Analysis and design of an ideal robot manipulatorhaving simple dynamics

Abstract

One distinct feature of robots is a flexibility, which requires that the endeffector of robots can have arbitrary position and orientation in its workspace. In addition, the motion of robots should be accurate in high speed. For the requirements, the robot is constructed with links connected by joints, which is necessarily very complex in kinematics and dynamics. The robot design consists of two stages; kinematic and dynamic design stage. In the kinematic design stage, joint type and kinematic link parameters such as offset angle and link length are determined, which are related to the workspace shape and volume and dexterity. For a given structure of robots, dynamic design stage determines dynamic link parameters such as mass, mass center, and inertia distribution of links, which are related to the dynamic characteristics and performance of robots. To position and orient the end-effector of robot arbitrarily, 6 degrees of freedom are required. It is convenient to divide 6 degrees of freedom into two parts; regional structure and orientation structure. In this thesis, possible combinations of simple chain for the regional structure and orientation structure have been analyzed. For the regional structure, there are 20 possible combinations among which sphere volume shape has maximum volume while cubic shape has minimum volume. For the large volume and simple structure of regional structure, there are five commercialized robot models. For the orientation structure, 5 combinations exist, which are evaluated when joint motions are constrained. In addition, the effect of regional structure and hand size on the dexterity are evaluated. The complex robot dynamic due to its nature of structure is one of the main problems in designing a robot controller. The complexity of robot dynamics can be reduced proper design of links. In this thesis the design conditions are derived form energy equation of robot, which clarify and simplify the robot design. The way and limitation...