Real‐time tracking of free object based on measurement and synthesis of range image sequence

Measurement and recognition of moving objects by a visual system is crucial to realization of robots that can handle a changing environment flexibly. In this article, we propose a system that tracks 6-DOF motion of a solid object of any shape in real time using a range image sequence. We compare range images measured by the Silicon Range Finder high-speed range image sensor with those synthesized from a computer model, and we assert that motion can be estimated independently of the form of objects. Furthermore, we propose a method to generate range images from a model very rapidly with CG rendering hardware. We also describe a process to model the shape of objects simultaneously with tracking, and a method to keep the object within the measurement region by rotating the measurement direction of the sensors. We performed experiments to verify the effectiveness of our method and found that all processes were performed at a speed of 7 frames per second and that the measurement errors were less than 1% of the scope of measurement. © 1999 Scripta Technica, Syst Comp Jpn, 30(5): 56–64, 1999