Tuning the gains of haptic couplings to improve force feedback stability in nanorobotics

This paper deals with the problem of bilateral haptic control in nanorobotics. At this scale, a human operator cannot interact directly with objects. He needs special tools manipulated through robotic systems. Therefore, force feedback devices are the only solution to provide him a sense of touch. However, the quality of the rendering strongly influences his ability to perform a given task. Stability is the main requirement that the system must fulfil to be usable. As the choice of the controller and its tuning are critical issues, a general method to tune the parameters of two haptic controllers is presented. A theoretical study is carried out and the methodology is validated with an experiment composed of several phases with high dynamic phenomena. Intrinsic limitations of the two controllers are also pointed out.