Nanoscale servo control using low precision sensors

The resolution of positioning sensors becomes low relative to the control accuracy in nanoscale control. In this case, the output of the low precision sensor includes quantization error, and the error may degrade the control performance. Thus, in this paper, an estimation problem of the quantization error based on least square method is considered. In the proposed method, the estimation accuracy is improved by taking account the effect of an input disturbance. Moreover, a bias adjustment method is proposed to satisfy the constraints on the quantization error. The effectiveness of the proposed method is demonstrated by simulations and experiments.