Abstract: In view of the problem of hypersonic aircraft in adjacent space, a folding wing aircraft was designed, which can adapt to various flight states and maintain the optimal aerodynamic characteristics. According to the characteristics of hypersonic glide in adjacent space, Gaussian pseudo-spectral method was used to optimize the trajectory of fixed-wing aircraft and fold-wing aircraft. By comparing the capability of range and the ability of avoiding heat flow of fold-wing aircraft with that of traditional fixed-wing aircraft, a trajectory optimization idea of comprehensive target was proposed. Compared with the traditional fixed-wing aircraft, the designed folding wing aircraft has better performance and is more suitable for the adjacent space environment. It improves the range by 17.67% and reduces the peak heat flow rate by 35.72%. It is verified by the design and simulation of the control system. The simulation results show that the maneuverability of the variant aircraft is improved significantly compared with that of the fixed-wing aircraft.

Key words: folding wing aircraft, trajectory optimization, Gaussian pseudospectral method, attitude control, hypersonic speed