Energy-Efficient Waypoint Tracking for Underwater Gliders: Theory and Experimental Results

In this article, a novel energy-efficient control method for waypoint tracking of underwater gliders is designed. The method can be divided into a planning layer and a control layer. In the planning layer, a novel steady/unsteady gliding depth intervals-based dead-reckoning is proposed to predict depth-averaged current velocity with lower consumption. Also a novel heading and depth modification strategy based on line-of-sight is proposed to implement waypoint tracking planning. In the control layer, heading control is implemented by two event-triggered extended state observers (ET-ESOs) and an event-triggered backstepping heading controller (ET-BHC). The ET-ESOs intermittently estimate the real states input to the ET-BHC, and the ET-BHC intermittently outputs the control signal. Simulation and sea trial results show that the UG achieves tracking waypoints, and in addition, energy efficiency is significantly improved.