Feedback control of triaxial attitude control testbed actuated by two proof mass devices

The triaxial attitude control testbed (TACT) has been developed as part of a research program on spacecraft multibody rotational dynamics and control. In the paper, an attitude control problem for the TACT actuated by two proof mass devices is studied. Under the assumption of uniform gravity, proof masses generate control moments about the roll and pitch axes of the base body. The control objective is to accomplish attitude stabilization about all three axes using only two proof mass actuators. Analysis shows that there do not exist stabilizing continuous time-invariant feedback controllers. For feedback design, we simplify the complex multibody equations of motion and we develop a discontinuous time-invariant feedback controller. The resulting closed loop shows exponentially converging responses for rotational maneuvers about all three axes.