Patent ID: 9551562
Date: 2017-01-24
CPC Classifications: G01B,G01D

Claim:
1. A method for determining absolute position of an element mobile in reference to two magneto-sensitive sensors, with a source of a magnetic field being fastened thereat, magnetic features being determined via the magneto-sensitive sensors such that a first sensor signal is measured by a first magneto-sensitive sensor and a second sensor signal by a second magneto-sensitive sensor, with the first sensor signal and the second sensor signal representing a component of the magnetic field and the sensor signals show a phasing φ in the range of 0°<φ<180° or 180°<φ<360°, comprising the following steps implemented by an analog and/or a digital processing unit: determining amplitude ratios by dividing a predetermined signal deviation by a difference of a maximum value and a minimum value of the respective sensor signals, determining off-set values about a respective zero-point of the sensor signals from the minimum and maximum values of the sensor signals, via subtraction of the off-set values from the sensor signals and by scaling with the amplitude ratios, calculating scaled sensor signals, with the determination of the minimum and maximum values occurring by a relative movement of the element and the source of the magnetic field fastened thereat over a full range of motion with simultaneously detecting the sensor signals of both sensors, forming a sum signal and a difference signal from the scaled sensor signals, scaling the sum signal and the difference signal in turn after the determination of the amplitude ratio wherein the determination of the minimum and maximum values occurring by the relative movement of the element and the source of the magnetic field fastened thereat over a full range of movement occurs with simultaneously measuring the sum signal as well as the difference signal, and evaluating the minimum and maximum values of the sum signal and the difference signal, and calculating, via the scaled sum signal and the scaled difference signal, an absolute position of the magnetic field.