US-12618692-B2 - Rotary inductive position sensing with 60° phase-shifted sense signals, and related apparatuses and methods

US12618692B2US 12618692 B2US12618692 B2US 12618692B2US-12618692-B2

Abstract

An apparatus comprises a support structure, one or more oscillator coils, a first sense coil, and a second sense coil. The one or more oscillator coils have a circular winding pattern around an axis of rotation for a target. The first sense coil has a coil winding pattern arranged around the axis and surrounded by the circular winding pattern of the one or more oscillator coils. The second sense coil has a coil winding pattern arranged around the axis and surrounded by the circular winding pattern of the one or more oscillator coils. The coil winding pattern of the second sense coil offset from the coil winding pattern of the first sense coil by an angle of substantially Φ degrees, where Φ=60°/N, and N is an integer number of pole pairs of the apparatus.

Inventors

Ganesh Shaga
Surendra Akkina
Sudheer Puttapudi

Assignees

MICROCHIP TECHNOLOGY INCORPORATED

Dates

Publication Date: 20260505
Application Date: 20240223
Priority Date: 20230224

Claims (20)

1 . An apparatus comprising: a rotary inductive position sensor to sense an angular position of a target adapted to rotate about an axis, the rotary inductive position sensor including: a support structure; one or more oscillator coils having a circular winding pattern around the axis of rotation for the target, the axis being perpendicular to a plane defined by the support structure; a first sense coil having a coil winding pattern arranged around the axis and surrounded by the circular winding pattern of the one or more oscillator coils; a second sense coil having a coil winding pattern arranged around the axis and surrounded by the circular winding pattern of the one or more oscillator coils; and the coil winding pattern of the second sense coil mechanically offset from the coil winding pattern of the first sense coil at an angle of substantially Φ degrees, where Φ = 60 ⁢ ° / N , and N is an integer number of pole pairs of the target.
2 . The apparatus of claim 1 , wherein: the coil winding pattern of the first sense coil defines multiple first lobes radially extending from an inner circle around the axis and equally circumferentially spaced around the inner circle, the coil winding pattern of the second sense coil defines multiple second lobes radially extending from the inner circle and equally circumferentially spaced around the inner circle, and respective ones of the multiple second lobes of the second sense coil mechanically offset from respective adjacent ones of the multiple first lobes of the first sense coil at the angle of substantially Φ degrees.
3 . The apparatus of claim 2 , wherein N=4, and Φ=15°.
4 . The apparatus of claim 2 , wherein N=2, and Φ=30°.
5 . The apparatus of claim 2 , wherein N=1, and Φ=60°.
6 . The apparatus of claim 2 , comprising: the target arranged to rotate about the axis, the target defined by an inner ring and one or more fins radially extending from the inner ring, the one or more fins being N in number, a respective one of the one or more fins having an arc length of substantially γ degrees, where γ=180°/N.
7 . The apparatus of claim 6 , wherein the target defines one or more apertures between fin edges, the one or more apertures being N in number, a respective one of the one or more apertures having an arc length of substantially γ degrees.
8 . The apparatus of claim 6 , comprising: a position sensor circuitry to: generate an excitation signal in the one or more oscillator coils to produce a varying magnetic field for inducing a first sense signal and a second sense signal in the first sense coil and the second sense coil, respectively, the first sense signal comprising a first sinusoidal signal, the second sense signal comprising a second sinusoidal signal.
9 . The apparatus of claim 6 , wherein the one or more oscillator coils comprise a first oscillator coil and a second oscillator coil, the apparatus comprising: a position sensor circuitry to: generate a first excitation signal in the first oscillator coil and a second excitation signal in the second oscillator coil to produce a varying magnetic field for inducing a first sense signal and a second sense signal in the first sense coil and the second sense coil, respectively, the second excitation signal substantially 180° out-of-phase with the first excitation signal, the varying magnetic field disturbed in accordance with an angular position of the target for modulating the first sense signal and the second sense signal, the modulated first and second sense signals having respective first and second sinusoidally modulated amplitudes substantially 60° out-of-phase with each other due to the mechanical offset at the angle of substantially Φ degrees, respective ones of the first and second sinusoidally modulated amplitudes exhibiting N cycles for every 360° rotation of the target.
10 . The apparatus of claim 6 , comprising: a position sensor circuitry to: generate an excitation signal in the one or more oscillator coils to produce a varying magnetic field for inducing a first sense signal and a second sense signal in the first sense coil and the second sense coil, respectively, the varying magnetic field disturbed in accordance with an angular position of the target for modulating the first sense signal and the second sense signal, the modulated first and second sense signals having respective first and second sinusoidally modulated amplitudes substantially 60° out-of-phase with each other due to the mechanical offset at the angle of substantially Φ degrees, respective ones of the first and second sinusoidally modulated amplitudes exhibiting N cycles for every 360° rotation of the target.
11 . The apparatus of claim 10 , wherein: the position sensor circuitry to: receive the modulated first and second sense signals from the first and the second sense coils, respectively; demodulate the modulated first and second sense signals to produce first and second demodulated amplitude position signals, respectively, the first and second demodulated amplitude position signals substantially 60° out-of-phase with each other; and output the first and second demodulated amplitude position signals at first and second outputs, respectively.
12 . The apparatus of claim 11 , wherein the varying magnetic field is to produce a sixth harmonic distortion signal in the first and second sinusoidally modulated amplitudes of the respective modulated first and second sense signals, the sixth harmonic distortion signal comprising a dominant harmonic distortion signal of harmonic distortion signals in the first and second sinusoidally modulated amplitudes.
13 . The apparatus of claim 11 , wherein: the position sensor circuitry to calculate the angular position of the target at least partially based on the first and second demodulated amplitude position signals.
14 . The apparatus of claim 11 , wherein: the position sensor circuitry to calculate the angular position of the target at least partially based on an expression, a ⁢ tan ⁢ 2 [ √ 3 × sin ⁡ ( θ + 60 ⁢ ° ) / ( ( sin ⁡ ( θ ) - sin ⁡ ( θ + 120 ⁢ ° ) ) ] , where sin(Θ) is a first value of the first demodulated amplitude position signal at the angular position of Θ, sin(Θ+60) is a second value of the second demodulated amplitude position signal at the angular position of Θ, and sin(Θ+120) is a third value based on the first value and the second value.
15 . A method comprising: at a position sensor circuitry for a rotary inductive position sensor, the rotary inductive position sensor comprising a support structure, multiple planar coils on or in the support structure, and a target arranged to rotate about an axis perpendicular to a plane defined by the support structure, the multiple planar coils including one or more oscillator coils in a circular winding pattern around the axis of rotation for the target, a first sense coil having a coil winding pattern arranged around the axis and surrounded by the circular winding pattern of the one or more oscillator coils, and a second sense coil having a coil winding pattern arranged around the axis and surrounded by the circular winding pattern of the one or more oscillator coils, the coil winding pattern of the second sense coil mechanically offset from the coil winding pattern of the first sense coil at an angle of substantially Φ degrees, where Φ=60°/N, and N is an integer number of pole pairs of the target; generating an excitation signal in the one or more oscillator coils to produce a varying magnetic field for inducing a first sense signal and a second sense signal in the first and the second sense coil, respectively, the varying magnetic field disturbed in accordance with an angular position of the target for modulating the first sense signal and the second sense signal, the modulated first and second sense signals having respective first and second sinusoidally modulated amplitudes substantially 60° out-of-phase with each other due to the mechanical offset at the angle of substantially Φ degrees; receiving the modulated first and second sense signals from the first and second sense coils, respectively; and demodulating the modulated first and second sense signals to produce first and second demodulated amplitude position signals, respectively.
16 . The method of claim 15 , wherein the coil winding pattern of the first sense coil defines multiple first lobes radially extending from an inner circle around the axis and equally circumferentially spaced around the inner circle, the coil winding pattern of the second sense coil defines multiple second lobes radially extending from the inner circle and equally circumferentially spaced around the inner circle, and respective ones of the multiple second lobes mechanically offset from respective adjacent ones of the multiple first lobes at the angle of substantially Φ degrees.
17 . The method of claim 16 , wherein the rotary inductive position sensor is configured such that N=4 and Φ=15°, N=2 and Φ=30°, or N=1 and Φ=60°.
18 . The method of claim 15 , wherein the target is defined by an inner ring, one or more fins radially extending from the inner ring, and one or more apertures between fin edges of the one or more fins, the one or more fins being N in number, a respective one of the one or more fins having an arc length of substantially γ degrees, the one or more apertures being N in number, a respective one of the one or more apertures having an arc length of substantially γ degrees, where γ=180°/N, respective ones of the first and second sinusoidally modulated amplitudes exhibiting N cycles for every 360° rotation of the target.
19 . The method of claim 18 , comprising: at the position sensor circuitry, outputting the first and second demodulated amplitude position signals at first and second outputs, respectively, the first and second demodulated amplitude position signals substantially 60° out-of-phase with each other; and calculating the angular position of the target at least partially based on the first and second demodulated amplitude position signals.
20 . The method of claim 19 , further comprising: at the position sensor circuitry, calculating the angular position of the target at least partially based on an expression, a ⁢ tan ⁢ 2 [ √ 3 × sin ⁡ ( θ + 60 ⁢ ° ) / ( ( sin ⁡ ( θ ) - sin ⁡ ( θ + 120 ⁢ ° ) ) ] , where sin(Θ) is a first value of the first demodulated amplitude position signal at the angular position of Θ, sin(Θ+60) is a second value of the second demodulated amplitude position signal at the angular position of Θ, and sin(Θ+120) is a third value based on the first value and the second value.

Description

PRIORITY CLAIM This application claims the benefit of the filing date of Republic of India Provisional Patent Application Serial No. 202341012597, filed Feb. 24, 2023, for “Rotary Inductive Position Sensing With 60° Phase-Shifted Sense Signals,” the disclosure of which is hereby incorporated herein in its entirety by this reference. TECHNICAL FIELD This disclosure relates generally to planar rotary inductive position sensing. More specifically, some examples relate to non-contacting planar rotary inductive position sensors for measuring the position of a movable target, without limitation. Additionally, devices, systems, and methods are disclosed. BACKGROUND If a coil of wire is placed in a changing magnetic field, a voltage will be induced at ends of the coil of wire. In a predictably changing magnetic field, the induced voltage will be predictable (based on factors including the area of the coil affected by the magnetic field and the degree of change of the magnetic field). It is possible to disturb a predictably changing magnetic field and measure a resulting change in the voltage induced in the coil of wire. Further, it is possible to create a sensor that measures movement of a disturber of a predictably changing magnetic field based on a change in a voltage induced in a coil of wire. BRIEF DESCRIPTION OF THE DRAWINGS While this disclosure concludes with claims particularly pointing out and distinctly claiming specific examples, various features and advantages of examples within the scope of this disclosure may be more readily ascertained from the following description when read in conjunction with the accompanying drawings, in which: FIG. 1 is a perspective view of an apparatus comprising a rotary inductive position sensor for position sensing of a target, according to one or more examples; FIGS. 2 and 3 are top-down views of the apparatus of FIG. 1, where in FIG. 3 the apparatus is shown with a target; FIGS. 4 and 5 are top-down views of the apparatus of FIGS. 1-3, each figure illustrating a respective one of first and second sense coils of the sensor with the other coil removed; FIG. 6 is a graph of ideal first and second sense signals produced from the apparatus comprising the rotary inductive position sensor of FIGS. 1-5, according to one or more examples; FIG. 7 is a graph of measured first and second sense signals produced from the apparatus comprising the rotary inductive position sensor of FIGS. 1-5, according to one or more examples; FIG. 8A is a schematic diagram of a position sensor circuitry for the apparatus of FIGS. 1-5, according to one or more examples; FIG. 8B is a flowchart for describing a method of operating an apparatus comprising a rotary inductive position sensor according to one or more examples; FIG. 9 is a top-down view of a rotary inductive position sensor known by the inventors of this disclosure; FIG. 10 is a graph of measured first and second sense signals produced from the rotary inductive position sensor of FIG. 9; FIG. 11 is an error plot of angle error over rotary mechanical position of a target according to a simulation; FIG. 12 is a graph of a spectrum of harmonic distortion which may be experienced in an environment of a rotary inductive position sensor, according to one or more examples; FIGS. 13A and 13B relate to application of one or more examples of the disclosure to an apparatus comprising a rotary inductive position sensor having a two (2) pole pair configuration, according to one or more examples; FIGS. 14A and 14B relate to application of one or more examples of the disclosure to an apparatus comprising a rotary inductive position sensor having a one (1) pole pair configuration, according to one or more examples; and FIG. 15 is a block diagram of circuitry that, in some examples, may be used to implement various functions, operations, acts, processes, and/or methods disclosed herein. DETAILED DESCRIPTION In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown, by way of illustration, specific examples of examples in which the present disclosure may be practiced. These examples are described in sufficient detail to enable a person of ordinary skill in the art to practice the present disclosure. However, other examples may be utilized, and structural, material, and process changes may be made without departing from the scope of the disclosure. The illustrations presented herein are not meant to be actual views of any particular method, system, device, or structure, but are merely idealized representations that are employed to describe the examples of the present disclosure. The drawings presented herein are not necessarily drawn to scale. Similar structures or components in the various drawings may retain the same or similar numbering for the convenience of the reader; however, the similarity in numbering does not mean that the structures or components are necessarily identical in