A warm-started trajectory planner for fixed-wing unmanned aerial vehicle formation

In this paper, an optimal control-based method with efficient warm-start is proposed to solve the trajectory planning problem for fixed-wing unmanned aerial vehicle formations. We first formulate the trajectory planning problem as an optimal control problem by analyzing the motion equations and various constraints. Secondly, an improved artificial potential field method is designed to meet the requirements of eliminating local oscillations, inter-formation coordination, and physical constraints with the objective of a high-quality homotopic warm-start. Last, a loose formation constraint strategy is employed to expand the solution space and thus facilitate the convergence process. Numerical simulations at different complexity levels show that the proposed planner is efficient and robust and that the designed warm-start strategy contributes significantly to the convergence of the method. Also, the proposed planner exhibits promising performance in solving the problem with multiple formations.