A novel approach for mitigating the effects of pre-rolling/pre-sliding friction on the settling time of rolling bearing nanopositioning stages using high frequency vibration

Nanopositioning stages are used for ultra-precise positioning in many different applications. Among the bearing options available for long-range nanopositioning stages, rolling bearings are the most cost effective. However, rolling bearing nanopositioning (RB-NP) stages are well known to take a long time to reach their target positions in point-to-point positioning tasks due to pre-rolling/pre-sliding friction. This paper presents vibration assisted nanopositioning (VAN) - a novel approach for reducing the settling time of RB-NP stages using high frequency vibration (aka dither). VAN synergistically combines the electromechanical design and control of RB-NP stages to mitigate pre-rolling/pre-sliding friction using dither, without jeopardizing positioning precision. It is shown in simulations to exhibit superior positioning performance and robustness compared to model-based friction compensation methods. Experiments carried out on a prototype stage incorporating the VAN approach show a 52% reduction of mean settling time, based on 50 trials, when compared to a case without VAN. Moreover, the heat and potential wear induced by dither are shown to be practically insignificant.