Patent ID: 7417563
Filing Date: 2008-08-26
Classification: G01D

Abstract:
1. A method for determining the absolute value of a rotational angle, the method comprising: imaging a continuous segment of a code track of a code carrier on a sensor array such that the sensor array generates a corresponding output signal, wherein the code track includes a code provided over an angular range of 360°, wherein the code contains a plurality of code words with each code word respectively corresponding to an angular value in the angular range; correlating the output signal with a reference signal in a correlation filter to produce a correlation function signal, wherein the reference signal is indicative of the code and the angular values corresponding to the code words; and processing the correlation function signal to determine the code word of the imaged segment of the code track as a function of the angular value where the output signal best coincides with the reference signal, wherein processing the correlation function signal includes determining the maximum value of the correlation function signal in a maximum value filter and determining the angular value where the output signal best coincides with the reference signal as the angular value corresponding to the maximum value of the correlation function signal.