Spatial Calibration of Airborne Ultrasound Tactile Display and Projector-Camera System Using Fur Material.

Airborne Ultrasound Tactile Displays (AUTD) are tactile displays that can generate vibrotactile sensation on human skin. Combining an AUTD with a projector-camera system, it is possible to present synchronous visual and haptic stimuli that is physically aligned in the 3D space. To maintain the synchronous sensation as realistic as possible, an accurate crucial to spatial calibration between the AUTD and the projector-camera system is required. This paper thereby proposes a calibration method for the AUTD system by utilizing fur material to recognize the output focal points of an AUTD in the camera coordinate system. Our method simplifies the calibration procedure with calibration error of 2.63 mm.