Research on path following control system of wave gliders based on maneuverability demand estimator

Abstract

The wave glider (WG) with a propeller-rudder system represents a novel kind of unmanned surface vehicle that has a hybrid driving capability of wave energy and solar energy, compared to the WG with only a rudder system. The propeller-rudder system can improve the flexibility and maneuverability of the WG, especially in low-speed and nearshore operations. However, owing to the limited solar power generation and high energy consumption of the propeller, studying the precise control switching strategy of the propeller is of great significance. In this paper, a path following control system is proposed for the WG with a propeller-rudder system based on an adaptive line-of-sight algorithm (ALOS), a maneuverability demand estimator and a maneuverability controller. The maneuverability demand estimator is determined by the cross-track error and sideslip angle. And the cross-track error and sideslip angle are fused by using fuzzy mathematics to establish the mobility demand estimation model. The maneuverability demand index (MDI) intuitively expresses the urgency of the mobility demand during the path following process and is input to the maneuverability controller to control the propeller revolution. Through numerical simulations and sea trials, the effectiveness and superiority of the proposed path-following control system is verified.