrated, and the upper limit value and the lower limit value of the damping force are determined

[0129] Step S22, based on the skyhook damping coefficient, the vehicle body vertical vibration speed, the pitch angular velocity, the roll angular velocity of the vehicle body mass center position, and the pre-established calculation formula of the damping force corresponding to each suspension, the reference damping force of each suspension of the vehicle is calculated.

[0130] Step S22: Based on the shock absorber speed, the vertical vibration speed, and the reference damping force of each suspension, determine the required damping force for each suspension.

[0131] The pre-established formulas for calculating the damping force of each suspension are as follows:

[0132]

[0133] in

[0134] F d =[F lf F rf F lr F rr ] T c z =4c sky c θ =t 2 c sky ;

[0135] F d ∈[F min F max ];

[0136] Among them, F d c is the reference damping force for each suspension. z c is the equivalent ceiling damping coefficient for vertical vibration. θ The equivalent ceiling damping coefficient for tilting vibration. The equivalent ceiling damping coefficient for pitch vibration; The vertical vibration velocity, The pitch angular velocity, Angular velocity of elevation; a s b is the distance from the front axle of the car to its center of gravity. s Let be the distance from the rear axle to the center of gravity of the car, t be the track width between the front and rear axles, and c be the distance between the rear axle and the center of gravity. sky The ceiling damping coefficient is calibrated based on the identification results of road surface unevenness and road surface excitation frequency.

[0137] In the embodiments of this application, such as Figure 3 As shown, this patent considers the correlation between the overall vehicle body posture and the damping forces of each suspension through a global ceiling damping strategy, enabling coupled control of the entire vehicle. By comprehensively controlling the body posture and distributing the calculated control results to the four suspensions, a better control effect is achieved.

[0138] In the above embodiments, the process of establishing the calculation formulas for the damping forces corresponding to each suspension includes:

[0139] Step Sa: Based on the vertical vibration velocity of the vehicle body, the calibrated ceiling damping coefficient, the front and rear axle track of the vehicle, the distance from the front axle to the center of mass of the vehicle, and the distance from the rear axle to the center of mass of the vehicle, calculate the first ceiling damping force when the vehicle is undergoing vertical vibration, the second ceiling damping force when the vehicle is undergoing lateral movement, and the third ceiling damping force when the vehicle is undergoing pitching movement.

[0140] Step Sb: Determine the first equivalent ceiling damping coefficient of the vehicle during vertical vibration based on the first ceiling damping force; determine the second equivalent ceiling damping coefficient of the vehicle during lateral movement based on the second ceiling damping force; and determine the third equivalent ceiling damping coefficient of the vehicle during lateral movement based on the second ceiling damping force.

[0141] Step Sc: Based on the first equivalent ceiling damping coefficient, the second equivalent ceiling damping coefficient, the third equivalent ceiling damping coefficient, and the preset parameter matrix, establish the calculation formula for the damping force corresponding to each suspension.

[0142] In this embodiment, it is assumed that a ceiling damper exists at each suspension point of the vehicle model and between the vehicle body and a fixed reference frame, with a damping coefficient of c. sky ,like Figure 4 As shown. When the vehicle body undergoes vertical vibration, the ceiling damping value experienced by the vehicle body is... The velocity of the vehicle body's vertical vibration; when the vehicle body only undergoes lateral tilting motion, the roof damping force on the left side of the vehicle body is -w. x tc sky w x Let ω be the angular velocity of the vehicle's roll motion, t be the vehicle's track width, and the anti-roll moment be -(ωt). x t 2 c sky Similarly, the anti-roll damping moment on the right side is -(w / 2). x t 2 c sky If ) / 2, then the total anti-rolling moment is -w x t 2 c sky Similarly, when the vehicle body only undergoes pitching motion, the roof damping force on the front side of the vehicle body is... w y The angular velocity of the vehicle's pitch motion, a s The distance from the vehicle's center of gravity to the front suspension is [value missing], and the roof damping force on the rear side of the vehicle is [value missing]. b s Let be the distance from the vehicle's center of gravity to the rear suspension. Then the total anti-pitch moment is... From the perspective of the center of mass, the motion state of the entire vehicle is viewed as follows: the equivalent vertical vibration ceiling damping coefficient of the entire vehicle is c. z =4c sky The equivalent ceiling damping coefficient for tilting vibration is c. θ =t2 c sky , the equivalent skyhook damping coefficient of the pitch vibration is Further, there is

[0143] In the above embodiment, the damping force of each suspension is determined based on the damper velocity, the vertical vibration velocity, and the damping force vector of each suspension, comprising:

[0144] When the damper velocity and the vertical vibration velocity are in the same direction, the required damping force corresponding to each suspension is the reference damping force;

[0145] When the damper velocity and the vertical vibration velocity are in opposite directions, the required damping force corresponding to each suspension is the minimum value in the preset damping force range.

[0146] In the embodiment of the present application, according to the skyhook damping control principle, when the damper piston velocity and the vehicle body vertical vibration velocity are in the same direction, the damping force is:

[0147] F ij = F min ;

[0148] When the damper piston velocity and the vehicle body velocity are in opposite directions, the damping force is:

[0149]

[0150] wherein, is the expression form of the generalized inverse matrix.

[0151] The above is the global skyhook damping control strategy, which starts from the vertical, roll, and pitch vibrations of the vehicle body, considers the correlation between the four sub-suspensions, and can better control the vehicle body posture. And the equivalent damping coefficients c z , c θ , and the parameter matrix can be calculated offline, reducing the online calculation amount.

[0152] Through the identification result of the road roughness, the values of c sky , F min , and F max can be calibrated to achieve better control effect under different road surfaces, and to ensure that the damping force is adjusted within a reasonable range, neither too large to affect ride comfort, nor too small to cause poor damping effect.

[0153] In addition, considering c skyThe value of the preset output damping force is switched between two states, resulting in discontinuous damping force and jerk. Therefore, the damping force is multiplied by a continuity coefficient v body / v suspen wherein v body is the vertical speed of the vehicle body at a certain point, and v suspen is the speed of the corresponding shock absorber.

[0154] Step S3: calculating the vertical control current of the vehicle based on the corresponding required damping force of each suspension, the damping external characteristic of the vehicle shock absorber, the road excitation frequency identification information, and the preset skyhook damping control rule, wherein the vertical control current is a current for controlling the body and wheel vibration of the vehicle caused by the vertical excitation of the road.

[0155] Specifically, the control unit determines the vertical skyhook control current corresponding to each suspension based on the corresponding required damping force of each suspension and the preset shock absorber damping characteristic. Further, if the road excitation frequency is in the preset wheel resonance frequency range, the vertical control current of the vehicle is calculated based on the vertical skyhook control current and the preset groundhook control algorithm.

[0156] In the embodiment of the present application, when the resonance frequency range of the wheel (8Hz-12Hz) is reached, the control method designed in the present application opens the groundhook control and calculates the final vertical control current by weighting the vertical skyhook control current corresponding to each suspension. The specific calculation process is as follows:

[0157]

[0158] wherein I Vert is the vertical current output by the skyhook-groundhook hybrid control, v wheel is the vertical speed of the wheel, I GH is the maximum groundhook current, and a GH is the groundhook weighting coefficient.

[0159] By introducing the groundhook control in the wheel resonance frequency range, the wheel jump in this working condition can be controlled without affecting the effect of the skyhook control outside the frequency range.

[0160] Step S4: determining the lateral control current of the vehicle based on the lateral working condition information and the first expert database containing expert evaluation data, wherein the first expert database includes the relationship between different lateral working condition information and corresponding lateral control current, and the lateral control current is a current for controlling the body posture change of the vehicle caused by the steering operation. The lateral control can reduce the roll degree caused by the driver's operation, reduce the load transfer between the left and right sides, and thus improve the handling and stability performance.

[0161] The first expert database represents a relationship between the lateral working condition information and a lateral control current of the vehicle.

[0162] Specifically, the step S4 comprises:

[0163] When the lateral working condition of the vehicle is a first steering working condition (i.e., a steady-state slow steering working condition), the magnitude of the lateral acceleration can represent the intensity of the current lateral motion, and thus, based on the vehicle lateral acceleration and a first expert database containing expert evaluation data established in advance, the lateral control current of the vehicle is determined.

[0164] When the lateral working condition of the vehicle is a second steering working condition (i.e., a transient rapid steering working condition), the lateral acceleration response has a certain inertial delay, and at this time, the steering wheel angular velocity can more directly represent the operation intention of the driver, and based on the steering wheel angular velocity and the first expert database containing expert evaluation data established in advance, the lateral control current of the vehicle is determined.

[0165] The step S5 comprises determining a longitudinal control current of the vehicle based on the longitudinal working condition information and a second expert database containing expert evaluation data established in advance, wherein the second expert database contains a relationship between different longitudinal working condition information and corresponding longitudinal control currents, and the longitudinal control current is a current for controlling the vehicle body posture change caused by acceleration or deceleration operation or deceleration operation, and the longitudinal control can reduce the nodding and lifting actions caused by the driver's operation, reduce the front and rear axle load transfer, and thus improve the handling performance.

[0166] The second expert database represents a relationship between the longitudinal working condition information and the longitudinal control current of the vehicle.

[0167] In the embodiment of the present application, the step S5 comprises:

[0168] When the longitudinal working condition of the vehicle is a second acceleration driving working condition (i.e., a steady-state slow acceleration working condition) or a second deceleration driving working condition (i.e., a steady-state slow deceleration working condition), the magnitude of the longitudinal acceleration / deceleration can represent the intensity of the current longitudinal motion, and thus, based on the vehicle longitudinal acceleration / deceleration and the second expert database containing expert evaluation data established in advance, the longitudinal control current of the vehicle is determined.

[0169] When the longitudinal working condition of the vehicle is a first acceleration driving working condition (i.e., a transient rapid acceleration working condition) or a first deceleration driving working condition (i.e., a transient rapid deceleration working condition), the longitudinal acceleration response has a certain inertial delay, and at this time, the change rate of the accelerator pedal and the brake pedal can more directly represent the operation intention of the driver, and based on the accelerator change amount, the brake pedal change amount and the second expert database containing expert evaluation data established in advance, the longitudinal control current of the vehicle is determined.

[0170] In step S6, a control mode of the semi-active suspension of the vehicle is acquired, a target control current is calculated based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and the damping of the suspension of the vehicle is adjusted according to the target control current.

[0171] In the embodiments of the present application, the control mode of the semi-active suspension is a first mode or a second mode, the first mode represents a mode meeting the comfort requirement, and the second mode represents a mode meeting the handling requirement. That is, the first mode is a comfort mode, and the second mode is a sport mode. Of course, the scheme involved in the present patent can also have other modes, and is not limited thereto.

[0172] Further, the target control current is determined based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and includes:

[0173] When the control mode is the first mode, a lateral weighting coefficient is determined based on the lateral working condition information of the vehicle;

[0174] a longitudinal weighting coefficient is determined based on the longitudinal working condition information;

[0175] a vertical weighting coefficient is determined based on the lateral weighting coefficient and the longitudinal weighting coefficient;

[0176] the vertical control current, the lateral control current and the longitudinal control current are weighted and summed according to the respective weighting coefficients to obtain the target control current;

[0177] When the control mode is the second mode, the maximum current is selected from the vertical control current, the lateral control current and the longitudinal control current as the target control current. At this time, the comfort performance is guaranteed, and the handling performance of part of the severe driving working conditions is also considered.

[0178] When the control mode is the second mode, the maximum current is selected from the vertical control current, the lateral control current and the longitudinal control current as the target control current. At this time, the handling performance is guaranteed to the maximum extent.

[0179] It should be noted that for the special working conditions in which the ABS / TCS / ESP system is triggered, in order to guarantee the stability of the vehicle system, the finally output current is a preset fixed value.

[0180] The method can establish the correlation between the overall vehicle body posture and the damping force of each suspension through the preset global skyhook damping strategy, realize the whole vehicle coupling control, and realize the simultaneous control of the vertical comfort and the lateral / longitudinal handling and stability performance. The vertical comfort control method links the four suspensions from the perspective of the whole vehicle coupling, focuses on the vertical vibration of the vehicle and the roll and pitch motion of the vehicle, and strives to obtain better vehicle ride comfort. Meanwhile, in combination with the identification results of the road surface excitation frequency and the road unevenness, the control strategy and parameters can be adjusted accordingly to ensure that the vehicle can still maintain a stable driving posture under complex road conditions. In addition, the determination method of the lateral and longitudinal control current based on the expert database can identify the driving intention of the driver and distinguish different driving conditions, realize targeted control, and further enhance the handling and stability performance of the vehicle. Finally, the vertical / lateral / longitudinal control currents are comprehensively arbitrated and output to the shock absorber, so as to achieve better comfort and handling and stability performance control effect.

[0181] Based on the same principle as the method shown in Figure 1 and Figure 2 The application also provides a continuous damping control system 200 of a semi-active suspension system of an automobile, as shown in Figure 5 The continuous damping control system 200 of the semi-active suspension system of the automobile mainly comprises:

[0182] A data acquisition module 201 is configured to acquire vehicle body motion state information, suspension system motion state information, and whole vehicle working condition information, wherein the vehicle body motion state information includes vehicle body vertical vibration speed, roll angle speed, and pitch angle speed, the suspension system motion state information includes shock absorber speed, road unevenness, and road surface excitation frequency identification information, and the working condition information includes lateral working condition information and longitudinal working condition information, the lateral working condition information represents the working condition corresponding to the steering operation of the automobile during driving, and the longitudinal working condition information represents the working condition corresponding to the acceleration operation or deceleration operation of the automobile during driving;

[0183] A damping force calculation module 202 is configured to calculate the required damping force of each suspension based on the vehicle body motion state information, the suspension system motion state information, and a preset global skyhook damping control strategy, and the preset global skyhook damping control strategy is the correlation between the overall vehicle body posture and the damping force of each suspension;

[0184] A vertical control current calculation module 203 is configured to calculate the vertical control current of the automobile based on the required damping force of each suspension, the damping external characteristic of the automobile shock absorber, the road surface excitation frequency identification information, and a preset skyhook damping control rule, and the vertical control current is the current for controlling the vehicle body and wheel vibration caused by the vertical excitation of the road surface;

[0185] The lateral control current calculation module 204 is used to determine the lateral control current of the vehicle based on the lateral operating condition information and a pre-established first expert database containing expert evaluation data. The first expert database includes the relationship between different lateral operating condition information and the corresponding lateral control current. The lateral control current is the current that controls the change in vehicle body posture caused by steering operation.

[0186] The longitudinal control current calculation module 205 is used to determine the longitudinal control current of the vehicle based on the longitudinal operating condition information and a pre-established second expert database containing expert evaluation data. The second expert database includes the relationship between different longitudinal operating condition information and the corresponding longitudinal control current. The longitudinal control current is the current that controls the vehicle body posture change caused by acceleration, deceleration or acceleration operations.

[0187] Arbitration scheme output module 206 is used to obtain the control mode of the semi-active suspension of the vehicle, calculate the target control current based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and adjust the damping of the vehicle suspension according to the target control current.

[0188] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0189] Figure 6 This is a structural block diagram of a control unit 300 according to an embodiment of this application.

[0190] like Figure 6 As shown, the control unit 300 includes a processor 301 and a memory 302, and may further include one or more of an information input / output (I / O) interface 303, a communication component 304, and a communication bus 305. The control unit 300 is used to execute the continuous damping control method for a semi-active suspension system of an automobile given in the above embodiments.

[0191] The following describes the computer-readable storage medium provided in the embodiments of this application. The computer-readable storage medium described below can be referred to in correspondence with the continuous damping control method of the semi-active suspension system of automobile described above.

[0192] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described continuous damping control method for a semi-active suspension system for automobiles.

[0193] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0194] The description above merely illustrates preferred embodiments of the present application and the principles of the technology employed. It should be understood by those skilled in the art that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and should also cover other technical solutions formed by the combinations of the above technical features or their equivalent features without departing from the above application concept. For example, the above technical features can be replaced with the technical features applied in the present application (but not limited to) having similar functions to form technical solutions.

Claims

1. A method for continuously controlling damping of a semi-active suspension system of an automobile, characterized by, The method comprises the following steps: acquiring body motion state information, suspension system motion state information and vehicle working condition information of the vehicle, wherein the body motion state information comprises vertical vibration speed, roll angle speed and pitch angle speed, the suspension system motion state information comprises shock absorber speed, road roughness and road excitation frequency identification information, the working condition information comprises lateral working condition information and longitudinal working condition information, the lateral working condition information represents the working condition corresponding to the steering operation of the vehicle during driving, and the longitudinal working condition information represents the working condition corresponding to the acceleration operation or deceleration operation of the vehicle during driving; calculating the required damping force of each suspension based on the body motion state information, the suspension system motion state information and a preset global skyhook damping control strategy, wherein the preset global skyhook damping control strategy represents the correlation between the body posture of the vehicle as a whole and the damping force of each suspension; calculating the vertical control current of the vehicle based on the required damping force of each suspension, the damping external characteristic of the shock absorber of the vehicle, the road excitation frequency identification information and a preset skyhook damping control rule, wherein the vertical control current is the current for controlling the body and wheel vibration of the vehicle caused by the vertical excitation of the road; determining the lateral control current of the vehicle based on the lateral working condition information and a first expert database containing expert evaluation data, wherein the first expert database comprises the relationship between different lateral working condition information and corresponding lateral control current, and the lateral control current is the current for controlling the body posture change of the vehicle caused by the steering operation; determining the longitudinal control current of the vehicle based on the longitudinal working condition information and a second expert database containing expert evaluation data, wherein the second expert database comprises the relationship between different longitudinal working condition information and corresponding longitudinal control current, and the longitudinal control current is the current for controlling the body posture change of the vehicle caused by the acceleration or deceleration operation; acquiring the control mode of the semi-active suspension of the vehicle, calculating the target control current based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and adjusting the damping of the suspension of the vehicle according to the target control current.

2. The method for continuous damping control of a semi-active suspension system for automobiles according to claim 1, characterized in that, The acquisition of the body motion state information, the suspension system motion state information and the vehicle working condition information comprises the following steps: acquiring the motion state signal of the body through a 6-axis IMU sensor, calculating the running state data of each body measuring point of the vehicle based on the motion state signal, and obtaining the body motion state information, wherein the plurality of body measuring points are respectively the body mass center position, the body left front suspension position, the body right front suspension position, the body left rear suspension position and the body right rear suspension position; acquiring the height sensor signal on the corresponding suspension swing arm of each suspension swing arm through the height sensor on each suspension swing arm, calculating the shock absorber speed of each suspension swing arm based on each height sensor signal, and identifying the road roughness and the road excitation frequency of the current road based on each height sensor signal to obtain the road roughness and the road excitation frequency identification information of the current road; The CAN message data of the automobile is acquired, and working condition recognition is performed on the CAN message data to obtain working condition information, the CAN message data including a steering wheel angle, a steering wheel angular velocity, a longitudinal acceleration or a longitudinal deceleration of the vehicle, a throttle change amount, and a brake pedal change amount, the longitudinal acceleration being an acceleration in the same direction as the vehicle travels, the longitudinal deceleration being a deceleration in the same direction as the vehicle travels, the lateral working condition including any one of a straight-line driving working condition, a first turning working condition, and a second turning working condition, and the longitudinal working condition information including any one of a constant-speed driving working condition, a first accelerating driving working condition, a second accelerating driving working condition, a first decelerating driving working condition, and a second decelerating driving working condition. The straight-line driving working condition represents a working condition in which the steering wheel angle is less than a preset angle threshold value, the first turning working condition represents a working condition in which the steering wheel angle is not less than a preset angle threshold value and the steering wheel angular velocity is less than a preset angular velocity threshold value, and the second turning working condition represents a working condition in which the steering wheel angle is not less than a preset angle threshold value and the steering wheel angular velocity is not less than a preset angular velocity threshold value; the constant-speed driving working condition represents a working condition in which the longitudinal acceleration is less than a preset acceleration threshold value or the longitudinal deceleration is less than a preset deceleration threshold value, the throttle change amount is less than a preset first change threshold value, and the brake pedal displacement change amount is less than a preset second change threshold value, the first accelerating driving working condition represents a working condition in which the throttle change amount is not less than a preset first change threshold value, the second accelerating driving working condition represents a working condition in which the longitudinal acceleration is greater than a preset acceleration threshold value and the throttle change amount is less than a preset first change threshold value, the first decelerating driving working condition represents a working condition in which the brake pedal displacement change amount is not less than a preset second change threshold value, and the second decelerating driving working condition represents a working condition in which the longitudinal deceleration is greater than a preset threshold value and the brake pedal displacement change amount is less than a preset second change threshold value.

3. The method for continuous damping control of a semi-active suspension system for automobiles according to claim 2, characterized in that, The global skyhook damping control strategy includes a preset calculation formula of the damping force corresponding to each suspension, the demand damping force corresponding to each suspension is calculated based on the vehicle body motion state information, the suspension system motion state information, and the preset global skyhook damping control strategy, and includes: The skyhook damping coefficient is calibrated based on the identification result of the road roughness and the road excitation frequency, and the upper limit value and the lower limit value of the damping force are determined; The reference damping force of each suspension of the automobile is calculated based on the skyhook damping coefficient, the vehicle body vertical vibration speed, the pitch angular velocity, the roll angular velocity of the vehicle body centroid position, and the preset calculation formula of the damping force corresponding to each suspension; The demand damping force corresponding to each suspension is determined based on the damper speed, the vertical vibration speed, and the reference damping force of each suspension; The preset calculation formula of the damping force corresponding to each suspension is: wherein F d = [F lf F rf F lr F rr ] T ; c z = 4c sky ; c θ = t 2 c sky ; where F d is the reference damping force of each suspension, c z is the equivalent skyhook damping coefficient of the vertical vibration, c θ is the equivalent skyhook damping coefficient of the roll vibration, is the equivalent skyhook damping coefficient of the pitch vibration; is the vertical vibration velocity, is the pitch angular velocity, is the pitch angular velocity; a s is the distance from the front axle to the center of mass of the vehicle, b s is the distance from the rear axle to the center of mass of the vehicle, t is the track of the vehicle, c sky is the skyhook damping coefficient calibrated based on the identification result of the road roughness and the road excitation frequency.

4. The method for continuous damping control of a semi-active suspension system for automobiles according to claim 3, characterized in that, The establishment process of the calculation formula of the damping force corresponding to each suspension includes: The first skyhook damping force, the second skyhook damping force and the third skyhook damping force are calculated respectively based on the vertical vibration speed, the calibrated skyhook damping coefficient, the wheelbase of the automobile, the distance from the front axle to the center of mass and the distance from the rear axle to the center of mass. The first equivalent skyhook damping coefficient, the second equivalent skyhook damping coefficient and the third equivalent skyhook damping coefficient are determined based on the first skyhook damping force, the second skyhook damping force and the third skyhook damping force respectively. The calculation formula of the damping force corresponding to each suspension is established based on the first equivalent skyhook damping coefficient, the second equivalent skyhook damping coefficient, the third equivalent skyhook damping coefficient and a preset parameter matrix.

5. The method for continuous damping control of a semi-active suspension system for automobiles according to claim 3, characterized in that, The demand damping force corresponding to each suspension is determined based on the shock absorber speed, the vertical vibration speed and the reference damping force of each suspension. When the shock absorber speed and the vertical vibration speed are in the same direction, the demand damping force corresponding to each suspension is the reference damping force. When the shock absorber speed and the vertical vibration speed are in opposite directions, the demand damping force corresponding to each suspension is the minimum value in the preset damping range.

6. The method of claim 2, wherein the damping force of the semi-active suspension system is continuously controlled by the controller. The vertical control current of the automobile is calculated based on the demand damping force corresponding to each suspension, the damping external characteristic of the automobile shock absorber, the road excitation frequency identification information and a preset skyhook damping control rule. The vertical skyhook control current corresponding to each suspension is determined based on the demand damping force corresponding to each suspension, the damping external characteristic of the automobile shock absorber and a preset damping characteristic table. If the road excitation frequency is in the preset wheel resonance frequency interval, the vertical control current of the automobile is calculated based on the vertical skyhook control current and a preset skyhook control algorithm. The lateral control current of the automobile is determined based on the lateral working condition information and a first expert database containing expert evaluation data established in advance. When the lateral working condition of the automobile is the first steering working condition, the lateral control current of the automobile is determined based on the vehicle lateral acceleration and the first expert database. When the lateral working condition of the automobile is the second steering working condition, the lateral control current of the automobile is determined based on the steering wheel angular velocity and the first expert database. The longitudinal control current of the automobile is determined based on the longitudinal working condition information and a second expert database containing expert evaluation data established in advance. When the longitudinal working condition of the automobile is the first acceleration driving working condition, the longitudinal control current of the automobile is determined based on the accelerator change amount and the second expert database. When the longitudinal working condition of the automobile is the second acceleration driving working condition, the longitudinal control current of the automobile is determined based on the vehicle longitudinal acceleration and the second expert database. When the longitudinal working condition of the automobile is the first deceleration driving working condition, the longitudinal control current of the automobile is determined based on the brake pedal change amount and the second expert database. When the longitudinal working condition of the automobile is the second deceleration driving working condition, the longitudinal control current of the automobile is determined based on the longitudinal deceleration of the vehicle and the second expert database.

7. The method of claim 1, wherein the damping force of the semi-active suspension system is continuously controlled by the controller. The control mode of the semi-active suspension is a first mode or a second mode, the first mode representing a mode meeting a ride comfort requirement, and the second mode representing a mode meeting a handling requirement. The target control current is determined based on the control mode, the vertical control current, the lateral control current, and the longitudinal control current, including: When the control mode is the first mode, a lateral weighting coefficient is determined based on the lateral working condition information of the automobile; a longitudinal weighting coefficient is determined based on the longitudinal working condition information; a vertical weighting coefficient is determined based on the lateral weighting coefficient and the longitudinal weighting coefficient; the target control current is obtained by weighting and summing the vertical control current, the lateral control current, and the longitudinal control current according to the respective weighting coefficients; When the control mode is the second mode, the maximum current is selected from the vertical control current, the lateral control current, and the longitudinal control current as the target control current.

8. A continuously controlled damping system for a semi-active suspension system of an automobile, characterized by The data acquisition module is configured to acquire body motion state information, suspension system motion state information, and vehicle working condition information of the automobile, wherein the body motion state information includes vertical vibration speed, roll angular velocity, and pitch angular velocity of the vehicle body, the suspension system motion state information includes shock absorber speed, road roughness, and road excitation frequency identification information, and the working condition information includes lateral working condition information and longitudinal working condition information, the lateral working condition information representing a working condition corresponding to a steering operation during driving of the automobile, and the longitudinal working condition information representing a working condition corresponding to an acceleration operation or a deceleration operation during driving of the automobile. The damping force calculation module is configured to calculate a required damping force corresponding to each suspension based on the body motion state information, the suspension system motion state information, and a preset global skyhook damping control strategy, the preset global skyhook damping control strategy representing a correlation between a body posture of the automobile as a whole and the damping force of each suspension. The vertical control current calculation module is configured to calculate the vertical control current of the automobile based on the required damping force corresponding to each suspension, an external damping characteristic of a shock absorber of the automobile, the road excitation frequency identification information, and a preset skyhook damping control rule, the vertical control current being a current for controlling body and wheel vibration of the automobile caused by road vertical excitation. The lateral control current calculation module is configured to determine the lateral control current of the automobile based on the lateral working condition information and a first expert database including expert evaluation data, the first expert database including a relationship between different lateral working condition information and corresponding lateral control currents, and the lateral control current being a current for controlling a body posture change of the automobile caused by a steering operation. ​ a longitudinal control current calculation module configured to determine a longitudinal control current of the vehicle based on the longitudinal working condition information and a second expert database including expert evaluation data, the second expert database including relationships between different longitudinal working condition information and corresponding longitudinal control currents, the longitudinal control current being a current for controlling a change in vehicle body posture caused by an adding or subtracting operation or a deceleration operation of the vehicle; an arbitration scheme output module configured to obtain a control mode of a semi-active suspension of the vehicle, calculate a target control current based on the control mode, the vertical control current, the lateral control current and the longitudinal control current, and adjust damping of the suspension of the vehicle according to the target control current.

9. A control unit, characterized by comprising a processor coupled to a memory; the processor is configured to execute a computer program stored in the memory to cause the control unit to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, comprising computer programs or instructions that, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 7.

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