The purpose of this project is to design and simulate a semi-active suspension system for a quarter car model by controlling two input, spring stiffness, ks, and damper rate, bs. The performance of this system will be compared with the passive suspension system. There are two parameters to be observed in this study namely, the sprung mass acceleration and the suspension distortion.
The performance of this system will be determined by performing computer simulations using the MATLAB and SIMULINK toolbox. For the first experiment, the damper rate was set to constant while spring stiffness was set from 10507 N/m to 131345 N/m. at lower spring stiffness leads improvement in ride quality but increased the suspension distortion at lower time. At second experiment, the spring stiffness was set to constant while the damper rate was from 1000 N.sec/m to 1400 N.sec/m. Increases in damper rate improve the ride quality but slower roll-off will occurred.
In the third experiment, the damper rate value was set to maximum while spring stiffness was set to minimum to achieve optimal performance. The simulation results show that the semi-active system could provide significant improvements in the ride quality and road handling compare with the passive system.
Source: Universiti Malaysia Pahang
Author: Mohd Asqalani Bin Naharudin