Patent ID: 7541802
Filing Date: 2009-06-02
Classification: G01D

Abstract:
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.