Papers by Author: Asan G.A. Muthalif

Abstract: Proportional Integral Derivative and clipped-optimal control strategy controllers are studied to control the response of Quarter-car suspension profile. A Semi-active device is used for this purpose because it carries valuable result which maintains the reliability of passive control methods and includes the advantage of the adjustable parameter characteristics of active systems. Semi-active devices like Magnetorheological fluids dampers are very effective to control vibration, which use MR fluids to produce controllable damping force and provide both the reliability of passive systems and the facility of active control systems with small power supply. The quarter car model is used here can be described as a nonlinear two degrees of freedom system which is subject to excitation from different road profile. For the best possible reduction of vibration in suspension systems, various Magnetorheological damper models are studied which Bouc-wen model, Neuro-fuzzy model and Bingham model. The performances of these models are evaluated to select a best model. The quarter-car model is executed using step input with two most common and effective control algorithm in vehicle suspension control which are linear quadratic regulator control, and Proportional Integral Derivative control algorithm. The main objective of this study is to evaluate performances of these control algorithms.

Abstract: In Free Space Optic (FSO) communication, the alignment between transmitter and receiver telescope is very important. The line of sight of their optics must be aligned during the entire communication time; this is crutial in large distance data transmission. One of the factors that causes misalignment is vibration, either at the transmitter or the receiver. In this work, active vibration isolation (AVI) system is designed and developed to tackle this issue. An AVI system isolates FSO devices from direct disturbances or ground vibrations. The LQR controller is proposed and implimented with LabVIEW. A mathematical model of the isolator is derived and the prototype model of the AVI system is designed in SolidWorks. This prototype model is integrated with LabVIEW software to perform virtual prototyping.

Abstract: This paper presents a guide to identify optimal damper location to reduce vibration on built-up structures. The guide is derived from simulation studies carried out on a set of benchmark models. Optimization is carried out using genetic algorithm. Optimal location is found using found using Generic algorithm and the hybrid method. The hybrid modelling method combines the finite element method (FEM) and Statistical energy analysis (SEA) to provide an efficient response predication for mid-high frequencies. The guide to find optimal damper location is tested on a fuselage model of Boeing 737. The fuselage model is developed using VA One software. Good agreement is seen for the optimal locations using the simple guide and result from VA One.