Goal directed design of serial robotic manipulators based on task descriptions.

摘要

The goal of robotics is to automate and delegate real-world tasks to robotic manipulators. Today robots are being applied to wide range of tasks; from the very traditional material handling tasks to the very sophisticated tele-robotic surgery. Even though general-purpose manipulators are commonplace they do not guarantee optimal task performance. Task optimized manipulators are more effective and efficient than general purpose manipulators. There is a great need for task optimized industrial manipulators that can perform a certain set of jobs with the best efficiency, in the shortest time, and with the least operating cost and power requirements.;Computing the optimal geometric structure of manipulators is one of the most intricate problems in contemporary robot kinematics. Robotic manipulators are designed and built to perform certain predetermined tasks. It is therefore important to incorporate such task requirements during the design and synthesis of the robotic manipulators. Such task requirements and performance constraints can be specified in terms of the required end-effector positions, orientations and velocities along the task trajectory.;There is a close relation between the structure of the manipulator and its kinematic performance. Robotic researchers have over the years tried to develop a framework to reverse engineer optimal manipulator geometries based on task requirements. Every robotic manipulator can only perform certain set of a set of tasks, and some more efficiently than others. Deciding the best manipulator structure for a required job at the design stage is done mainly on the basis of experience and intuition. The rigorous analysis of a few widely used manipulator structures and a collection of a few ad hoc analytical tools can be of some help. However, the need for a comprehensive framework to reverse engineer manipulator structures from task descriptions that can guarantee optimal task performance under a set of operating constraints is still lacking. The ultimate goal of this task-based design approach is to be able to generate both the kinematic and dynamic parameters from task descriptions and operating constraints.;In this work, we define, develop and test a methodology that can generate optimal manipulator geometric structures based on the task requirements. Another objective of this work is to guarantee task performance under user defined joint constraints. Using this methodology, task-based optimal manipulator structures can be generated that guarantee task performance under set operating constraints.