Yahaya Md. Sam

A class of proportional-integral sliding mode control with application to active suspension system

The purpose of this paper is to present a new robust strategy in controlling the active suspension system. The strategy utilized the proportional-integral sliding mode control scheme. A quarter-car model is used in the study and the performance of the controller is compared to the linear quadratic regulator and with the existing passive suspension system. A simulation study is performed to prove the effectiveness and robustness of the control approach.

LQR controller for active car suspension

The suspension system is classified as a passive, semi-active, and active suspension, according to its ability to add or extract energy. An automotive active suspension control has been one of the favourite subjects in the automotive research area. The advantages of an automotive active suspension system have been promised for many years. The objectives of the control scheme are to improve the ride quality and handling performance within a given suspension stroke limitation. The ride quality is measured by the vertical acceleration of the vehicle body called the sprung mass. The handling performance is determined by the tyre deflection, which is the difference of position between the wheel and the road surface input. The paper analyses the aspects of passive and active suspensions and focuses on the ride quality improvement. The LQR control scheme is selected to control an actuator in an active suspension. The result shows that the ride quality can be improved using an active suspension.

Modeling and controller design of an industrial hydraulic actuator system in the presence of friction and internal leakage

This paper presents a robust controller scheme and its capabilities to control the position tracking performance of an electro-hydraulic actuator system. Sliding mode control with fixed and varying boundary layer is proposed in the scheme. It is aimed to compensate nonlinearities and uncertainties caused by the presence of friction and internal leakage. Its capabilities are verified through simulations in Matlab Simulink environment. The friction was represented by the LuGre model and the internal leakage was assumed to change. The results indicate that the scheme successfully improves the robustness and the tracking accuracy of the system. This improvement offers a significant contribution in the control of modern equipment positioning applications.

Modeling and control active suspension system for a full car model

The purpose of this paper is to investigate the performance of a full car model active suspension system using LQR controller. Dynamic model used in this study is a linear model. A linear model can capture basic performances of vehicle suspension such as body displacement, body acceleration, wheel displacement, wheel deflection, suspension travels, pitch and yawn. Performance of suspension system is determined by the ride comfort and vehicle handling. It can be measured by car body displacement and wheel displacement performance. Two types of road profiles are used as input for the system. Simulation is based on the mathematical model by using MATLAB/SIMULINK software. Results show that the performance of body displacement and wheel displacement can be improved by using Linear Quadratic Regulator control (LQR).

Active suspension control: performance comparison using proportional integral sliding mode and linear quadratic regulator methods

The purpose of this paper is to compare the performance of the active suspension system using two different control strategies. The first strategy utilized the proportional integral sliding mode control scheme and the second one using the linear quadratic regulator method. A quarter-car model is used in the study and the performance of the controller is compared to the linear quadratic regulator and with the existing passive suspension system. A simulation study is performed to prove the effectiveness and robustness of the control approach.

On-line identification of an electro-hydraulic system using recursive least square

This paper presents experimental on-line identification of an electro-hydraulic system represented by a discrete time model. A recursive least square (RLS) method is used to estimate the unknown parameters of the system based on auto regression with exogenous input (ARX) model. Residual analysis is used for model validation. Results are presented which show variations in parameters of the electro-hydraulic system.

Open-loop and closed-loop recursive identification of an electro-hydraulic actuator system

This paper presents experimental work on recursive identification of an electro-hydraulic system that represented by a discrete-time model in open-loop and closed-loop configurations. A recursive least square (RLS) method is used to estimate the unknown parameters of the system based on auto regression with exogenous input (ARX) model. Residual analysis is utilized for a model validation. Results are presented which show variations in parameters of the electro-hydraulic system. From the results obtained, position tracking for electro-hydraulic system can be implemented by using conventional proportional-integral-derivative (PID) controller with the aim of the modeling validation.

Yaw stability improvement for four-wheel active steering vehicle using sliding mode control

Active steering control is one of the approach that can be used to improve the vehicles lateral and yaw stability. By combining active front steering and active rear steering control, the vehicles handling and stability can be improved via four wheel active steering (4WAS) control. In this paper, a robust control algorithm of sliding mode control is designed for 4WAS vehicle. Single track 2 d.o.f linear model is utilized for controller design and simulation purpose. Simulation for 4WAS and front steering (AFS) is carried out in Simulink for step steer and double lane change maneuver to verify the effectiveness of the proposed control system. The result shows that the 4WAS perform better than the AFS in tracking the desired response trajectory.

Position tracking control of an electro-hydraulic servo system using sliding mode control

This paper evaluates the position tracking performance of an electro-hydraulic hydraulic servo (EHS) system using sliding mode control (SMC). The EHS system is established in modelling process by consider its nonlinearities with a friction model. The control strategy is derived from developed dynamics equation and stability of the control system is theoretically proven by Lyapunov theorem. Simulation results demonstrate the proposed controller is highly robust and capable to cope with the uncertainties and disturbances occur during the position tracking control. It is also shows that the proposed controller can achieve better tracking performance compared with conventional PID controller.

A Yaw Rate Tracking Control of Active Front Steering System Using Composite Nonlinear Feedback

In this paper, the composite nonlinear feedback (CNF) technique is applied for yaw tracking control of active front steering system with the objectives to improve the transient performance of yaw rate response. For lateral and yaw dynamics analysis, nonlinear and linear vehicle models are utilized as actual vehicle plant and for controller design respectively. The designed controller is evaluated using J-turn cornering manoeuvre condition in computer simulation. The simulation results demonstrate that the application of CNF for yaw rate tracking control improves the yaw stability and vehicle handling performances.