Design And Research On Underwater Biomimetic Robotic Fish Control System Based On Sliding Mode Control Methodology

With the progress and rapidly expanding of society,oceans attract the attention of human containing abundant mineral resources.As a new type of autonomous underwater vehicle,the underwater biomimetic robotic fish not only has excellent swimming performance as biological fish,but also has the characteristics of simple structure,low noise and so on.However,the highly non-linear model and uncertainty hydrodynamics make the control difficulty.Therefore this thesis focuses on the model optimization and sliding mode control mechanism to improve the model and control accuracy of underwater biomimetic robotic fish.In this thesis the control system is divided into the forward velocity control and the steering angular velocity control to realize two-dimension motion control of underwater biomimetic robotic fish.Firstly,the forward velocity dynamic model is established,and the head yawing model is proposed to optimize the forward velocity model.At the same time,the steering angular velocity dynamic model is established.Secondly,the forward velocity control is realized by using the discrete integral terminal sliding mode controller considering with head yawing and compared with the discrete sliding mode controller and the discrete sliding mode controller with head yawing;the steering angular velocity control is realized by using the discrete sliding mode controller.Finally,two groups of experimental schemes are designed for the straight and steering process.Experiments are carried out on the experimental platform of the underwater biomimetic robotic fish control system.The experimental results show that the data-assitated modeling of the underwater biomimetic robotic fish based on the head yawing is more accurate than the traditional model.Also,the discrete integral terminal sliding mode controller with head yawing can further improve the movement performance for the forward velocity control of the underwater biomimetic robotic fish control system compared with other two controllers.In addition,the steering angular velocity tracking of underwater biomimetic robotic fish can also be realized by the prosed discrete sliding mode controller.