Encoder Template Matching for Robust Position Detection
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Solution Overview
Problem
Existing optical rotary encoders require high-definition patterns on code plates for accurate detection, which increases costs and is prone to reduced accuracy due to contamination or damage.
Innovation Solution
An encoder using template matching with a base portion, a rotatable rotation portion, imaging element, and storage to determine rotation states based on marked images, allowing for high accuracy detection even without high-definition marks and in the presence of contamination, with adjustable search regions and reference image attitudes for improved accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high-definition pattern is formed on a code plate to increase detection accuracy, then manufacturing cost increases
Solution Approach 1:
The invention uses template matching to create a digital copy of the mark pattern. Instead of requiring physically high-definition marks on the code plate, the system captures an image of the mark and creates a template that can be matched against captured images. This digital copying approach allows detection of rotation position with high accuracy while using simpler, lower-cost physical marks on the code plate.
2Measurement precision
If a high-definition pattern is formed on a code plate to increase detection accuracy, then the system becomes more susceptible to accuracy reduction from contamination or damage
Solution Approach 1:
The system performs preliminary action by capturing an image of the mark and creating a template before actual detection begins. This template is stored and can be used for matching even if the physical mark becomes contaminated or damaged later. The preliminary capture and template creation allow the system to maintain detection accuracy despite subsequent degradation of the physical mark.
3Measurement precision
If template matching is performed on the entire captured image to improve detection accuracy, then calculation time increases
Solution Approach 1:
The invention applies local quality by setting a search region that is only a partial region of the captured image rather than processing the entire image. The determination portion identifies and processes only the relevant area where the mark is located, performing template matching locally. This approach maintains high detection accuracy by focusing computational resources on the critical region while significantly reducing the overall calculation time.
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
The solution enables high detection accuracy while reducing costs, maintaining accuracy even with damaged marks and high angular velocities, and minimizing calculation time, thus enhancing the performance of robots and printers.
Implementation Method 1
an imaging element that is disposed in the base portion and images the marks
Data Source
AI summary
An encoder includes a base portion, a rotation portion that is provided to be rotatable about a rotation axis with respect to the base portion, a mark that is disposed around the rotation axis on the rotation portion, an imaging element that is disposed in the base portion and images the marks, a storage portion that stores a reference image, and a determination portion that performs template matching on the mark imaged by the imaging element by using the reference image, so as to determine a rotation state of the rotation portion with respect to the base portion.