博士 / 國立中興大學 / 電機工程學系所 / 104 / This dissertation presents the development of a 6-DOF mathematical model for a robotic fish that considers surge, sway, heave, roll, pitch, and yaw. The model analyzes the conditions of a fish swimming in ocean current perturbations similar to the ocean current perturbations of the slender-body autonomous underwater vehicles. For swimming and turning behaviors, a nonlinear dynamic model of a body and/or caudal fin (BCF) type especially carangiform locomotion is derived by using a planar four-link model. Considering the fish behavior mimicking, fish robot behavior scenarios in terms of swimming, turning, and spring-like behaviors of carangiform locomotion are investigated by using a 4-links planar tails and AUVs-like model. The mimicking of a predator fish behavior creates the excellent acceleration when the fish robot suddenly stretches its body from S shape to straight line as same as spring behavior.
A 2-DOF barycenter mechanism is proposed to provide body stabilization and to serve as an actuating device for active control design. A barycenter control scheme is developed to change the center of gravity of the fish robot body by moving balancing masses along two axes. The projected torque on x and y axes propel pitch and roll angles to the desired settings. The swimming scenarios composed of the forward swimming, multi-direction swimming, descended swimming, ascended swimming, depth regulating, and self-stabilization are achieved by incorporating a four link fish-tail and the 2-DOF barycenter as actuators. A stabilizing control, fish-tail mechanism, 2-DOF barycenter mechanism, AUV-like dynamics, and rigid-body kinematics are incorporated to enable the fish robot to move in three-dimensional spaces. Simulation results have demonstrated maneuverability and control system performance of the developed LQR controller which is proposed to conduct the trajectory tracking in the north-east-down (NED) frame of the fish robot as it swims under current perturbations.
Furthermore, the robust sliding mode and nonlinear H guidance control for a fish robot, with the AUV-like feature, for trajectory tracking in the NED frame are proposed. The four link fish-tail and the 2-DOF barycenter are also incorporated as actuators. The swimming speed, turning radius, pitch adjustment, and roll self-stabilization are accomplished by means of the proposed sliding mode and nonlinear H controller directly driving fish-tail and stabilizing mechanisms without any inner loop control systems. The simulation study also validates the satisfactory performance of the both proposed robust controllers under in both cases of model errors and ocean current perturbations.
| Identifer | oai:union.ndltd.org:TW/104NCHU5441012 |
| Date | January 2016 |
| Creators | Pichet Suebsaiprom, 黃平偉 |
| Contributors | 林俊良 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 98 |
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