Controller Design Solutions for Long Distance Telesurgical Applications

Robotic teleoperation has proved to be an effective way to explore remote areas, access dangerous sites, or to provide telepresence. Currently, research projects are pushing the boundaries to develop methods for meaningful health care support through teleoperated robots. Surgical robotics have already shown the feasibility of radical concepts, such as intercontinental surgery, and it is believed that technology will eventually enable to extend its rage to space exploration missions. One of the key problems to tackle is the degrading effect of signal latency on system performance and stability. In this paper, we present a case study investigating solution for handling large delays during real-time teleoperation of a remote surgical robot. Modeling approaches are discussed, and simplified human and machine representations are derived to accommodate long distance telesurgical applications. We have shown that a cascade control structure relying on empirical design can be effectively used in this scenario. A suitable controller was designed based on the extension of Kessler’s methods in the inner loop, supported by predictive technique in the outer loop. Several tuning methods resulting in proportional-integral-derivative (PID) controllers in the outer loop are analyzed. This paper suggests the use of PID–fuzzy controllers to improve the control system performance. The proposed cascade loop may be a good solution to support future teleoperational missions.