Adaptive Smith predictor controller design for industrial processes with time-varying time delay

The design of an adaptive Smith predictor controller for control of industrial hydraulic processes subjected to the simultaneous effect of load disturbances and time-varying time-delay is developed in this paper. In order to improve the performance of the Smith predictor, an adaptive block is introduced into the control structure to estimate and update the current value of the time-varying time-delay. Furthermore, a disturbance compensator is introduced to reject the effect of load disturbances. Simulations of the control system are carried out with the proposed controller and with a classical Smith predictor. The comparison of the obtained results shows the higher performance of our proposed controller, both in rejecting load disturbances and in maintaining the closed-loop stability when the time-delay is time-varying.