Adaptive tracking control of a class of non-affine plants using dynamic feedback

In this paper we propose a systematic procedure for adaptive tracking control design for a class of nonlinear plants that are nonaffine in the control input. The procedure is based on differentiating the original state equation so that, in the augmented resulting model, the derivative of the control input appears linearly and is used as the new control variable. The resulting control strategy is referred to as the dynamic feedback control. While this idea is not new, in this paper we extend it to the case of unknown parameters that appear linearly in the state equation. The approach to adaptive control design is based on a. suitable coordinate transformation that results in an error model for which stable adaptive laws can be readily specified. The corresponding proofs of stability and robustness to time-varying parameters are included. The properties of the adaptive dynamic feedback controller are illustrated through computer simulations