An accurate 3D localization technique using a single camera and ultrasound

We propose a novel technique for 3D localization that integrates a single camera and ultrasound. We use the Extended Phase Accordance Method and the ultrasound to measure accurately the distance to a moving target and we use the camera to identify the target´s 2D position on the image plane. A prototype system consists of a transmitter unit mounting one ultrasound transmitter and three infrared LEDs around it, and a receiver unit with one inexpensive camera and one ultrasound receiver. We implemented these units in a lightweight and compact way (receiver unit size: 55 mm × 44 mm), to make the system robust against the no-line-of-sight problems that frequently occur in trilateration or multicamera-based systems. Experimental results show that the RMSEs of the proposed system are 1.20 mm and 1.66 mm for static and mobile (velocity: 1.0 m/s) targets, respectively. These indicate that the performance of the system is comparable with that of high-end systems.