Performance Based Multidisciplinary Integrated Design Of Hypersonic Vehicle

Scramjet powered air-breathing hypersonic vehicles are viewed as the next generation of hypersonic transportation systems due to the reliability and the ability of global reach, etc. Historically, control discipline is introduced into the vehicle design after the conceptual design phase, and vehicle plant design does not incorporate control relevant considerations. Based on such an approach, the achieved system might not meet its specifications or requires a complex controller to do so. Therefore, vehicle designers might need to go through several times of iterations to obtain an acceptable plant and controller design. Based on the analysis of limits of hypersonic vehicle performance, an integrated approach for the plant and controller design is proposed to explicitly incorporate control relevant constrains and performance into the design of vehicle.In this paper, the object of study is the dynamical model for the longitudinal dynamics of a typical air-breathing hypersonic vehicle. The main characteristics of vehicle model include input/output coupling, instability, non-minimum phase, actuator saturation constraints, etc., which restrict the achievable performance. This paper focuses on the constraints and specifications that could be computed efficiently. The controller design can be formulated as a linear matrix inequality(LMI) problem. And then several common plant-centric and control-centric constrains could be incorporated into vehicle optimization design simultaneously. By analyzing coupling property between plant and control system, the sequential structure of decentralized optimization approach is chosen, and the particle swarm optimization(PSO) is used to search the optimal set in relation to plant design variables.Several trade-off studies are performed to examine the impact on vehicle design variables associated with static and dynamic properties and control relevant performance indicators. The results of trade-off studies could guide the integrated design of the hypersonic vehicle. Two vehicle design examples are presented to illustrate the effectiveness of the proposed integration design approach.