Dynamics and Motion of a Six Degree of Freedom Robot Manipulator
In this thesis, a strategy to accomplish pick and place operations using a six degree offreedom (DOF) robotic arm attached to a wheeled mobile robot is presented. This research work is part of a bigger project in developing a robotic assisted nursing to be used in medical settings. The significance of this project relies on the increasing demand for elderly and disabled skilled care assistance which nowadays has become insufficient. Strong efforts have been made to incorporate technology to fulfill these needs. Several methods were implemented to make a 6 DOF manipulator capable of performing pick and place operations. Some of these methods were used to achieve specific tasks such as: solving the inverse kinematics problem, or planning a collision free path. Other methods, such as forward kinematics description, workspace evaluation, and dexterity analysis, were used to describe the manipulator and its capabilities. The manipulator was accurately described by obtaining the link transformation matrices from each joint using the Denavit Hartenberg (DH) notations. An Iterative Inverse Kinematics method (IIK) was used to find multiple configurations for the manipulator along a given path. The IIK method was based on the specific geometric characteristic of the manipulator, in which several joints share a common plane. To find admissible solutions along the path, the workspace of the manipulator was considered. Algebraic formulations to obtain the specific workspace of the 6 DOF manipulator on the Cartesian coordinate space were derived from the singular configurations of the manipulator. Local dexterity analysis was also required to identify possible orientations of the end effector for specific Cartesian coordinate positions. The closed form expressions for the range of such orientations were derived by adapting an existing dexterity method. Two methods were