A Comprehensive Architecture for Dynamic Role Allocation and Collaborative Task Planning in Mixed Human-Robot Teams

Abstract

The growing deployment of human-robot collaborative processes in several industrial applications, such as handling, welding, and assembly, unfolds the pursuit of systems which are able to manage large heterogeneous teams and, at the same time, monitor the execution of complex tasks. In this paper, we present a novel architecture for dynamic role allocation and collaborative task planning in a mixed human-robot team of arbitrary size. The architecture capitalizes on a centralized reactive and modular task-agnostic planning method based on Behavior Trees (BTs), in charge of actions scheduling, while the allocation problem is formulated through a Mixed-Integer Linear Program (MILP), that assigns dynamically individual roles or collaborations to the agents of the team. Different metrics used as MILP cost allow the architecture to favor various aspects of the collaboration (e.g. makespan, ergonomics, human preferences). Human preference are identified through a negotiation phase, in which, an human agent can accept/refuse to execute the assigned task. In addition, bilateral communication between humans and the system is achieved through an Augmented Reality (AR) custom user interface that provides intuitive functionalities to assist and coordinate workers in different action phases. The computational complexity of the proposed methodology outperforms literature approaches in industrial sized jobs and teams (problems up to 50 actions and 20 agents in the team with collaborations are solved within 1 s). The different allocated roles, as the cost functions change, highlights the flexibility of the architecture to several production requirements. Finally, the subjective evaluation demonstrating the high usability level and the suitability for the targeted scenario.

AR-supported Human-Robot Collaboration: Facilitating Workspace Awareness and Parallelized Assembly Tasks

“…The most recent attempts to implement dynamic task allocation [45] found it to reduce the overall cycle time compared to both manual assembly and static task allocation, however, only used a tablet as a user interface. While Lamon et al [30] used AR for their comprehensive architecture for dynamic role allocation and collaborative task planning in mixed human-robot teams, their interface and user study are focused on task allocation.…”

“…Recent years have seen an increase in research for supporting collaboration between humans and robots [39]. Augmented reality (AR) has shown great promise to support this collaboration [51], in particular within: communicating robot intent (e.g., [2,44,52]), dynamic task allocation (e.g., [30,45]), and step-by-step instructions (e.g., [3,19]). These works show promising results within their individual subjects, however, there is a lack of work that explores how these topics influence each other.…”