Joint Task Assistance Planning via Nested Branch and Bound (Extended Version)

TL;DR

This paper presents a nested branch-and-bound algorithm for joint task assistance planning in robotic collaboration, efficiently optimizing robot paths to maximize assistance duration despite complex combinatorial challenges.

Contribution

The paper introduces a novel nested branch-and-bound framework for solving the joint task assistance planning problem, improving computational efficiency over baseline methods.

Findings

Achieves up to 100x speedup compared to baseline

Effectively handles combinatorial explosion in path planning

Demonstrates practical applicability in robotic collaboration scenarios

Abstract

We introduce and study the Joint Task Assistance Planning problem which generalizes prior work on optimizing assistance in robotic collaboration. In this setting, two robots operate over predefined roadmaps, each represented as a graph corresponding to its configuration space. One robot, the task robot, must execute a timed mission, while the other, the assistance robot, provides sensor-based support that depends on their spatial relationship. The objective is to compute a path for both robots that maximizes the total duration of assistance given. Solving this problem is challenging due to the combinatorial explosion of possible path combinations together with the temporal nature of the problem (time needs to be accounted for as well). To address this, we propose a nested branch-and-bound framework that efficiently explores the space of robot paths in a hierarchical manner. We empirically evaluate our algorithm and demonstrate a speedup of up to two orders of magnitude when compared to a baseline approach.