Ascent Guidance Trajectory Optimization for Winged Rocket Using Evolutionary Computation

This paper presents the trajectory optimization method for the ascent guidance of the vertically-launched suborbital spaceplane. The optimization of guidance trajectory must be performed taking mission requirements, flight safety and design constraints into account. In this paper, a trajectory optimization problem of a subscale demonstrator called WIRES#015 is considered for maximizing the altitude and down range at the apogee point under the constraints of longitudinal trim and elevon's hinge moment. The formulated problem is solved by the evolutionary computation which has powerful global search performance. It provides multiple near-optimal trajectories, from which the guidance trajectory can be selected onboard or by the operator. As a result of numerical simulation, feasible trajectories that satisfy the constraints are obtained. In the optimized trajectory, the flight path angle is reduced at the early phase of flight to increase down range, and then the trajectory is pulled up when dynamic pressure becomes maximum.