Binocular Visual Tracking : Integration of Perception and Control

This paper presents an active binocular tracking system including both the perceptual and control points of view. In the perceptual part, a signiicant aspect is that we make use of a space variant sensor geometry implementing a focus of attention in the center of the visual eld, which favours the tracking process. Simple and fast low-level vision algorithms are employed, allowing real-time (16.7 Hz) and reliable performance. The control part is developed according to the visual servoing framework, including the kinematics and dynamics of our system. We show that under certain assumptions the kinematic relations in our system become very simple and decoupled as well as system dynamics can be expressed in the image feature space. These facts allow the design of simple dynamic controllers for each degree of freedom directly from the image feature space properties. The overall system is implemented in the Medusa stereo head without any speciic processing hardware. Results of tracking experiments are presented and illustrate the performance of the system with diierent control strategies and with objects of diierent shapes and motions.