Apparatus and method for ascertaining a rotation angle

Abstract

The present disclosure relates to an apparatus for ascertaining a rotation angle of a magnetic field orientation-influencing test object with an axis of rotation in the z-direction. The apparatus mayinclude at least three first magnetic field sensor elements, which are sensitive to magnetic field components in the z-direction; at least three second magnetic field sensor elements, which are sensitive to magnetic field components in an xy-plane; a device for ascertaining the rotation angle on the basis of first, second, third and fourth combination signals, the first combination signal being based on a first combination of first magnetic field sensor element measurement signals, the second combination signal being based on a second combination of first magnetic field sensor element measurement signals, the third combination signal being based on a first combination of second magnetic field sensor element measurement signals, and the fourth combination signal being based on a second combination of the second magnetic field sensor element measurement signals.

Description

technical field [0001] The present disclosure relates generally to position or angle sensors, and more particularly to angle sensors that take into account mechanical misalignment between a sensor element and a measurement object. Background technique [0002] Magnetic position or angle sensors are used, for example, in the automotive environment to resolve linear and angular position. The angle sensor can be realized, for example, by means of a magnetic field sensor which is placed in the vicinity of a rotating measuring object such as a shaft. In this case, the first measured value (X) can be determined as a function of the magnetic field depending on the rotation angle θ of the measurement object. Furthermore, the second measurement value (Y) can be determined from the magnetic field depending on the rotation angle θ of the measurement object. Ideally, the two measurements correspond to periodic signals of the form X=A*cos(θ) and Y=A*sin(θ). The rotation angle θ of the...

AI Technical Summary

Problems solved by technology

The angular accuracy of this arrangement is usually strictly limited by the positioning tolerances of the sensors

If one-tenth of the magnet diameter has been displaced or misaligned, this limits the achievable accuracy to approximately 1°

[0006] In practice, however, mechanical misalignment between the sensor element and the measurement object or magnet is usually not completely avoided, so there are different amplitudes, offsets and phase shifts of the periodic signals X and Y, which in turn lead to erroneous angle estimates

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