Benchmarking Shortcutting Techniques for Multi-Robot Arm Motion Planning

Philip Huang1        Yorai Shaoul1        Jiaoyang Li1
        1Carnegie Mellon University

Motivation

Motion Planning techniques such as RRT can produce paths that are long or jerky.
Shortcutting Teaser Image
For multiple robot arms, shortcutting the path of one robot may introduce collisions with other robots.
The specifics of shortcutting techniques are often overlooked or vague in existing multi-arm planning literature.

Abstract

Generating high-quality motion plans for multiple robot arms is challenging due to the high degrees of freedom and potential for inter-arm collisions. Traditional motion planning methods often produce motions that are suboptimal in terms of smoothness and execution time for multi-arm systems. Post-processing via shortcutting is a common approach to improve motion quality for efficient and smooth execution. However, in multi-arm scenarios, optimizing one arm’s motion must not introduce collisions with other arms. While existing multi-arm planning works often use some form of shortcutting techniques, their exact methodology and impact on performance are often vaguely described. In this work, we present a comprehensive study quantitatively comparing existing shortcutting methods for multi-arm trajectories across diverse simulated scenarios. We carefully analyze the pros and cons of each shortcutting method and propose a simple strategy for combining these methods to achieve the best performance-runtime tradeoff.

Dataset

We benchmark shortcutting techniques across a variety of multi-robot arm configurations and tasks, with 1034 multi-arm trajectories in total generated by two motion planning algorithms.

Dual Yaskawa GP4 Robots

Dual GP4 Robots

Four Panda Robots with Bins

Four Pandas & Bins

Four Panda Robots Setup

Four Pandas Setup

Three Panda Robots Setup

Three Pandas Setup

Two Panda Robots Setup

Two Pandas Setup

Two Panda Robots with Rod

Two Pandas & Rod

Method Overview

We evaluate several shortcutting approaches for multi-robot arm trajectories:

Composite Shortcutting Method

Composite Shortcutting

Prioritized Shortcutting Method

Prioritized Shortcutting

Path Shortcutting Method

Path Shortcutting

Method Labels

and propose a simple strategy for combining these methods to achieve the best performance-runtime tradeoff.

Results

Our benchmarking highlights the performance of different shortcutting techniques:

Benchmarking Results

BibTeX

@misc{Huang2025BenchmarkingShortcut,
        author    = {Philip Huang and Yorai Shaoul and Jiaoyang Li},
        title     = {Benchmarking Shortcutting Techniques for Multi-Robot Arm Motion Planning},
        year      = {2025},
        howpublished = {\url{https://philip-huang.github.io/mr-shortcut/}},
        note      = {Website}
      }

Related Works

This work is part of our research on Multi-Robot Task and Motion Planning. Please explore our other works below.
RMA Image

APEX-MR: Multi-Robot Asynchronous Planning and Execution for Cooperative Assembly

Philip Huang*, Ruixuan Liu*, Shobhit Aggarwal, Changliu Liu, and Jiaoyang Li
RSS, 2025

Paper Website

RMA Image

Cooperative Task and Motion Planning for Multi-Arm Assembly Systems

Jingkai Chen, Jiaoyang Li, Yijiang Huang, Caelan Garrett, Dawei Sun, Chuchu Fan, Andreas Hofmann, Caitlin Mueller, Sven Koenig, Brian C. Williams
arXiv, 2022

Paper Video

RMA Image

Accelerating Search-Based Planning for Multi-Robot Manipulation by Leveraging Online-Generated Experiences

Yorai Shaoul*, Itamar Mishani*, Maxim Likhachev, Jiaoyang Li
International Conference on Automated Planning and Scheduling (ICAPS), 2024

Paper website

RMA Image

Unconstraining Multi-Robot Manipulation: Enabling Arbitrary Constraints in ECBS with Bounded Sub-Optimality

Yorai Shaoul*, Rishi Veerapaneni*, Maxim Likhachev, Jiaoyang Li
International Symposium on Combinatorial Search (SoCS), 2024

Paper