Position detection by an inductive position sensor
AssigneeB&R Industrial Automation GmbH
InventorsFlorian Höller, Roland Reichhartinger
Life of this patent
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Abstract
For an easily implementable method for position determination using an inductive position sensor with increased precision of the position information, the position sensor generates a measurement signal from which a frequency functional dependent on the excitation frequency is formed, which represents a measure of the noise signal and the excitation frequency of the excitation signal is changed so that the frequency functional is minimized or maximized and the excitation frequency that minimizes or maximizes the frequency functional is used for the excitation signal.
Claims13
A method for determining a position of a moving part relative to a stationary part by an inductive position sensor, wherein an excitation winding is arranged on one of the moving part or the stationary part and at least one secondary winding is arranged on the other of the moving part or the stationary part, the method comprising:
- feeding an electrical excitation signal with an excitation frequency and an excitation amplitude into the excitation winding, which generates an electromagnetic excitation field;
- detecting a measurement signal induced in the secondary winding by the generated electromagnetic excitation field, wherein the measurement signal includes a superimposed noise signal,
- forming a frequency functional which is dependent on the excitation frequency and represents a measure of the superimposed noise signal, and
- changing the excitation frequency of the excitation signal so that the frequency functional representing the measure of superimposed noise signal is minimized or maximized and using the changed excitation frequency that minimizes or maximizes the frequency functional representing the measure of superimposed noise signal for the excitation signal,
- wherein the position of the moving part of the position sensor is determined from the measurement signal.
An evaluation unit for an inductive position sensor having a moving part with one of an excitation winding or at least one secondary winding and a stationary part having the other of the one of an excitation winding or at least one secondary winding, in which an electrical excitation signal with an excitation frequency and an excitation amplitude is fed into the excitation winding, which generates an electromagnetic excitation field that induces a measurement signal in the secondary winding which is fed to the evaluation unit with a superimposed noise signal on the measurement signal, the evaluation unit, which determines a position of the moving part relative to the stationary part of the position sensor from the measurement signal, comprises:
- at least one memory and at least one processor configured to execute at least one set of instructions stored in the at least one memory to:
- form a frequency functional, which is dependent on the excitation frequency and represents a measure of the superimposed noise signal, and
- determine the excitation frequency of the excitation signal which minimizes or maximizes the frequency functional representing the measure of the superimposed noise signal and
- use the excitation frequency which minimizes or maximizes the frequency functional representing the measure of the superimposed noise signal for the excitation signal.
Dependencies are inferred from the claim text.