Time delay compensation method based on reflected wave rejection

Several time delay compensation methods for teleoperation systems have been researched for a long time (e.g. Smith predictors, communication disturbance observers, etc). Based on the communication disturbance observer, the authors have proposed a vibration suppression scheme for resonant systems, based on reflected wave rejection and a wave compensator. From this method, it is found that vibration in resonant system can be suppressed by making use of a time delay compensation method and it is observed that a reflected wave induces vibrations. Taking a dual approach, this paper proposes a time delay compensation method, based on our previously developed reflected wave rejection, used for the vibration suppression in the resonant system. Firstly, a wave representation of time delay system is derived and an equivalence of wave and time delay systems is clarified. It is also clarified that a cause of vibration in the time delay system is a reflected wave as well as in a resonant system. Finally, it is shown how the reflected wave rejection can be seems as a time delay compensation method, to be used in time delay systems. The validity of the proposed method is verified by the experimental results.