Control design for road-friendly suspension systems using an optimal weighting of LQ theorem

The paper comprises the control design of a road-friendly suspension system and the optimal choice of linear quadratic (LQ) weighting. By designing the influence of the dynamic loads of wheels it is possible to reduce the loads and stresses of roads and increase their lifespan. In the vehicle model the dynamics of the sprung and unsprung masses with their suspension system is considered. For road-friendly control design it is necessary to guarantee the reduction of the dynamic load of wheels. Besides, it is also important to guarantee passenger comfort and road stability of the vehicle. Considering these performances an active suspension system based on the LQ control theory is designed. Taking into consideration the effects of the variations in the weighting values of quality performances the properties of controlled system are analyzed in terms of road-friendliness and traveling comfort. The used LQ theorem and optimal weighting method are practicable for both active and semi-active suspension systems