Active Visual Guidance of Robotic Arm

Abstract

Incorporating vision system to control the robot arms has increasing the accuracy of the hand-eye system decreases the workspace size. This paper describes an approach to control the robot arm using active stereo camera system. The proposed system is able to overcome the about mentioned problem. A new qualitative approach to control the robot arm wing visual feedback is developed. It computes the relative depth between two points from a pair of stereo image. By incorporating this attribute into the image space, a pseudo three-dimensional (3D) image space is obtained. Subsequently, the pseudo image space is used to compute the required transformation from the image space to the robot space. Such an approach does not require the recovery of the intrinsic and extrinsic parameters of the stereo vision system or the 3D coordinates of world space. Therefore, it is robust to changes in the parameters of the vision system and thus allows the integration of active vision system. A method to cater for focal length changes for achieving variable resolution is also described. Experiments are conducted to verify the accuracy and performance of the proposed method.