A Novel Modified Robust Model-Free Adaptive Control Method for a Class of Nonlinear Systems with Time Delay

In this work, a novel robust model free adaptive control (Ro-MFAC) algorithm is proposed for a class of discrete nonlinear systems existing both large time delay and disturbance. The main feather of Ro-MFAC is that the controller is designed only based on the input and output data of the system by using a new dynamic linearization technique with a time-varying parameter termed pseudo gradient. Moreover, by combining a novel augmented pseudo gradient, the Ro-MFAC can effectively suppress the system disturbance, such that the Ro-MFAC has strong robustness. Meanwhile, by using the tracking differentiators, the Ro-MFAC controller can also deal with the time delay existing in the system. Furthermore, the numerical simulation results verify the effectiveness of proposed Ro-MFAC.