Hierarchical Intention Tracking for Robust Human-Robot Collaboration in Industrial Assembly Tasks

Abstract

Collaborative robots require effective human intention estimation to safely and smoothly work with humans in less structured tasks such as industrial assembly, where human intention continuously changes. We propose the concept of intention tracking and introduce a collaborative robot system that concurrently tracks intentions at hierarchical levels. The high-level intention is tracked to estimate human’s interaction pattern and enable robot to (1) avoid collision with human to minimize interruption and (2) assist human to correct failure. The low-level intention estimate provides robot with task related

information. We implement the system on a UR5e robot and demonstrate robust, seamless and ergonomic human-robot collaboration in an ablative pilot study of an assembly use case.

Method

In less structured human-robot collaboration tasks,

• human intention usually changes at different stages;

• human intention is often composed of a multi-layer hierarchy.

To take these factors into account,

• we derive intention tracking with a graphical model of human-robot collaboration where human intention is a Markov process;

• we extend intention tracking to intention hierarchy with arbitrary number of layers.