For the past two decades, extensive research has been undertaken in the field of parallel robots. Such robots have proved advantageous over their serial counterparts, essentially, in two ways: They can achieve higher speeds (due to low moving inertia of the system) and higher precision (due to non-cumulative joint errors). These properties are very desirable in today’s ever increasing primary demands in the manufacturing industry, namely, fabrication and assembly of products with higher accuracy and at a much faster pace. A pertinent application area is the electronics industry, whereby such robots can be extensively utilized. As such, the global motivation of this thesis is the development of a three-degree-of-freedom planar parallel robot for high-speed, high-precision wire-bonding and electronic-component placement tasks.
The primary objective of this thesis is the kinematic-architecture selection of the above defined planar robot: A novel concept of “effective base area”, E b, is proposed for utilization together with the global workspace, Gw, of the parallel robot to define a ratio GW/EB for choosing the best possible architecture amongst the six potential kinematic configurations. A high ratio, which is the desirable feature, indicates that the robot yields a large workspace while occupying a minimal area: The RPR provided us with the highest ratio but was discarded due to its high moving inertia, hence, the PRR architecture (with the second highest ratio) was selected for implementation of the robot.
Further in-depth analyses of the selected architecture included: Identification of constant platform-orientation regions (for 0, π/2 and π radians) within the global workspace of the planar robot, based on the manipulator task requirements; investigation of singularities; and, simulation of the robot motion, using a mechanical simulation software, Visual Nastran 4D.
Finally, a preliminary vibration analysis of the robot components was performed using the Finite-Element module o f Visual Nastran 4D. An experimental modal test procedure and different test case scenarios were also developed and proposed with the aim of generating a comprehensive set of modal properties for the robot structure.