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A Quaternion-based Sliding Mode Controller for UVMS

As an important tool for underwater operations, underwater vehicle manipulator system (UVMS) is becoming more flexible and miniaturized. Because of the flexibility, the posture of UVMS can be more diversified, which might lead representation singularities of orientation in the case of Euler angles. And the lightweight vehicle increases the torque coupling between the vehicle and the manipulator. In order to avoid singularity and obtain a good dynamic control performance, a sliding mode controller is designed by unit quaternion feedback for this nonlinear and strong coupling system. The stability of the controller is proved by a generalized Lyapunov theory, and the parameters of the controller are optimized by genetic algorithm (GA). The simulation results show that the proposed control law has good performance .