SpectraTac: A Compact Camera-Free Optical Tactile Sensor with Distributed Color Sensing

2026-08-31

AI Summary

本文介绍了一种无摄像头的光学触觉传感器SpectraTac，通过分布式色彩感应方法解决了在保持硬件紧凑、低成本和低计算开销的同时获取丰富触觉信息的问题。

Abstract

Tactile sensing is essential for physical interaction in robotics and human--machine systems. However, combining rich tactile information with compact hardware, low cost, and low computational overhead remains challenging. This work presents SpectraTac, a compact, camera-free optical tactile sensor that combines active red--green--blue (RGB) illumination with spatially distributed color sensing. Contact deforms a compliant transparent elastomer and modulates its internal light field, producing spatially differentiated changes in color and intensity. Three distributed color sensors capture these responses as low-dimensional spatio-spectral features, avoiding cameras, imaging optics, and high-dimensional image processing. The device measures 19.2 mm in diameter and 4 mm in height, with a material cost below USD~5. A data-driven decoding framework simultaneously estimates three-dimensional (3D) force and the contact region from the optical measurements. For 3D force prediction, the sensor achieved mean absolute errors (MAEs) of 0.161, 0.164, and 0.429 N along the x-, y-, and z-axes, respectively. The nine-region contact-classification accuracy was 99.9%. We further evaluated real-time 3D force tracking and contact-region-based human--machine interaction through an interactive control task. These results indicate that distributed color-resolved optical sensing offers a compact, low-cost alternative to camera-based tactile sensing for robotics, wearable sensing, and interactive systems.

Problem

• tactile sensing
• compact hardware
• low cost
• low computational overhead

Innovation

• compact optical tactile sensor
• distributed color sensing
• low-dimensional spatio-spectral features
• 3D force estimation