Attitude control of a space robot with initial angular momentum

We propose an attitude control law of a space robot with initial angular momentum. We consider a class of the 3-state and 2-input affine nonholonomic systems with a drift term as general system representation for a planar two-link space robot with initial angular momentum. We propose the coordinate and input transformation algorithm which converts an affine system with a drift term into the time-state control form, and propose a controller design method using exact linearization. An asteroid sample-return robot with nonzero initial angular momentum is considered as an example. By using the transformation algorithm. We obtain the time-state control form for the robot. The attitude controller of the robot is designed on the basis of the time-state control form, and simulation and experiment have been carried out.