Communication delay and jitter influence on bilateral teleoperation

One of the most challenging problems during the design of bilateral teleoperation systems implemented over Wide Area Networks is to assure the stability and transparency in the presence of time varying communication delay between the master and the slave. In this work the influence of the delay and jitter on the passivity controller - passivity observer type stabilizers is analyzed. This control design approach does not require the explicit knowledge on the communication delay. In spite of this fact in this work it is shown that time varying the delay influences the teleoperation performances. Firstly, the relation between the delay and the dissipated energy by the controller was studied. Secondly, it was shown that in the presence of jitter the passivity controller can induce undesired oscillations into the received signals, affecting the transparency of the teleoperation. To handle this problem an extended passivity controller was proposed which assures better performances in the presence of jitter. Experimental measurements, including teleoperation experiments between two universities situated in different countries, are performed to validate the theoretical results.