Study On Control Strategy For Nonlinear Automotive Suspension

With the improvement of living standards，people put forward a higher requirementabout the comfortable of vehicle. Automobile suspension is an important part in affectingthe riding comfort. Automotive controllable suspension system can improve the vehicle’sride comfort and driving safety effectively, which by monitoring the road surface, thecar’s operating conditions and loads, etc, real-time to product the required controlfunction of suspension, by adjusting the suspension characteristics and workingconditions to make the characteristics of the suspension and road conditions of drivingadapt.It is an important trend of studying on control strategy and electric controltechnology for the vehicle suspension technology. The control strategy can ensure thesuspension system of achieve optimal control. In fact, the automobile suspension systemis a nonlinear system. In the past, vehicle suspension control strategy mostly chose linearmodel suspension system as the research object, and the method is single. This paperbased on the comparison of existing control methods, the analysis of the suspensionsystem’s basic performance index and the build of the road input model, mainly in thefollowing two aspects do innovative research work.Study on the vehicle nonlinear automotive suspension’s adaptive tracking controlmethod of chaotic vibration. Firstly, the paper from1/4vehicle suspension single degreeof freedom nonlinear mathematical model car analyzes the dual sinusoidal excitationroad suspension system chaotic vibration phenomena. Then with the purpose ofimproving the ride comfort of vehicle suspension system, based on time-varying systemparameters and random road incentives suspension system model, Implementing activecontrol strategy, proposes a kind of adaptive feedback tracking control methodcharacteristics. Finally, using the Lyapunov stability theory proves asymptotic stabilityof the controller. The simulation results of MATLAB/Simulink software show that whenthe Vehicle traveling at different speeds and grades road excitation case, the controlmethod not only can restrain the chaotic vibration of suspension, but also can reduce thevertical vibration acceleration suspension effectively.Study on the nonlinear automotive suspension’s optimal fuzzy control strategy inparallel. The paper use a1/4nonlinear vehicle suspension model with2-DOF. Firstly,using the linear optimal control theory, based on the suspension vertical vibrationacceleration, suspension dynamic travel and tire building dynamic displacementweighted build a quadratic objective function. Then according to the principle ofminimum objective function and fuzzy control theory to design optimal controllerrespectively and suspension systems two-input single-output fuzzy controller, to carryout a single control strategy. Finally, combining the optimal controller and fuzzycontroller, respectively study with or without control actions coupled link of compound control strategy. The simulation results of MATLAB/SIMULINK software show thatcompared with the single control strategy, the optimal controller and fuzzy controllercomposed of composite control strategy has better control effect. Particular aspects of theintroduction of control action coupling compound control method can further reduce thesuspension’s vertical vibration acceleration and dynamic travel, improving the vehicle’sride comfort and driving safety significantly.The results provide a useful reference method for exploring a better control strategy,improving the vehicle ride comfort and handling stability.