An Optimization Based Vision Calibration Method for PTZ Camera's Errors in Model and Execution

Abstract

Traditional vision calibration methods only consider the identification of intrinsic and extrinsic parameters of camera. However, if merely traditional methods are used, too much deviation on target locating for biped walking robot, which camera sensor is mounted on a pan-tilt unit, would caused by unavailability of distance from pan-tilt unit to imaging plane and the inevitable error in execution of pan-tilt unit. In this paper we present an optimization based vision calibration method for errors in model and execution of pan-tilt unit in humanoid robot. This calibration method is constructed as an optimization problem to simultaneously get intrinsic and extrinsic parameters of camera, mechanical installation error, and pan-tilt unit's operation error to guarantee the accuracy of target locating. The effectiveness of the method proposed has been validated on the kid size humanoid robot Wukong.