Virtual Reality Simulation of Active Car Suspension System

Abstract

This paper presents the design of a Nonlinear Energy Sink (NES) controller and its application to active sus-pension systems in the Virtual Reality Environment. In this en-vironment, the design engineers are immersed in an audio-visually coupled tele-operated environment whereby direct in-teraction with and control of the design process is achieved in real time. In this manner, the behavior of synthetic models of the full car can be monitored by literally walking around the car and adjusting the design parameters of the suspension as needed to ensure optimal performance while satisfying design and operational requirements. The control actuators which provide forces equivalent to nonlinear stiffness and damping elements are attached to the vehicle in order to actively isolate it from road excitation. The effect of the parameters of the NES controller on the vehicle performance is studied both in the frequency and time domain. The effectiveness of the NES controller is validated by numeri-cal simulation. The robustness of the nonlinear energy pumping process is studied by varying the magnitude of road excitation. The simulation results in the Virtual Reality Environment show that under certain conditions, the nonlinear energy pumping can be induced and significant vibration isolation can be achieved. The performance of vehicle including the ride com-fort and road holding capability can be improved significantly. When the magnitude of road excitation is increased, the capaci-ty of the NES to absorb energy from the main system is also enhanced. This is very important to achieve vibration isolation objectives. The virtual reality simulation results also show that the nonlinear NES controller performs better than the classical LQR controller particularly as the road condition becomes worst.