A Thin Pinhole-Based Tactile Sensor With Rotational Scanning for Field-of-View Expansion

Vision-based tactile sensors (VBTSs) play a crucial role in robotic manipulation tasks that require high-resolution contact information. However, existing VBTS designs (i.e. the GelSight sensors) often suffer from excessive bulk due to the use of traditional optical lenses. Recently, pinhole-based imaging has been introduced as a means of reducing sensor thickness. Despite its success, the approach significantly restricts the sensor’s field of view (FOV). In this paper, we propose a novel VBTS architecture that overcomes the limitation through the integration of a rotating pinhole mechanism. By rotating the sensing module, the sensor captures a series of overlapping tactile images from distinct viewpoints. The image series is then computationally fused into a single composite one to effectively expand the overall sensing area. The proposed design achieves an approximately twofold increase in FOV compared to conventional configurations. Comparative experiments demonstrate the sensor’s capability for accurate 3D surface reconstruction, highlighting its potential for compact and versatile tactile sensing applications.