A Novel Adaptive Control Method Based on Continuous Characteristic Models

Abstract

For a class of nonlinear systems, a novel adaptive control scheme is proposed in this paper. Firstly, the continuous characteristic model is constructed, which is equivalent to its original system in output for the same input at any time. Thus, the original system can be replaced with its characteristic model for designing controllers. As the original nonlinear system has unknown parameters and unmodeled dynamics, the characteristic parameters are also unknown and fast time-varying. A novel adaptive control method is proposed by combining the continuous characteristic model with the adaptive dynamic surface control technique. The method is independent on the original system model and only utilizes the information about system output for controlling. On account of the fact, the system inner states, unknown parameters and unmodeled dynamics are not needed to be observed. Finally, the stability of the closed loop system is proved by utilizing Lyapunov theory and simulation results have demonstrated the effectiveness of the proposed method.