Study On The Stability And Ride Comfort Of A Semi - Active Air Suspension

The semi-active air suspension system improves the handling or riding performance through adjusting the damper or the stiffness of the suspension system. Semi-active suspension system could achieve the purpose of improving riding or handling performance and be easier to be implemented so that it’s becoming an important researching direction. This paper studied on a certain light bus of which the rear suspension is a kind of air suspension system. The rear air suspension system was established. Based on the fuzzy PID control method, the simulation of body height adjustment, the ride and handling performance of the passive and semi-active vehicle were implemented through the combination of ADAMS and Matlab.The model of the air suspension system was established through ADAMS and Matlab. The frequency characteristics of the suspension was demonstrated to be close to the real suspension system. The height of the vehicle center affects the ride and handling performance of the vehicle so that this paper made the strategy of body height control based on fuzzy PID control method and compared the control results obtained by utilizing different methods.The simplified vehicle model and virtual test bench were established in ADAMS-View and combined with air spring model to make up the whole co-simulation model in Matlab/Simulink. The integral white noise road excitation was the input of the whole system, the stiffness control strategy was made based on the fuzzy PID control theory under the purpose of decreasing the vertical body acceleration on the condition of driving along a line at a constant speed. The simulation results shows that the vehicle under control has a better riding performance and at the same time the handing performance does not become bad. During the analysis of the handling performance, through the combination of ADAMS-Car and Matlab, the body roll angle control was applied to make the vehicle have a smaller roll angle during the corner driving condition.To sum up, this paper established the vehicle models and designed the relative control strategy based on co-simulation of ADAMS and Matlab. The simulation shows that, compared to passive suspension, the semi-active suspension based on the fuzzy PID control method could relatively improve the vehicle riding and handling performance according to different driving conditions.