Observation and control for air-breathing hypersonic aircrafts based on sliding mode method

In this paper, the state observation and control problems are studied for air-breathing cruise hypersonic aircrafts. As many variables in flight cannot be measurable, a sliding mode observer is firstly introduced to derive all unmeasurable states. Secondly the feedback linearization is executed on the longitudinal model of air-breathing hypersonic aircrafts using all states, then a sliding mode controller is designed based on tracking errors, which guarantee the reachability condition in the sliding mode system and the stability of the whole system. Simulation results validate that the sliding mode observer can reproduce all unmeasurable states and the sliding mode controller can deal with the tracking control of velocity and altitude for air-breathing cruise hypersonic aircrafts.