Concentric Inductive Sensor Assembly for Angle Sensing
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Solution Overview
Problem
Conventional rotary inductive sensing coils interfere with conductors, preventing low impedance connections and accurate angle sensing, and are not suitable for concentric secondary electronic sensors due to interference and lateral offset errors.
Innovation Solution
A position sensor assembly using a radial multi-pole arc-linear inductive sensing assembly with concentrically arranged receiver coils and a coupler member that modifies inductive coupling, allowing for redundant sensing with Hall Effect techniques and reducing sensed angle errors through series connection and gap placement on the circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional rotary inductive sensing coil is used, then inductive sensing capability is achieved, but the coil interferes with conductors placed over it, preventing low impedance connections and accurate angle sensing
Solution Approach 1:
The sensing system is divided into two independent parts: an inductive sensing coil for detecting conductor position and a Hall Effect sensor for detecting magnetic field changes. This segmentation allows each sensor type to operate independently without interference, resolving the contradiction between achieving accurate angle sensing and avoiding interference with conductors
Solution Approach 2:
The Hall Effect sensor is positioned concentrically within the inductive sensing coil, with both sensors sharing the same central axis. This nested arrangement allows the smaller Hall Effect sensor to be placed inside the coil's inner diameter area, enabling both sensors to coexist without interfering with each other's operation
2Adaptability or versatility
If an arc-linear sensing coil with offset target is used to allow secondary sensor placement, then concentric secondary sensor placement becomes possible, but lateral offset of the target pivot results in sensed angle error
Solution Approach 1:
The system uses a multi-pole asymmetric target structure with non-uniform magnetic field distribution around the pivot. This asymmetric design creates distinct magnetic field patterns that remain recognizable even when the target pivot experiences lateral offsets, allowing the Hall Effect sensor to accurately determine angular position despite minor positioning variations
Solution Approach 2:
The system changes the sensing parameter from direct geometric position measurement to magnetic field pattern recognition. By detecting changes in magnetic field strength and direction caused by the multi-pole target's rotation, the system becomes less sensitive to lateral pivot offsets and achieves more robust angle sensing
3Measurement precision
If conventional rotary sensing coils are used, then inductive sensing is achieved, but they inhibit use of concentric secondary electronic sensor within one circuit board
Solution Approach 1:
The inductive sensing coil and Hall Effect sensor are integrated onto a single circuit board in a concentric arrangement, with both sensors sharing the same mounting plane and central axis. This merging of multiple sensing technologies into one compact unit reduces overall system complexity and enables easier integration into the final application while maintaining both sensing capabilities
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate position sensing with reduced susceptibility to lateral pivot shifts and interference, allowing for concentric secondary sensors without mechanical slack or misalignment, improving accuracy and reliability compared to conventional sensor assemblies.
Implementation Method 1
The at least one receiver coil is configured to generate a receiver signal when the transmitter coil is excited due to a change in an inductive coupling between the transmitter coil and the at least one receiver coil
Implementation Method 2
a change in an inductive coupling between the transmitter coil and the at least one receiver coil caused by the movement of the at least two projecting protrusions
Data Source
AI summary
Embodiments herein are directed to a position sensor. The position sensor includes an inductive sensor assembly, a secondary sensor, and a coupler member. The inductive sensor assembly includes a transmitter coil and at least one receiver coil located proximate to the transmitter coil. The at least one receiver coil generating a receiver signal when the transmitter coil is excited. The receiver signal being sensitive to a position of a part. The secondary sensor is positioned within an inner diameter of the transmitter coil. The coupler member is coupled to the part and configured to move with a movement of the part. The coupler member overlies at least a portion of the at least one receiver coil. The coupler member including a body, at least one projecting portion extending from the body and at least one magnet concentrically positioned with the body.