| US 7,541,802 B2 | ||
| Method and apparatus for evaluating a sensor signal associated with a rotating object | ||
| Simon Hainz, Villach (Austria); Dirk Hammerschmidt, Villach (Austria); and Tobias Werth, Villach (Austria) | ||
| Assigned to Infineon Technologies AG, Munich (Germany) | ||
| Filed on Dec. 08, 2006, as Appl. No. 11/636,178. | ||
| Prior Publication US 2008/0136406 A1, Jun. 12, 2008 | ||
| Int. Cl. G01R 33/025 (2006.01); G01B 7/30 (2006.01); G01P 3/487 (2006.01) | ||
| U.S. Cl. 324—207.12 [324/207.25; 324/173] | 14 Claims |
| 1. A method for evaluating a sensor signal provided by a magnetic field sensor which is arranged at a distance from an object
which is rotatable about an axis of rotation comprising:
defining an encoding pattern with a sequence of symbols, the sensor signal being dependent on the encoding pattern and at
least one physical parameter;
regenerating the symbols of the encoding pattern from a corrected sensor signal using a threshold value detector to obtain
an output signal;
generating a filtered signal from the output signal using a filter having a plurality of filter coefficients;
superposing the sensor signal and the filtered signal to obtain the corrected sensor signal; and
wherein the corrected sensor signal and the output signal are used to estimate the at least one physical parameter, and the
filter coefficients are derived from the estimated physical parameter, and wherein the at least one physical parameter is
an air gap length.
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