Unobstructed Programming-by-Demonstration for Force-Based Assembly Utilizing External Force-Torque Sensors

Abstract

Programming-by-Demonstration (PbD) or Imitation Learning (IL) provides a powerful approach to program robots intuitively. In industrial settings, these approaches are not commonly deployed since several factors negatively impact their productive use. The most common reasons are safety concerns on various levels. First, industrial robots are only allowed to be operated in direct contact if the operator has sufficient experience. Secondly, many PbD systems do not incorporate force measurements in their model directly. This renders them ineffective for assembly tasks, such as snap- fit connections. In this paper we (a) present an approach to incorporate force measurements into a generative model (b) using only external sensors without relying on measurements from the robot during demonstrating to decouple the teaching process from the robot and (c) show the benefit of explicit force measurement and modeling on a Franka Emika Panda robot by the example of assembling terminal clamps on a DIN rail.