Papers by Author: Saiful Amri Mazlan

Abstract: Magnetorheological (MR) valve is one of the basic ways to apply and accommodate the MR fluid (MRF) into most of hydraulic applications. MRF can change its rheological properties controllably, reversibly and instantaneously by exposing it to the magnetic field, where the viscosity of the fluid increased variably proportionate to the intensity of the magnetic field applied to the fluid. Within the MR valve, the region where the MRF is allowed to be flown and exposed to the magnetic field is called the effective region, and the longer the effective region is in the MR valve, the higher the pressure drop can be, which means that the valve can withstand higher pressure from input and output of the valve. Hence, lots of studies and previous researches have been focused on improving the performance of MR valve by elongating the effective region in the valve. This paper presents one of the ways to increase the effective region in the MR valve by using the serpentine flux path method. This method is a way to weave the magnetic flux into the effective region of MR valve by alternating the magnetic and non-magnetic materials to guide the magnetic flux to be exposed into the effective region. In this paper, the method is simulated by using Finite Element Method Magnetics (FEMM) software for analyzing the magnetic flux path and flux density in the valve, to see the various effects of length and gap size of effective region, electromagnetic circuits and geometrical placements of magnetic and non-magnetic materials in the valve before it can be applied into real hardware for experimentation.

Abstract: Simulation studies on a new concept of modular Magnetorheological (MR) valve using annular-radial gap combination are discussed in this paper. This study predicts and compares the performance of MR valve module with three different commercial kind MR fluids namely the MRF-122EG, MRF-132DG, and MRF140CG. Magnetorheological effect in various types of MR fluid is analyzed using finite element method (FEM) software in term of simulation magnetic field density within the valve module. The approximated functions of permeability and field dependent yield stress for each kind of MR fluid are derived and presented in this paper as a prerequisite for simulation works. The result has shown that the highest pressure drop rating is reached by applying an MR fluid type MRF140CG, for another kind has shown smallest of pressure drop rating because of the ability to produce the achievable pressure drop highly depends on MR fluid properties.

Abstract: This paper focuses on the preliminary characterization of alternative magnetic particles as a replacement for commercial carbonyl iron particles for magnetorheological elastomers (MREs). Magnetite powder (Fe₃O₄) can be found in electronic waste (E-waste), iron ore as well as toner waste. In this study, three types of powders namely electronic waste based ferrite powder, iron sand, and toner waste are characterized according to their size and morphology (SEM), chemical elements (EDAX), chemical compound (XRD) and magnetic properties (VSM). The results are used as considerations to choose the most suitable powders that could replace carbonyl iron. The average size of all powders types is about 1 to 50 microns and having irregular shapes. The highest content of magnetite (Fe₃O₄) compound is found in electronic waste based ferrite powders by referring to magnetite patterns (reference code: JCPDS 01-088-0315). Electronic waste based ferrite powder has the highest magnetic moments saturation of 92.9 emu/g compared the counterparts. Finally, electronic waste based ferrite powder appears to be the most potential materials for replacing the carbonyl iron.

Abstract: This paper presents performance comparison of Magnetorheological (MR) damper with two different coil arrangements. Two coils at different location have been introduced that could enhance the activation areas in the MR damper. The experimental tests were conducted in three different conditions of coil; internal coils, external coils and the combination of coils. For each trial, the effect of the applied current and the condition of coils were analyzed and investigated. The results showed that the internal coil could produce higher damping force than the external coil, and the combination of internal and external coils could increase the damping force up to 125 N for the same experimental parameters.

Abstract: Magnetorheological elastomer (MRE) is a controllable smart material that demonstrates changes in rheological properties depending on the magnetic field strength. This paper presents thedevelopment of a new concept of MRE isolator in terms of design and magnetic simulation. All features of geometry parameters were considered and altered expeditiously in order to provide ample and uniform magnetic field. Finite Element Method Magnetics (FEMM) was used to design the electromagnetic circuit to generate magnetic fluxes penetrate through the MRE. The study, eventually, leads to the conclusion of different design parameters approach; selection of materials, diameter of the shaft, shape of MRE, length of shaft and thickness of housing.

Abstract: This paper focuses on designing a controller to enhance the traction and handling of an Independent-Wheel-Drive Electric Vehicle (IWD-EV). It presents a traction torque distribution controller for an IWD-EV in order to maintain vehicle handling and stability during critical maneuvers. The proposed controller is based on the Direct Yaw-moment Control (DYC) and Active Front Steering control (AFS) which intended to increase the handling and stability of the vehicle respectively by applying the yaw rate and the lateral acceleration as the control variables. The performance of the controller is evaluated by numerical simulations of two standard high speed maneuvers which are the double lane change (DLC) and J-Curve. The proposed scheme presents a new controller design for IWD-EV which can effectively improved the vehicle handling and stability.

Abstract: Trajectory tracking for autonomous vehicle is one of the field that researchers pay attention. The ultimate goal for trajectory tracking is to track the pre-defined path and follow the reference path with zero steady state error. The common modules for trajectory tracking field are reference generator, controller and plant. While most of the researchers are focusing on the controller development, less work has focused on the optimized reference generator. Optimized reference generator ensures the reference input to the controller is the optimized desired points in order to develop a good controller. Therefore, this work presents the reference generator algorithm that select the best point from the road coordinate profile before being send to the controller. The method is using the vehicle potential field and the modification from Dijkstra’s algorithm to generate the path. This algorithm is useful for trajectory tracking controller development. The algorithm is verified using simulation and experiment.

Abstract: Semi-active suspension system is a promising device to improve performance of the suspension system by using optimal controller for magnetorheological damper. The importance of magnetorheological damper is the capability to control the semi-active suspension system by adjusting the input current exerted to the coil of wire to produce magnetic field. In this paper, a fuzzy-PID controller has been applied in a quarter car semi-active suspension system to examine the performance of the system. The whole suspension system is modelled in Simulink environment/MATLAB software in which a neuro-fuzzy model of magnetorheological damper is utilized as a mathematical model of the damper. A disturbance profile is utilized to evaluate performance of the system. Simulation results show that the proposed semi-active suspension system has successfully absorbed disturbances much better than PID controller. In addition, the accuracy of the magnetorheological damper model influences the performance of the semi-active suspension system.

Abstract: Magnetorheological damper is a controllable device in semi-active suspension system to absorb unwanted movement. The accuracy of magnetorheological damper model will affect performance of the control system. In this paper, a combination of genetic algorithm (GA) and adaptive-network-based fuzzy inference system (ANFIS) approaches is utilized to model the magnetorheological damper using experimental results. GA algorithm is implemented to modify the weights of the trained ANFIS model. The proposed method is compared with ANFIS and artificial neural network (ANN) methods to evaluate the prediction performance. The result illustrates that the proposed GA-weighted adaptive neuro-fuzzy model has successfully predicted the magnetorheological damper behaviour and outperformed other compared methods.

Abstract: The objective of this paper is to design a linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) controllers for an active anti-roll bar system. The use of an active anti-roll bar will be analysed from two different perspectives in vehicle ride comfort and handling performances. This paper proposed the basic vehicle dynamic modelling with four degree of freedom (DOF) on half car model and are described that show, why and how it is possible to control the handling and ride comfort of the car, with the external forces also control strategies on the front anti-roll bar. By simulation analysis, the design model is validity and the performance under control of linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) controller are achieved. Both two controllers are modeled in MATLAB/SIMULINK environment. It has to be determined which control strategy delivers better performance with respect to roll angle and the roll rate of half vehicle body. The result shows, however, that LQG produced better response compared to a LQR strategy.