Bi-objective switching control design for a tradeoff between acceleration and unstart in hypersonic airframe/propulsion models

Based on a dual-mode scramjet engine model, in which three operation modes (i.e., scramjet mode, ramjet mode and unstarted mode) and four transition boundaries are defined, a longitudinal dynamical model of an air-breathing hypersonic vehicle is applied. Based on the model, this paper aims at presenting preliminary results on the integrated airframe/propulsion control, which obtains a regulation/protection switching control strategy, for realizing a suitable tradeoff between the acceleration performance of the vehicle and the safety of the propulsion system. The existent of the inlet unstart boundary might restrict not only the propulsion capability of the engine but also the acceleration capability of the vehicle. And, in a wide range of flight Mach numbers, the mode transitions between the scramjet mode and the ramjet mode is inevitable. The effectiveness of the bi-objective switching control strategy and the integrated airframe/propulsion control framework is illustrated in four case studies in this paper.