Vehicle semi-active suspension damping control method, apparatus, and device, and medium

Abstract

A vehicle semi-active suspension damping control method, comprising: establishing a multi-degree-of-freedom vehicle dynamics model on the basis of motion postures of a vehicle and by means of the influence of each motion posture on the ride comfort of the vehicle; computing a vehicle vibration equation on the basis of the established degree-of-freedom vehicle dynamics model, and computing a variable damping output value on the basis of semi-active suspension damping force output control logic; and adjusting PID parameters on the basis of a preset intelligent algorithm, and implementing variable damping output control by means of a PID controller having the parameters adjusted. Also disclosed are a vehicle semi-active suspension damping control apparatus, a vehicle semi-active suspension damping control device, and a computer-readable storage medium. The method can effectively implement full-band self-adaptive correction of semi-active suspension control strategies, and ensure the stability of vehicle body postures.

Description

Vehicle semi-active suspension damping control method, device, equipment and medium Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a vehicle semi-active suspension damping control method, device, equipment and medium. Background Art

[0002] The performance of a vehicle's suspension system directly impacts ride comfort and handling safety. Traditional passive suspension, due to its fixed parameters, suffers from suboptimal performance. Active suspension, while offering superior performance, consumes excessive energy and is therefore not widely adopted. In recent years, semi-active suspension has shown promising development prospects, as it requires less energy and offers performance close to that of active suspension.

[0003] Semi-active suspension is a controllable suspension system that uses sensors to detect road conditions and vehicle posture, adjusting damping parameters to improve ride smoothness and stability. Semi-active suspension offers full-band control optimization for both active and passive suspension and is currently widely used on a wide range of vehicle models.

[0004] Currently, semi-active suspension control strategies often employ classical algorithms, while also specializing the suspension system. These strategies focus on a single control objective and are applicable to a single operating condition, failing to address both low- and high-frequency conditions. Therefore, improving the comprehensiveness of semi-active suspension damping control to ensure vehicle body stability is a pressing issue.

[0005] Summary of the Invention

[0006] The present application provides a vehicle semi-active suspension damping control method, device, equipment and medium, which can effectively solve the full-band adaptive correction of the semi-active suspension control strategy and ensure the stability of the vehicle body posture.

[0007] In a first aspect, an embodiment of the present application provides a vehicle semi-active suspension damping control method, the vehicle semi-active suspension damping control method comprising:

[0008] Based on the vehicle's motion posture and the impact of each motion posture on vehicle ride comfort, a multi-degree-of-freedom vehicle dynamics model is established;

[0009] Based on the established vehicle dynamics model with the right degree of freedom, the vehicle vibration equation is calculated, and the variable damping output value is calculated based on the semi-active suspension damping force output control logic.

[0010] The PID parameters are adjusted based on a preset intelligent algorithm, and variable damping output control is achieved through the PID controller after parameter adjustment.

[0011] In conjunction with the first aspect, in one embodiment, the multi-degree-of-freedom vehicle dynamics model is established based on the vehicle's motion posture and in combination with the impact of each motion posture on vehicle ride comfort, specifically:

[0012] The vehicle body is set as a rigid body with concentrated mass, and only the effects of vertical, roll and pitch motions on vehicle smoothness are considered;

[0013] The vehicle is assumed to be bilaterally symmetrical along its longitudinal centerline and to move in a uniform straight line. The road surface is assumed to be a normal random process with steady traversal of various states, and a seven-degree-of-freedom vehicle dynamics model is established.

[0014] In conjunction with the first aspect, in one implementation, the vehicle vibration equation is specifically:

[0015] Among them, M represents the mass matrix of the vehicle, C represents the damping matrix of the vehicle, K represents the stiffness matrix of the vehicle, and Z represents the displacement vector of each degree of freedom of the vehicle. Represents the first-order derivative of the displacement vector of each degree of freedom of the vehicle, Represents the second-order derivative of the displacement vector of each degree of freedom of the vehicle, K t represents the tire stiffness matrix, Q represents the road surface input vector, i.e., the road surface roughness, C t represents the tire damping matrix, and F represents the vehicle stiffness matrix;

[0016] Among them, the vehicle stiffness matrix is ​​specifically:

[0017] Where a is the distance from the front axle to the vehicle's center of mass, b is the distance from the rear axle to the vehicle's center of mass, c is the distance from the right tire's contact point to the vehicle's center of mass, d is the distance from the left tire's contact point to the vehicle's center of mass, k1 is the stiffness of the left front tire, k2 is the stiffness of the left front suspension, k3 is the stiffness of the right front tire, k4 is the stiffness of the right front suspension, k5 is the stiffness of the left rear tire, k6 is the stiffness of the left rear suspension, k7 is the stiffness of the right rear tire, k8 is the stiffness of the right rear suspension, and L is the wheelbase of the left and right wheels.

[0018] Among them, the vehicle's damping matrix is ​​specifically:

[0019] Among them, C1 represents the equivalent damping coefficient of the left front tire, C2 represents the equivalent damping coefficient of the left front passive suspension, C3 represents the equivalent damping coefficient of the right front tire, C4 represents the equivalent damping coefficient of the right front passive suspension, C5 represents the equivalent damping coefficient of the left rear tire, C6 represents the equivalent damping coefficient of the left rear passive suspension, C7 represents the equivalent damping coefficient of the right rear tire, and C8 represents the equivalent damping coefficient of the right rear passive suspension.

[0020] In combination with the first aspect, in one embodiment, the variable damping output value is calculated according to the semi-active suspension damping force output control logic, specifically:

[0021] Based on the vehicle vibration equation, the semi-active suspension damping force output control logic is determined to obtain the adjustable damping output damping force of each shock absorber and the relative motion speed of each shock absorber;

[0022] According to the obtained relative motion speed of each shock absorber, the variable damping output value is determined by optimizing the target method.

[0023] In conjunction with the first aspect, in one embodiment,

[0024] The semi-active suspension damping force output control logic is determined to obtain the adjustable damping output damping force of each shock absorber and the relative motion speed of each shock absorber. The specific calculation method for the adjustable damping output damping force of each shock absorber is:

[0025] Among them, F1 represents the adjustable damping output damping force of the left front shock absorber, F2 represents the adjustable damping output damping force of the right front shock absorber, F3 represents the adjustable damping output damping force of the left rear shock absorber, F4 represents the adjustable damping output damping force of the right rear shock absorber, c1 max Indicates the maximum damping of the left front suspension variable adjustment, c2 max Indicates the maximum damping of the right front suspension variable adjustment, c3 max Indicates the maximum damping of the left rear suspension with variable energy adjustment, c4 max Indicates the maximum damping of the right rear suspension with variable energy adjustment, c1 mex Indicates the actual output damping of the left front suspension variable damping, c2 mex Indicates the actual output damping of the right front suspension variable damping, c3 mex Indicates the actual output damping of the left rear suspension variable damping, c4 mex Indicates the actual output damping of the right rear suspension variable damping. Indicates the relative movement speed of the left front shock absorber, Indicates the relative movement speed of the right front shock absorber, Indicates the relative movement speed of the left rear shock absorber, Indicates the relative movement speed of the right rear shock absorber, It represents the first derivative of the vertical displacement at the connection point between the suspension and the left front position of the vehicle body, Represents the first-order derivative of the vertical displacement at the connection point between the suspension and the right front position of the vehicle body, It represents the first derivative of the vertical displacement at the connection point between the suspension and the left rear of the vehicle body, It represents the first derivative of the vertical displacement at the connection point between the suspension and the right rear position of the vehicle body, represents the first derivative of the vertical displacement of the left front wheel, represents the first derivative of the vertical displacement of the right front wheel, Represents the first-order derivative of the vertical displacement of the left rear wheel, Represents the first derivative of the displacement of the right rear wheel in the vertical direction;

[0026] The semi-active suspension damping force output control logic is determined to obtain the adjustable damping output damping force of each shock absorber and the relative motion speed of each shock absorber. The specific calculation method for the relative motion speed of each shock absorber is: bw1 =z1-z 5lf z bw2 =z2-z 5rf z bw3 =z3-z 5lr z bw4 =z4-z 5rr

[0027] Among them, z bw1 Indicates the relative motion displacement of the left front shock absorber, z bw2 Indicates the relative motion displacement of the right front shock absorber, z bw3 Indicates the relative motion displacement of the left rear shock absorber, z bw4 represents the relative motion displacement of the right rear shock absorber, z1 represents the vertical displacement of the left front wheel, z2 represents the vertical displacement of the right front wheel, z3 represents the vertical displacement of the left rear wheel, z4 represents the vertical displacement of the right rear wheel, and z 5lf Indicates the vertical displacement of the connection point between the suspension and the left front position of the vehicle body, z 5rf Indicates the vertical displacement of the connection point between the suspension and the right front position of the vehicle body, z 5lr Indicates the vertical displacement of the connection point between the suspension and the left rear of the vehicle body, z 5rr Indicates the vertical displacement of the connection point between the suspension and the right rear position of the vehicle body;

[0028] Among them, the vertical displacement at the connection point between the suspension and the vehicle body is calculated as follows: 5lf =z5+a·z7-d·z6 z 5rf =z5+a·z7+c·z6 z 5lr =z5-b·z7-d·z6 z 5rr =z5-b·z7+c·z6

[0029] Among them, z5 represents the vertical displacement of the vehicle body's center of mass, z6 represents the roll angular displacement of the vehicle body, z7 represents the pitch angular displacement of the vehicle body, a represents the distance from the front axle to the vehicle's center of mass, b represents the distance from the rear axle to the vehicle's center of mass, c represents the distance from the right tire's contact point to the vehicle's center of mass, and d represents the distance from the left tire's contact point to the vehicle's center of mass.

[0030] In combination with the first aspect, in one embodiment, the variable damping output value is determined by optimizing the target according to the obtained relative motion speed of each shock absorber, specifically:

[0031] When it is monitored that any one of the relative movement speed of the left front shock absorber, the relative movement speed of the right front shock absorber, the relative movement speed of the left rear shock absorber, and the relative movement speed of the right rear shock absorber is less than 0, the optimization target mode is executed to determine the variable damping output value;

[0032] Continuous and stepless adjustment of damping output is achieved based on changes in vehicle pitch and roll, as well as the relative movement of the vehicle's suspension connection points.

[0033] The optimization target method is specifically as follows:

[0034] Where, J represents the variable damping output value, sqr represents the square, represents the second-order derivative of the vertical displacement of the vehicle body’s center of mass, represents the second-order derivative of the roll angle displacement of the vehicle body, Represents the second-order derivative of the pitch angular displacement of the vehicle body.

[0035] In combination with the first aspect, in one embodiment, the PID parameters are adjusted based on a preset intelligent algorithm, specifically:

[0036] Initialize the parameters and randomly generate the initial population. Specifically: X={x1,x2,L,x n} T

[0037] Among them, X represents the initial population, x n represents sparrow, T represents matrix transpose;

[0038] Execute the search algorithm:

[0039] in, represents the j-th dimension position information of the i-th sparrow in the t-th iteration, exp represents the exponential function with the natural constant e as the base, α t Represents a random number, the value range is [0,1], T maxrepresents the maximum number of iterations, R2 represents the warning value, which is a random number between [0, 1], ST represents the safety threshold, which is a constant between [0.5, 1], q represents a random number that follows a normal distribution, L represents a 1×d-dimensional matrix of all 1s, and d represents a positive integer;

[0040] Update joiner location:

[0041] in, represents the worst individual in the tth iteration, n represents the total number of sparrows, represents the position of the best finder in the t+1th iteration;

[0042] Update aware of the danger:

[0043] in, represents the best individual in the t-th iteration, β represents a normal distribution random number with a mean of 0 and a variance of 1, and f i represents the current individual fitness value, f g represents the current maximum fitness value, k represents a random number with a value of [-1,1], the positive and negative represent the direction of the sparrow's movement, the size represents the step size control parameter, ε represents a constant, and f w Indicates the current minimum fitness value;

[0044] Based on the calculation method of updating the awareness of danger, it is judged whether the stopping condition is met. If so, the optimal sparrow position is output. If not, the search algorithm is executed again, and the joiner position is updated and the awareness of danger is updated. This cycle is repeated until the stopping condition is met.

[0045] In a second aspect, an embodiment of the present application provides a vehicle semi-active suspension damping control device, the vehicle semi-active suspension damping control device comprising:

[0046] A creation module configured to establish a multi-degree-of-freedom vehicle dynamics model based on the vehicle's motion posture and the impact of each motion posture on vehicle ride comfort;

[0047] a calculation module configured to calculate a vehicle vibration equation based on the established degree-of-freedom vehicle dynamics model, and to calculate a variable damping output value based on the semi-active suspension damping force output control logic;

[0048] The control module is configured to adjust PID parameters based on a preset intelligent algorithm and implement variable damping output control through the PID controller after parameter adjustment.

[0049] In a third aspect, an embodiment of the present application provides a vehicle semi-active suspension damping control device, which includes a processor, a memory, and a vehicle semi-active suspension damping control program stored in the memory and executable by the processor, wherein when the vehicle semi-active suspension damping control program is executed by the processor, the steps of the above-mentioned vehicle semi-active suspension damping control method are implemented.

[0050] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a vehicle semi-active suspension damping control program is stored, wherein when the vehicle semi-active suspension damping control program is executed by a processor, the steps of the above-mentioned vehicle semi-active suspension damping control method are implemented.

[0051] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0052] (1) Based on the vehicle's motion posture and the influence of each motion posture on vehicle smoothness, a multi-degree-of-freedom vehicle dynamics model is established. Then, based on the established degree-of-freedom vehicle dynamics model, the vehicle vibration equation is calculated, and the variable damping output value is calculated based on the semi-active suspension damping force output control logic. Then, based on the preset intelligent algorithm, the PID parameters are adjusted, and the variable damping output control is realized through the PID controller after parameter adjustment, effectively solving the full-band adaptive correction of the semi-active suspension control strategy and ensuring the stability of the vehicle body posture.

[0053] (2) By establishing a seven-degree-of-freedom vehicle dynamics model, including the semi-active suspension output damping force control strategy, an improved control algorithm is adopted, and an intelligent algorithm is integrated to adjust the PID parameters to avoid human interference, thereby achieving a significant improvement in the algorithm efficiency and robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG1 is a flow chart of a method for controlling damping of a semi-active suspension of a vehicle according to the present application;

[0055] FIG2 is a schematic diagram of the established seven-degree-of-freedom vehicle dynamics model;

[0056] FIG3 is a schematic diagram of the functional modules of the vehicle semi-active suspension damping control device of the present application;

[0057] FIG4 is a schematic diagram of the hardware structure of the semi-active suspension damping control device of the vehicle of the present application. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0060] In a first aspect, an embodiment of the present application provides a vehicle semi-active suspension damping control method.

[0061] In one embodiment, referring to FIG1 , FIG1 is a flow chart of a method for controlling the damping of a semi-active suspension of a vehicle according to the present invention. As shown in FIG1 , the method for controlling the damping of a semi-active suspension of a vehicle includes:

[0062] S1: Based on the vehicle's motion posture and the impact of each motion posture on vehicle smoothness, a multi-degree-of-freedom vehicle dynamics model is established.

[0063] Furthermore, in one embodiment, based on the vehicle's motion posture and in combination with the impact of each motion posture on vehicle ride comfort, a multi-degree-of-freedom vehicle dynamics model is established, specifically:

[0064] S101: The vehicle body is set as a rigid body with concentrated mass, and only the effects of vertical, roll, and pitch motions on vehicle ride comfort are considered;

[0065] S102: Assuming that the vehicle is bilaterally symmetrical along its longitudinal centerline and that the vehicle moves in a uniform linear motion, and that the road surface is a normal random process with steady traversal of various states, a seven-degree-of-freedom vehicle dynamics model is established.

[0066] Typically, there are three approaches to studying suspension systems: a seven-degree-of-freedom vehicle model, a four-degree-of-freedom suspension model, and a two-degree-of-freedom suspension model. When the suspension mass distribution coefficient approaches 1, the vertical vibrations of the front and rear suspension systems are almost independent, allowing the suspension system model to be simplified to a two-degree-of-freedom vibration system. This system not only captures the dynamic characteristics of the vehicle body but also reflects the dynamic characteristics of the wheels at high-frequency resonances in the 10-15 Hz range. This significantly impacts ride comfort and wheel contact, and more closely reflects the actual state of the vehicle suspension system.

[0067] In order to take the roll of the vehicle into consideration, this application establishes a seven-degree-of-freedom vehicle dynamics model, as shown in FIG2 , which takes into account the vertical, roll, and pitch movements of the vehicle body.

[0068] For the seven-degree-of-freedom vehicle dynamics model in this application, the following assumptions are set: the vehicle body is regarded as a rigid body with concentrated mass, and only the influence of the vertical, roll and pitch vibrations of the vehicle body on the smoothness of the vehicle is considered, and the influence of the body torsion on the smoothness is ignored; the vehicle is symmetrical left and right along the longitudinal center line and moves in a uniform straight line; the road surface is a normal random process with smooth traversal of various states and is isotropic; other vibration sources other than the road surface are ignored.

[0069] The meaning of each number in Figure 2 is explained by taking the left front wheel as an example. The meanings and types of the numbers at other wheels are as follows: m1 represents the mass of the left front wheel, C1 represents the equivalent damping coefficient of the left front tire, C2 represents the equivalent damping coefficient of the left front passive suspension, k1 represents the stiffness of the left front tire, k2 represents the stiffness of the left front suspension, F1 represents the adjustable damping output damping force of the left front shock absorber, z1 represents the vertical displacement of the left front wheel, and z 01 Represents the vertical displacement excitation of the left front wheel by the road surface. x The moment of inertia of the vehicle body about the longitudinal axis of the center of mass, I y The moment of inertia of the vehicle body around the transverse axis of the center of mass, I z It represents the moment of inertia of the vehicle body about the vertical axis of the center of mass.

[0070] S2: Based on the established degree of freedom vehicle dynamics model, the vehicle vibration equation is calculated, and the variable damping output value is calculated based on the semi-active suspension damping force output control logic.

[0071] Specifically, the vehicle vibration equation is:

[0072] Among them, M represents the mass matrix of the vehicle, C represents the damping matrix of the vehicle, K represents the stiffness matrix of the vehicle, and Z represents the displacement vector of each degree of freedom of the vehicle. Represents the first-order derivative of the displacement vector of each degree of freedom of the vehicle, Represents the second-order derivative of the displacement vector of each degree of freedom of the vehicle, K t represents the tire stiffness matrix, Q represents the road surface input vector, i.e., the road surface roughness, C t represents the tire damping matrix, and F represents the vehicle stiffness matrix;

[0073] Among them, the vehicle's stiffness matrix is ​​specifically:

[0074] Where a is the distance from the front axle to the vehicle's center of mass, b is the distance from the rear axle to the vehicle's center of mass, c is the distance from the right tire's contact point to the vehicle's center of mass, d is the distance from the left tire's contact point to the vehicle's center of mass, k1 is the stiffness of the left front tire, k2 is the stiffness of the left front suspension, k3 is the stiffness of the right front tire, k4 is the stiffness of the right front suspension, k5 is the stiffness of the left rear tire, k6 is the stiffness of the left rear suspension, k7 is the stiffness of the right rear tire, k8 is the stiffness of the right rear suspension, and L is the wheelbase of the left and right wheels.

[0075] Among them, the vehicle's damping matrix is ​​specifically:

[0076] Among them, C1 represents the equivalent damping coefficient of the left front tire, C2 represents the equivalent damping coefficient of the left front passive suspension, C3 represents the equivalent damping coefficient of the right front tire, C4 represents the equivalent damping coefficient of the right front passive suspension, C5 represents the equivalent damping coefficient of the left rear tire, C6 represents the equivalent damping coefficient of the left rear passive suspension, C7 represents the equivalent damping coefficient of the right rear tire, and C8 represents the equivalent damping coefficient of the right rear passive suspension.

[0077] Furthermore, the variable damping output value is calculated based on the semi-active suspension damping force output control logic, specifically:

[0078] S201: Based on the vehicle vibration equation, determine the semi-active suspension damping force output control logic to obtain the adjustable damping output damping force of each shock absorber and the relative movement speed of each shock absorber.

[0079] For the adjustable damping output damping force of each shock absorber, the specific calculation method is:

[0080] Among them, F1 represents the adjustable damping output damping force of the left front shock absorber, F2 represents the adjustable damping output damping force of the right front shock absorber, F3 represents the adjustable damping output damping force of the left rear shock absorber, F4 represents the adjustable damping output damping force of the right rear shock absorber, c1 max Indicates the maximum damping of the left front suspension variable adjustment, c2 max Indicates the maximum damping of the right front suspension variable adjustment, c3 max Indicates the maximum damping of the left rear suspension with variable energy adjustment, c4 max Indicates the maximum damping of the right rear suspension with variable energy adjustment, c1 mex Indicates the actual output damping of the left front suspension variable damping, c2 mex Indicates the actual output damping of the right front suspension variable damping, c3 mex Indicates the actual output damping of the left rear suspension variable damping, c4 mex Indicates the actual output damping of the right rear suspension variable damping. Indicates the relative movement speed of the left front shock absorber, Indicates the relative movement speed of the right front shock absorber, Indicates the relative movement speed of the left rear shock absorber, Indicates the relative movement speed of the right rear shock absorber, It represents the first derivative of the vertical displacement at the connection point between the suspension and the left front position of the vehicle body, Represents the first-order derivative of the vertical displacement at the connection point between the suspension and the right front position of the vehicle body, It represents the first derivative of the vertical displacement at the connection point between the suspension and the left rear of the vehicle body, It represents the first derivative of the vertical displacement at the connection point between the suspension and the right rear position of the vehicle body, represents the first derivative of the vertical displacement of the left front wheel, represents the first derivative of the vertical displacement of the right front wheel, Represents the first-order derivative of the vertical displacement of the left rear wheel, Represents the first derivative of the vertical displacement of the right rear wheel.

[0081] For the relative motion speed of each shock absorber, the specific calculation method is: bw1 =z1-z 5lf z bw2 =z2-z 5rf z bw3 =z3-z 5lr z bw4 =z4-z 5rr

[0082] Among them, z bw1 Indicates the relative motion displacement of the left front shock absorber, z bw2 Indicates the relative motion displacement of the right front shock absorber, z bw3 Indicates the relative motion displacement of the left rear shock absorber, z bw4 represents the relative motion displacement of the right rear shock absorber, z1 represents the vertical displacement of the left front wheel, z2 represents the vertical displacement of the right front wheel, z3 represents the vertical displacement of the left rear wheel, z4 represents the vertical displacement of the right rear wheel, and z 5lf Indicates the vertical displacement of the connection point between the suspension and the left front position of the vehicle body, z 5rf Indicates the vertical displacement of the connection point between the suspension and the right front position of the vehicle body, z 5lr Indicates the vertical displacement of the connection point between the suspension and the left rear of the vehicle body, z 5rr Indicates the vertical displacement of the connection point between the suspension and the right rear position of the vehicle body;

[0083] Among them, the vertical displacement at the connection point between the suspension and the vehicle body is calculated as follows: 5lf=z5+a·z7-d·z6 z 5rf =z5+a·z7+c·z6 z 5lr =z5-b·z7-d·z6 z 5rr =z5-b·z7+c·z6

[0084] Among them, z5 represents the vertical displacement of the vehicle body's center of mass, z6 represents the roll angular displacement of the vehicle body, z7 represents the pitch angular displacement of the vehicle body, a represents the distance from the front axle to the vehicle's center of mass, b represents the distance from the rear axle to the vehicle's center of mass, c represents the distance from the right tire's contact point to the vehicle's center of mass, and d represents the distance from the left tire's contact point to the vehicle's center of mass.

[0085] S202: Determine a variable damping output value by optimizing a target method according to the obtained relative motion speeds of the shock absorbers.

[0086] Furthermore, in one embodiment, the variable damping output value is determined by optimizing the target according to the obtained relative motion speed of each shock absorber, specifically:

[0087] S2021: When any of the monitored relative movement speeds of the left front shock absorber, the right front shock absorber, the left rear shock absorber, and the right rear shock absorber is less than 0, executing an optimization target method to determine a variable damping output value;

[0088] S2022: Continuously adjust damping output based on changes in vehicle pitch and roll, as well as the relative motion of the vehicle's suspension connection points.

[0089] The optimization target method is specifically as follows:

[0090] Where, J represents the variable damping output value, sqr represents the square, represents the second-order derivative of the vertical displacement of the vehicle body’s center of mass, represents the second-order derivative of the roll angle displacement of the vehicle body, Represents the second-order derivative of the pitch angular displacement of the vehicle body.

[0091] That is, the variable damping adjustment strategy of the present application is: when any of the relative movement speeds of the left front shock absorber, the right front shock absorber, the left rear shock absorber, and the right rear shock absorber is monitored to be less than 0, the optimization target method is executed to determine the variable damping output value to ensure the stability of the vehicle body posture. At the same time, according to the changes in the pitch and roll of the vehicle body, as well as the relative movement of the suspension connection points of the entire vehicle, continuous stepless adjustment of the damping output is achieved to achieve the purpose of real-time control of the entire frequency band.

[0092] S3: PID parameters are adjusted based on a preset intelligent algorithm, and variable damping output control is achieved through the PID controller after parameter adjustment.

[0093] In this application, damping output control is achieved specifically through a PID controller. The PID controller's control strategy is simple in principle, mature in technology, and relatively easy to tune in practical applications, making it widely used in industrial control. Its greatest advantage is that it does not require an accurate understanding of the controlled object's mathematical model. Satisfactory results can be achieved by simply tuning the regulator parameters online based on simple parameters such as the system error and the rate of change of the error, demonstrating its great adaptability and flexibility.

[0094] The integral action in PID control can reduce steady-state error, but it can also easily lead to integral saturation, increasing system overshoot. The differential action can improve system response speed, but it is particularly sensitive to high-frequency interference and can even cause system instability. Therefore, correctly calculating PID controller parameters and effectively and rationally implementing PID controller design are of great theoretical and practical significance for their widespread application in process control.

[0095] In actual applications, designing a PID controller involves determining its proportional, integral, and differential coefficients. Different values ​​for these coefficients determine the strength of the proportional, integral, and differential effects. Control system tuning involves appropriately selecting controller parameters to match the characteristics of the control instrument with those of the controlled object, once the control system structure has been determined and the control instrument and controlled object are in their normal states. This allows the control system to operate optimally and achieve the best control results.

[0096] In this application, the PID parameters are adjusted by a preset intelligent algorithm to obtain a PID controller with adjusted parameters, and then the calculation process of the optimization target method is solved based on the PID controller with adjusted parameters to obtain a variable damping output value and realize the output control of the damping.

[0097] Specifically, in this application, the PID parameters are adjusted based on a preset intelligent algorithm, specifically:

[0098] S301: Initialize parameters and randomly generate an initial population. Specifically: X={x1,x2,L,x n} T

[0099] Among them, X represents the initial population, x n represents sparrow, T represents matrix transpose;

[0100] S302: Execute search algorithm:

[0101] in, represents the j-th dimension position information of the i-th sparrow in the t-th iteration, exp represents the exponential function with the natural constant e as the base, α t Represents a random number with a value range of [0,1], that is, the random number taken at the tth iteration, T max represents the maximum number of iterations, R2 represents the warning value, which is a random number between [0, 1], ST represents the safety threshold, which is a constant between [0.5, 1], q represents a random number that follows a normal distribution, L represents a 1×d-dimensional matrix of all 1s, and d represents a positive integer;

[0102] For α t The value of is calculated as follows:

[0103] Among them, α t-1 represents the random number taken at the t-1th iteration, λ represents a random number with a value range of [0,1], and needs to be randomly generated for each iteration;

[0104] S303: Update the joiner's location:

[0105] in, represents the worst individual in the tth iteration, n represents the total number of sparrows, represents the position of the best finder in the t+1th iteration;

[0106] S304: Updated awareness of danger:

[0107] in, represents the best individual in the t-th iteration, β represents a normal distribution random number with a mean of 0 and a variance of 1, and f i represents the current individual fitness value, f g represents the current maximum fitness value, k represents a random number with a value of [-1,1], the positive and negative represent the direction of the sparrow's movement, the size represents the step size control parameter, ε represents a constant, and f w Indicates the current minimum fitness value;

[0108] S305: Based on the calculation method of updating the awareness of danger, determine whether the stopping condition is met. If so, output the optimal sparrow position. If not, execute the search algorithm again, update the joiner position, update the awareness of danger, and repeat this cycle until the stopping condition is met.

[0109] The vehicle semi-active suspension damping control method of the embodiment of the present application establishes a multi-degree-of-freedom vehicle dynamics model based on the vehicle's motion posture and combined with the influence of each motion posture on the vehicle smoothness. Then, according to the established degree-of-freedom vehicle dynamics model, the vehicle vibration equation is calculated, and the variable damping output value is calculated according to the semi-active suspension damping force output control logic. Then, the PID parameters are adjusted based on the preset intelligent algorithm, and the variable damping output control is realized through the PID controller after parameter adjustment, which effectively solves the full-band adaptive correction of the semi-active suspension control strategy and ensures the stability of the vehicle body posture. By establishing a seven-degree-of-freedom vehicle dynamics model, it includes the semi-active suspension output damping force control strategy, adopts an improved control algorithm, and integrates the intelligent algorithm to adjust the PID parameters to avoid human interference, thereby achieving a significant improvement in the algorithm efficiency and robustness.

[0110] In a second aspect, an embodiment of the present application also provides a vehicle semi-active suspension damping control device.

[0111] In one embodiment, referring to Figure 3 , which is a functional module diagram of the vehicle semi-active suspension damping control device of the present application, the vehicle semi-active suspension damping control device includes a creation module, a calculation module, and a control module.

[0112] The creation module is configured to establish a multi-degree-of-freedom vehicle dynamics model based on the vehicle's motion posture and in combination with the impact of each motion posture on the vehicle's smoothness; the calculation module is configured to calculate the vehicle vibration equation based on the established degree-of-freedom vehicle dynamics model, and calculate the variable damping output value based on the semi-active suspension damping force output control logic; the control module is configured to adjust the PID parameters based on a preset intelligent algorithm, and realize variable damping output control through the PID controller with adjusted parameters.

[0113] Among them, the functional implementation of each module in the above-mentioned vehicle semi-active suspension damping control device corresponds to the various steps in the above-mentioned vehicle semi-active suspension damping control method embodiment, and their functions and implementation processes are no longer repeated here.

[0114] In a third aspect, an embodiment of the present application provides a vehicle semi-active suspension damping control device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0115] Referring to Figure 4, which is a schematic diagram of the hardware structure of a vehicle semi-active suspension damping control device involved in an embodiment of the present application, the vehicle semi-active suspension damping control device may include a processor, a memory, a communication interface, and a communication bus.

[0116] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0117] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the vehicle semi-active suspension damping control device, as well as interfaces used to interconnect the vehicle semi-active suspension damping control device with other devices (such as other computing devices or user devices). Physical interfaces can be Ethernet, fiber optic, or ATM interfaces; user devices can be displays, keyboards, and other devices.

[0118] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0119] The processor may be a general-purpose processor that can invoke a vehicle semi-active suspension damping control program stored in a memory and execute the vehicle semi-active suspension damping control method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the vehicle semi-active suspension damping control program is invoked can be described in detail in the various embodiments of the vehicle semi-active suspension damping control method of the present application and will not be further described here.

[0120] Those skilled in the art will understand that the hardware structure shown in FIG4 does not constitute a limitation on the present application, and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0121] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0122] The computer-readable storage medium of the present application stores a vehicle semi-active suspension damping control program, wherein when the vehicle semi-active suspension damping control program is executed by a processor, the steps of the vehicle semi-active suspension damping control method as described above are implemented.

[0123] Among them, the method implemented when the vehicle semi-active suspension damping control program is executed can refer to the various embodiments of the vehicle semi-active suspension damping control method of the present application, and will not be repeated here.

[0124] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0125] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0126] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0127] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0128] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0129] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0130] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A vehicle semi-active suspension damping control method, characterized in that: The vehicle semi-active suspension damping control method comprises: Based on the vehicle's motion posture and the impact of each motion posture on vehicle ride comfort, a multi-degree-of-freedom vehicle dynamics model is established; Based on the established vehicle dynamics model with the right degree of freedom, the vehicle vibration equation is calculated, and the variable damping output value is calculated based on the semi-active suspension damping force output control logic. The PID parameters are adjusted based on a preset intelligent algorithm, and variable damping output control is achieved through the PID controller after parameter adjustment.

2. The vehicle semi-active suspension damping control method according to claim 1, characterized in that: Based on the vehicle's motion posture and the influence of each motion posture on vehicle smoothness, a multi-degree-of-freedom vehicle dynamics model is established, specifically: The vehicle body is set as a rigid body with concentrated mass, and only the effects of vertical, roll and pitch motions on vehicle smoothness are considered; The vehicle is assumed to be bilaterally symmetrical along its longitudinal centerline and to move in a uniform straight line. The road surface is assumed to be a normal random process with steady traversal of various states, and a seven-degree-of-freedom vehicle dynamics model is established.

3. The vehicle semi-active suspension damping control method according to claim 2, characterized in that: The vehicle vibration equation is specifically: Among them, M represents the mass matrix of the vehicle, C represents the damping matrix of the vehicle, K represents the stiffness matrix of the vehicle, and Z represents the displacement vector of each degree of freedom of the vehicle. Represents the first-order derivative of the displacement vector of each degree of freedom of the vehicle, Represents the second-order derivative of the displacement vector of each degree of freedom of the vehicle, K t represents the tire stiffness matrix, Q represents the road surface input vector, i.e., the road surface roughness, C t represents the tire damping matrix, F represents the vehicle The stiffness matrix of Among them, the vehicle's stiffness matrix is ​​specifically: Where a is the distance from the front axle to the vehicle's center of mass, b is the distance from the rear axle to the vehicle's center of mass, c is the distance from the right tire's contact point to the vehicle's center of mass, d is the distance from the left tire's contact point to the vehicle's center of mass, k1 is the stiffness of the left front tire, k2 is the stiffness of the left front suspension, k3 is the stiffness of the right front tire, k4 is the stiffness of the right front suspension, k5 is the stiffness of the left rear tire, k6 is the stiffness of the left rear suspension, k7 is the stiffness of the right rear tire, k8 is the stiffness of the right rear suspension, and L is the wheelbase of the left and right wheels. Among them, the vehicle's damping matrix is ​​specifically: Among them, C1 represents the equivalent damping coefficient of the left front tire, C2 represents the equivalent damping coefficient of the left front passive suspension, C3 represents the equivalent damping coefficient of the right front tire, C4 represents the equivalent damping coefficient of the right front passive suspension, C5 represents the equivalent damping coefficient of the left rear tire, C6 represents the equivalent damping coefficient of the left rear passive suspension, C7 represents the equivalent damping coefficient of the right rear tire, and C8 represents the equivalent damping coefficient of the right rear passive suspension.

4. The vehicle semi-active suspension damping control method according to claim 3, characterized in that: The variable damping output value is calculated based on the semi-active suspension damping force output control logic, specifically: Based on the vehicle vibration equation, the semi-active suspension damping force output control logic is determined to obtain the adjustable damping output damping force of each shock absorber and the relative motion speed of each shock absorber; According to the relative motion speed of each shock absorber, the variable damping output is determined by optimizing the target method. Output value.

5. The vehicle semi-active suspension damping control method according to claim 4, characterized in that: The semi-active suspension damping force output control logic is determined to obtain the adjustable damping output damping force of each shock absorber and the relative motion speed of each shock absorber. The specific calculation method for the adjustable damping output damping force of each shock absorber is: Among them, F1 represents the adjustable damping output damping force of the left front shock absorber, F2 represents the adjustable damping output damping force of the right front shock absorber, F3 represents the adjustable damping output damping force of the left rear shock absorber, F4 represents the adjustable damping output damping force of the right rear shock absorber, c1 max Indicates the maximum damping of the left front suspension variable adjustment, c2 max Indicates the maximum damping of the right front suspension variable adjustment, c3 max Indicates the maximum damping of the left rear suspension with variable energy adjustment, c4 max Indicates the maximum damping of the right rear suspension with variable energy adjustment, c1 mex Indicates the actual output damping of the left front suspension variable damping, c2 mex Indicates the actual output damping of the right front suspension variable damping, c3 mex Indicates the actual output damping of the left rear suspension variable damping, c4 mex Indicates the actual output damping of the right rear suspension variable damping. Indicates the relative movement speed of the left front shock absorber, Indicates the relative movement speed of the right front shock absorber, Indicates the relative movement speed of the left rear shock absorber, Indicates the relative movement speed of the right rear shock absorber. It represents the first derivative of the vertical displacement at the connection point between the suspension and the left front position of the vehicle body, Represents the first-order derivative of the vertical displacement at the connection point between the suspension and the right front position of the vehicle body, It represents the first derivative of the vertical displacement at the connection point between the suspension and the left rear of the vehicle body, It represents the first derivative of the vertical displacement at the connection point between the suspension and the right rear position of the vehicle body, Indicates that the left front wheel is The first derivative of the displacement in the vertical direction, represents the first derivative of the vertical displacement of the right front wheel, Represents the first-order derivative of the vertical displacement of the left rear wheel, Represents the first derivative of the displacement of the right rear wheel in the vertical direction; The semi-active suspension damping force output control logic is determined to obtain the adjustable damping output damping force of each shock absorber and the relative motion speed of each shock absorber. The specific calculation method for the relative motion speed of each shock absorber is: With bw1 =z1-z 5lf With bw2 =z2-z 5rf With bw3 =z3-z 5lr With bw4 =z4-z 5rr Among them, z bw1 Indicates the relative motion displacement of the left front shock absorber, z bw2 Indicates the relative motion displacement of the right front shock absorber, z bw3 Indicates the relative motion displacement of the left rear shock absorber, z bw4 represents the relative motion displacement of the right rear shock absorber, z1 represents the vertical displacement of the left front wheel, z2 represents the vertical displacement of the right front wheel, z3 represents the vertical displacement of the left rear wheel, z4 represents the vertical displacement of the right rear wheel, and z 5lf Indicates the vertical displacement of the connection point between the suspension and the left front position of the vehicle body, z 5rf Indicates the vertical displacement of the connection point between the suspension and the right front position of the vehicle body, z 5lr Indicates the vertical displacement of the connection point between the suspension and the left rear of the vehicle body, z 5rr Indicates the vertical displacement of the connection point between the suspension and the right rear position of the vehicle body; The vertical displacement at the connection point between the suspension and the vehicle body is calculated as follows: z 5lf =z5+a·z7-d·z6 z 5rf =z5+a·z7+c·z6 z 5lr =z5-b·z7-d·z6 z 5rr =z5-b·z7+c·z6 Among them, z5 represents the vertical displacement of the vehicle center of mass, z6 represents the roll angle displacement of the vehicle, z7 represents the pitch angle displacement of the vehicle, a represents the distance from the front axle to the vehicle center of mass, b represents the distance from the rear axle to the vehicle center of mass, c represents the distance from the front axle to the vehicle center of mass, represents the distance from the right tire contact point to the vehicle's center of mass, and d represents the distance from the left tire contact point to the vehicle's center of mass.

6. The vehicle semi-active suspension damping control method according to claim 4, characterized in that: The variable damping output value is determined by optimizing the target according to the relative motion speed of each shock absorber, specifically: When it is monitored that any one of the relative movement speed of the left front shock absorber, the relative movement speed of the right front shock absorber, the relative movement speed of the left rear shock absorber, and the relative movement speed of the right rear shock absorber is less than 0, the optimization target mode is executed to determine the variable damping output value; Continuous and stepless adjustment of damping output is achieved based on changes in vehicle pitch and roll, as well as the relative movement of the vehicle's suspension connection points. The optimization target method is specifically as follows: Where, J represents the variable damping output value, sqr represents the square, represents the second-order derivative of the vertical displacement of the vehicle body’s center of mass, represents the second-order derivative of the roll angle displacement of the vehicle body, Represents the second-order derivative of the pitch angular displacement of the vehicle body.

7. The vehicle semi-active suspension damping control method according to claim 1, characterized in that: The PID parameters are adjusted based on the preset intelligent algorithm, specifically: Initialize the parameters and randomly generate the initial population. Specifically: X ={x1,x2,L,x n } T Among them, X represents the initial population, x n represents sparrow, T represents matrix transpose; Execute the search algorithm: in, represents the j-th dimension position information of the i-th sparrow in the t-th iteration, and exp represents the The exponential function with constant e as base, α t Represents a random number, the value range is [0,1], T max represents the maximum number of iterations, R2 represents the warning value, which is a random number between [0, 1], ST represents the safety threshold, which is a constant between [0.5, 1], q represents a random number that follows a normal distribution, L represents a 1×d-dimensional matrix of all 1s, and d represents a positive integer; Update joiner location: in, represents the worst individual in the tth iteration, n represents the total number of sparrows, represents the position of the best finder in the t+1th iteration; Update Aware of the Danger: in, represents the best individual in the t-th iteration, β represents a normal distribution random number with a mean of 0 and a variance of 1, and f i represents the current individual fitness value, f g represents the current maximum fitness value, k represents a random number with a value of [-1,1], the positive and negative represent the direction of the sparrow's movement, the size represents the step size control parameter, ε represents a constant, and f w Indicates the current minimum fitness value; Based on the calculation method of updating the awareness of danger, it is judged whether the stopping condition is met. If so, the optimal sparrow position is output. If not, the search algorithm is executed again, and the joiner position is updated and the awareness of danger is updated. This cycle is repeated until the stopping condition is met.

8. A vehicle semi-active suspension damping control device, characterized in that: The vehicle semi-active suspension damping control device comprises: A creation module configured to establish a multi-degree-of-freedom vehicle dynamics model based on the vehicle's motion posture and the impact of each motion posture on vehicle ride comfort; a calculation module configured to calculate a vehicle vibration equation based on the established degree-of-freedom vehicle dynamics model, and to calculate a variable damping output value based on the semi-active suspension damping force output control logic; The control module is configured to adjust PID parameters based on a preset intelligent algorithm and implement variable damping output control through the PID controller after parameter adjustment.

9. A vehicle semi-active suspension damping control device, characterized in that: The vehicle semi-active suspension damping control device includes a processor, a memory, and a vehicle semi-active suspension damping control program stored on the memory and executable by the processor, wherein when the vehicle semi-active suspension damping control program is executed by the processor, the steps of the vehicle semi-active suspension damping control method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a vehicle semi-active suspension damping control program, wherein when the vehicle semi-active suspension damping control program is executed by a processor, the steps of the vehicle semi-active suspension damping control method according to any one of claims 1 to 7 are implemented.

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