Abstract:In this paper, aiming at the penetration and guidance of hypersonic vehicles in the dive phase, a method of spiral dive trajectory design based on optimal control is proposed. First, according to strong coupling and nonlinear characteristics of the second-order line-of-sight angular acceleration relative to the equation of motion, the feedback linearization technology is introduced to transform the nonlinear system into a linear system. On this basis, the terminal angle constraint was added. And, the optimal control is adopted to obtain control input in the form of acceleration for zeroing the line-of-sight angular rate and minimizing energy. Then, in order to make the speed of the aircraft rotate around the instantaneous line of sight, a spiral signal was designed. Finally, considering the conflict between maneuvering and guidance, the optimal and spiral signals are weighted combined. The simulation results show that when facing the same air defense threat, the dive trajectory designed in this paper has better penetration than the spiral trajectory via proportional guidance.