Optical Grid Interference for Bolt Preload Estimation
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Solution Overview
Problem
Existing systems for preload measurement in bolted joints, such as ultrasonic measurement or preload indicating washers, are often complex and require improved simplicity for effective load estimation and monitoring.
Innovation Solution
A method involving a deformable component with a grid of equidistant lines or dots, where the loaded and unloaded states are captured to generate an interference pattern, analyzed either analytically or using machine learning, to estimate the load based on deformation patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultrasonic measurement or preload indicating washers are used for preload measurement, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical measurement systems (ultrasonic devices, preload indicating washers) with a simple optical imaging system using a smartphone camera. The grid pattern on the washer head is captured optically and analyzed to determine preload, eliminating the need for specialized measurement equipment while maintaining measurement capability.
Solution Approach 2:
The patent creates a visual copy of the deformation state by projecting a grid pattern onto the washer head and capturing its deformed state through imaging. This optical copy of the physical deformation allows for indirect measurement of preload without direct mechanical contact or complex sensors.
2Measurement precision
If existing preload measurement systems are implemented, then measurement accuracy is improved, but ease of operation deteriorates
Solution Approach 1:
The measurement system uses the smartphone's own camera and processing capabilities to perform the measurement task. The grid pattern is captured, analyzed, and processed entirely by the mobile device without requiring external measurement equipment or specialized operational procedures, making the system as easy to use as taking a photograph.
Solution Approach 2:
The patent utilizes the smartphone's existing camera and processing capabilities for a new measurement function. The same device that takes photographs is now used for precise preload measurement, eliminating the need for separate specialized measurement tools and simplifying the operational workflow.
3Manufacturing precision
If a grid pattern is engraved on the component surface, then manufacturing precision is improved, but manufacturing complexity increases
Solution Approach 1:
The grid pattern is engraved on the washer head during the manufacturing process before the component is put into service. This preliminary creation of the measurement feature eliminates the need for separate marking or calibration steps later, integrating the measurement capability directly into the manufacturing process.
Solution Approach 2:
The patent replaces complex mechanical measurement systems with a simple optical grid pattern that can be created using laser engraving or other precise marking methods. This substitution transforms a complex measurement problem into a simple visual pattern recognition task that can be performed with standard imaging equipment.
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 approach simplifies load estimation by generating a beat pattern from the interference of the deformed grid, allowing for accurate preload measurement using a smartphone app or data processing device, suitable for various bolted joint configurations.
Implementation Method 1
superimposing the captured grid with the grid of the unloaded component for generating an interference pattern, particularly a beat pattern
Implementation Method 2
the surface being deformable under a load of the component
Data Source
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AI summary
The invention provides a method for estimating or calculating a load (LO) on a component (44), the component (44) having a suitably defined grid (30) of a plurality of equidistant lines (32) and/or dots arranged on a surface (46) thereof, the surface (46) being deformable under the load (LO) of the component (44), the method comprising: a) capturing the grid (30) of the component (44) under a load (LO); b) superimposing the captured grid (30) with the grid (30) of the unloaded component (44) for generating an interference pattern (36), particularly a beat pattern (38); and c) estimating or calculating the load (LO) on the component (44) based on the interference pattern (36).