Micron-Level Displacement Detection Using Cross-Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring displacement of objects, especially in hazardous or inaccessible locations, lack accuracy and safety, and are often costly or impractical, particularly when requiring micron-level precision and long-range measurements.
Innovation Solution
A system utilizing an optical device, such as a digital camera or CCD, in combination with an object displacement detector computer, applies an enhanced Cauchy-Shwartz Cross-Correlation algorithm to determine displacement with micron-level accuracy by capturing images of identifiers on objects and fixed reference surfaces, processing them to calculate peak cross-correlation coefficients with 1/100th pixel accuracy, and correcting for noise and camera movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional displacement sensors or cameras are used to measure object displacement, then measurement capability is provided, but measurement precision deteriorates beyond micron level accuracy
Solution Approach 1:
The patent introduces an intermediary reference object with high-contrast features that serves as a mediator between the optical device and the target object. By capturing images of both the reference object and the target object, and processing their cross-correlation, the system achieves micron-level displacement measurement without direct contact in hazardous environments.
Solution Approach 2:
The patent replaces conventional mechanical displacement sensors with an optical measurement system. Instead of physical contact measurement, the system uses optical devices to capture images and computational algorithms to determine displacement, enabling measurement in hazardous locations where mechanical sensors cannot be placed.
2Measurement precision
If laser range finders are used to measure displacement, then distance measurement is provided, but measurement precision deteriorates due to laser recoil and inability to measure perpendicular displacement
Solution Approach 1:
The patent transitions from measuring only along the line of sight (one dimension) to measuring displacement in the plane perpendicular to the line of sight (two dimensions). By capturing images of the target object and reference object and analyzing their cross-correlation, the system determines displacement components perpendicular to the optical axis, providing comprehensive 2D measurement capability.
3Measurement precision
If standard imaging units are used to capture object movement, then displacement measurement is provided, but device complexity and cost increase without achieving required precision
Solution Approach 1:
The patent uses a simplified reference object with high-contrast patterns that creates a copy of the measurement reference in the image plane. This reference copy enables the system to achieve micron-level precision through cross-correlation processing without requiring complex expensive sensors, as the reference pattern provides stable, easily distinguishable features for precise measurement.
4Measurement precision
If cameras are used to track movement within limited field of view, then displacement measurement is provided, but measurement range deteriorates beyond one inch
Solution Approach 1:
The patent performs preliminary action by capturing images of both the reference object and the target object at different positions. By pre-establishing the reference object with known characteristics and capturing its image alongside the target object, the system creates a baseline for measurement that enables accurate displacement calculation over larger ranges while maintaining precision.
Data Source
AI summary
Embodiments of systems, program products, and computer implemented methods to measure the displacement of an object located in a hazardous or otherwise inaccessible location at a long range from an optical device with micron-level accuracy are provided the object being. The objects can be machinery, valves, containers, or any other object whose displacement is to be measured. The object can be located in radioactive, chemically reactive, high voltage, or otherwise hazardous or inaccessible locations that are not accessible for conventional displacement measurement by personnel. A system can comprise an identifier on the object to be tracked, an optical device, an computer with at least processing, storage, and memory facilities, and a communications network.