Development of an automotive suspension system using active force control

Abstract

This research was carried out to investigate the response characteristics of a two-degrees-of-freedom (DOF) vehicle suspension system with the proposed active force control (AFC) as the main control element. The characteristics are related to the riding comfort and handling of the vehicle. Both simulation and experimental studies were accomplished in the research work for this purpose. In the simulation study, two active suspension control methods were examined and compared involving the classic proportional-integral-derivative (PID) to be used together with the continuous skyhook and AFC with embedded iterative learning method (ILM) and fuzzy logic (FL) control schemes. The potentials of the AFC schemes as robust systems are particularly highlighted. Appropriate road disturbance and other loading conditions are modelled and applied to the proposed systems to test for the system robustness. The results of the simulation study show that active suspension system using AFC with FL control show its superiority in terms of body mass displacement and acceleration, dynamics tyre load, suspension working space, hydraulic actuator force and the track error. In the experimental study, a prototype of the suspension rig was fully developed and tested. The laboratory scale physical rig was developed using the MATLAB/SIMULINK with Real Time Workshop (RTW) tool that is interfaced with a suitable data acquisition card via a personal computer (PC) as the main controller. Experimental results obtained in the study further verified the potential and superiority of the proposed AFC scheme as a robust active suspension control compared to the other schemes considered in the study.