Design and control of ROV manipulators

This thesis is about the design and production of a manipulator for a ROV for the student driven company UiS Subsea. The ROV will be used in the MATE ROV competition. The design and mechanisms were chosen based on weight optimization, lifting capacity, and how well it can execute the tasks in the MATE competition. Autodesk Inventor was used to design all the non-standard parts and the software Adams was used to simulate the movement of the arm. The manipulators from previous years varied from very large and heavy, to small and with limited movement. Some ideas and mechanisms were re-used and implemented into the final design of the manipulator, while other new types of mechanisms were tested from early on and selected based on efficiency and lifting capacity. The first prototype was 3D-printed, and any visible sign of weaknesses or potential of failure was improved. This was an iterative testing phase and the result was that the final design has two main rotational joints and one rotational joint for the end effector, in total three 3 DOF. There are 4 electrical motors in total to execute the movements of the manipulator. One motor for each main joint, one for the rotation of the end effector, and one to pull the wire for gripping. Three stepper motors are placed on the base, behind the arm. A smaller BLDC motor is placed in the arm, right behind the end effector. Compared to manipulators from previous years, the manipulator in this thesis is much lighter while only sacrificing one DOF. Comparing to the manipulator from 2015 the new manipulator is approximately 45% lighter