Abstract:

A vehicles active suspension system by using the phase plane division control and LQG control strategies was proposed. A halfcar fourdegreeoffreedom active suspension mathematical model was built and simulated in the environment of Matlab/Simulink. The simulation results were analyzed by the timedomain and frequencydomain methods. The performance indices, including the body acceleration，the body pitch angle，the suspension working space and the tire dynamic deflection, were compared among  the integrated control active suspension, the LQG active suspension and the conventional passive suspension. The simulation results indicat that the vehicle body pitch angle is reduced evidently and the ride comfort is ameliorated by using the integrated control, which has a small influence on the LQG control effect.

Key words: vehicle engineering, active suspension, integrated control, liner quadratic gauss(LQG) control, phase plane division control, halfcar model