Dynamical Behavior And Control Strategies Of The Hybrid Autonomous Underwater Vehicle

Hybrid Autonomous Underwater Vehicle (HAUV) is a new kind of Underwater Vehicle which can be used as Autonomous Underwater Vehicle (AUV) or Autonomous Underwater Glider (AUG). When long distance cruising or good concealing is needed, HAUV can work as AUG, which has the advantages of wide cruise range, less power consumption and lower noise. When high speed or good positioning accuracy is needed, HAUV can work as AUV, which has the advantages of high positioning accuracy and high maneuverability.A new kind of HAUV is developed in this dissertation. Lake trials of the HAUV show that the functions and performances of it are coherent with the design goals. The dynamic model and controller of the HAUV are developed which can be used to analyze the behavior and to identify the design parameters of the HAUV. The following contributions have been made.1. The first HAUV in China is developed. It can be driven by the propeller mounted at the tail-end and can also be driven by the buoyancy changing caused by the buoyancy regulating system mounted at the head-end. The pose of the HAUV can be adjusted by the rudder or the rotating of an eccentric column and the translation of a coaxial column mass in the pressure hull of the HAUV.2. The nonlinear six-degree of freedom dynamic model of the HAUV is formulated. Cosidering the simultaneous effects of the rudder, the eccentric rotating mass and the translation mass, the model can show exactly the dynamic behavior of the HAUV and can be used to the dynamic analysis of other similar HAUV. The validity of the model is verified by the simulation results.3. The dynamical behavior of HAUV is analyzed. Based on the analysis of the coupling relationships between the horizontal plane and the vertical plane, the method to decouple the dynamic model is proposed. Then the simplified dynamic models are formulated by restricting the 3D dynamic model in horizontal plane and vertical plane. Aiming at the maximal gliding efficiency, the maximal gliding velocity and improving the maneuverability of HAUV, the optimal control parameters are chosen.4. The fuzzy PID controller is applied to HAUV, and then the trajectory tracking strategy is emphatically discussed. The method by which the maximal cruise range can be obtained with the limited onboard electric power is developed.