Ansys and FLIR provide FLIR thermal camera models for virtual validation using Ansys Speos. In conjunction with these models, two supplementary tools have also been developed which are the Thermal Camera Wrapper and the Thermal Camera Editor.
This article describes the complete workflow of using FLIR thermal camera models in Ansys Speos to generate the temperature map of a scene. This involves specifically the usage of the Thermal Camera Wrapper which processes a raw irradiance map generated by a Speos simulation into a temperature map.
The FLIR camera models and the associated tools will be available through the Optical Libraries package in the Speos 2024 R2 release. Prior to this release, interested parties may obtain them by contacting an Ansys representative.
Overview & Prerequisites
The workflow of using FLIR thermal camera models in Speos to generate the temperature map of a scene consists of two main steps:
Step 1: Defining and running a Speos simulation
This involves configuring the scene, setting up a Speos camera sensor using a FLIR thermal camera model, executing the simulation, and retrieving the associated irradiance map.
Step 2: Generating the temperature map
This involves using the retrieved irradiance map as input in the Thermal Camera Wrapper and generating a temperature map.
Five FLIR thermal cameras are available:
- FLIR ADK 640x512 GMSL2 75deg FOV
- FLIR Boson 320x320 50deg HFOV 4.3mm
- FLIR Boson 640x640 32deg HFOV 14mm
- FLIR Boson 640x640 50deg HFOV 9.2mm
- FLIR Tura 640x512 GMSL2 70deg FOV
Each of these cameras is associated with five files:
- An *.OPTDistortion file
- A sensor sensitivity *.spectrum file
- A lens transmission *.spectrum file
- An *.thermalpbcam file
- An *.png image file
The first three are used as input to define a FLIR thermal camera within a Speos simulation during the first step of the workflow. The *.thermalpbcam file is used as input in the Thermal Camera Wrapper during the second step. The image file displays information and instructions on how exactly to model a FLIR thermal camera as a Speos camera sensor within the Speos environment.
Step 1: Defining and running a Speos simulation
The ultimate required outcome of this step is an irradiance map of the scene.
Setting up the FLIR thermal camera
The FLIR thermal camera to observe the scene must be modeled as a "Camera" Speos sensor. The parameters that define a Camera sensor in order to accurately represent a FLIR thermal camera are outlined in the *.png image files associated with each FLIR thermal camera. For example, the complete definition of the FLIR ADK 640x512 GMSL2 75deg FOV camera is shown in the following image.
With the exception of the "Axis System" section that is up to the user to specify as needed, every other field of the Definition panel must be filled in as indicated. It can be seen that the *.OPTDistortion file and the two *.spectrum files that are associated with each FLIR thermal camera are used as input in the fields of "Transmittance", "Distortion", and "Spectrum".
Considerations when configuring the simulation
An inverse simulation is used with Camera sensor to generate the irradiance map. Moreover, any type of light source can be used as long as it is not monochromatic. Of course, the "Thermic" type is the most intuitive in thermal camera applications, but other sources such as "Surface" or "Uniform Ambient" can be used as well. Attention should be given to the spectrum range that is observable by the selected FLIR thermal camera, which can be inspected by opening the lens transmission and sensor sensitivity *.spectrum files in each case. For example, the sensor sensitivity spectrum of the FLIR ADK 640x512 GMSL2 75deg FOV camera ranges from 7000 nm to 14000 nm with a peak at 11000 nm:
Generating the irradiance map
After executing the simulation, an irradiance map is generated among other results. To inspect the map in the XMP viewer, one should select to view the map in radiometric units and in false color:
Step 2: Temperature map generation
The functionality of FLIR Thermal Camera Wrapper
To convert the acquired irradiance map into a temperature map, the postprocessing tool Thermal Camera Wrapper is used. This Wrapper applies imager processing (sensitivity, noise) and electronics processing (amplification, temperature conversion and FLIR Automatic Gain Control) for FLIR thermal cameras. It converts the provided irradiance map (*.xmp) to temperature map (*.xmp) or to final greyscale image (*.png). The inputs are the irradiance map generated by Speos (*.xmp) and the *.thermalpbcam file containing imager and electronics parameters of the corresponding FLIR thermal camera:
How to launch FLIR Thermal Camera Wrapper
The Wrapper is launched through a batch file. To do this, the instructions below shall be followed:
- Create a batch file named LaunchFLIRWrapper.bat in a directory of your choice or use the template in the "Thermal_Camera_Wrapper" folder.
- Write the content of the batch file containing five entries in the first row according to the
following template:- Absolute or relative path of the FLIRThermalCameraWrapper-BETA.exe application
- Absolute or relative path of the *.thermalpbcam file of the used FLIR thermal camera
- Absolute or relative path of the XMP irradiance map generated by the respective camera
- Absolute or relative path of the *.png temperature map to be generated. The directory should be already existing.
- Absolute or relative path of the *.xmp temperature map to be generated. The directory should
be already existing.
An example of a completely and correctly written batch file is the following:
- Run the batch file
Acquiring the temperature map and the final image
The *.xmp temperature map that is generated can be opened and inspected using the Virtual Photometric Lab. The temperature elevation is displayed, and all the tools, such as the Measures tool, can be utilized:
In addition to the *.xmp temperature map, a *.png file of the final image generated by the FLIR thermal camera is created.
Conclusion
With the completion of these steps, users can obtain accurate temperature maps, enabling virtual validation, enhanced analysis and insights into thermal imaging applications. This integration not only facilitates efficient workflow but also ensures precision and reliability in thermal analysis within the Speos environment.
As mentioned in the introduction, the FLIR camera models and the associated tools will be available through the Optical Libraries package in the Speos 2024 R2 release. Prior to this release, interested parties may obtain them by contacting an Ansys representative.