A controller design for nonlinear systems with time-delay using closed-loop step response data

Abstract

This paper proposes a controller design method for the Hammerstein models which are linear models with static input nonlinearities and are a kind of nonlinear systems. The method requires only closed-loop step response data for controller design. The information in time domain of the data is used to estimate the plant model, and that in frequency domain is used to confirm the validity of the linear part of the plant model. Since the method estimates the plant model and compensates the nonlinearity of the plant, the controller for the linearized plant can be designed in consideration of the trade-off between the closed-loop bandwidth and the stability margin by a model-based approach.