Constrained trajectory optimization for coordinated maneuver planning of spacecraft with dual manipulators

Application of spacecraft with movable mechanisms is more effective in attitude maneuver missions than rigid three-axis spacecraft owning to extra degrees of freedom, but also raises challenges on attitude trajectory planning. This paper investigates the application of a hierarchical mixed-strategy optimization method to coordinated attitude trajectory planning of the spacecraft with dual manipulators. In order to overcome the computation complexity issue, decoupled strategy is employed to split demanded pointing into the body quaternion and manipulator joint angles. Having the pointing path compliant with pointing constraints, objectives of energy consumption and joint angle change are designed. The secondary rotation of quaternion sequence is utilized as design variables in conjunction with a hierarchical swarm optimization algorithm using mixed search strategy for attitude trajectory optimization. The optimal solutions of body attitude and joint angle path are parametrized with quintic polynomials to solve complete trajectories of system states using inverse dynamics while imposed constraints are satisfied. Simulation results are presented for coordinated attitude trajectory planning of spacecraft with two manipulators and demonstrate the effectiveness of the proposed optimization method.