Economic MPC-Based Planning for Marine Vehicles: Tuning Safety and Energy Efficiency

Energy efficiency and safety are two critical objectives for marine vehicles operating in environments with obstacles, and they generally conflict with each other. This article proposes a novel online motion planning method for marine vehicles, which can take practical limitations into account and make tradeoffs between the two objectives by exploiting the economic model predictive control (EMPC) technique. To achieve this, a trajectory generation method is first proposed, which provides the smooth reference evolved from the safest path and facilitates the measurement of safety degree. Then the EMPC-based motion planning framework, which accounts for system and environmental constraints, energy consumption, and safety margin, is proposed after the tailored energy cost function is designed. Furthermore, the receding horizon planning strategy for the developed planning framework is proposed, which explicitly addresses the nonnegligible calculation time and the limited detection range. Finally, the effectiveness and feasibility of the proposed method are also validated through experiments.