Safety protection control for aeroengines based on finite times of controller switches

Abstract

For the simplified hypersonic air-breathing propulsion model, focusing on the safety boundaries existing during the working progressing, this paper studies the output regulation/ safety protection switching control problem. Command switching strategies based on the protected output and on the safety margin are studied respectively, and the scheme mentioned in our previous work is modified in several aspects to get better performances. In both cases, the protected output will be forced to escape from the safety boundaries once the dangers approach. In the protected output based scheme, two PI controllers work in turn to balance the two objectives. And in the safety margin based switching strategy, a dynamical state feedback controller and a protection controller switch in a hysteresis way to guarantee the asymptotic tracking in a safe way. The principles guaranteeing asymptotic tracking are given and the control parameters could be calculated by solving optimal problems. Finally, simulation researches are performed to verify the effectiveness of the given results, which also indicate that the commands switching control can improve both safety margin and setting time, the estimation of the safety margin and the conditions for finite times of switches are also included in this paper.