Patent ID: 9562758
Date: 2017-02-07
CPC Classifications: B60G,G01B

Claim:
1. A distance measuring device comprising: a permanent magnet; an evaluating module; a first magnetic field sensing array; and a second magnetic field sensing array, wherein the first magnetic field sensing array comprises a first magnetic field sensor and a second magnetic field sensor; wherein the first magnetic field sensor is stationary relative to the second magnetic field sensor; wherein the second magnetic field sensing array and the permanent magnet are mountable to move with respect to each other along a movement trajectory, the permanent magnet having a magnetic pole axis substantially aligned with the movement trajectory, wherein the first magnetic field sensing array is offset from the movement trajectory by a predetermined distance, wherein an angle between the movement trajectory and a horizontal axis between the second magnetic field sensing array and the first magnetic field sensing array is substantially orthogonal, wherein the first magnetic field sensing array and the second magnetic field sensing array sense signals from the permanent magnet, the signals being transferred from the first magnetic field sensing array and the second magnetic field sensing array to the evaluating module, and wherein the evaluating module is adapted to determine the distance from the first magnetic field sensing array to the permanent magnet by determining a directional angle of the first magnetic field sensing array with respect to the permanent magnet based on the signals from the first magnetic sensing array, the predetermined distance, an orientation of a main sensing direction of the first magnetic field sensor, and an orientation of a main sensing direction of the second magnetic field sensor, wherein an orientation of the second magnetic field sensing array is used to correct for effects of stray magnetic fields.