A Rapid Glide Entry Trajectory Planning Method Based on Analytical Method

Abstract

To solve the problem of enormous computation in on-board reentry-trajectory planning by numerical method, a planning method for glide reentry trajectory was presented based on analytical theory. By this method, the high-precision glide reentry trajectories can be planned rapidly. The whole reentry trajectory was divided into two phases based on motion characteristic of reentry vehicle, and the division reasons were given. High-precision analytical solutions of motion equations of glide reentry trajectory were deduced. The typical inequality reentry path-constraints were transformed into functions of trajectory parameter according to analytical theory. The correction method of parameter was introduced. Based on the one-to-one correspondence between trajectory parameter and bank angle, the proper reentry trajectory which satisfies the mission requircoment can be found in the range of trajectory parameter. The simulation results show that the analytical theory is more precise than the Loh's second-order analytical theory, and closed to the numerical results. The analytical method of planning glide reentry trajectory avoids enormous integral operation in numerical method, and is able to rapidly plan the glide reentry trajectory with high precision like numerical method, which meets the mission requirements.