Nonlinear analysis and control of an underactuated 3-DOF control moment gyroscope with experimental validation

Nonlinear controllers have been extensively abstracted in recent times. Nevertheless, real time implementation for underactuated MIMO physical systems is rarely attempted. This work proposes a nonlinear framework based on dynamical analysis and the sliding mode based control technique to control a highly coupled and nonlinear MIMO underactuated control moment gyroscope. First, an analytical formulation based on dynamic characterization is proposed to understand both the unactuated dynamics and the performance constraints of the gyroscope. This characterization helps in designing a feasible nonlinear sliding mode controller which helps in a simple and straightforward control of the system through the entire operating regime. The effectiveness of the proposed nonlinear control and analytical framework is established by successful implementation on the experimental gyroscope setup.