Biomimetic underwater vehicles propelled by undulatory fins have many advantages such as high maneuverability, good stability, strong anti-disturbance capability, low noise and producing small disturbance to the surrounding environment when they swim at low speed. Hence the biomimetic underwater vehicles are expected to be widely used in the field of civil and military applications. This thesis focuses on the system design, 3-dimentional motion control, depth control, course control and path-following control of a biomimetic underwater vehicle propelled by undulatory fins. The main contents of this thesis are as follows. Firstly, a biomimetic underwater vehicle is designed based on modular design concept. The vehicle can swim in 3-dimentional space and its fin rays are driven by independent servo motors. Then a FPGA- and PC104-based control system and a driver system for undulatory fins are designed to achieve the motion control of undulatory fins. Then a prototype of the biomimetic underwater vehicle is fabricated by integrating the above hardware and software. Secondly, the kinematic model of undulatory fins is developed. And the constraints restricting the motion of undulatory fins are studied and the thrust produced by undulatory fins is qualitatively analyzed. Then a 3-dimentional motion control method for the biomimetic underwater vehicle is proposed by coordinated control of both left and right fins. As a result, multiple motion patterns such as marching, receding, swaying, submerging, surfacing, turning and rotation are achieved. Thirdly, aiming at the depth control and course control of the biomimetic underwater vehicle, a depth controller and a course controller are proposed independently based on the active disturbance rejection control technology. Considering that the control signals given by depth controller and course controller are different with the control input of the biomimetic underwater vehicle, a parameter mapping model that maps the heave force to wave parameters of undulatory fins and a parameter mapping model that maps the yaw torque to wave parameters of undulatory fins are developed based on fuzzy inference methods. Finally, in order to solve the path-following control problem for the biomimetic underwater vehicle, a 3-D path following control scheme is proposed based on the Line-of-Sight guidance law. As a result, the 3-D path-following control problem is transformed to surge speed control, depth control and course cont...
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