Dynamic Modeling And Motion Control For A Hybrid-driven Underwater Glider

The winged hybrid-driven underwater gliders combine the best features of conventional autonomous underwater vehicles, legacy underwater gliders and Argo free-drifting profiling floats, and can be served as important platforms for marine environment observation and ocean resource exploration. Actuated by net buoyancy and hydrodynamic lift from fixed wings, the hybrid gliders perform glide operation and roam the ocean in a zigzag path with high efficiency, long endurance and low noise. Driven by one single prop and steered with deflection of tail fins or redistribution of internal masses, the hybrid gliders undertake thrust operation and penetrate the strong current in the estuary's littoral zone with high maneuverability and burst speed.In this paper, the architecture desigh and the operating principle of the hybrid gliders are introduced, the simplified and accurate dynamic models are built by using the theorem of multi-rigid-body with a floating base, the stability and maneuverability are analyzed and the three dimensional motion simulation under both thust operation and glide operation are performed. According to the paticular hydrodynamic profile, the hydrodynamic model was researched and the appropriate pramenters are seleted and calculated. In addition, the control model of the hybrid vehicle is developed based on the neural network algorithm, and its feasibility was verified by the control simulation. The main contributions are summarized as follows:1. One mini prototype of the hybrid-driven underwater glider is designed which tend to integrate together all the advantages of the conventional autonomous underwater vehicles, legacy underwater gliders and Argo free-drifting profiling floats. The critical design and calculation is presented and the fundamental data of the unit experiment and field tial are given which can serve as guidance for the fabrication of the marine platforms.2. The dynamic model of the hybrid gliders is built by using the therom of the multi-rigid-body with a floating base, and the impacts of the translational and rotational motion of internal masses on its attitude are taken into consideration. The hydrodynamic efficiencies of torpedo are introduced to add the accuracy of the dynamic model of the hybrid glider. Based on the analysis of the stability and maneuverability and the three dimensional motion simulation in both thrust operation and glide operation, the ranges of the design parameters of the hybrid-driven underwater glider are proposed.3. The BP neural network based controller for dynamic positioning and trajectory tracking of hybrid driven underwater glider are developed and anaylized, and the PID neural network based controller for fixed-depth navigation, target tracking and attitude decoupling are tailored. The capability of adaptive control and fault tolerance are brought about by the neural networks based control method.