Trajectory planning of a space manipulator with constant zero-disturbance to base attitude

The end effector's position & attitude trajectory planning of a free-floating space robot (FFSR) with constant zero-disturbance to the base attitude was investigated. For a kinematically non-redundant three-degree-of-freedom FFSR, a state transformation between the position & attitude of the end effector and the joint angles was deduced, and then the system equations using the base attitude and joint angles as state variables was presented. According to the system equations, the feasibility of the constant zero-disturbance path planning of the end effector's position & attitude was proved via the controllability condition of a nonlinear system, and then a constant zero-disturbance path planning algorithm was developed by an optimal control strategy. Numerical examples validate the effectiveness of the proposed feasibility conclusion and the path planning algorithm.