Muhamad Khairi Aripin

A review of active yaw control system for vehicle handling and stability enhancement

Yaw stability control system plays 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.

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.

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.

Quality inspection of engraved image using shape-based matching approach

The role of machine vision system as a vital component for quality control mainly in manufacturing process cannot be denied. The system is developed to overcome the discrepancy from human vision and illumination changes. This paper proposes shape-based vision algorithm, a hierarchical template-matching approach that implemented in flexible manufacturing system to verify the quality of engraved image. Color and gray scale charged couple device (CCD) cameras are used to acquire engraved image for different kind of environment. The engraved image is preprocessed using image processing technique. Region of interest (ROI) is then selected and digitized into gray level to extract the contour of the object using segmentation technique. The extracted contour is used as template for object recognition during matching process. Several objects are engraved on the acrylic souvenir bases with different color background to test the algorithm. This experiment result shows that the algorithm works better with detection rate of 100% and matching accuracy of more than 98%. The approach can be applied in packaging, pharmacy, education, medical or any other areas which apply shape in their application.

The Effect of Matrix C in Sliding Mode Control with Composite Nonlinear Feedback Control Strategy in MacPherson Active Suspension System

The C matrix in Sliding Mode Control (SMC) is significant to the control performance in MacPherson active suspension system. The SMC was combined with Composite Nonlinear Feedback (CNF) controller due to its characteristics on the transient response and fast settling time. The Neural Network is used to determine the matrix of C based on the road profiles used in this research work. The Proportional Integral (PI) was combined with SMC to overcome the uncertainties, unmatched condition and steady state error occurred in the MacPherson active suspension system. The three road profiles have been applied to this research work. The multi-body dynamics system software called CarSim is used for validation. The numerical experiment results are shown the effect of the C matrix in SMC with CNF controller performance in acceleration of sprung mass.

A reduce chattering problem using composite nonlinear feedback and proportional integral sliding mode control

This paper present the Composite Nonlinear Feedback Control and Proportional Integral Sliding Mode Control (CNF-PISMC). The advantages of Composite Nonlinear Feedback Control are reducing overshoot; improve transient performance and fast response. The advantages of PISMC are to overcome uncertainties and steady state error in the system. The used of a boundary layer solution in the control law of CNF-PISMC is to reduce the chattering problem. The result of the boundary layer thickness is representing the ability of the CNF-PISMC controller in MacPherson strut active suspension system. The value of boundary thickness is tuned by using Evolutionary Strategy (ES) to provide the two values of boundary layer thickness. The multi-body dynamics system software so called CarSim is used for validation purposes.