IR Thermography Technology and On Line Processes fileIR Thermography Technology and On Line...
Transcript of IR Thermography Technology and On Line Processes fileIR Thermography Technology and On Line...
IR Thermography
Technology and
On Line Processes
Alberto Isasi
10 de junio de 2014Computer Vision
Tecnalia Industry & Transport Division
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)
Tecnalia Research & Innovation INTRODUCTION
Thermal Analysis
• Non contact measure
• Real Time measure
• Temperature map
Tecnalia Research & Innovation INTRODUCTION
Thermography image vs. Thermal Image
• Thermography = Colored image
• Thermal = Temperature map
Tecnalia Research & Innovation INTRODUCTION
More than standard Image Analysis
• Image processing basis
• Process domain knowledge
• Thermodynamic considerations
• Object characteristics
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)
Tecnalia Research & Innovation Thermography Basis
Heat & Temperature
• Heat = Energy
• Temperature = Speed
+ =100ºC 100ºC 100ºC
+ =100J 100J 200J
Tecnalia Research & Innovation Thermography Basis
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”
Tecnalia Research & Innovation Thermography Basis
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.
Tecnalia Research & Innovation Thermography Basis
Black Body
• Law of Stefan – Boltzmann
𝑊𝑐𝑛 = 𝜎 ∙ 𝑇4
FLIR laboratory at Sweden
Tecnalia Research & Innovation Thermography Basis
Taking measures (Real Bodies):
Potency curve
compensation with
emissivity values
Real signal
compensation from
real measure to black
body equivalent
Tecnalia Research & Innovation Thermography Basis
Emissivity Factor:
• Depends on the material
• Depends on the surface
• Depends on the object geometry
• Depends on the camera’s angle
Tecnalia Research & Innovation Applications
Thermal Imaging Applications
• Thermal efficiency in buildings
Tecnalia Research & Innovation Applications
Thermal Imaging Applications
• Electronics and Electrics domain
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):
• Tube detection and location in the image
• 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):
• Tube detection and location in the image
• 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
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
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.