A Study of Vehicle Ride Performance Using a Quarter Car Model and Half Car Model

Abstract

This paper studies the responses of a quarter car and a half car model. The vehicle ride performance was assessed at the design stage by simulating the vehicle response to road excitation. This required the development of a vehicle model to analyze its responses. The disturbances from the road were assumed to be constant or step function and the time responses and frequency responses of the sprung and unsprung masses have been studied. Simple yet, in practice, meaningful state-space formulations of the optimal suspension control problem for a half-car 2-D and 4-D vehicle model are given. Using an efficient equivalent representation, a complete analytical solution of the system was obtained. The optimal solution here was the damping, which has been optimised with the given set of fixed parameters. This paper provides insight on the suspension dynamics of the two most extensively used models in vehicle dynamics with their complete state space realization, simulated using the MATLAB platform.