Multi-robot Rigid Formation Navigation via Synchronous Motion and Discrete-time Communication-Control Optimization

2025-10-02

AI Summary

Coordinating rigid formations of multiple nonholonomic mobile robots along complex curved trajectories under wireless network constraints—characterized by packet loss, latency, and limited computational resources—remains a significant challenge. Method: This paper proposes a “Hold-and-Strike” communication-control framework that integrates discrete-time synchronization with intra-cycle optimization, enabling low-latency, packet-loss-resilient real-time coordination on resource-constrained microprocessors. Implemented as a lightweight ROS-based closed-loop communication-control architecture, it jointly respects kinematic constraints and network-induced uncertainties. Contribution/Results: The framework is experimentally validated on a physical quad-robot square formation tracking an S-shaped trajectory at 0.1 m/s. It achieves mean inter-robot spacing errors ≤ ±0.069 m and heading deviations ≤ ±19.15°, demonstrating substantial improvements in trajectory accuracy and robustness against communication interference compared to prior approaches.

Technology Category

• Intelligent Robots: Localization, Mapping, and Navigation
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Multiagent Systems: Agent Communication

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

Rigid-formation navigation of multiple robots is essential for applications such as cooperative transportation. This process involves a team of collaborative robots maintaining a predefined geometric configuration, such as a square, while in motion. For untethered collaborative motion, inter-robot communication must be conducted through a wireless network. Notably, few existing works offer a comprehensive solution for multi-robot formation navigation executable on microprocessor platforms via wireless networks, particularly for formations that must traverse complex curvilinear paths. To address this gap, we introduce a novel "hold-and-hit" communication-control framework designed to work seamlessly with the widely-used Robotic Operating System (ROS) platform. The hold-and-hit framework synchronizes robot movements in a manner robust against wireless network delays and packet loss. It operates over discrete-time communication-control cycles, making it suitable for implementation on contemporary microprocessors. Complementary to hold-and-hit, we propose an intra-cycle optimization approach that enables rigid formations to closely follow desired curvilinear paths, even under the nonholonomic movement constraints inherent to most vehicular robots. The combination of hold-and-hit and intra-cycle optimization ensures precise and reliable navigation even in challenging scenarios. Simulations in a virtual environment demonstrate the superiority of our method in maintaining a four-robot square formation along an S-shaped path, outperforming two existing approaches. Furthermore, real-world experiments validate the effectiveness of our framework: the robots maintained an inter-distance error within $pm 0.069m$ and an inter-angular orientation error within $pm19.15^{circ}$ while navigating along an S-shaped path at a fixed linear velocity of $0.1 m/s$.

Problem

• Optimizing multi-robot rigid formation navigation under wireless constraints
• Enabling precise curvilinear path following with nonholonomic robots
• Synchronizing motion robust to network delays and packet loss

Innovation

• Hold-and-hit framework synchronizes robot motion robustly
• Intra-cycle optimization enables rigid formation path following
• Discrete-time communication-control suits microprocessor wireless implementation