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Faster, smarter, smaller, more versatile imaging

Imaging is an enabling technology in a vast range of industries. No longer confined to traditional manufacturing and processing inspection applications, industrial vision finds applications in industries as diverse as security, transport, sport, space exploration and even as part of the attempt to set a new world land speed record in 2015.

Industrial camera systems will be deployed on ‘BLOODHOUND SSC’, a jet and rocket powered car designed to travel at 1,000 mph. These will include rear- facing cameras looking at the output from the rocket and jet engine exhausts and cameras monitoring critical engineering parameters such as the wheel- ground interface (Figure 1).
Not surprisingly, therefore, vision technology is in a continuous state of evolution as suppliers strive to produce systems that can produce higher quality images, fit into spaces that previously were too small, and are able to carry out faster and more complex inspections.

Smart cameras

All-in one units that combine image capture and processing in a single housing, smart cameras process the image within the camera itself and output the results from the analysis over industry standard connections. Smart cameras can be used in all of the traditional industrial vision applications such as high volume component inspection, robot guidance, 1D and 2D (DataMatrix) code reading and verification, optical character recognition etc. The availability of faster and dual-core processors means that smart cameras can benefit from more sophisticated image processing and measurement software – in some cases they can offer processing capabilities previously only available on PC-based systems. For example, the Boa 200 smart camera from Teledyne DALSA features a 1.2 GHz dual core processor that brings 4 times the processing speed compared to standard Boa models. As with traditional cameras, smart cameras are getting smaller, yet higher resolution image sensors continue to be introduced, enhancing the range of applications.

3D imaging

The emergence of affordable 3D imaging systems as a credible alternative to 3D contact measurement and metrology is due to the availability of processors capable of handling the computational overhead required (at production line speeds) to create and process complex 3D images. Probably the most popular 3D imaging technique is laser profiling using triangulation. The object to be measured passes through a line of laser light and a camera mounted at a known angle to the laser records the changing profile of the laser line (Figure 2). The resultant point cloud can be analysed to allow calculation of shape and volume and even ‘golden template’ matching between the expected and measured shape of a 3D object. 3D systems can be built using individual components or systems where the illumination and camera are combined in a single housing. Smart 3D systems, like their 2D counterparts, perform acquisition, measurement, decision and control within the unit, although data can be output for further processing, if required. Another approach is to mimic nature with a stereo set-up where two cameras are used to record 2D images of an object. A 3D image can then be calculated using triangulation. While the laser profiling method requires the object to move through the laser line, the stereo system can also work with static objects. For example the new 3D ‘snapshot sensor’ Gocator 3100 from LMI Technologies is a smart 3D stereo system with powerful built-in measurement tools that include rectangular opening, circular opening, slot, cylinder, threaded stud, corners, edges, and gap & flush.

Contact image sensors

Contact image sensors (CIS) are an interesting alternative to line scan cameras for the inspection of flat products. They also form an image line by line and the new Mitsubishi Electric KD series of CIS features a double-row lens array, using gradient index rod-lenses, matched to a colour tri-linear CMOS sensor. Each individual rod-lens captures an image of a very small region of the target, producing a quasi-telecentric image at each pixel, giving remarkable image uniformity with virtually no distortion and a resolution of 600 dpi. Excellent colour rendition and fast scan speed make the CIS ideal for print inspection. Integrated white LED illumination allows for detailed defect inspection in textiles, foils and other web-like materials. Flexible lighting in combination with external illumination allows inspection of glass and metal. Other applications include inspection of PCBs, wafers and solar cells.

Independent advice

As Europe’s largest independent supplier of vision technology and services to industrial and scientific OEMs, system integrators and reseller markets, STEMMER IMAGING has organised a Vision Technology Forum which will be held on May 22 at the Silverstone Wing Exhibition and Conference Centre in Northamptonshire. Visitors will be able to choose their own programme from around 40 seminars on a wide range of vision topics that will be run over five parallel ‘tracks’. In addition, over 25 machine vision manufacturers will be running hands-on demonstrations of hardware and software throughout the day, and for good measure, there will be a talk by Richard Noble OBE, leader of the BLOODHOUND Project team and previous land speed record holder!