Total pressure control of supersonic wind tunnel based on model feedforward and PID feedback

The control accuracy of total pressure is one of the important indexes to evaluate the performance of supersonic wind tunnel test. In order to upgrade the quality of wind tunnel tests, this paper investigates the improvement of total pressure control accuracy in a supersonic wind tunnel. Aiming at the problem of insufficient control accuracy of currented used PID control algorithm, a control strategy based on the combination of feedforward compensation of air source pressure and PID feedback control algorithm is proposed. This method establishes the model of the opening of the main pressure regulating valve and the air source pressure. The disturbance caused by the drop of air source pressure is eliminated through this model; The disturbance caused by modeling error and unknown disturbance is eliminated by PID feedback controller. Through the engineering application of this control strategy in the wind tunnel, the control accuracy of the total pressure is improved to meet the new test index standard.