Capacitive distance sensor
AssigneeHexagon Technology Center GmbH
InventorsMarcel Rohner, Lukas Baumann, Michael Reiterer, Claudio Iseli, Alberto Tarizzo
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Abstract
A capacitive distance sensor for determining distances from an object, wherein the distance sensor has at least one sensor electrode and at least one compensation electrode. Deviations from an ideal parallel orientation of distance sensor and object and/or errors caused by capacitive edge effects can be compensated by means of the compensation electrode.
Claims14
A capacitive distance measuring sensor for measuring a distance to an object, wherein the capacitive distance sensor comprises:
- at least one first planar sensor electrode, wherein the at least one first planar sensor electrode is designed, together with an opposite area of the object, to form a capacitance dependent on the distance, such that the distance is determined on the basis of a capacitance measurement;
- and
- at least two edge effect compensation electrodes separate from and assigned to the at least one first planar sensor electrode, wherein the first planar sensor electrode and the separate at least two edge effect compensation electrodes lie in a plane and the separate at least two edge effect compensation electrodes have together the same perimeter but different area as the first planar sensor electrode, such that measurement errors which are caused by capacitive edge effects of the first planar sensor electrode i.e. deviations from an ideal edgeless or infinitely extended first planar sensor electrode is compensated on the basis of the capacitance of the separate at least two edge effect compensation electrodes.
A method for continuously determining a distance between two machine parts, which are intended for parallel displacement relative to one another, the method comprising:
- measuring the distance between
- two machine parts using a capacitive distance sensor comprising:
- at least one first planar sensor electrode, wherein the first planar sensor electrode is designed, together with an opposite area of the object, to form a capacitance dependent on the distance, such that the distance is determined on the basis of a capacitance measurement;
- and
- at least two edge effect compensation electrodes separate from and assigned to the at least one first planar sensor electrode,
- wherein the first planar sensor electrode and the separate at least two edge effect compensation electrodes lie in a plane and the separate at least two edge effect compensation electrodes have together the same perimeter but different area as the first planar sensor electrode, such that measurement errors which are caused by capacitive edge effects of the first planar sensor electrode i.e. deviations from an ideal edgeless or infinitely extended first planar sensor electrode is compensated on the basis of the capacitance of the separate at least two edge effect compensation electrodes.
Dependencies are inferred from the claim text.