Active milliseconds zooming and tracking optics based on liquid lenses and a high-speed gaze controller

Abstract

The traditional method of monitoring cameras is employed in robot vision, surveillance cameras, and so on. However, it cannot track as fast as expected due to the large inertia of the camera and mechanical pan-tilt. It also decreases the optical resolution because of the digital zoom on the interest area. Therefore, we proposed high-speed zooming and tracking optics that consists of an optical zooming unit and an active tracking unit. The two units are designed with coaxial optical paths by a beam splitter. The zooming unit is built with three liquid lenses, one glass lens, and a high-speed camera. It can continuously change the magnification from 1x to 2x. By controlling the optical powers of three liquid lenses, the focal length of the zooming unit can be changed from 40 to 80 mm within milliseconds. The tracking unit composed of a high-speed mirror-based gaze controller, a high-speed camera, and pupil shift optics, can track the object and keep it in the center of both views. In addition, the zooming unit provides a compensation algorithm for the zooming unit to achieve adaptive zoom accurately. The experiment shows that the zooming unit performs adaptive optical zoom, and the tracking unit recognizes the object by adaptive tracking algorithm within 6 milliseconds.