Laser scanning cameras offer low-cost 3D inspection

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Firstsight Vision (which will be renamed Stemmer Imaging from 1 January 2009) is introducing new, attractively priced cameras for industrial inspection applications that require three-dimensional imaging and a new approach to 3D measurement.

Automation Technology's C3 family of robust laser scanning cameras is claimed to offer outstanding speed and resolution for 3D imaging applications. On-board FPGA pre-processing of the raw image data is said to enable the C3 cameras to provide previously unattainable frame rates for 3D inspection, measurement and sorting.

The C3 cameras are designed for use with laser line illumination for 3D imaging and have a resolution of 2352x1728 pixels. Very fast profile measurement speeds of up to 25KHz deliver up to 58million 3D points per second. By evaluating the laser line data within the camera, only the information that is relevant to the application is determined, such as profile height and intensity values. This information can then be sent over the interface to a further processing system, such as the Common Vision Blox imaging toolkit from Stemmer Imaging. This integrated processing determines the height profile of the measured surface with a sub-pixel precision of 1/16 pixel without losing speed.

Capture and compare 3D data

Common Vision Blox now features algorithms for capturing and comparing 3D objects and their surfaces, developed by the Spanish company AQSENSE. The AQSENSE Shape Processor software allows the alignment and comparison of dense 3D clouds of points with their respective models. Based on a ‘best-fit’ approach, the patent-pending alignment procedure relies on a very fast and accurate technology, which, combined with an optimised comparison engine, operates on huge clouds of points in a fraction of a second. In practical terms, it compares the 3D image data of a good part – the so called ‘golden template’ – with the upcoming test parts. One of the most impressive features is that the tool aligns the test parts image with the template image in 3D before the comparison. Although this is a major calculation, the accuracy and processing speed of the algorithms mean that the tool can be used for real in-line production processes.

The C3 family is available in CameraLink and Gigabit Ethernet versions for straightforward integration into both new and existing systems. In addition, the CameraLink models include a GeniCam Transport Layer (normally found only on GigE Vision cameras) for DALSA X64, Xcelera, PCCamlink, PC2Camlink, Euresys Grablink, Matrox Meteor and National Instruments framegrabbers. This means that cameras on these framegrabbers can be detected, configured and accessed in exactly the same way as a GigE Vision camera.

For added versatility, a multi-region of interest readout on the sensor allows output of an area-scan image, a 3D image and a scatter image, allowing for 2D and 3D image comparison.

Follow the link for more information about the Automation Technology C3 camera.

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