An Experimental Investigation into the Design of Vehicle Fuzzy Active Suspension

A vehicle active suspension was put forward based on the electro-hydrostatic actuator which is a kind of power-by-wire actuation system. The system includes a variable speed and direction brushless direct current motor, a fixed displacement pump, hydraulic cylinder and controller. In this paper, a quarter-car dynamic model was exactly established involving mathematical models of EHA parts. Under the input conditions of the given road profile and designed fuzzy controller, active suspension was computationally simulated by MATLAB tools. To truly validate suspension, physical prototype and experimental rig for active suspension were designed and built. A mechanical cam vibration exciter was developed to generate sinusoidal road signals. As a result, the experimental tests of the fuzzy active suspension system using a quarter-car model have been completed. The computer simulation results show sprung mass acceleration for fuzzy active suspension descends by 35.5% by contrast with passive suspension. Experimental test data indicate that sprung mass acceleration for fuzzy active suspension drops by 27.38% and suspension deflection for fuzzy active suspension drops by 26.76% by contrast with passive suspension. The fuzzy control active suspension provides better ride comfort, handling and stability than passive suspension system.