Opinion

Robotic Manipulation of Deformable Linear Objects: A Survey

Archive editionSofia MarquesSep 15, 2024· 20,007 views

A comprehensive review of modeling, perception, planning, and control for DLOs, highlighting challenges and future directions.

In context

In September 2024, robotic manipulation research was largely focused on rigid objects, leaving deformable linear objects (DLOs) such as cables, ropes, and elastic rods underexplored despite their prevalence in manufacturing, healthcare, and service applications. This survey, published in the journal Robot, provided a timely synthesis of the state of the art and outlined the fundamental challenges that hindered autonomous DLO manipulation.

What was reported

The survey systematically reviewed DLO manipulation from both fundamental and applied perspectives. Fundamental research covered modeling, perception, planning, and control. Modeling approaches were categorized into physics-based methods (e.g., continuum mechanics, mass-spring-damper, position-based dynamics, and Kirchhoff elastic rod models) and data-driven methods using neural networks. Physics-based models offered physical accuracy but were computationally heavy and required manual parameter calibration. Data-driven models avoided complex modeling but demanded large training datasets and struggled with generalization across different DLOs.

Perception challenges included segmenting, detecting, and tracking DLOs in cluttered environments, with methods like FASTDLO and RT-DLO achieving real-time instance segmentation. Planning and control methods were discussed in the context of tasks such as knotting, routing, and insertion, which simplified the problem by exploiting task-specific constraints.

The survey highlighted that DLOs possess high degrees of freedom, strong nonlinearity, and significant variability between individual objects, making them far more difficult to manipulate than rigid bodies. It noted that most existing systems still require substantial human involvement, with automation levels remaining relatively low.

Why it mattered

This survey underscored the growing importance of DLO manipulation for industrial automation, particularly for autonomous assembly of flexible components like cables and PCBs, and for service robots assisting in daily tasks. By identifying key research gaps and future directions, it provided a roadmap for advancing robot dexterity beyond rigid objects, which is essential for the next generation of intelligent manufacturing and human-robot collaboration.

“Deformable linear objects exhibit strong deformation features, complex models, and significant individual differences, making autonomous and dexterous manipulation by robots significantly challenging.”

Source: 《机器人》期刊 (robot.sia.cn) · Published 2024-09-15 · “面向线状柔性物体的机器人操作研究进展与展望”