Motion control algorithms for mobile vehicles and marine crafts

The mobile robots can have various appearances, dynamics and configurations of actuators: wheels for ground vehicles; legs for walking robots; propellers, waterjets, rudders and fins for marine robots; propellers, reactive engines and wings for aircraft. Nevertheless, many problems of their navigation and motion control can be solved in a unified manner. The navigation modules implemented in proprietary industrial-grade autopilots or open-source motion controllers mainly support only very basic functionalities, e.g. traveling with a predefined heading at a prescribed speed. However, many practical applications require to fulfill more complicated control tasks, such as obstacle avoidance, monitoring, surveillance or patrolling of a given area, convoying and covert tracking of mobile targets. The first problem addressed in this research is the precise path following control problem by using the nonlinear guiding vector field approach for underactuated and constrained robots for which the class of trajectories a robot can follow is restricted by its dynamics. Special attention is given to examine stability and convergence properties of the motion control algorithm and explicitly estimate a region of initial conditions, for which convergence to the desired path can be ensured. The second problem of motion control, addressed in this research, is active oscillation damping using the theory of optimal universal controllers. The proposed solution is developed in the context of roll stabilization for marine crafts, which guaranties optimal damping of roll oscillations for a wave-induced disturbance; however, the proposed approach can also be used for active vibration control of aircraft and automobiles