Overcoming Current Quantization Effects for Precise Current Control using Dithering Techniques

カテゴリ: 論文誌(論文単位)

グループ名: 【D】産業応用部門（英文）

発行日: 2013/01/01

タイトル(英語): Overcoming Current Quantization Effects for Precise Current Control using Dithering Techniques

著者名: Hongzhong Zhu (Department of Electrical Engineering, The University of Tokyo), Hiroshi Fujimoto (Department of Electrical Engineering, The University of Tokyo)

著者名(英語): Hongzhong Zhu (Department of Electrical Engineering, The University of Tokyo), Hiroshi Fujimoto (Department of Electrical Engineering, The University of Tokyo)

キーワード: dither，quantization，analog-to-digital converter，current control，AC motor

要約(英語): Accurate current signals are required for precise current control of AC motor drives. However, current measurement errors that involve metering error and quantization error are unavoidable because of the inaccuracy of current sensors and the quantizing feature of analog-to-digital converters in all digital motion control systems. The quantization error contains harmonic components that can induce torque ripple, thus deteriorating the control performance. Therefore, it is necessary to suppress the quantization effects. In this paper, two dithered systems, namely, the subtractively dithered system and nonsubtractively dithered system, are presented in order to remove the quantization-based harmonic components of the measured current signals by whitening the quantization error. Moreover, for ease of practical implementation, the design of dither signals is analyzed for nonsubtractively dithered system, considering cases where the metering error is uniform noise or Gaussian noise. It is shown that by applying the dither having a suitably chosen probability density function, the total measurement error can be rendered spectrally white. The effectiveness of the proposed methods is verified through simulations and experiments using a high-precision linear stage.

本誌: IEEJ Journal of Industry Applications Vol.2 No.1 （2013） Special Issue on Motion Control and its Related Technologies

本誌掲載ページ: 14-21 p

原稿種別: 論文／英語

電子版へのリンク: https://www.jstage.jst.go.jp/article/ieejjia/2/1/2_14/_article/-char/ja/