Smith predictor correction by time delay estimation with communication disturbance observer

In the last years the demand for haptic system increased, in order to perform most safe surgical operation or to control robot system with better feedback. Haptic system is a control method that allow to feel the response not only of position and velocity but also of force in the master side. The possible applications of such technology are quite wide, and they spread from surgery to industrial application, but not only. If it is used in an offline system, time delay could be easily estimated and there are usually no variations in it, allowing to use simple control system as Smith’s predictor. However, when a haptic system is used online, the time delay between master and slave system is not known and often not constant, since it depends mainly on internet delay. For this reason, it would be interesting to know this value time by time to implement a better control system based on the real time delay and not on an estimated and variable one