Research On Optimization Methods Of Plant-control Integrated Design Of Hypersonic Vehicle

Historically, aircraft design methodologies have not included control relevant considerations, especially in conceptual design phase. Such an approach may make that system design might not meet the expected close-loop specification in control system design, and the whole design process often goes through several iterations between the plant and control system design to obtain an acceptable design result.Plant system design of air-breathing hypersonic vehicle has a significant influence on the control system design due to the aero-propulsion-elasticity couplings. This paper considers integrated plant-control design optimization framework. The goal of this proposed framework and algorithm is to realize the integrated optimization design and reduce the number of system-control design iterations by introducing the control-relevant factors in the system design phase.First, this paper describes optimization metrics and optimization methods in relation to the integrated plant-control design, and these are the research basis of following chapters. Second, dynamic model of hypersonic vehicle is constructed. And this model uses hypersonic aerodynamics and Reyleigh flow theory to calculate aerodynamic force and thrust, and at the same time vehicle is considered to be a single free-free Euler-Bernoulli beam to analyze the aero-elastic features. Furthermore, the impacts on closed-loop system design are analyzed due to the non-minimum phase and unstable pole of the open loop system, and the impacts on the control-relevant metrics are discussed by changing the single parameter in design space. Beyond this, the exact and approximate optimization models are built for the integrated plant-control design, and the iterative optimization framework in the conceptual design stage is presented. Furthermore the approximate optimization problem in this framework is changed to a BMI problem, and a BMI solver can be used to implement the integrated optimization design. However, considering the limitation of a BMI solver, the iterative algorithm based on auxiliary variables and two-step iterative LMI algorithm is proposed as an alternative algorithm of BMI for the integrated plant-control design of hypersonic vehicle. Finally, the illustrative examples of the integrated design are analyzed in the simulation, and the effectiveness of the proposed methods is verified for the hypersonic vehicle.