Challenges of robustness/transparency of scaled bilateral teleoperation systems

This paper presents a force-reflecting scaled teleoperator operating in a remote micro environment. Due to the transmission time delay, it is very difficult to ensure a tradeoff between robustness/transparency performances. Then, in order to manipulate micro-object it is inevitable to consider the scaling effect problem between worlds with different physical characteristics, with minimal loss of physical information and robustness against variation of scaling gains. Accordingly, in this paper, challenges of robustness/transparency of scaled bilateral controllers are designed based on the framework bilateral generalized predictive controller (BGPC) and H_infin loop shaping procedure design (LSPD) techniques. These approaches allows a convenient means to achieve robustness for large time-delay margins, variation of force scaling factors and uncertainties in master and slave modelling. Furthermore, both BGPC and LSPD improve the force transparency limitations due to different scaled manipulation worlds. A study of robustness/transparency performances is carried out in order to compare BGPC and H_infin bilateral controllers.