Design and Research of Underwater Manipulator

• Main Authors: MIN-WEI HUNG, 洪敏偉
• Other Authors: C.C.Wang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/15523321268113207216

碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 94 === The goal of this thesis is to design and fabricate a four degrees freedom underwater manipulator for small to midsize remotely operated vehicles. DC servo motors were used to actuate the manipulator joints such that the size and the necessary auxiliary components can be reduced. In terms of hardware design process, the selection of servo motors and their arrangement is the key to the overall performance of the manipulator. The design of any joint, including its location and fixture to the frame, is coupled with that of the neighboring joints such that the design itself is an iterative process. Proper choice of the torque and power of an actuator not only reduces its size but also ease the loading the joints proximal to the base. In this project, the water resistance between stationary and rotary interfaces are achieved by O-ring and mechanical seals respectively. A gripper, synthesized and analyzed with kinematic chain theory, was implemented with a single degree freedom six-bar linkage as the end-effector of the manipulator. Because the robot is designated to operate in underwater environment, the dynamics of the system is relative slow and insignificant. Therefore, the only the linearized kinematics of the manipulator is concerned, and the motion controller is implemented with Jacobian in Visual Basic. Under 50 Hz servo rate, gravity compensation is added for operation in the air, and in the water as well. For the operating speed limited to 20 mm/sec, the overall positioning error is confined to be less than 1 mm for all time.