解角/數位轉換器已廣泛使用在工業應用之中，用以提供準確的位置資訊；解角/數位轉換器的準確度卻與位置感測訊號有關，然而沒有任何一個位置感測器能提供理想的位置訊號，位置感測訊號的非理想特性主要為：振幅不平衡、正交誤差、直流偏差與諧波失真。
本文提出小波轉換應用於解角/數位轉換器，以解決位置感測訊號的非理想特性所造成的轉換誤差。小波轉換同時具有時域與頻域的資訊，且有多層解析的能力，可以解決位置感測訊號中直流偏差與諧波失真的非理想特性；接著本文進ㄧ步利用振幅相位補償法得到振幅與相位的修正因子，用以消減位置感測訊號中振幅不平衡與正交誤差的非理想特性。經此處理後建立誤差補償表，可提供及時的誤差補償，此為一種自我校正的補償。
本文以光碟機主軸馬達為研究對象，其位置感測器為霍爾元件；實驗硬體架構方面先建構實驗平台與周邊電路，再以複雜可程式邏輯元件設計解角/數位轉換器；以小波轉換消除霍爾訊號的非理想特性提升解角/數位轉換器的準確度。最後，以實驗來驗證其有效性。

Abstract

Resolver-to-Digital Converter (RDC) can offer accurate position information and has been applied to many industrial applications. The accuracy of a RDC depends on the signals of position sensor, but no sensor generates ideal signal in reality. The main non-ideal characteristics of position sensor signals are: imbalanced amplitude, imperfect quadrature, noticeable dc offset and harmonics distortion.

This thesis presents a wavelet transform based RDC design to reduce the error caused by these non-ideal characteristics. The wavelet transform has good properties both in time and frequency domain and is capable of multi-resolution analysis (MRA). The wavelet transform can effectively reduce the dc offset and harmonics distortion. Then combing with the gain-phase correction scheme can eliminate the imbalanced amplitude and imperfect quadrature further. After this processing, an error compensation table can be built upon to provide a real-time error compensation. This is a self- calibrating scheme.

The plant under study in the thesis is the spindle of an optical disk drive. The position sensor of the spindle is three Hall sensors with 1200 apart spatially. First, an experiment platform and peripheral circuits were devised. Then a RDC was implemented utilizing the CPLD (Complex Programmable Logic Device). The signals of Hall sensors were processed adopted using wavelet transform to eliminate the non-ideal characteristics. Thus the accuracy of RDC can be enhanced. Experiments were performed to show its efficacy.

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