Optimal Projection Pattern for Active Visual Servoing (AVS)

Visual servo control uses images that are obtained by a camera for robotic control. This study focuses on the problem of positioning a target object using a robotic manipulator with image-based visual servo (IBVS) control. To perform the positioning task, IBVS requires visual features that can be extracted from the appearance of the target object. Therefore, a positioning error tends to increase especially for textureless objects, such as industrial parts, since it is difficult to extract differences of the visual features between current and goal images. To solve these problems, this paper presents a novel visual servoing named “Active Visual Servoing." Active Visual Servoing (AVS) projects patterned light onto the target object using a projector. The design of the projection pattern affects the positioning error. AVS uses an optimal pattern which is theoretically derived and maximizes differences between current and goal images. The experimental results show that the proposed AVS reduces the positioning error by more than 59% compared to conventional IBVS.