Based On Active Suspension Control Of Vehicle Riding Comfort

The use of suspension systems in vehicles is to provide rider comfort,suspension deflection,safety,ensure contact with the road terrain and of course to carry the weight of the chassis and the riders.conventional passive suspension systems normally used in vehicles consist of a spring and damper system with fixed dynamic characteristics, it can only store or dissipate energy.however,active suspension can continuously change the vibration enengy of the vehicle body induced by the road excitation.so the latter have a great potential to improve both ride comfort and handling performance.The key problem in the implementation of the active suspension systems has been the design of an appropriate implementable controller algorithm,so several algorithms have been presented in this paper to improve the performance of active vehicle suspension designs,such as PID control,Optimal control,Model reference adaptive control,Sliding control.PID control have the advantage of little work of accounting,good control effect,strong robustness.Optimal control minimize a defined performance index and different performance can be get by the choice of weighting matrices for the vector regulated responses and control forces.Model reference adaptive control automatically self tunes the active suspension such that disturbance and vibration of a vehicle is reduced to a level determined by an "ideal" conceptual suspension reference model.Sliding mode control is effective to achieve high-performance robust control against external disturbances and unpredictable.Finally a new control strategy,Optimal sliding control,which is based on the four algorithms is applied.This strategy combines the advantages of Optimal control and Model reference adaptive control and improves the suspension performance more.As a complex system,it is difficult to establish the accurate suspension model.so we choose model of two degrees of freedom as the research object because of the focus of this study is the vertical movement of suspension.this model not only easy to establish but also present the nature of the problem.then the road roughness model is introduced and the active suspension controllers based on various controller algorithms are designed and verified in SIMULINK,a comparative work between the proposed controller and passive suspension is also undertaken.Simulation indicates that the four proposed different forms of active suspension can remarkably deduce the body accerration of the vehicle than passive suspension and the suspension deflection,dynamic deflection of tyre is also under control.The optimal sliding control has the advantage of both optimal control and model reference adaptive control and is more robust than the PID control.It also offers a new idea to the development of the vehicle suspension.