The analysis and design of Smith predictors using singular Nyquist arrays

A modified form of the Smith predictor (Smith 1957, 1959) for systems with significant dead times is proposed and analysed using singular Nyquist arrays. This new controller eliminates steady state offset errors using only proportional control elements. A design procedure for the predictor is developed using the methods of Rosenbrock (1969, 1974) and Kantor and Andres (1979). This procedure explicitly accounts for the effects of process modelling errors. An illustrative example comparing the new controller with the traditional Smith controller and with PI control shows the decided advantages of the predictor.