Inductive Position Sensor Coil Layout for Absolute and High-Resolution Sensing
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Solution Overview
Problem
Existing inductive position sensors struggle to provide both absolute and high-resolution position data while minimizing space requirements, leading to increased size, cost, and complexity in industrial and automotive applications.
Innovation Solution
A combined inductive position sensor design incorporating an absolute position receive coil pair and a high-resolution position receive coil pair on the same printed-circuit board, with overlapping measurement areas, allowing for high-accuracy and high-resolution position sensing without separate targets or additional wiring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate absolute and incremental sensors are used, then both absolute and high-resolution position data are provided, but the space requirement increases significantly
Solution Approach 1:
The patent combines absolute and incremental position sensing functions into a single sensor system by integrating two receive coil pairs (first receive coil pair for absolute position, second receive coil pair for high-resolution incremental position) on the same PCB, sharing common transmit coils and processing electronics, thereby reducing the overall space requirement while maintaining both measurement capabilities
Solution Approach 2:
The sensor system is designed to perform multiple functions simultaneously: the first receive coil pair provides absolute position information while the second receive coil pair provides high-resolution incremental position data, and both functions share common hardware resources (transmit coils, PCB, processing unit), making the system multi-functional and space-efficient
2Measurement precision
If two separate coil systems are placed next to each other, then both absolute and high-resolution sensing are achieved, but the PCB size and cost increase
Solution Approach 1:
The patent merges two separate coil systems into a unified structure where the first and second receive coil pairs are integrated on the same PCB with shared transmit coils, reducing PCB size and simplifying the overall system architecture while maintaining the capability to provide both absolute and high-resolution position data
3Measurement precision
If multiple receiver coil patterns are used to increase resolution, then mechanical accuracy improves, but the absolute position information is lost
Solution Approach 1:
The patent segments the receive coil system into two distinct pairs: the first receive coil pair configured to provide absolute position information and the second receive coil pair configured to provide high-resolution incremental position data, allowing both types of information to be preserved simultaneously through separate measurement channels
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 a compact, high-resolution absolute sensor implementation with improved mechanical accuracy and robustness, supporting on-axis and through-shaft applications while reducing space and cost, and providing immunity to magnetic strayfields.
Implementation Method 1
inductive position sensor comprising at least one transmit coil, an absolute position receive coil pair, a high-resolution position receive coil pair and a conductive moving target
Implementation Method 2
The two receiver coils are arranged such that one generates a sine and the other a cosine signal every 360° mechanical rotation of the target
Data Source
AI summary
An inductive position sensor including at least one transmit coil, an absolute position receive coil pair, a high-resolution position receive coil pair and a conductive moving target, the absolute position receive coil pair and the high-resolution receive coil pair together define a measurement area of the inductive position sensor and the moving target can move in this measurement area, the absolute position coil pair has a first sine receive coil and a first cosine receive coil, both having one period over the measurement area of the inductive position sensor, the high-resolution position receive coil pair has a second sine receive coil and a second cosine receive coil, both having at least two periods over the measurement area of the inductive position sensor, the absolute position receive coil pair and the high-resolution position receive coil pair are arranged in the same area of a printed-circuit board of the inductive position sensor.