An adaptive control approach for an active suspension to deal with a nonlinear time varying (NTV) vehicle-plant is discussed. A robust stable adaptive controller with time varying parameters is designed for control of an active suspension for a vehicle-plant to obtainnear optimal performance and maintain static equilibrium during parametric variations. Adaptive control of an active suspension for a NTV single input single output (SISO) vehicle-plant is considered. Adaptive controller based on error augmentation approach of model reference adaptive control (MRAC) with a velocity error term is derived to obtain the optimal performance without a priori knowledge of variations in vehicle-plant parameters. The controller is designed for the first time to maintain static equilibrium irrespective of dynamicload shifts that occur during acceleration and deceleration manoeuvres. Optimal performance between good vibration isolation and stability or curving that can be achieved by this method is illustrated bysimulation results. Results for drastic online and nominal parameter variations for deterministic and stochastic input are discussed. Ablock diagram illustrating the adaptive controller for practical implementation is also discussed. (A).
Abstract