Inductive Position Sensor Using Vernier Principle for Absolute Measurement
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Solution Overview
Problem
Existing inductive position-measuring devices face challenges in determining absolute relative positions with high precision and simplicity, particularly in configurations where multiple receiver tracks with different periodic patterns are required.
Innovation Solution
The proposed inductive position-measuring device incorporates a scanning element with two receiver tracks, each featuring receiver conductors that extend along a first direction according to distinct periodic patterns. The graduation element has a graduation track with ridges and gaps of varying widths or depths, allowing the electromagnetic field to be modulated. This configuration enables the generation of signals with specific period lengths, which are then processed to determine the absolute position using the Vernier principle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple receiver tracks with different periodic patterns are used to determine absolute position, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The receiver track is divided into multiple segments (first receiver track and second receiver track), each with different periodic patterns. This segmentation allows the system to determine absolute position by combining measurements from multiple segments with different resolutions, thereby improving measurement precision while keeping each individual segment relatively simple
Solution Approach 2:
The patent introduces a temporal dimension by using receiver tracks with different periodic patterns that generate signals with different period lengths. By combining signals from multiple dimensions (different periodicities), the system achieves absolute position determination without requiring a complex single-track design
2Measurement precision
If receiver conductors extend over long lengths to improve position resolution, then measurement precision is improved, but manufacturing precision requirements increase
Solution Approach 1:
Instead of using a single long receiver conductor that would require high manufacturing precision over its entire length, the system segments the measurement function across multiple receiver tracks of moderate length. Each track has manageable length L, reducing cumulative manufacturing tolerance issues while achieving high overall resolution through signal combination
Solution Approach 2:
The patent changes the periodic pattern parameters of different receiver tracks to have relatively prime relationships (n times first period length equals m times second period length). This parameter relationship allows the system to achieve fine resolution through signal processing rather than requiring extremely precise single-track dimensions
3Device complexity
If simple receiver track configurations are used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent merges the output signals from multiple simple receiver tracks with different periodic patterns to achieve absolute position determination. By combining the measurements from the first receiver track and second receiver track through signal processing, the system attains high measurement precision while maintaining relative simplicity in each individual track's structure
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 solution allows for the precise determination of absolute positions by combining signals from receiver tracks with different periodic patterns, achieving high resolution and simplicity in position measurement.
Implementation Method 1
an electromagnetic field generated by the at least one excitation conductor can be modulated by the graduation track
Implementation Method 2
signals which are dependent on the relative position are generated in the receiver coils during relative movement between the graduation element and the scanning element
Data Source
AI summary
An inductive position-measuring device includes a scanning element and a graduation element movable relative thereto along a direction. The scanning element has an excitation conductor, and first and second receiver tracks each having a receiver conductor, which extends along the direction according to first and second periodic patterns, respectively, over a length. A graduation track has graduation structures formed of ridges and gaps. The ridges have different widths, or the gaps have different depths or different widths, in the direction. The receiver conductors of the first and second receiver tracks are configured to generate first and second signals having first and second period lengths, respectively, wherein n times the first period length equals m times the second period length, with m and n being relatively prime, and n times the first period length and m times the second period length both being less than or equal to the length.