Vibration Control Of Suspension System Research Articles

Parameter optimization of electromagnetic suspension-type maglev train control system based on multi-objective grey wolf non-dominated sorting hybrid algorithm-Ⅱ hybrid algorithm

This paper presents a novel hybrid algorithm based on CMOGWO-ADNSGA-II to solve the vibration stability problem during the operation of a EMS-type maglev train dynamics model subjected to strong non-linear magnetic buoyancy. The proposed algorithm optimizes the control system parameters of EMS-type maglev train suspensions by combining an improved multi-objective chaotic grey wolf algorithm (CMOGWO) with an improved non-dominated Sorting genetic algorithm-II (ADNSGA-II) to enhance the search capability of the algorithm and ensure population diversity. The efficacy of the algorithm is demonstrated by applying it to the EMS-type maglev train suspension frame control system to find the optimal control parameters. Experimental results show that the system with the optimal parameters applied significantly reduces the suspension gap amplitude and the corresponding standard deviation, as well as the vertical acceleration amplitude and the corresponding standard deviation during operation. The proposed algorithm provides a good solution for EMS-type maglev train suspension vibration control, which can improve its performance and safety.

Gray skyhook predictive control of magnetorheological semi-active seat suspension with time delay

Semi-active seat suspension with a magnetorheological (MR) damper has been a popular study issue in recent years. Since the response time delay of the MR damper can reduce the control effect and even make the vibration more severe, there is an urgent need to compensate for the response time delay. In this paper, gray prediction is introduced into the vibration control study of commercial vehicle seat suspension. A gray skyhook prediction controller is designed to compensate for the response time delay. This proposed controller does not rely heavily on controller parameter optimization and requires fewer state variables than other typical time delay compensation controllers. The mechanical property of the MR damper has been tested, modeled, and analyzed. A seat suspension dynamic model considering geometric nonlinearity is established based on the motion relationship between the components of the suspension. Subsequently, the effect of the response time delay on seat suspension vibration control has been verified by simulation. The results show that the control effect deteriorates significantly after considering the response time delay. Finally, prediction accuracy and vibration reduction performance of the designed gray skyhook predictive controller are verified by simulation and bench testing. The results illustrate that the gray skyhook predictive controller provides excellent time delay compensation and can significantly improve the ride comfort and handling stability of the driver. This study provides a reference for vibration control research of the MR seat suspension.

Self-sensing automotive magnetorheological dampers for low frequency vibration

This paper presents a magnetorheological (MR) automobile damper with a self-sensing function. The self-sensing structure is designed based on the principle of triboelectric nanogeneration. The self-sensing performance of the MR automobile damper is verified from the theoretical analysis and experimental results. A vehicle suspension vibration control system composed of 1/4 vehicle suspension, fuzzy control algorithm, and vibration excitation platform is established to test the vibration control performance of self-sensing MR automobile damper (SMRAD). The experimental results show that the fuzzy control system reduces the body acceleration of the vehicle suspension compared with the passive control. The root mean square value of vehicle suspension body acceleration is reduced by 28.8 compared with the vehicle body acceleration under passive control. This verifies the effectiveness of the self-sensing performance of the speed self-sensing structure of the MR automobile damper. The application of the SMRAD in the vehicle suspension improves the vibration reduction performance of the vehicle suspension.

Applications of Approximate Optimal Control to Nonlinear Systems of Tracked Vehicle Suspensions

Technique of approximate optimal vibration control and simulation for vehicle active suspension systems are developed. Considered the nonlinear damping of springs, mechanical model and a nonlinear dynamic system for a class of tracked vehicle suspension vibration control are established and the corresponding system of state space form is described. To prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and using optimal control approach, an approximate optimal vibration controller is designed, and an algorithm is presented for the vibration controller. Numerical simulation results illustrate the effectiveness of the proposed technique.

Response time of magnetorheological dampers to current inputs in a semi-active suspension system: Modeling, control and sensitivity analysis

A new magnetorheological (MR) damper has been recently developed that delivers a very fast response to the input current (or magnetic field). This study investigates the effect of the MR-damper response time on the vibration control of a full-car semi-active suspension system subjected to parameter uncertainties. After briefly reviewing the response-time characteristics of the fast-response MR damper, a full-car suspension model with seven degrees of freedom (DOF) is derived by considering the time constant of the actuator. Subsequently, a robust sliding mode controller is formulated for achieving effective vibration control of the suspension system for three different motions: heave, pitch, and roll. For the synthesis of the controller, the sprung mass is considered the uncertain parameter, and the stability of the overall control system is proved via Lyapunov stability. By evaluating the performance at a random road profile, it is shown that both ride comfort and road holding (steering stability) can be enhanced by utilizing the fast-response MR damper. In addition, to analyze the control results, the nonlinear suspension model is linearized. Using the linearized model, the state outputs from the road input are observed, and the sensitivities of the closed loop feedback system considering response time of MR dampers are analyzed in the Nyquist domain.

An Electromagnetic Variable Stiffness Device for Semiactive Seat Suspension Vibration Control

This article introduces a rotary semiactive variable stiffness (VS) device, including its system design and model validation. A variable damping (VD) device and springs can form mechanical networks with specific topologies, and the VD device can control the equivalent stiffness of the network by varying its damping. The proposed rotary electromagnetic VS device consists of an electromagnetic VD device and a torsion spring, which are in series, while a planetary gear reducer is used to amplify the torque output of the VS device. The models of the electromagnetic VD and VS devices are both built and validated with tests. Then, a seat suspension applies the VS device by installing the device in the center of its scissors structure. Bump and random vibration experiments are implemented to validate the effectiveness of the proposed VS system for seat suspension vibration control. The new system has merits in controllability and energy efficiency. It is easier to design the controller than the conventional one with magnetorheological damper due to the linear damping of the electromagnetic VD device. Besides, the system energy consumption is low and has energy harvesting capability. The proposed semiactive electromagnetic VS device also has potential in other practical applicationss.

An electromagnetic variable inertance device for seat suspension vibration control

Abstract This paper designs and builds an electromagnetic variable inertance (VI) device for a heavy duty vehicle seat suspension to reduce the vibration transferred to driver bodies. The conventional semi-active vibration control mainly applies the variable damping (VD) and variable stiffness (VS) devices. The VI device is equivalent to an inerter with the capability to vary its inertance, which is a new semi-active system inspired by the VS device design. The VI device consists of a transmission device, a VD device and two flywheels. By varying the damping of the VD device, the equivalent inertance of the VI device is controllable in real time. The VI device prototype is built with an electromagnetic VD device which is controlled by the duty cycle of the pulse width modulation signal. The test results verify the proposed system model and identify the unknown model parameters. Then, a seat suspension applies the VI device prototype for improving the ride comfort. Based on the system model, an implementable controller is proposed and experimentally validated. The proposed seat suspension system shows excellent performance in a random vibration experiment. Compared with a conventional passive seat suspension, the frequency-weighted root mean square acceleration of the proposed one reduces 35.7%. The VI device has expanded the application of the inerter and the area of the semi-active research; it shows great potential in vibration control.

Torque response characteristics of a controllable electromagnetic damper for seat suspension vibration control

Abstract In this paper, a novel resistance switching method is proposed to control an electromagnetic damper (EMD) system of a vehicle seat suspension, and torque response characteristics of the EMD system are investigated in detail. First, the relationship between electromagnetic torque and circuit resistance of the EMD system is established. The basic parameters of the EMD system are identified by least squares fitting, and the resistance distribution is optimized to meet the demand damping of seat suspension. Second, the electromagnetic torque response time and the continuously dynamic torque tracking performance of the EMD system are investigated experimentally. The time required for the torque change from its initial to 80% of the final state and the final state is measured, respectively. The results show that the response time required for torque decrease is shorter than the response time required for torque increase; the EMD system has excellent torque response and torque tracking performance and is suitable for seat suspension vibration control. Finally, two typical vehicle body vibration excitations are exerted on the EMD seat suspension. The test results verify that the EMD seat suspension has excellent controllable damping and can significantly isolate the vibration of driver body when applying a sliding mode control method.

A rotary variable admittance device and its application in vehicle seat suspension vibration control

In this paper, a novel semi-active variable admittance (VA) concept is proposed, and a seat suspension prototype with a magnetorheological fluid damper based rotary VA device is designed, manufactured, and experimentally validated. The conventional inerter with a single flywheel has a constant inertance, which can effectively improve the suspension performance by being integrated into a mechanical network with springs and dampers. The proposed rotary VA device comprises a gear reducer, two flywheels and a variable damping (VD) device which is used to connect the two flywheels. With carefully designing, the rotary VA device is compacted and is similar with a VD device in size. The rotary VA device is installed in the centre of a seat suspension's scissors structure to form a VA seat suspension. According to the test results, the equivalent inertance of the seat suspension can vary from 11.3 Kg–76.6 Kg with a 3 Hz frequency and 5 mm amplitude sinusoidal movement by changing the current from 0 A–1 A. By analysing the system characteristics, a hybrid controller with two acceleration feedbacks is proposed. Thereafter, the seat suspension and controller are validated in experiments by comparing the performance with a conventional passive seat suspension. The random vibration test shows the excellent performance of the proposed seat suspension; the frequency weighted root mean square acceleration of the seat is reduced by 43.6%, which indicates a great improvement of the ride comfort. The VA device shows great prospect in the suspension application.

Optimal vibration control for nonlinear systems of tracked vehicle half-car suspensions

Technique of optimal vibration control and simulation for vehicle active suspension systems is developed. Considered the nonlinear damping of springs, mechanical model and nonlinear dynamic system for a class of tracked vehicle half-car suspensions vibration control are established and the corresponding system of state space form is described. In order to prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and used optimal control approach, an optimal vibration controller is designed, and an algorithm is presented for the vibration controller. Numerical simulation results illustrate the effectiveness of the proposed technique.

The PID Semi-Active Vibration Control on Nonlinear Suspension System with Time Delay

To improve the accuracy and precision of suspension system model of vehicle, the nonlinearity and time delay of vibration control of suspension system were considered and discussed, and a quarter car two-degree-of-freedom of vehicle nonlinear suspension system model with time delay was established. A PID semi-active control algorithm, which is easily realized in practical application and performs with strong robustness was designed to control the established suspension system. A comprehensive performance assessment criterion on suspension system was established in considering of the sprung mass acceleration, the dynamic load of tire, the suspension working space and the semi-active control force, and it was used to assess the effectiveness on the improvement of suspension system comprehensive performances with different control algorithms. Genetic algorithm was introduced and studied to optimize the parameters of PID controller. Comparisons were made to analyze the performance of PID semi-active control algorithm under simulation condition and experiment condition. The results show 1) the riding comfort of vehicle is improved dramatically (26.342%) with PID semi-active control, while the handling stability of vehicle is deteriorated by 9.964%, and the comprehensive performance is improved by 27.628%, which indicates that the designed PID semi-active control algorithm is effective and functional in improving the running performance of vehicle; 2) the sprung mass acceleration and dynamic tire deformation of suspension system with the PID parameter obtained based on linear model under experiment condition are worse (−15.191% and −16.099%) than that of passive suspension system, and much worse than that of suspension system with the PID parameter obtained based on the established nonlinear model (20.959% and 2.786%), which means that the established nonlinear suspension system model with time delay are more accuracy than the linear model; 3) the sprung mass acceleration and dynamic tire deformation of suspension system with the PID parameters optimized with genetic algorithm under experiment condition are improved (22.421% and 4.644%) than that of passive suspension system, and a little better than that of suspension system with original PID parameters, which manifests that the genetic algorithm is effective in optimizing the parameters of PID controller.

Optimal Vibration Control for Tracked Vehicle Suspension Systems

Technique of optimal vibration control with exponential decay rate and simulation for vehicle active suspension systems is developed. Mechanical model and dynamic system for a class of tracked vehicle suspension vibration control is established and the corresponding system of state space form is described. In order to prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and using optimal control approach, an optimal vibration controller with exponential decay rate is designed. Numerical simulations are carried out, and the control effects of the ordinary optimal controller and the proposed controller are compared. Numerical simulation results illustrate the effectiveness of the proposed technique.

Semi-active control of a vehicle suspension using magneto-rheological damper

A semi-active magneto-rheological (MR) damper was experimentally investigated and compared to an original equipment manufacturer (OEM) damper for a passenger vehicle, by using a quarter car models. A full-scale two-degree-of-freedom quarter car experimental set-up was constructed to study the vehicle suspension. On-off skyhook controller and Fuzzy-Lyapunov skyhook controller (FLSC) were employed to control the input current for MR damper so as to achieve the desired damping force. Tests were done to evaluate the ability of MR damper for controlling vehicle vibration. Test results show that the semi-active MR vehicle suspension vibration control system is feasible. In comparison with OEM damper, on-off and FLSC controlled MR dampers can effectively reduce the acceleration of vehicle sprung mass by about 15% and 24%, respectively.

Design of Suspension Vibration Control System Based on ON-OFF Algorithm

Aimed to satisfy damping force change requirement of vehicle MRF suspension vibration control system, a controller of MRF suspension system based on On-Off control algorithm is designed, and a control system is carried out. The system takes single chip AT90CAN128 which obey the CAN bus protocols as micro-controller, and it accomplish AD conversion of sensor signal, design of On-Off algorithm and output of PWM voltage power control signal. The system also is used in vibration control experiment of tracklayer vehicle suspension system. The experiment shows that the controller can improve control accuracy, and the control effect is obviously.

Semi-Active Control of a Vehicle Suspension Based on Magneto-Rheological Damper

The focus of this study is to experimentally investigate a semi-active magneto-rheological (MR) damper for a passenger vehicle, by using a quarter car models. After verifying that the damping force of the MR damper can be continuously tuned by the intensity of the magnetic field, a full-scale two-degree of freedom quarter car experimental set up is constructed to study the vehicle suspension. On-off skyhook controller is employed to achieve the desired damping force. The experimental results show that the semi-active vehicle suspension vibration control system based on MR dampers is feasible and can effectively improve ride comfort of vehicle.

Design of a modified linear quadratic regulator for vibration control of suspension systems

Abstract This paper is concerned with the construction of a prototype active vehicle suspension system for a one-wheel car model by using a modified Linear Quadric Regulator (LQR). The experimental system is approximately described by a non-linear system with two degrees of freedom subject to excitation from a road profile. The active control at the suspension location is designed by using feedback constant gain controller structure. The experimental results show that the active suspension system with LQR more improves the control performance than standard PID controller. On the other hand, the results improved that the modified LQR has superior performance for controlling suspension systems in real time.

Design of a Modified linear quadratic regulator for vibration control of suspension systems of military and civiL vehicle

Abstract The army and the people use many types of vehicles for industrial applications and military applications. This paper is proposed a construction of a prototype active vehicle suspension system for a one-wheel car model by using a modified Linear Quadric Regulator (LQR). The experimental system is approximately described by non-linear system with two degrees of freedom subject to excitation from profile different road disturbance profile. The active control at the suspension location is designed by using feedback constant gain controller structure. Furthermore, the experimental results show that the active suspension system with LQR more improves the control performance than standard PID controller. On the other hand, the results improved that the modified LQR has superior performance for controlling suspension systems in real time.

LPV gain-scheduling controller design for a non-linear quarter-vehicle active suspension system

There always exists a conflict between ride comfort and suspension deflection performances during the vibration control of suspension systems. Active suspension control systems, which are designed by linear methods, can only serve as a trade-off between these conflicting performance criteria. Both performance objectives can only be accomplished at the same time by using a nonlinear controller. This paper addresses the non-linear induced L2 control of an active suspension system, which contains non-linear spring and damper elements. The design method is based on the linear parameter varying (LPV) model of the system. The proposed method utilizes the bilinear damping characteristic, stiffening spring characteristic when the suspension deflection approaches the structural limits, mass variations and parameter-dependent weighting filters. Simulation studies both in time and frequency domain demonstrate that the active suspension system controlled by the proposed method always guarantees an agreement between acceleration (comfort) and suspension deflection magnitudes together with a high ride performance.

Active Vibration Control for Suspension by Considering Its Stroke Limitation

Active Vibration Control for Suspension by Considering Its Stroke Limitation

Active Vibration Control for Suspension in Consideration of Limitation on Stroke Displacement

When large external forces come from road, a suspension stroke reaches the limitation and the riding comfort may reduce. In order to overcome this problem we propose a new control method for an active suspension which can avoid reaching the stroke limitation. A sliding mode controller is designed in consideration of rigidity variation of the spring. Also in order to estimate the internal state of the suspension, VSS (Variable Structural System) observer is designed without information of nonlinear force which occurred in rigidity variation when the suspension reaches the stroke limitation. By carrying out simulation and experiment of a quarter-car suspension model it is verified that the performance of the controller is superior to that of the method, which switches to a passive damper near the stroke limitation from LQR (Linear Quadratic Regulator) in the range of small stroke.