Three dimensional attitude and shape control of spacecraft with articulated appendages and reaction wheels

Three dimensional attitude and shape control problems are studied for a class of spacecraft with articulated appendages and reaction wheels. We provide a new unified formulation which includes many of the attitude control problems that have been studied previously. The development is based on a nonlinear, drift-free, control model that characterizes the attitude and shape change dynamics, assuming zero angular momentum of the system. Controllability results are presented for the general case, and specialized results are identified for interesting multibody spacecraft configurations. These results are made explicit by providing computable formulas for the Lie brackets in terms of the spacecraft geometry, inertial properties, and shape. Emphasis is given to the interplay between the shape change dynamics and the attitude change dynamics