Fuzzy Logic Based Motion Control For Underwater Vehicle

The research on how to acquire stable movement of the vehicle is one of the most important subjects to the real application of the Autonomous Underwater Vehicle. There are several characteristics when AUV is moving:high nonlinearity of dynamic model, unpredictable operating environment, time-vary and unpredictable system;large working radius, large spectrum of speed and so on. The control system must adapt to such factors, and it must be robust , self-adaptive and high precision .So it's a big challenge to design a good performance motion control system。Up to now, fuzzy control technology has been applied widely in the uncertain and nonlinear system. In this thesis, we aimed at the application of the fuzzy technology in the motion control and try to design a good control system for the underwater vehicle.Based on the need of practice and the convenience of designing the controller the model is properly simplified into the dynamic model with 6 directions of freedom. It must take ocean current into consideration when modeling, so we have to study hydrodynamics. Given the characteristics of the environment when the AUV is moving, it's suitable to use fuzzy control theory, on the base of introduction of fundamental and previous model, It is time to design fuzzy controller. Given the differences between linear and angular movement, It has to design different movement controller .The simulation results prove the controllers are reliable and feasible.