Combined flow and pressure control for industrial pumps with adaptive MPC

We show a simple adaptive linear MPC is suitable to simultaneously control flow rates and pressures in hydraulic processes over wide operating ranges. The predictive controller is adaptive in that the nonlinear process model is re-linearized whenever setpoint changes occur. While its implementation is hardly more complicated than for linear MPC and no additional signals or observers are required, the adaptive controller improves the performance considerably. We apply the proposed approach to the simultaneous flow rate and pressure control for a side-channel pump, and compare it to standard linear MPC and multivariate PID control by applying all three methods to a laboratory setup. As a side-effect, the paper contains a nonlinear model of a side-channel pump and process that is suitable as a benchmark for other control concepts. In contrast to centrifugal pumps, models of this type are not available in the literature for side-channel pumps to the knowledge of the authors.