Active camera control with obstacle avoidance for remote operations with industrial manipulators: Implementation and experimental results

Abstract

Abstract-Remote controlled robots on offshore oil and gas platforms can potentially reduce costs and improve environment, health and safety issues. A key to successful remote control is to provide onshore operators with a sufficient overview of the processes offshore. To this end, robot manipulators constitute flexible camera platforms, compared to e.g. simple pantilt units, for monitoring offshore operations. In this paper, we present a system solution and experimental results for real-time active camera control with obstacle avoidance for industrial manipulators based on weighted pseudoinverse redundancy resolution method. We extend the pseudoinverse solution for joint limit avoidance in combination with obstacle avoidance such that joint limits are graceful avoided. A novel choice of stereographic projection provides robustness with respect global stability and singularities. Implementation issues are addressed and the monitoring approach is experimentally validated on two Kuka KR-16 robot manipulators. Experimental results show that a follower robot with a camera is able to monitor and track a leader robot while simultaneously avoiding collisions. In addition, a robot control system architecture which ensures efficient and safe testing of new Matlab-implemented robot controllers is presented.

A Learning Camera Platform for Remote Operations with Industrial Manipulators

“…Both manipulators' joint configuration states q, or respective wrist operational space states p, may be retrieved. We refer the reader to Bjerkeng et al (2011b) for more specifics on this architecture.…”

“…The algorithm of Bjerkeng et al (2011b), summarized in section 2.3, is implemented as a Matlab-based controller on top of this architecture. The controller is interfaced through setting the current operation manipulator wrist coordinates, the requested zoom distance, as well as a maximum increment parameter controlling the dynamic properties of the camera platform manipulator.…”

“…We base our control strategy on the active camera control algorithm of Bjerkeng et al (2011b). This algorithm makes the camera platform tool point to the wrist of the operation manipulator at a set distance which we denote the zoom distance, as shown in Fig.…”

Stereographic projection for industrial manipulator tasks: Theory and experiments

“…This provides the operator with a clear view of the operation performed with the GR. Further details regarding the experiment, laboratory setup and the computer system used is found in [17].…”

“…The control law proposed in this paper and the experimental system used is further elaborated on in [17]. Pseudoinverse weighting and nullspace control is used to achieve obstacle avoidance while respecting the inherent joint range limitations With the current approach, the follower's knowledge of the leader's state is limited to position measurements.…”