Study on the Pitching and Depth Control of Biomimetic Robot Fish
仿生机器鱼俯仰与深度控制方法

In the paper,a heave locomotion robotic fish TPF (Three DOFs posture-controllable fish robot)is proposed,which is composed of a multi-linked oscillating tail and a barycenter- adjustor which can change the robot-fish's center of gravity by moving an inside weight.The pitching angle and submergence of the robotic fish are analyzed.In order to make such a biomimetic robot realize heave locomotion and suspend in water,a control paradigm is proposed.In this paradigm,multi-link propulsive system and pitching angle are controlled separately and work together.The propulsive system keeps the robotic fish at a uni- form speed based on swimming gaits and oscillating frequency. And a controller with deformation compensation is presented to adjust the turning angle of the barycenter-adjustor's servo mo- tor on the basis of the depth feedback.Experimental results show that the proposed control method is valid,and its perfor- mance is much better than that of a general controller in depth maintaining of robotic fish TPF.