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Abstract
Over the last few years, parallel robots have been under increasing developments from ACKI a theoretical view point as well as for practical applications. They have good features such as high payload, high stiffness and high speed. ABSI In this dissertation, the Cartesian Parallel Manipulator (CPM) which proposed by Han TABL Sung j’im, and Lung-Wen Tsai is investigated. This manipulator has three degrees of LIST freedom and the moving platform is constrained to only translational motion. The CPM LIST consists of a moving platform that is connected to a fixed base by three limbs. Each limb is made up of one prismatic and three revolute joints and all joint axes are parallel to one another. In this way, each limb provide.s two rotational constraints to the moving platform 1 Inti and the combined effects of the three limbs lead to an over constrained mechanism with I three translational degrees of freedom. The manipulator behaves like a conventional X-Y-Z 1 Cartesian machine due to the orthogonal arrangement of the three limbs. Two actuation 1 methods are analyzed. However, the rotary actuation method is discarded because of the 1 existence of singularities within the workspace. For the linear actuation method, there exists a one-to-one correspondence between the input and output displacements of the manipulator. A closed-form solution for the dynamic problem has been derived which 2 Ro gives a more complete characterization of the model dynamics. Modem motion controllers of robot manipulators require knowledge of the system’s dynamics in order to intelligently predict the force command. One of the main objectives for this thesis is to apply various motion controllers on the CPM in simulations and verify if one can take advantage of the model knowledge to improve performance of controllers. The controllers used in this thesis varied from simple PD control with position and velocity reference only applied independently at each joint to more advanced PD control with full dynamic feedforward terms arid computed torque control, which incorporate full dynamic knowledge of the manipulator. Also, background theories of various controllers used in this thesis have been presented and their simulation results on the CPM have been compared.