Follow-up control method for electromechanical inerter suspension
By adjusting the resistance of the tie rod in the electromechanical inertial capacitance suspension system, the suspension can be dynamically controlled, which solves the problem of insufficient vibration reduction performance of the suspension system when the road conditions change, improves the adaptability and stability of the suspension system, and reduces costs.
Patent Information
- Application Number
- CN202511389660.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-26
- Publication Date
- 2025-11-18
AI Technical Summary
Existing automotive suspension systems cannot dynamically adjust their damping performance according to road conditions, resulting in insufficient road adaptability. Semi-active and active suspensions are costly, energy-intensive, and complex to control, making them difficult to widely apply.
An electromechanical inertial capacitance suspension system is adopted, which uses tie rod resistors instead of traditional resistors. The tie rod resistance value is adjusted in real time through displacement sensors and control units, and follow-up control is achieved according to the change of suspension travel. The suspension performance is optimized by combining mechanical network and electrical network systems.
It significantly reduces tire dynamic load, improves vehicle handling and stability, has a simple structure and low cost, has good engineering application prospects, and does not affect the performance of the suspension system in the event of failure.
Smart Images
Figure CN120963277A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of vehicle suspension system control, in particular to a follow-up control method of an electromechanical inertance suspension. BACKGROUND
[0002] Professor Smith of Cambridge University in the UK proposed the theoretical structure of inertance container, which imitates the capacitor element and is provided with independent end points at the upper and lower ends. With the continuous evolution of mechanical isolation systems, the inclusion of inertance containers has gradually become an important direction of innovation in suspension design theory. The new passive inertance suspension system mainly composed of inertance suspension breaks through the structure of the original passive suspension composed of parallel spring and damping elements, forms a coupled vibration system of "mass above spring-mass below spring", and makes up for the deficiency of mass impedance, thereby providing a new research direction for the field of vehicle suspension system vibration isolation. Therefore, this field has become one of the current hotspots of suspension research. At present, the exploration of new technologies for vehicle suspensions is continuously deepening, but compared with the entire automotive industry, there are still very few vehicles with follow-up control suspensions. Passive suspensions cannot dynamically adjust the damping performance according to the road conditions because the spring stiffness and damping coefficient are not adjustable, which leads to insufficient road adaptability and lack of follow-up control capability. Semi-active suspensions can adapt to different driving conditions by introducing a stiffness or damping adjustable mechanism based on passive suspensions, thereby significantly improving the overall performance. Active suspensions increase actuators based on traditional passive suspensions, comprehensively consider the road and vehicle conditions, and ensure that the vehicle maintains a relatively ideal state under different road conditions by outputting actuating force. However, semi-active suspensions and active suspensions have follow-up control capabilities, but they generally face problems such as high cost, high energy consumption, and complex control strategies, and cannot be widely applied at present. SUMMARY
[0003] The purpose of the present application is to solve the problems of passive suspensions that cannot change their damping characteristics with changes in road conditions, and the problems of semi-active suspensions and active suspensions that are expensive, have high energy consumption, and have complex control. A follow-up control method of a vehicle electromechanical inertance suspension is proposed, which uses a pull rod resistor to replace the traditional resistor, so that the inertance container can be adjusted synchronously with the change in the vehicle body dynamic stroke, and the follow-up control of the vehicle suspension is realized.
[0004] The technical solution of the present application for achieving the above-mentioned purpose is a follow-up control method of an electromechanical inertance suspension, comprising the following steps: (1) determining the dynamic model of vehicle suspension vibration; (2) according to the performance optimization target, under the positive real inequality constraint, using the particle swarm algorithm to optimize and solve the electromechanical network system of the vehicle electromechanical inertance suspension, and obtaining the corresponding impedance transfer function coefficient; (3) In the random road input conditions, the time domain analysis is carried out on the derived suspension, and the performance verification of the servo control method of the electromechanical inerter suspension is completed.
[0005] Further supplement to the technical solution, the electromechanical inerter suspension is composed of a sprung mass, a displacement sensor, an inerter, a spring, a damper, a wheel mass, a tire equivalent spring, a control unit, a rotary motor and an external electrical network. The displacement sensor is arranged at the upper support point of the inerter, the upper support point of the spring is connected with the sprung mass, and the lower support point of the spring is connected with the wheel mass to bear the sprung mass; the upper support point of the inerter is connected with the sprung mass, and the lower support point of the inerter is connected with the wheel mass; the upper support point of the damper is connected with the sprung mass, and the lower support point of the damper is connected with the wheel mass; the upper support point of the tire equivalent spring is connected with the wheel mass, and the lower support point of the tire equivalent spring is connected with the ground.
[0006] Further supplement to the technical solution, the displacement sensor is connected with the control unit through a signal line.
[0007] Further supplement to the technical solution, the following steps are adopted: ① The displacement sensor collects the displacement signals of the two end points of the inerter in real time s to the control unit; ② The control unit controls the pull rod resistance in the external electrical network according to the input displacement signals, and adjusts the resistance value according to the resistance value change equation , so that the resistance value of the pull rod resistance can be adjusted according to the suspension dynamic stroke; when the vehicle dynamic stroke increases, the adjusting handle of the pull rod resistance is elongated, and the effective resistance value increases; when the vehicle dynamic stroke decreases, the adjusting handle of the pull rod resistance is shortened, and the effective resistance value decreases, so as to realize the servo control of the vehicle suspension.
[0008] Further supplement to the technical solution, the step one vehicle suspension dynamics model mainly considers the road roughness displacement input, the linear tire model, the non-sprung mass, the suspension system and the sprung mass. The expression form of the four-degree-of-freedom automobile quarter electromechanical inerter suspension system under the action of Newton's second law is obtained by using the dynamic Lagrange equation, which is as follows: , wherein, 、 , respectively represent the sprung mass and the unsprung mass, 、 , respectively represent the stiffness of the suspension elastic element and the equivalent spring stiffness of the tire, represents the suspension damping coefficient, , , represents the displacement input of the road in the longitudinal direction, the longitudinal displacement of the unsprung mass, and the longitudinal displacement of the sprung mass, b represents the mass coefficient of the ball screw inertial container, B(s) represents the equivalent complex impedance of the ball screw electromechanical inertial container; , and are the Laplace transformed forms of the road input, the unsprung mass, and the sprung mass vertical displacement, respectively, is expressed as a Laplace variable, and the specific value is: , , , ; The vehicle electromechanical inertial suspension system is composed of a mechanical network system and an electrical network system, wherein the mechanical network system includes three types of two-terminal mechanical elements, namely, inertial containers, springs, and dampers; wherein the spring, the damper, and the inertial container are connected in parallel; the electrical network is composed of three types of elements, namely, a pull rod resistor, an inductor, and a resistor; the electrical network converts vibration energy into mechanical displacement by selecting the pull rod resistor, the resistance value changes with the mechanical displacement occurring at both ends of the inertial container, realizes the regulation and control of electromagnetic damping, and completes the follow-up control of the vehicle suspension, and its expression is: ; wherein, is the base resistance of the pull rod resistor, is the resistance of the pull rod resistor.
[0009] Further supplement to the technical solution, step two is derived based on the suspension structure and the double quadratic impedance function. Since the pull rod resistor is a key variable element, it directly determines the equivalent impedance characteristics of the electromechanical inertial container. The resistance base value and the resistivity of the pull rod resistor are solved, and if the mechanical element exists, the necessary condition for the optimization variable is: , ; Taking the steering stability as the suspension optimization guide, in the optimization of the vehicle electromechanical inertial suspension system, the ratio of the tire dynamic load of the vehicle electromechanical inertial suspension to the traditional passive suspension is established as the objective function, and the expression of the objective function and its constraint condition are as follows: ; In the formula, is the fitness function (i.e., the unified objective function); DTL ( X ) is the root mean square value of the tire dynamic load. The root mean square value of the tire dynamic load of a conventional passive suspension for comparison; X denotes a set of parameters to be optimized; UB and LB denote the upper and lower limits of the parameters to be optimized, respectively.
[0010] Further supplement to the technical solution, step three carries out time domain analysis on the derived suspension, assuming that a vehicle travels at a speed of 20 meters per second on a C-class road, and a random road input model is used in the simulation process, as described by the following formula: ; In the above formula, represents the driving speed, represents the longitudinal displacement due to road unevenness, represents the road unevenness coefficient, represents a white noise signal.
[0011] The beneficial effects are that the pull rod resistor replaces the original traditional resistor, compared with the passive suspension, the mechatronic suspension with pull rod resistor considers the factors of road changes, through the adjustment of the pull rod resistor, the resistance value can be changed with the change of the suspension dynamic travel caused by the change of road conditions, the external electrical network of the suspension has certain adaptability, thereby significantly reducing the tire dynamic load, and significantly improving the overall handling of the vehicle; compared with the semi-active suspension and the active suspension, the structure is simple, and the relative cost is low; at the same time, even if the servo control system fails during driving, the pull rod resistor is still equivalent to a fixed resistor, which will not cause performance instability of the suspension system, and the advantages of perfect impedance of the vehicle mechatronic suspension are continued, and good engineering application prospect is possessed. BRIEF DESCRIPTION OF DRAWINGS
[0012] Fig. 1 is a quarter vehicle suspension dynamics model diagram; Fig. 2 is an external electrical network model diagram; Fig. 3 is a tire dynamic load time domain response comparison diagram. DETAILED DESCRIPTION
[0013] In order to make the technical personnel in the art more clearly understand the technical solution, the following will be combined with the attached Figs. 1-3 The technical solution will be described in detail: A vehicle mechatronic suspension servo control method is composed of a sprung mass, a displacement sensor, an inerter, a spring, a damper, a wheel mass, a tire equivalent spring, a control unit, a rotary motor, and an external electrical network.
[0014] The attached Fig. 1The vehicle quarter suspension system model shown is taken as an example, the displacement sensor is arranged on the inertial container, the upper support point of the spring is connected with the spring-loaded mass, the lower support point of the spring is connected with the wheel mass to bear the spring-loaded mass; the upper support point of the inertial container is connected with the spring-loaded mass, the lower support point of the inertial container is connected with the wheel mass, the upper support point of the damper is connected with the spring-loaded mass, the lower support point of the damper is connected with the wheel mass, the upper support point of the tire equivalent spring is connected with the wheel mass, and the lower support point of the tire equivalent spring is connected with the ground.
[0015] The displacement sensor is connected with the control unit through a signal line for transmitting a displacement signal s The control unit controls the pull rod resistance in the outer end electric network to be synchronously adjusted according to the input suspension dynamic displacement signal, so that the follow-up control of the vehicle suspension is realized. The pull rod resistance is an electronic element for changing the resistance value through mechanical displacement. From the structure, the pull rod resistance is composed of a sliding resistance sheet and an adjusting handle. The effective resistance value in the circuit is changed by changing the position of the adjusting handle through a mechanical mode. The pull rod resistance has unique mechanical structure and performance advantages. The resistance value is directly changed through mechanical displacement, and the adjusting process has physical certainty. However, the digital potentiometer and other electronic variable resistors usually need additional AD / DA conversion links, and there are quantization errors and sampling delays. At the same time, when the electric network structure causes the pull rod resistance to fail to adjust due to special factors, the digital potentiometer is usually open after power off, and the analog switch resistance is in a high resistance state when it fails. However, the pull rod resistance can still be equivalent to a fixed resistance in the mechanical contact state, ensuring the normal operation of the electric network. The suspension system usually requires millisecond-level response. Compared with the electronic resistance, the pull rod resistance directly transmits the displacement signal through rigid connection, and does not need to be sampled through the sensor. The displacement signal is converted for multiple times. Due to the additional links, the phase lag is caused, and the tire dynamic load control effect is affected.
[0016] The main steps are: (1) Determine the dynamic model of vehicle suspension vibration and its performance evaluation index. The dynamic model of the vehicle suspension mainly considers the road roughness displacement input, the linear tire model, the non-spring mass, the suspension system and the spring mass. As shown in Fig. 1 The vehicle quarter suspension vibration model constructed in the embodiment of the application is shown, and the suspension system is composed of a mechanical network system and an electric network system. In the suspension model construction, the suspension elastic support spring and the electromechanical inertial container are mainly considered.
[0017] The four-degree-of-freedom automobile quarter electromechanical inertial suspension system under the action of Newton's second law is obtained by using the Lagrange equation of dynamics, and is specifically as follows: ; ; wherein, 、 respectively represent the sprung mass, the unsprung mass, 、 respectively represent the stiffness of the suspension elastic element and the equivalent spring stiffness of the tire, represents the suspension damping coefficient, represents the longitudinal displacement input of the road surface, the longitudinal displacement of the unsprung mass, the longitudinal displacement of the sprung mass, b represents the mass coefficient of the ball screw inertial container, B(s) represents the equivalent complex impedance of the ball screw electromechanical inertial container; and are respectively the Laplace transform forms of the road input, the unsprung mass, the sprung mass vertical displacement, is expressed as a Laplace variable, and the specific value is: , , , The vehicle electromechanical inertial suspension system is composed of a mechanical network system and an electrical network system. The mechanical network system includes three types of two-terminal mechanical elements, namely, inertial containers, springs, and dampers. The spring, damper, and inertial container are connected in parallel. The electrical network is composed of three types of elements, namely, a tie rod resistor, an inductor, and a resistor. The electrical network converts vibration energy into mechanical displacement by selecting a tie rod resistor. The resistance value changes with the mechanical displacement of the two ends of the inertial container, realizes the regulation and control of electromagnetic damping, and completes the follow-up control of the vehicle suspension. Its expression is: wherein, is the basic resistance value of the tie rod resistor, is the resistance of the tie rod resistor.
[0018] (2) According to the performance optimization target, the particle swarm algorithm is used to optimize and solve the vehicle electromechanical inertial suspension electromechanical network system under the positive real inequality constraint, to obtain the corresponding impedance transfer function coefficient. Based on the suspension structure and double quadratic impedance function, since the tie rod resistor is a key variable element, it directly determines the equivalent impedance characteristics of the electromechanical inertial container. The resistance base value and resistivity , of the tie rod resistor are solved. If the mechanical element exists, the necessary condition of the optimization variable is: With the steering stability as the suspension optimization guide, in the optimization of the vehicle electromechanical inerter suspension system, a target function is established. ; In the formula, is the fitness function (i.e. the unified target function); DTL ( X ) is the root mean square value of the tire dynamic load; is the root mean square value of the tire dynamic load of the conventional passive suspension used for comparison; X represents a set of parameters to be optimized; UB and LB respectively represent the upper limit and the lower limit of the parameter to be optimized.
[0019] (3) The suspension is subjected to time domain analysis, assuming that a vehicle travels at a speed of 20 meters per second on a C-class road, and a random road input model is used in the simulation process, as follows: ; In the above formula, represents the driving speed, represents the longitudinal displacement due to road unevenness, represents the road unevenness coefficient, represents a white noise signal Fig. 3 The time domain response comparison chart of the servo-controlled electromechanical inerter suspension and the conventional passive suspension shows that the vehicle electromechanical inerter suspension servo control method proposed by the application significantly reduces the tire dynamic load compared with the conventional passive suspension, has good steering stability, and therefore has good application prospects.
[0020] The above technical solution only embodies the preferred technical solution of the application, and some changes made by the person skilled in the art to some parts thereof all embody the principles of the application and are within the protection scope of the application.
Claims
1. A method of servo control for an electromechanical inerter suspension, characterized by, It comprises the following steps: (1) determining a dynamic model of vehicle suspension vibration; (2) according to a performance optimization target, using a particle swarm algorithm to optimize and solve a vehicle electromechanical inerter suspension electromechanical network system under positive real inequality constraints, and obtaining corresponding impedance transfer function coefficients; (3) under random road input conditions, performing time domain analysis on the obtained suspension, and verifying the performance of the electromechanical inerter suspension servo control method.
2. The method of claim 1, wherein the method further comprises: The electromechanical inerter suspension is composed of a sprung mass, a displacement sensor, an inerter, a spring, a damper, a wheel mass, a tire equivalent spring, a control unit, a rotary motor and an external electrical network. The displacement sensor is arranged at the upper support point of the inerter, the upper support point of the spring is connected to the sprung mass, and the lower support point of the spring is connected to the wheel mass to bear the sprung mass; the upper support point of the inerter is connected to the sprung mass, the lower support point of the inerter is connected to the wheel mass, the upper support point of the damper is connected to the sprung mass, the lower support point of the damper is connected to the wheel mass, the upper support point of the tire equivalent spring is connected to the wheel mass, and the lower support point of the tire equivalent spring is connected to the ground.
3. The method of claim 2, wherein the method further comprises: The displacement sensor is connected to the control unit through a signal line.
4. The method of claim 3, wherein the method further comprises: The following steps are adopted: The displacement sensor acquires the displacement signals of the two ends of the inerter in real time s to the control unit; ② Control unit controls the pull rod resistance in the outer end electric network according to the input displacement signal, according to the resistance value change equation The resistance value is regulated so that the pull rod resistance value can be adjusted with the suspension dynamic stroke change. When the vehicle dynamic stroke increases, the adjusting handle of the pull rod resistance is elongated, the effective resistance value increases; when the vehicle dynamic stroke decreases, the adjusting handle of the pull rod resistance is shortened, the effective resistance value decreases, thereby realizing the follow-up control of the vehicle suspension.
5. The method of claim 1, wherein, The step one vehicle suspension dynamics model mainly considers road roughness displacement input, linear tire model, non-sprung mass, suspension system and sprung mass; The expression form of the four-degree-of-freedom automobile quarter electromechanical inerter suspension system under the action of Newton's second law is obtained by using the dynamic Lagrange equation, and is specifically as follows: ； ； wherein, 、 respectively represent the sprung mass, the unsprung mass, 、 respectively represent the stiffness of the suspension elastic element and the equivalent spring stiffness of the tire, represents the suspension damping coefficient, , , represents the longitudinal displacement input of the road surface, the longitudinal displacement of the unsprung mass, the longitudinal displacement of the sprung mass, b represents the mass coefficient of the ball screw inertial container, B(s) represents the equivalent complex impedance of the ball screw electromechanical inertial container; , and are respectively the Laplace transform form of the road input, the vertical displacement of the unsprung mass, the vertical displacement of the sprung mass, is expressed as a Laplace variable, and the specific value is: , , , ; The vehicle electromechanical inerter suspension system is composed of a mechanical network system and an electrical network system, wherein the mechanical network system includes three types of two-terminal mechanical elements, namely inerter, spring and damper; wherein the spring, damper and inerter are connected in parallel; the electrical network is composed of three types of elements, namely pull rod resistance, inductance and resistance; the electrical network converts vibration energy into mechanical displacement by selecting pull rod resistance, the resistance value changes with the mechanical displacement of the two ends of the inerter, realizes the regulation and control of electromagnetic damping, and completes the servo control of the vehicle suspension, and its expression is: ； wherein, is a base resistance value of the pull rod resistance, is a resistance of the pull rod resistance.
6. The method of claim 5, wherein the method further comprises: The step two is derived based on the suspension structure and double quadratic impedance function. Since the rod resistance is a key variable element, it directly determines the equivalent impedance characteristics of the electromechanical inerter. The resistance base value and resistivity of the rod resistance are solved , The necessary conditions of the optimization variables are that if the mechanical element exists, the optimization variables are Taking handling stability as the suspension optimization guide, in the optimization of the vehicle electromechanical inerter suspension system, a target function is established, the ratio of the tire dynamic load of the vehicle electromechanical inerter suspension to that of the traditional passive suspension is taken as the target function, and the expression of the target function and its constraint conditions are as follows: wherein is the fitness function (i.e. the global objective function); DTL is the tire dynamic load root mean square value; X is the tire dynamic load root mean square value of a traditional passive suspension used as a reference; is the tire dynamic load root mean square value of a traditional passive suspension used as a reference; X denotes the set of parameters to be optimized; UB and LB denote the upper and lower limits of the parameters to be optimized, respectively.
7. The method of claim 6, wherein the method further comprises: In step three, the obtained suspension is analyzed in time domain, it is assumed that a vehicle travels at a speed of 20 meters per second on a C-class road, and a random road input model is used in the simulation process, as follows: In the above equation, represents the running speed, represents the longitudinal displacement due to the road unevenness, represents the road unevenness coefficient, represents the white noise signal.