Inductive Position Sensor Using Partial Winding Segmentation
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Solution Overview
Problem
Existing methods for determining the position of a mobile unit relative to a stationary unit are limited in accuracy and complexity, particularly in using inductive coupling, as they rely on single coupling measurements and require extensive signal evaluation.
Innovation Solution
The method employs two coils with partial windings, where the inductive coupling strengths and phase shifts between these windings are measured to create a unique pattern, allowing for position determination by comparing relative coupling strengths, and a second independent arrangement is used perpendicularly to determine two-dimensional position coordinates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single inductive coupling measurement is used to determine position, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The coils are divided into multiple partial windings (e.g., four partial windings per coil). By measuring inductive coupling between corresponding partial windings and evaluating their relationships (ratios, differences), the system achieves higher measurement precision through pattern recognition while keeping the device structure relatively simple.
Solution Approach 2:
The patent transitions from single coupling strength measurement to multi-dimensional evaluation by measuring coupling strengths between multiple partial windings and analyzing their relationships. This creates a pattern space that enables more precise position determination within a position range.
2Measurement precision
If multiple inductive coupling measurements are performed to improve position accuracy, then measurement precision is improved, but signal evaluation complexity increases
Solution Approach 1:
The patent changes the evaluation approach from absolute coupling strength values to relative relationships between coupling strengths (ratios, differences). This parameter transformation simplifies the evaluation process while maintaining high measurement precision, as the relationships between partial winding couplings are more stable and position-sensitive than absolute values.
Solution Approach 2:
The system creates a characteristic pattern (signature) for each position range based on the relationships between multiple coupling measurements. This pattern serves as a reference copy that can be matched against real-time measurements, simplifying the evaluation process through pattern recognition rather than complex calculations.
3Measurement precision
If pattern recognition method is used for position determination, then measurement precision is improved, but difficulty of detecting and measuring increases
Solution Approach 1:
The patent transforms the measurement task from determining absolute position directly to identifying which position range pattern matches the measured coupling relationships. This parameter change from continuous position calculation to discrete pattern matching reduces measurement difficulty while improving precision within each position range.
Solution Approach 2:
The measurement space is segmented into multiple position ranges, each with its own characteristic pattern. By dividing the overall position determination task into smaller range-specific pattern recognition tasks, the system reduces the complexity of detecting and measuring while achieving high precision within each segment.
4Measurement precision
If coils with spatial extent are used to create coupling patterns, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The coils are segmented into multiple partial windings arranged in space. This segmentation creates the necessary spatial extent for pattern generation while maintaining a modular structure that doesn't excessively increase device complexity. The partial windings can be integrated into a compact coil assembly.
Solution Approach 2:
The same coil assembly with partial windings serves multiple functions: generating the alternating magnetic field, providing multiple coupling measurement paths, and creating the position-dependent pattern. This multi-functionality reduces overall device complexity while enabling precise measurement.
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
This approach simplifies position determination by reducing signal evaluation to relative coupling strength comparisons, enabling accurate and unambiguous positioning within a plane using a pattern recognition method, and allows for easy manufacturing and implementation.
Implementation Method 1
a winding energized with alternating current causes an induced voltage in another winding, with the inductive coupling decreasing as the distance between the coils increases
Implementation Method 2
a winding energized with alternating current causes an induced voltage in another winding
Data Source
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AI summary
Method for determining the position of a mobile unit having a first coil relative to a second coil which is arranged in a fixed position, and an installation for executing a method wherein the first coil has two partial windings, wherein the second coil also has two partial windings, wherein respective inductive coupling strengths of the partial windings of the first coil or of the first coil relative to the partial windings of the second coil or to the second coil are determined, wherein a phase shift of the induced alternating voltage signals is determined, wherein a position range is determined from the coupling strengths, in which position range the phase shift is an unambiguous function of the position, wherein the position is determined from the phase shift.