Control of MacPherson active suspension system using sliding mode control with composite nonlinear feedback technique

The MacPherson active suspension system is able to support the weight of vehicle and vibration isolation from road profile, and is also able to maintain the traction between tyre and road surface. It also provides both additional stability and maneuverability by performing active roll and pitch control during cornering and braking, and the most significant are ride comfort and road handling performance. However, a drawback of MacPherson model is the self-steer phenomenon in the active suspension system. The problem might be solved by controlling the actuator force and control arm of the system. The MacPherson model has a similar layout to a real vehicle active suspension system. The mathematical model of the system produces a nonlinear mathematical model with uncertainties. Therefore, the proposed control strategy must be able to cater the uncertainties in mathematical model and simultaneously provide a fast response to the system. The control strategy combines Composite Nonlinear Feedback (CNF) algorithm and Proportional Integral Sliding Mode Control (PISMC) algorithm to achieve quick response and to reduce uncertainties. Optimisation of parameters in the CNF was performed using Evolutionary Strategy (ES) algorithm for fast transient performance. Thus, the controller is called Proportional Integral Sliding Mode Control – Evolutionary Strategy – Composite Nonlinear Feedback (PISMC-ES-CNF). To validate the proposed controller, the conventional Sliding Mode Control (SMC) and CNF were utilised to control the system under various road profiles. The ISO 2631-1, 1997 was used as a reference of ride comfort level for the acceleration of sprung mass. Results show that the proposed controller, PISMC-ES-CNF achieved the best control performance under various road profiles. The results obtained also prove that the PISMC-ES-CNF managed to improve ride comfort quality and road handling quality and has also delivered better control performance in terms of transient response of acceleration of sprung mass, reducing overshoot and chattering problem compared to conventional SMC and CNF

A Review of Active Yaw Control System for Vehicle Handling and Stability Enhancement

Yaw stability control systemplays a significant role in vehicle lateral dynamics in order to improve the vehicle handling and stability performances. However, not many researches have been focused on the transient performances improvement of vehicle yaw rate and sideslip tracking control. This paper reviews the vital elements for control system design of an active yaw stability control system; the vehicle dynamic models, control objectives, active chassis control, and control strategies with the focus on identifying suitable criteria for improved transient performances. Each element is discussed and compared in terms of their underlying theory, strengths, weaknesses, and applicability. Based on this, we conclude that the sliding mode control with nonlinear sliding surface based on composite nonlinear feedback is a potential control strategy for improving the transient performances of yaw rate and sideslip tracking control

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 vehicle's lateral and yaw stability. By combining active front steering and active rear steering control, the vehicle's 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

Modeling and design control strategy for unwind/rewind system

This paper presents the mathematical modeling and designing a control strategy for unwind and rewind system. Unwind and rewind system is widely used in industry that involved the web transportation such as textile, plastic, paper and metal. Basically, the unwind and rewind system consists of three motors which are to control the Unwind, Traction and Rewind. Currently, the system used Programmable Logic Controller (PLC) to control the whole system operation. Strain gauge is used for the system feedback. This project was replaced the PLC to computer controlled method. A new control algorithm that based on the regulator feedback was proposed. The tension observer is introduced as a regulator feedback and dynamic simulation requirement.The mathematical modeling of the system is established base on the tension control, speed control and other elements related to the system. In the control strategy, PID (Propotional Integral and Differential) controller is used to the tension controller and speed controller for simulation and experiment. The xPC-target box is used as a prototype controller to the unwind and rewind tension and speed synchronization. The validation process of the results was performed for both simulation and experimental to see the performance of the system

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 vehicle’s lateral and yaw stability. By combining active front steering and active rear steering control, the vehicle’s 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

Modeling and control of a nonlinear active suspension using multi-body dynamics system software

This paper describes the mathematical modeling and control of a nonlinear active suspension system for ride comfort and road handling performance by using multi-body dynamics software so-called CarSim. For ride quality and road handling tests the integration between MATLAB/Simulink and multi-body dynamics system software is proposed. The control algorithm called the Conventional Composite Nonlinear Feedback (CCNF) control was introduced to achieve the best transient response that can reduce to overshoot on the sprung mass and angular of control arm of MacPherson active suspension system. The numerical experimental results show the control performance of CCNF comparing with Linear Quadratic Regulator (LQR) and passive syste

Enhancement of robust control law for active front steering control strategy

In vehicle lateral dynamic studies, the transient performances of yaw stability control system are essential. Due to uncertainty of cornering stiffness when the road surface is changing, this perturbation may influence the transient performances and affected the handling quality of the vehicle. By designing a yaw rate tracking controller for active front steering control strategy with the enhanced control law using the sliding mode control algorithm, the transient performances are improved. The vehicle lateral dynamic behaviours are described using the linear and nonlinear vehicle models for controller design, simulations and evaluations. To achieve the control objective, the enhanced robust control law is proposed to cater the uncertainty of front wheels cornering stiffness. The proposed control strategy is evaluated using the step steer manoeuvre test for three road surface conditions. The simulation results obtained showed that the transient performances of yaw rate with the enhanced robust control law are better compared to the conventional control law and uncontrolled vehicle especially for wet and snow/icy road surfaces. An enhancement of robust control law that solved the cornering stiffness uncertainty is expected as a knowledge contribution to vehicle lateral dynamic studies

Composite Nonlinear Feedback For Vehicle Active Front Steering

In this paper, Composite Nonlinear Feedback (CNF) is applied on Active Front Steering (AFS) system for vehicle yaw stability control in order to have an excellent transient response performance. The control method, which has linear and nonlinear parts that work concurrently capable to track reference signal very fast with minimum overshoot, fast settling time, and without exceed nature of actuator saturation limit. Beside, modelling of 7 degree of freedom for typical passenger car with magic formula to represent tyre nonlinearity behaviour is also presented to simulate controlled vehicle as close as possible with a real situation. An extensive computer simulation is performed with considering a various profile of cornering manoeuvres with external disturbance to evaluate its performance in different scenarios. The performance of the proposed controller is compared to conventional Proportional Integration and Derivative (PID) for effectiveness analysis

A control performance of linear model and the Macpherson Model for active suspension system using composite nonlinear feedback

The purposes or functions of the commercial car suspension system are to take care on the car body weight, to isolate the car body from road profiles disturbance and to maintain the grip force between the wheel and road profiles. The Composite Nonlinear Feedback (CNF) control law is proposed in this comparative study between conventional linear model and Macpherson model. The control performance consists of velocity of car body, suspension deflection, wheel deflection and velocity of a car wheel. The main measurement in this study is the acceleration of the car body. The Linear Quadratic Regulator (LQR) and passive model are involved in this control performance is for comparison purposes. The mathematical model of linear model and MacPherson model are focused on the quarter car model active suspension system. The simulation work is done by using MATLAB and SIMULINK to see the control performance on the quarter car active suspension model. In this paper we can conclude that the CNF achieved the main objective of active suspension which is the ride comfort and road handling