Undulating Propulsion Underwater Robot Control Method Based on ADRC and Fuzzy Logic

The article is devoted to the development a closed-loop depth and course control algorithms for underwater robot with pair undulating fin. The controller was proposed based on the Active Disturbance Rejection Control (ADRC) technique and fuzzy logic. A brief review of the underwater robot with pair undulating fin (AUV) is carried out. The dynamic and kinematic robot model is given, and the robot model with the environment is presented in the Simscape-MATLAB library. To solve the problem of controlling course and depth of the robot, a method of Active Disturbance Rejection Control (ADRC) is proposed. This robust control method based on extension of the system model with an additional and fictitious state variable, representing everything that is not included in the mathematical description of the plant. This method allows to treat the considered system with a simpler model, since the negative effects of modeling uncertainty are compensated in real time. The advantage of the proposed method is that an exact analytical description of the system is not required, since it can be assumed that the unknown parts of the dynamics are internal noise in the installation. The fuzzy control method is used to build a non-linear relationship between controller outputs and fin parameters that determine the generated fin forces. The results of modeling of the problem of heading and depth control using a complete nonlinear dynamic model with six degrees of freedom are presented. The conducted studies confirm the operability, adequacy, and anti-disturbance ability of the ADRC controller.