Virtual displacement guidance for hypersonic glide vehicle

Hypersonic glide vehicles have strong lateral mobility which will lead to great bank-angle in flight. Hence, great longitudinal and lateral loop coupling will greatly increase the difficulty of guidance. Since traditional decoupling guidance strategy is difficult to adapt to this situation; to solve this problem, this paper introduces a concept of virtual displacement from analytical mechanics and designs virtual displacement guidance method for hypersonic glide vehicle, based on the small control changes' impact on the whole trajectory. In every guidance period, virtual displacement guidance method predicts the vehicle's landing point, searching the optimal bank-angle and angle of attack successively to correct the error. Simulation results show that virtual displacement is able to achieve higher guidance accuracy in both standard and uncertain conditions than traditional methods. In addition, lateral error corridor introduced can restrain the control's chatter phenomenon.