Design and Simulation of Adaptive Fuzzy Controller for Active Suspension System

An adaptive fuzzy controller which fuzzy control rule table can be obtained with the numerical calculation is designed in order to improve vehicle comfort and road holding capability. There is no membership function choice of fuzzy subset for input and output of controller. The rectification factor is adjusted online according to adaptive method. The factor can be influenced by exciting signal and controlled signal, so the adaptive fuzzy controller has adaptive ability. For two degree-of-freedom (DOF) vehicle model, the simulation of vehicle performance in road signal is studied, its results show the acceleration of sprung mass can be declined effectively in resonance frequency band, even more obviously in the lower frequency, and its power spectral density (PSD) is reduced to 5%. The dynamic tyre load of wheels, is declined 20% in the resonance band of high frequency. It proves that the dynamic tyre load can meet the request for handling safety under random road excitation.