Wider view

Ease of use and lower prices mean machine vision technology is broadening its appeal for application in new sectors. Julia Pierce reports

Machine vision technologies, once the preserve of selected industries, are now expanding into new markets. But with this has come a problem: manufacturers are finding innovations are only attractive if coupled with simplicity and ease of use.

‘It is an exciting time for such systems,’ said Declan O’Dea, northern Europe manager at global vision systems firm Cognex. ‘Some new industries are now adopting systems, whereas once they viewed them as not being viable.’

Traditional users of machine vision systems, such as the automotive industry and its Tier 1 suppliers, have been driven by their need to deliver products of high and consistent quality.

‘A combination of the decreasing price of technologies, together with increased ease of use, means that sectors such as food and beverages and the packaging industry are now interested in using these systems, whereas beforehand they were perhaps perceived as being hard to use,’ said O’Dea. ‘The ability for all workers — including those who do not speak good English — to find the technology easy to use and be able to set it up on new parts is vital.’

Another factor attracting new users is that systems are now more robust and reliable. ‘The food and beverage industries, for example, are under pressure over factors such as date codes,’ said O’Dea. ‘These need to be printed legibly, and as companies are fined if a recall is required, it is easier to justify the cost of investment.’

Another firm using ease of use as a selling point is Hexagon Metrology, which recently launched the latest incarnation of its high-speed, hand-held scanner, the Leica T-Scan. The next-generation product — the TS50 — is 30 per cent smaller and weighs 20 per cent less than its predecessor. The device is based on a technologically-advanced laser beam, which comprises individual dots, the intensity of which can be adjusted on the fly.

This means surfaces of different reflective properties, from shiny to black, can be scanned in one step without the need for any operator adjustments.

With margins getting smaller and quality assurance paramount, making an investment in a vision system looks more attractive then ever. The addition of infrared can add extra functionality during observation and testing, ensuring that waste is minimised while product quality is assured.

Infrared camera specialist FLIR Systems has recently launched its A320 and A320G infrared camera systems, which are smaller and Genicam and Gigabit Ethernet compliant. With GigE Vision, hardware and software from different vendors can inter-operate over GigE connections. As 10GigE becomes the mainstream protocol, GigE will be the fastest connection in the industry. Meanwhile, Genicam is a standard interface designed to work hand in hand with GigE, allowing devices to communicate their functions to generic software using a standardised XML file.

Flir’s devices, available with a frame rate of nine to 60Hz, are sensitive to within 0.7º C because their highly accurate temperature sensors provide excellent levels of thermal sensitivity.

‘When it comes to the advantages of infrared cameras, people say “but a normal vision camera can do this”,’ said Paul Sacker, FLIR’s sales and marketing manager. ‘However, with a thermal system you do not need to worry about light levels; for instance, the brightness caused during welding means you can also measure process temperatures.’

This ability to measure two factors at once can be especially useful when working with polymers. ‘If you are welding a polymer it can be damaged by too much energy,’ said Sacker. ‘However, with infrared imaging you can see exactly how much is going in.’

The technology also allows manufacturers to measure factors such as how much liquid has been placed within a bottle during the production process, as its thermal signature is changed by the liquid inside. Other applications include the testing of heated windscreens by automotive manufacturers.

‘In the case of food production, the system removes the need to stab a product with a food temperature probe,’ said Sacker. ‘Normally, the tested product would have to be thrown away afterwards, but this removes that waste.’

The technology is certainly moving forward, and demand is increasing. Firstsight Vision, an independent distributor of vision components and services to the industrial and scientific OEM, has begun distributing Israeli firm Opgal Optronic Industries’ highly-sensitive cooled and uncooled thermal imaging systems, infrared cameras engines and custom systems.

Designed for the industrial, security and defence markets, Opgal makes fourth-generation infrared cameras, based on indium antimonide or MCT cryogenically cooled detectors and on VOx or silicon microbolometer uncooled detectors.

‘While a standard camera system may cost around £2,000, an infrared system can cost around £7,000,’ said Sacker. ‘The investment may be larger, but the cost of failure is even bigger.’

Now machine vision technologies have proved their robustness and usefulness, they are being modified for a host of new uses. Responding to demand for a device that can quickly check and validate that food industry date codes are correct and in the right place, Cognex has introduced the Checker. Though this does not have the capability of a complete machine vision system, it uses selected technologies to provide the information needed at a competitive price.

The company is also adapting machine vision technology to develop a camera-based scanner to read data matrix barcodes, billed as the successor to traditional barcodes.

Meanwhile, Flir is investigating the potential of its A320 series products elsewhere. ‘We see the systems as being particularly suitable for fire and safety applications,’ said Sacker. ‘They are also ideal for remote asset management.’

With a large range of functions and increased processing speed, machine vision technology is now expanding its remit beyond traditional users. If manufacturers can fulfil their promise to couple this with ease of use, there will be interesting times ahead for the sector.