Application of Model Reference Adaptive Control to Active Suspension Systems

Application of Model Reference Adaptive Control (MRAC) to vehicle active suspension subsystem is investigated. The MRAC objective is to automatically self-tune the controller of the active suspension such that disturbance and vibration of a vehicle is reduced to a level which is determined by an "ideal" conceptual suspension system (a reference model). An MRAC vehicle suspension can thus accommodate for variances in sprung load and suspension component characteristics. An MRAC was designed using Lyapunov stability approach and was tested using different scenarios such as ±10% to ±30% variances of suspension components and sprung load. It is shown that the MRAC suspension closely followed the performance of the prespecified reference model and achieve significant improvements over passive suspension. Real-Time Simulation and Animation (RTSA) software was developed to provide an excellent visual aid for understanding and interpreting the better ride performance achieved by the MRAC suspension.