Lessons Learned Developing an Assembly System for WRS 2020 Assembly Challenge

Abstract

The World Robot Summit (WRS) 2020 Assembly Challenge is designed to allow teams to demonstrate how one can build flexible, robust systems for assembly of machined objects. We present our approach to assembly based on integration of machine vision, robust planning and execution using behavior trees and a hierarchy of recovery strategies to ensure robust operation. Our system was selected for the WRS 2020 Assembly Challenge finals based on robust performance in the qualifying rounds. We present the systems approach adopted for the challenge.

Optimal decision making in robotic assembly and other trial-and-error tasks

“…In [20], the iTASC [21] framework is proposed, but reaches its limitations in automatically sequencing behavior primitives. Using Behavior Trees (BTs) for enhanced robustness of the assembly process has been suggested in [22], and BTs have been extended to stochastic behavior trees to reflect the different outcomes, and associated behavior therewith, that a robotic experiment can take. In [23] a discrete time Markov chain framework has been proposed, but only considers true positive and true negative outcomes.…”