Precise Control Method for Directional Swimming of a Robotic Fish Based on CPG and Fuzzy Control

Robotic fish detection under water, waves, vortices, etc. can affect the accuracy of the swimming direction of a robotic fish, making it virtually for corresponding tasks to be completed. To solve the problem of ensuring the accuracy of the swimming direction of robotic fish, this study proposes an accurate control method based on the central pattern generator(CPG) theory and fuzzy controller. The proposed method can realize the directional swimming of a robotic fish of the genus Plover. In this method, a Hopf oscillator is used to build a CPG model of a robotic fish based on a limit cycle. In the early stage of robotic fish swimming, a small swing high-frequency CPG control signal is used to obtain a large propulsion force, and a large swing low-frequency CPG signal realizes stable swimming. Then, the attitude angle information of the robotic fish is obtained based on an attitude sensor, and the deviation of the robotic fish from the target direction is corrected in real time using the fuzzy controller. Finally, directional swimming and anti-interference experiments of the robotic fish are conducted to verify the feasibility and effectiveness of the precise directional swimming method. Results show that the proposed method has broad application prospects for precise directional swimming of robotic fish in complex environments.