Modelling and robust control of a dam-river system

The paper deals with the modelling and the automatic control of a dam-river system, where the action variable is the upstream flow rate and the controlled variable the downstream flow rate. The system is modeled with a linear model (second order transfer function with delay). Two control methods (pole placement and Smith predictor) are compared in terms of performance and robustness. The pole placement is done on the sampled model, whereas the Smith predictor is based on the continuous model. Robustness is estimated with the use of margins, and also with the use of a bound on multiplicative uncertainty for variable reference discharges. Simulations are carried out on a nonlinear model of the river, and performance of both controllers are compared to the one of a continuous-time PID controller.