Optimal control for far-distance rapid cooperative rendezvous

Abstract

This study investigated the far-distance cooperative rendezvous problem for two spacecrafts. The orbital dynamics equations were represented based on the orbital elements with an improved vernal equinox and were normalized. Pontryagin’s extremum principle was introduced into the dynamics equations and the co-state equations were obtained. A performance evaluation function was created by particle swarm optimization algorithm based on simulated annealing. The convergent co-state initial vector was obtained using an improved particle swarm optimization algorithm. The initial vector was set as the initial value for optimization and a rapid small-population genetic algorithm was applied, before the approximate global optimum was obtained rapidly. The fine adjustment of the search process was performed based on sequential quadratic programming and the results were sufficiently precise. The process of optimization was simulated for problems that involved far-distance coplanar cooperative rendezvous and active-pa...