A delayed force-reflecting haptic controller for master–slave neurosurgical robots

Abstract

This paper presents a new force-reflecting control system for master-slave haptic devices. This controller has been implemented and tested on the robotic systems for minimally invasive neurosurgery developed by our Research Group. Robot-assisted surgery is a very valuable treatment, since it allows benefits of high precision, accuracy, and repeatability of robotic devices. The proposed controller is meant to be used for master-slave haptic robotic surgery, but it can be used for any device that provides haptic feedback. The new controller merges the paradigms of force reflection (FR) control and delayed reference control. Unlike the FR control, the proposed solution enhances the safety since it does not allow an unwanted motion of the slave device once the operator releases the haptic controller. Experimental tests are provided to show the capabilities and the performance of the controller. Closed-loop stability is investigated both theoretically and experimentally. The analytic results on stability impose a limit on the ratio between the measured contact force and the sampling frequency of the closed-loop controller.

Deformation Control in Rest‐to‐Rest Motion of Mechanisms with Flexible Links

“…For the same reason, DRC schemes are sometimes referred to as "nontime-based" controllers, since the position reference is not explicitly defined as a function of the time. The concept of non-time-based control for dynamic systems, also referred to as "event-based" control, has been introduced in the 90s, and several successful controllers have been proposed thereafter, for instance, in neurosurgery [14], manufacturing processes [15], coordinated motion control [16], and robot control [17].…”