A Sequential Hermaphrodite Coupling Mechanism for Lattice-based Modular Robots

2025-12-28

AI Summary

Large-scale lattice modular robot construction for extreme environments—such as space—faces critical challenges: achieving unilateral autonomous coupling/decoupling of heterogeneous modules, ensuring surface planarity in the decoupled state, and supporting both active and passive interface compatibility. This paper introduces a novel sequential hermaphroditic mechanical coupling mechanism: modules are fully female in the decoupled state to guarantee surface flatness; during coupling, unilateral controlled reconfiguration to male enables single-sided operation; upon decoupling, bidirectional forced reversion to female ensures full reversibility. The mechanism relies solely on shape-matching geometry—requiring no sensors or external power—while enabling passive docking and compatibility with robotic end-effector quick-change systems. Experimental validation confirms its reliability in unilateral operation, surface planarity, and cross-module interoperability. This work provides a general-purpose coupling solution applicable to diverse lattice architectures and tool-swapping scenarios.

Technology Category

• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Multiagent Systems: Mechanism Design
• Computer Vision: Multi-modal Vision

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments

Abstract

Lattice-based modular robot systems are envisioned for large-scale construction in extreme environments, such as space. Coupling mechanisms for heterogeneous structural modules should meet all of the following requirements: single-sided coupling and decoupling, flat surfaces when uncoupled, and coupling to passive coupling interfaces as well as coupling behavior between coupling mechanisms. The design requirements for such a coupling mechanism are complex. We propose a novel shape-matching mechanical coupling mechanism that satisfies these design requirements. This mechanism enables controlled, sequential transitions between male and female states. When uncoupled, all mechanisms are in the female state. To enable single-sided coupling, one side of the mechanisms switches to the male state during the coupling process. Single-sided decoupling is possible not only from the male side but also from the female side by forcibly switching the opposite mechanism's male state to the female state. This coupling mechanism can be applied to various modular robot systems and robot arm tool changers.

Problem

• Designing a single-sided coupling mechanism for heterogeneous modular robots
• Enabling sequential male-female state transitions for controlled coupling
• Achieving decoupling from both male and female sides in modular systems

Innovation

• Sequential hermaphrodite coupling for modular robots
• Shape-matching mechanism enabling male-female state transitions
• Single-sided coupling and decoupling with flat uncoupled surfaces