Elevator Car Position Detection With Shaft Equipment Images
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Solution Overview
Problem
Existing methods for determining the position of an elevator car in a shaft lack reliability, especially after system restarts, due to the uncertainty in image comparisons without prior position knowledge.
Innovation Solution
A method involving a start phase, review phase, and decision phase to determine the elevator car's position, using image capture and comparison with stored images, ensuring multiple reviews before finalizing the position, and employing pixel-by-pixel correlation analysis to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If image comparison is used to determine position without prior position knowledge, then position determination is possible after system restart, but reliability is reduced due to uncertainty in matching images
Solution Approach 1:
The patent applies preliminary action by performing multiple review phases before finalizing the position determination. The system conducts several iterative comparisons and validations of assumption positions against shaft equipment images, allowing the position to be confirmed through repeated verification rather than a single comparison, thus improving reliability while maintaining the ability to determine position after restart
Solution Approach 2:
The patent implements feedback by using the results of each image comparison to refine and adjust the assumed position, then performing subsequent comparisons based on the refined assumption. The system continuously evaluates matching characteristics and uses this feedback to converge on the correct position, transforming the uncertain single-comparison approach into a reliable iterative process
2Reliability
If multiple review phases are conducted to validate position assumptions, then position determination reliability is improved, but system complexity increases
Solution Approach 1:
The patent applies dynamics by making the review process adaptive rather than fixed. The system dynamically determines when to conduct review phases and how many reviews are needed based on the matching characteristics obtained during comparison. This dynamic approach allows the system to perform additional reviews only when necessary to achieve sufficient confidence, improving reliability without unnecessarily increasing system complexity
3Adaptability or versatility
If image comparison is performed for position determination, then position can be found without prior knowledge, but measurement precision is reduced due to lack of absolute matching results
Solution Approach 1:
The patent applies preliminary action by performing multiple preliminary review phases before finalizing the position determination. Each review phase conducts additional image comparisons and validations to progressively refine the position estimate, transforming a single imprecise measurement into a precisely determined position through repeated preliminary verification
Solution Approach 2:
The patent applies parameter changes by evaluating multiple matching characteristics (such as correlation coefficients, edge alignment metrics, and feature point matches) rather than relying on a single comparison parameter. By changing and evaluating multiple parameters simultaneously, the system achieves higher measurement precision while maintaining independent position determination capability
Data Source
AI summary
A method and system for determining the position of an elevator car movable in a shaft of an elevator installation capture images of shaft components and/or shaft equipment serving other functions using an image capture unit on the car. A current image is compared with at least one stored comparison image of the components and/or equipment in a travel direction of the car to determine a current position of the car in the travel direction. If there is no information regarding the position of the car from a previous determination step, for example if the elevator installation is restarted, a current image is compared with all the stored comparison images. Based upon this comparison, one possible position or a plurality of possible positions of the car are determined. These possible positions are checked at least once before one of these positions is adopted as the current position of the car.