MetaSonic: Advancing Robot Localization with Directional Embedded Acoustic Signals

Indoor positioning in environments where GPS cannot be used is a fundamental technology for robotics navigation and human-robot interaction. However, existing vision-based localization systems cannot work in dark environments, and existing wireless or acoustic localization systems require specific transceivers, making them expensive and power-intensive — particularly challenging for micro-robots. This paper proposes a new metasurface-assisted ultrasound positioning system. The key idea is to use a low-cost passive acoustic metasurface to transfer any speaker into a directional ultrasound source, with the acoustic spectrum varying based on direction. This allows any microrobot with a simple, low-cost microphone to capture such modified sound to identify the direction of the sound source. We develop a lightweight convolutional neural network-based localization algorithm that can be efficiently deployed on low-power microcontrollers.

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Anchor Deployment

Our localization scenarios are evaluated in the following three rooms: a 3.5 m × 4 m small room, a 2 m × 14 m lobby, and a 5 m × 12 m large room. Four anchors are deployed in each scene. The deployment of anchors is as follows.

Demo Video

The video demonstrates a scenario where four anchors are deployed in the environment. As the robot moves, the spectrograms of the four anchors, as perceived by the robot, dynamically change with variations in position.

References

To cite our paper, use the following BibTeX entry:

@article{wang2025metasonic,
  title={MetaSonic: Advancing Robot Localization with Directional Embedded Acoustic Signals},
  author={Wang, Junling and An, Zhenlin and Guo, Yi},
  journal={IEEE Robotics and Automation Letters},
  year={2025},
  publisher={IEEE}
}