This paper presents modeling and simulation of spring-mass damper system for quarter car in the Simulink environment. The simulations in this research have been carried out by using the Simulink of Matlab. The parameters in the simulation model for the suspension system under study include car body mass, wheel mass, spring and damping elements of shock absorber, and tire. A road disturbance profile comprising a combination of two sinusoidal curves is modeled. Controllers that are used in this study are the proposed fuzzy logic controller. The purpose of this research is to improve vehicle comfort using the Fuzzy Logic Controller (FLC). The simulation results of the system perform well fulfill the minimum percentage requirements and fast stability time, provide good leveling of stability and ride comfort.

Based on the number of previous studies, this study aims to investigate the effects of process parameters of an Electrochemical Machining process which are electrolyte concentration, voltage applied to the machine, feed rate of the electrode and Inter-Electrode Gap between tool and work -piece. Aluminum samples of 25 mm diameter x 25 mm height and 30mm diameter x 25mm height of the tool is made up of copper with a circular cross section with 2 mm internal hole. The design of the system is based on the Taguchi method. Here, the signal-to-noise (S/N) model, the analysis of variance (ANOVA) and regression analyses are applied to determine optimal levels and to investigate the effects of these parameters on surface quality. Finally, the experiments that use the optimal levels of machining parameters are conducted to verify the effects of the process parameters to the surface quality of the products. The results pointed a set of optimal parameters of the ECM process. The Inter-Electrode Gap between tool and work -piece has extremely effected on these Material Removal Rate and surface roughness. The Material Removal Rate increases with diseases in Inter-Electrode Gap, and Ra diseases with diseases in Inter-Electrode Gap. The experimental results show that maximum Material Removal Rate have obtained with electrolyte concentration at 100 g/l, feed rate at 0.0375 mm/min, voltage at 15V, and Inter-Electrode Gap at 0.5mm. The minimum Ra have obtained with electrolyte concentration at 80 g/l, feed rate at 0.0468 mm/min, voltage at 10V, and Inter-Electrode Gap at 0.5mm. This results has led to need studies on these parameters in Electrochemical Machining which are improving productivities and surface roughness of the products. Cite this article : Nhung N T B, Liem D T, Thanh T Q. The effects of the process parameters in electrochemical machining on the surface quality. Sci. Tech. Dev. J. -Engineering and Technology; 2(SI):xxx-xxx. 1 U n c o r r e c t i o n P r o o f Science & Technology Development Journal -Engineering and Technology, 2(SI):xxx-xxx contrast to the mechanical machining, and without 45 strong heating in the machining zones in distinction 46 to the methods like Electrical Discharge Machining 47