Nonlinear Adaptive Control of Active Vehicle Suspensions

We describe the design of nonlinear active control systems for an off-road vehicle based on the Army HMMWV. We use recent results in nonlinear control theory to design adaptive nonlinear control laws for vehicle suspensions. Using adaptive, asymptotic tracking control laws, we show that it is possible to isolate the sprung body dynamics (center of mass velocity and pitch rate) from the road disturbances and indeed control them independently under some circumstances. This permits substrantial in vehicle performance in several areas including increased travel speed and platform stability, and decreased passenger absorbed power, among others. An integrated symbolic-numerical software system was used to derive the vehicle models, design the nonlinear, adaptive control laws, and generate simulations for performance evaluations.