Search Strategy for Layered Peg-In-Hole Using Dual Manipulator System

Abstract

This study introduces a novel assembly, layered peg-in-hole, and suggests a search strategy. Distinct from the traditional peg-in-hole assembly, where two workpieces (i.e., peg/hole) are present, the layered peg-in-hole assembly contains three workpieces (i.e., peg, hole, and thru-hole). To handle the additional moving part, the through-hole, without relying on task-specific devices, a dual-manipulator system is preferable to a single manipulator system. However, existing research has primarily concentrated on the traditional peg-in-hole assembly regardless of the number of manipulators. In this respect, as the main contribution, a search strategy is proposed for the layered peg-in-hole assembly, which consists of two phases. In the first phase, both manipulators actively engage in the search task. In the second phase, the compliant behavior of the manipulator grasping the through-hole is advocated to assist the counterpart. Finally, the proposed search strategy is verified through the real robot experiment that replicates an industrial environment with two 7-DOF torque-controlled manipulators.