Optimal-fuel control design of nonlinear spacecraft rendezvous system with the collision avoidance constraint

This paper studies the optimal-fuel control problem of spacecraft rendezvous with collision avoidance constraint. A nonlinear spacecraft rendezvous model is established. Based on this model, an optimal control problem with state constraint is formulated. An exact penalty function method is used to transform the constrained optimal control problem into a sequence of approximate unconstrained optimization problems. Finally, it is shown that the solutions of these approximate unconstrained optimization problems converge to the solution of the original problem.