The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2007
Filed:
Jan. 27, 2006
John A. Stolan, San Jose, CA (US);
John A. Stolan, San Jose, CA (US);
Alliant Techsystems Inc., Edina, MN (US);
Abstract
An apparatus and method for determining an angular position of a shaft are disclosed, which comprise resolving an excitation signal at an excitation frequency into at least two orthogonal signals, converting the orthogonal signals to a digital estimate, for each of the orthogonal signals, and evaluating an amplitude and a polarity of the orthogonal signals to determine the angular position. The process of converting the orthogonal signals comprises comparing the orthogonal signal to an analog feedback signal to generate a comparison result and incrementally adjusting the digital estimate in response to sampling the comparison result at an estimation frequency. The converting process also includes converting the digital estimate to the analog feedback signal, collecting a digital estimate history at a sample frequency that is a binary multiple of the excitation frequency, and analyzing the digital estimate history to determine the amplitude and the polarity substantially near the excitation frequency.