Switching control of thrust regulation and inlet unstart protection for scramjet engine based on Min strategy

Scramjet engine encounters many safety restrictions during the ascent trajectory. These restrictions make the engine a multi-objective control system. In order to obtain optimal thrust performance while avoiding the inlet unstart, switching control based on Min strategy has been focused on in the working process of scramjet engine. Firstly, on the basis of experimental data, the dynamic mathematical models of fuel supply system, thrust regulation control loop and inlet unstart protection loop were established. Min strategy and PI controller were applied to the scramjet engine and the influence of integral limiter of PI controllers on the control process was discussed using the hardware-in-the-loop simulation. Finally, the validity of switching control was verified on the ground experiment facility. The results showed that it is useful to introduce the multi-objective switching control to scramjet engine. Switching control based on Min strategy could effectively maximize the engine performance while avoiding the inlet unstart.