Sine-Cosine Position Detection Correction for Variable Gaps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position detection devices face challenges in accurately determining the position of a detection body due to variations in magnetic field reception caused by irregularly disposed magnets, leading to detection inaccuracies.
Innovation Solution
A position detection device that outputs sine and cosine wave signals corresponding to the detection body's position, with a signal processing unit that corrects these signals using a correction function based on gap variations between the detection body and the arrangement unit, reducing errors at different gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If magnets are disposed irregularly on the detection body, then the device complexity is reduced, but the measurement precision deteriorates due to detection inaccuracies
Solution Approach 1:
The patent changes the parameters of the sine and cosine signals by introducing correction functions that adjust for amplitude ratios and phase differences. The signal processing unit applies correction values derived from the relationship between detection body position and signal characteristics, transforming the raw signals into corrected signals that compensate for irregular magnet placements and gap variations.
Solution Approach 2:
The patent implements a feedback mechanism where the signal processing unit continuously monitors the detected position and signal characteristics, then applies correction functions based on the relationship between position and signal parameters. The correction values are determined by analyzing the amplitude ratio and phase difference at detected positions, creating a closed-loop system that compensates for deviations caused by irregular magnet arrangements.
2Adaptability or versatility
If the gap between the arrangement unit and detection body varies, then the adaptability is improved, but the measurement precision deteriorates due to detection errors at different gaps
Solution Approach 1:
The patent addresses gap variations by changing the parameters of the correction function, which is derived based on the relationship between detection body position and signal characteristics. The correction function adjusts amplitude ratios and phase differences dynamically, allowing the system to maintain measurement precision across different gap conditions without requiring physical adjustments to the device structure.
Solution Approach 2:
The patent performs preliminary characterization of the relationship between detection body position and signal characteristics (amplitude ratio, phase difference) to establish correction functions before actual position measurement. This preliminary action creates a lookup table or correction model that enables rapid compensation during operation, eliminating the need for real-time complex calculations while maintaining accuracy across gap variations.
3Measurement precision
If correction functions are applied to signals, then the measurement precision is improved, but the device complexity increases due to additional signal processing
Solution Approach 1:
The patent performs the complex correction function derivation and characterization work in advance, storing correction values in a lookup table or pre-computed model. During actual position measurement, the system only needs to perform simple table lookups or basic calculations using pre-determined correction values, significantly reducing the computational burden and processing complexity while maintaining high measurement precision.
Solution Approach 2:
The patent creates a simplified representation of the complex magnetic field interactions by copying the essential correction relationships into a lookup table or pre-computed model. Instead of performing complex real-time calculations of magnetic field variations due to irregular magnet placements, the system uses pre-captured correction data that replicates the effect of complex physics calculations, reducing processing requirements while maintaining accuracy.
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
Improves detection accuracy by minimizing errors at various gaps, ensuring precise position detection regardless of irregular magnet placements.
Implementation Method 1
a linear position sensor detects a position of a detection body based on a change in a magnetic field received from multiple magnets disposed on the detection body
Data Source
AI summary
A position detection device that detects a position of a detection body includes a signal processing unit that calculates a detection body position. The signal processing unit corrects a first signal and a second signal different in phase from the first signal, calculates a pre-correction position of the detection body based on the first and second signals, calculates a correction function based on an error of the pre-correction position, and corrects the pre-correction position using the correction function. The signal processing unit corrects the first signal and the second signal based on cases where a gap between an arrangement unit and the detection body is at a reference gap, one or different near gaps, and one or different far gaps. The signal processing unit derives a correction value used in the correction function for each of sections of a detection range.