A Visual Servoing with Collision Avoidance Mechanism for Redundant Manipulators

This paper presents a visual servoing method for a redundant manipulator to control quickly and accurately by image error in a complicated environment. The proposed approach combines two parts, one is position-based visual servoing, and another is avoiding obstacles by using virtual repulsive torque. The image features are found and mapped by Oriented FAST and Rotated BRIEF (ORB) and the image errors are calculated. Furthermore, the object pose is estimated in the world coordinate by the image errors and the current pose of the manipulator and the target EOAT pose compute will be obtained. After confirming the EOAT pose, this method introduces a virtual repulsive torque for solving generalized inverse kinematics problems by analytical and numerical methods. The proposed approach uses the property of the redundant manipulator to maintain the distance between links and obstacles. For the applicability, we transform the programs to the nodes and use Robot Operating System as the core to build the communication protocol for exchanging information. The validity and efficiency of the proposed method are measured in simulations, by which it verifies that the method is not only feasible to constrained motions but also has good performances in collision avoidance.