Keeping multiple objects in the field of view of a single PTZ camera

This paper introduces a novel visual servo controller designed to keep multiple moving objects in the camera field-of-view using a pan/tilt/zoom camera. In contrast to most visual servo controllers, there is no goal pose or goal image. In this paper, a set of task functions are developed to regulate the mean and variance of a set of image features. Regulating these task functions will deter feature points from leaving the camera field-of-view. An additional task function is used to maintain a high level of motion perceptibility, which ensures that desired feature point velocities can be achieved. To provide proper control of a pan/tilt/zoom camera, an image Jacobian is developed utilizing actuation of the focal length. Simulations of several object tracking tasks have verified the performance of the proposed method.