ir thermography technology and on line processes fileir thermography technology and on line...

IR Thermography

Technology and

On Line Processes

Alberto Isasi

[email protected]

10 de junio de 2014Computer Vision

Tecnalia Industry & Transport Division

1. Thermal Imaging

Background

Tecnalia Research & Innovation Background

BACKGROUND• TECNALIA has wide experience working in foundry and iron and steel industry

• There is a Business Area in TECNALIA’s Industry Division oriented to this

sector

• Strategic partners: Arcelor Mittal, Gerdau, Tubacex, Olarra, Tubos Reunidos…

• Steel sector has a big impact in Bask Country GDP

• Linked to this relationship between TECNALIA and steel sector, some issues

appeared that can be solved using this thermal technology

• Partner of FEAF (Federacion Española Asociacion Fundidores)

2. Introduction

Tecnalia Research & Innovation INTRODUCTION

Thermal Analysis

What can you say about it?


Thermal Analysis

• Non contact measure

• Real Time measure

• Temperature map


Thermography images


Thermography images

Be careful with Temperature Scale!!


Thermography image vs. Thermal Image

• Thermography = Colored image

• Thermal = Temperature map


More than standard Image Analysis

• Image processing basis

• Process domain knowledge

• Thermodynamic considerations

• Object characteristics

3. Thermography

Basis

Tecnalia Research & Innovation Thermography Basis

Heat

• Generates from other energy sources

• All objects have thermal energy

• Measure unit: Jules (J)

Temperature

• Defines thermal state in relation to others

• Direct relation to heat variation

• Measure unit: Kelvin (K)


Heat & Temperature

• Heat = Energy

• Temperature = Speed

+ =100ºC 100ºC 100ºC

+ =100J 100J 200J


Law of Conservation of Energy:

“Energy cannot be created or destroyed, it can only

be changed from one form to another”

First law of thermodynamics:

“Because energy is conserved, the internal energy

of a system changes as heat flows in or out of it”


Heat propagation:

• Conduction: Heat transmission by direct contact from

one object to another

• Convection: Heat transmission through fluids

• Radiation: Emission of electromagnetic waves from

objects above absolute zero.


Thermal Analysis Radiation measures


Black Body

• Law of Stefan – Boltzmann

𝑊𝑐𝑛 = 𝜎 ∙ 𝑇4

FLIR laboratory at Sweden


Taking measures (Real Bodies):

Potency curve

compensation with

emissivity values

Real signal

compensation from

real measure to black

body equivalent


Emissivity Factor:

• Depends on the material

• Depends on the surface

• Depends on the object geometry

• Depends on the camera’s angle

4. Thermal Image

Applications

Tecnalia Research & Innovation Applications

Thermal Imaging Applications

• Thermal efficiency in buildings



• Electronics and Electrics domain



• Health domain



• Fluids



• Mechanical domain

Temperature

Inspection

Control for Hot

Iron Tubes

Tecnalia Research & Innovation IR Control: Introduction

• Objective:

– Application to obtain temperature values (maximum,

minimum, mean) from iron tubes in different process

steps (stopped and moving).

Tecnalia Research & Innovation IR Control: Architecture

TCP/IP

Control Point 1

PLC Production

Database

SDK Coms Camera

Image Process

Coms

PLC

Configuration Data

Shot Temperature

Interface

Conf

Control Point 2 Control Point 3 Control Point 4

Tecnalia Research & Innovation IR Control: Control Point (I)

• Control Point 1– Mean Surface Temperature (stopped):

• Tube detection and location in the image

• ROI adjust to tube perimeter

• Configuration values for border avoiding

Tecnalia Research & Innovation IR Control: Control Point (II)

• Control Point 2– Maximum inner temperature (stopped):


• ROI adjust to tube inner area

• Maximum temperature detection in the inner ROI

Tecnalia Research & Innovation IR Control: Control Point (III)

• Control Point 3– Several temperatures calculation (moving):

• Inner Region: Maximum temperature

• Ring Region: Mean temperature

• Surface Region: Mean temperature

Tecnalia Research & Innovation IR Control: Control Point (IV)

• Control Point 4– Mean Surface Temperature (stopped):


• ROI adjust to tube perimeter

• Configuration values for border avoiding

Tecnalia Research & Innovation IR Control: Conclusions

• Conclusions:

– Thermal images for Computer Vision algorithms (Image + Video)

– Robust thermal measures analyzing all the object surface

(computer vision + Thermal camera) instead of punctual

measures (standard pyrometer)

– Advance measurement capabilities thanks to vision algorithms

for object tracking and region detection

INSIRLIN: On

Line Infrared

Inspection –

Welding Analysis

Tecnalia Research & Innovation

• Objective:

– Low cost on line infrared inspection development for

industrial applications

– Sensor based on linear detector (1x256) of VDP

PbSe

• Technology test by designing and manufacturing a specific IR

inspection system for manufacturing processes of steel plain

product

– Visualize and analysis in real time of steel band seam welding.

• Partners (INNPACTO):

INSIRLIN: Introduction

Tecnalia Research & Innovation INSIRLIN: Architecture

Welding machine

Thermal Camera

Sensor

Electronic board

Optics

TCP/IP Processing SW

INSIRLIN

Sample:

Tecnalia Research & Innovation INSIRLIN: Characteristics (I)

• Characteristics:– Specific driver development (TCP/IP, USB)

– Signal corrections:

• Background noise removal

• Non-linear sensors (different response to the same radiation power):

Tecnalia Research & Innovation INSIRLIN: Characteristics (II)

• Tools:– General: Isotherms, Maximum, Minimum, ROIs, Visualization

color palettes, Histogram, Profile analysis…

– Specific:

• Ripple Algorithms: Radiation/Temperature abrupt changes:

• Hole detection: Morphology, segmentation, blobs, …

• Others: Thresholds, Temporal component analysis, image subtraction, …

Tecnalia Research & Innovation INSIRLIN: Characteristics (III)

• Classifiers:– According to the thermal signature provided by the sensor,

classify the main components of the welding defects

automatically:

Burn welding:

Cold welding:

Lack of fusion:

Tecnalia Research & Innovation INSIRLIN: Conclusions

• Conclusions:

– Low cost thermal sensor development

– 100% Welding inspection after each welding operation

– Image analysis, enhancement and classification applied to

thermal images

4. Conclusions

Tecnalia Research & Innovation Conclusions

• Conclusions:

– Thermal analysis can provide advance information about the

process.

– Computer Vision algorithms can be used as if thermal image it

was a standard gray image.

– Merging thermal information with computer vision can provide a

more robust and controlled process.

www.computervisionbytecnalia.com

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