Constrained reentry trajectory optimization based on improved particle swarm optimization algorithm

This paper proposes an improved particle swarm optimization (PSO) using "step-phase" adjustment strategy for inertia weight to generate the minimum time reentry trajectory for hypersonic reentry vehicles based on the parameterized bank angle profile. According to engineering experience, the velocity-dependent bank angle profile is developed using the "two-flip strategy", thereby reducing the dimensionality of particles. The reentry constraints are processed by penalty function. Especially, the no-fly zone (NFZ) constraint is enforced by extreme method that setting penalty weight to be an extremely large positive number on the condition that the trajectory passes through the NFZ. Simulation results illustrate that the improved PSO algorithm based on the parameterized bank angle profile proves to be capable to generate a complete and optimal three degrees of freedom (3-DOF) reentry trajectory rapidly.