Abstract
This paper introduces a multirate sampling visual feedback control technique on an active vision system using parallel mechanism. Active vision systems are mechanical systems that consist of multidegrees of freedom machines and vision sensors, and the systems perform track target points. The proposed system is based on a six degrees of freedom parallel mechanism and a vision sensor which is set on the motion base plate of the mechanism. Even if the target is a point on 3D space, the point is expressed as a 2D point on the screen of the vision system. Then, the active vision system has four degrees of redundancy. Making use of zero space ralated to the redundancy, the proposed system has the tracking functions realized by basic, translation, and orientation control modes. On the other hand, there is a problem that control performance of the system is not high because of long operating time of the vision sensor relative to sampling ratio of the motor control. In order to improve the control performance, this paper introduces an image based visual feedback controller including multirate sampling disturbance observer. Finally, experimental results are shown for evaluation.
