Computer simulation of passive and active suspension system using Simulink

Abstract

The objectives of this project are to present a new mathematical model and control technique for modeling and control of active and passive suspension system for a quarter car model. The purpose of a car suspension system is to improve riding quality while maintaining good handling characteristics subject to different road profile. The objective of designing the controller for the car suspension system is to reduce the traditional design as a compromise between ride and handling by directly controlling the suspension force to suit the road and driving conditions. However, from the derived mathematical expression for the systems, it is found that the passive system suffer from mismatched condition problem due to the nature of the road disturbance which is not in phase with the control input. Thus, an active suspension system is proposed that will be able to overcome the mismatched condition problem inherent in the system. Extensive simulations are performed for different road profiles for active and passive suspension system and the results showed that the proposed controller performed well in improving the ride comfort and road handling for the quarter car model using active suspension system. The result also showed that the active system is insensitive to the external disturbance due to the road surface irregularities. Thus, it is also proved that the proposed active controller suspension is capable to overcome the mismatched condition problem that present in the active suspension system.