Motion Planning for Intelligent Manipulations by Sliding Operations with Parallel Two-fingered Grippers.

Abstract

Human beings have various manipulation skills and execute tasks using them intelligently. Intelligent manipulation is a series of manipulation skills combined to execute a task. However robot manipulation skills in practical use are limited to pick-and-place operations, i.e. to move an object grasping fixedly. There have been previously some researches on intelligent manipulations by pick-and-place operations. But the problem is that, when using only pickand-place operations in some environments, it may happen that the goal cannot be achieved or the motions become uneffective. This paper describes a motion planning system using not only pick-and-place operations but also sliding operations with a parallel two-fingered gripper. This system can plan manipulator motions which we have failed to plan before or which are more efficient using sliding operations in addition to pick-and-place operations. The motions are ones to escape an object from situations where the gripper cannot grasp some parts of it. In the following, first we describe the situations and actions to escape from there. Then we propose a new method to plan the manipulator motions using sliding and pick-and-place operations based on geometrical information.