Delayed Teleoperation System In Presence of Moving Virtual Fixture

This paper presents a hybrid PD-Based controller for delayed teleoperation systems in presence of moving virtual fixtures. Virtual fixtures in such systems are used to preventslave robots from entering the undesired areas of the workspace. For example, in Minimal Invasive Surgery (MIS), it is veryimportant to restrain the surgical robot. It appears that employing virtual fixtures in bilateral teleoperation systems can make them unstable. In other words, virtual and softwareconstraints, sampling rate and data quantization can cause instability and vibrate the slave robot entering into unauthorizedareas. Another possible reason for instability is time delay in the communication channel. This factor has not been investigated insuch systems so far. To carry out the stability of the closed loopsystem, passivity theorem is utilized. Moreover experimental results demonstrate the performance of the proposed controller with a reasonable accuracy.

Keywords:

Delayed teleoperation system , moving virtual fixture , passivity theory