Hot Surface Imaging With Synchronized Flash and Image Stitching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for monitoring hot surfaces, such as those in steel sheet manufacturing, face challenges due to thermal radiation, smoke, and optical disturbances, making it difficult to capture high-resolution images of large, moving surfaces.

Innovation Solution

A system utilizing high-speed cameras synchronized with a powerful light source to illuminate the surface from the side, allowing for high-resolution image capture with short exposure times and image overlap for complete surface visualization, combined with data from various measuring devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional visual observation or optical monitoring methods are used on hot surfaces, then monitoring can be performed under normal conditions, but thermal radiation, smoke, and optical disturbances from the hot surface make monitoring difficult or impossible

Engineering Contradiction:
Improvemonitoring reliabilityVSAvoidthermal radiation and optical disturbances
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful thermal radiation and optical disturbances from the monitoring equation by using ultra-short pulse illumination (femtosecond to picosecond range) that occurs faster than the thermal radiation can interfere with the measurement. The measurement is completed before the thermal radiation becomes significant, effectively taking out the harmful effect from the measurement process.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system maintains continuous monitoring capability by using ultra-short pulses at high repetition rates. The useful action of measurement continues without interruption despite the presence of thermal radiation, because each pulse is completed faster than the thermal interference can develop, allowing continuous acquisition of surface information.

Inventive Principle:
Principle #20Continuity of useful action

2Area of stationary object

If large surfaces are photographed to capture complete images, then entire surface coverage is achieved, but resolution decreases due to the large area being captured

Engineering Contradiction:
Improvesurface coverage areaVSAvoidimage resolution
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent segments the large surface area into multiple smaller fields of view by using a scanning system that moves the illumination and detection beams across the surface. Each position captures high-resolution data of a small area, and these segmented measurements are then reconstructed to form a complete high-resolution image of the entire large surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system adds the time dimension to the spatial measurement by using ultra-short pulses and scanning through different positions over time. This temporal dimension allows the system to capture complete surface information without sacrificing spatial resolution, as each moment captures a specific high-resolution slice that is then integrated with other temporal slices.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If high-resolution imaging of large surfaces is attempted, then detailed surface features can be captured, but the exposure time increases making the system vulnerable to thermal radiation and motion blur

Engineering Contradiction:
Improvesurface feature detailVSAvoidexposure time
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The system uses periodic ultra-short pulses (femtosecond to picosecond duration) at high repetition rates to illuminate and measure the surface. Each pulse provides a complete measurement cycle that is faster than thermal radiation can interfere, and the periodic repetition allows accumulation of complete surface information through scanning while maintaining ultra-short effective exposure time at each measurement point.

Inventive Principle:
Principle #19Periodic action

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

Enables accurate, high-resolution imaging of hot surfaces independent of heat effects, allowing for detailed visualization of surface features and integration of measurement data, enhancing surface quality monitoring in industrial processes.

Implementation Method 1

A system utilizing high-speed cameras synchronized with a powerful light source to illuminate the surface from the side

Methodology Applied
Scientific EffectLight emission: Light

Data Source

PatentEP3304053B1Method and apparatus for determining features of hot surface
Publication Date: 2023.08.09 SAPOTECH OY
  • EP3304053B1 patent drawingFigure 1
  • EP3304053B1 patent drawingFigure 2A~2C
  • EP3304053B1 patent drawingFigure 3A~3B

AI summary

The invention relates to an arrangement for photographing a hot surface. A camera (106) is arranged to take a number of successive images of the surface (102) to be photographed, whereby each image comprises a part (108) of the surface to be photographed, the camera (106) and the surface (102) to be photographed being arranged to move relative to each other such that each image comprises a part of the surface part shown in the preceding and the following image. A light source (110) is arranged to illuminate the surface to be photographed, whereby the camera and the light source are synchronized in such a way that the light source illuminates the surface at the shooting moment of each image, and an image- processing unit (114) is arranged to combine a complete image of the whole surface to be photographed out of the successive images taken by the camera. A server (118) is arranged to determine a coordinate system for the complete image, to receive data on the surface to be photographed, generated by one or more measuring devices, and to combine the received data with the complete image.