VISION SYSTEM INSPECTS X-RAY DOSIMETER BADGES – HELMHOLTZ-ZENTRUM

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In Germany, the inspection of x-ray dosimeters worn by people who may be exposed to radiation is a governmental responsibility. Only a handful of institutions are qualified to perform such tasks. One of which, the Helmholtz-Zentrum (Munich, Germany) is responsible for the analysis of approximately 120,000 film badge dosimeters a month.

Previously these 120,000 film badges were evaluated manually. To speed this inspection and increase reliability, the Helmholtz-Zentrum has developed a machine-vision system to automatically inspect these films. The film from each dosimeter badge is first mounted on a plastic adhesive foil, which is wound into a coil. This coil is then mounted on the vision system so that each film element can be inspected automatically (see figure). To analyze each film, a DX4 285 FireWire camera from Kappa optronics (Gleichen, Germany) is mounted on a bellows stage above the film reel.

Data from this camera is then transferred to a PC and processed using HALCON 9.0 from MVTec Software (Munich, Germany). Resulting high-dynamic-range images are then displayed using an ATIFire GL V3600 graphic board from AMD (Sunnyvale, CA, USA) on a FlexScan MX 190 S display from Eizo (Ishikawa, Japan). Before the optical density of the film is measured, its presence and orientation must be determined. As each film moves under the camera system’s field of view, this presence and orientation task is computed using HALCON’s shape-based matching algorithm.

Both the camera and a densitometer are used to measure the optical density of the film. The densitometer measures the brightness at each of seven points on the film in high precision and is used to calibrate the camera measurement for every film image. To increase the dynamic range of the gray-level image of the film, two images with different exposure times are computed and combined into a high-dynamic-range image. Because the background lighting is not homogenous, shading correction is performed to eliminate any lighting variation. Any lens vignetting and variations caused by pixel-to-pixel sensitivity variation is eliminated by flat-field correction. The optical density is converted into a photon dose using a linear algebraic function to calculate the x-ray dose to which the film was exposed.

Every film reading must be correlated with the unique specimen number associated with each badge. Since these numbers are deposited onto the film material, approximately 10,000 characters needed to be trained and saved to an OCR database using HALCON. After the film is identified, the system must also detect which type of dosimeter cassette has been used to house the film. Since each cassette uses a different x-ray filter, the shadow cast on the film can be either rectangular or round. Thus, a grayscale analysis of these shadows can be used to detect the differences between the different types of cassettes that were used to house the film. To pinpoint the specific causes of x-ray exposure, the system is also programmed to detect whether any potential exposure is caused by errors in film developing or x-ray contamination. If the imaging system detects contamination events, these are then reported manually.

 

TO KNOW MORE ABOUT MACHINE VISION SYSTEM IN SINGAPORE, CONTACT MVASIA INFOMATRIX PTE LTD AT +65 6329-6431 OR EMAIL US AT INFO@MVASIAONLINE.COM

 

Source – MVTEC.COM

 MV ASIA INFOMATRIX PTE LTD

3 Raffles Place, #07-01 Bharat Building,
Orchard Road
Singapore – 048617
Tel: +65 63296431
Fax: +65 63296432

E-mail: info@mvasiaonline.com / menzinfo@starhub.net.sg

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INDUSTRIAL CAMERAS – LETTING ROBOTIC ARMS SEE

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Robotic arms are widely used in industrial automation. They complete tasks which humans cannot accomplish, are considered too time consuming or dangerous, or which require precise positioning and highly repetitive movements. Tasks are completed in high quality with speed, reliability and precision. Robotic arms are used in all areas of industrial manufacturing from the automobile industry to mold manufacturing and electronics but also in fields where the technology might be less expected such as agriculture, healthcare and service industries.

ROBOTIC ARMS “SEE” WITH MACHINE VISION

Like humans, robotic arms need “eyes” to see and feel what they grasp and manipulate: machine vision makes this possible. Industrial cameras and image processing software work together to enable the robot to move efficiently and precisely in three dimensional space which enables them to perform a variety of complex tasks: welding, painting, assembly, picking and placing for printed circuit boards, packaging and labeling, palletizing, product inspection, and high-precision testing. Not all industrial cameras are compatible with or can be installed in robotic arms, but The Imaging Source’s GigE industrial cameras provide an optimal solution.

GIGE INDUSTRIAL CAMERAS FROM THE IMAGING SOURCE – THE COST EFFECTIVE AND HIGHLY VERSATILE IMAGING SOLUTION

THE IMAGING SOURCE’S GIGE INDUSTRIAL CAMERAS are best known for their outstanding image quality, easy integration and rich set of features. They are shipped with highly sensitive CCD or CMOS sensors from Sony and Aptina, which offer very low noise levels, provide multiple options in terms of resolution and frame rate, guarantee precise positioning capture and output first-rate image quality. External Hirose ports make the digital I/O, strobe, trigger inputs and flash outputs easily accessible. Binning and ROI features (CMOS only) enable increased frame rates and improved signal to noise ratios. The cameras’ extremely compact and robust industrial housing means straightforward integration into robotic assemblies.

In addition, The Imaging Source’s GigE industrial cameras are shock-resistant, so camera-shake and blurred images can be avoided. The cameras are shipped with camera-end locking screws, and the built-in Gigabit Ethernet interface allows for very long cable lengths (up to100 meters) for maximum flexibility.

The Imaging Source’s GigE industrial cameras come bundled with highly compatible end-user software and SDKs which makes the setup and integration with robotic arms fast and simple. Trained personnel without extensive robot programming experience can reprogram the cameras to complete new tasks in a snap. These camera characteristics, along with their competitive price, make The Imaging Source GigE industrial cameras the perfect solution for robotic arm applications.

Suitable cameras for robotic arms:

  • GigE color industrial cameras
  • GigE monochrome industrial cameras

TO KNOW MORE ABOUT IMAGING SOURCE MACHINE VISION CAMERAS, SINGAPORE, CONTACT MVASIA INFOMATRIX PTE LTD AT +65 6329-6431 OR EMAIL US AT INFO@MVASIAONLINE.COM

Source – THEIMAGINGSOURCE.COM

MV ASIA INFOMATRIX PTE LTD

3 Raffles Place, #07-01 Bharat Building,
Orchard Road
Singapore – 048617
Tel: +65 63296431
Fax: +65 63296432

E-mail: info@mvasiaonline.com / menzinfo@starhub.net.sg