Innovation: Watching the detectors

THE PRICE of machine vision systems has plunged, opening up the prospect of widespread use replacing human quality controllers on production lines, writes Nuala Moran.

Systems costing between pounds 250,000 and pounds 500,000 when the technology was introduced are down to between pounds 25,000 and pounds 50,000, reports Robert Smith of the contract research organisation ERA Technology.

Mr Smith is heading a programme to apply vision equipment to furniture making and glass packaging. The technology uses cameras mounted over production lines to photograph work in progress. The pictures are digitised and checked against images, held on a computer database, of what the product should look like.

This method of non-contact visual inspection can be used in furniture making to assess such factors as dimensions, blemishes, the quality of laminated coverings and the position of drill-holes. Large areas of board can be inspected more rapidly and to a far more consistent standard than can be achieved by human checkers.

The systems can also detect minute but critical defects that the naked eye would miss.

In the glass packaging industry, the technology will be applied to detect potentially dangerous surface damage, called scuffing. This occurs on high-speed filling lines as a result of bottle-to-bottle or bottle-to-metal impact. Scuffing can reduce the strength of a container so that it explodes when filled.

Bottles will be revolved in front of the camera to take a picture of the cylindrical outer surface, which will then be converted to a flat rectangular image and assessed.

Despite the potential for improving quality and reducing costs, there has been little take- up of the technology among glass and furniture firms. Mr Smith says this is due to the dominance of smaller companies, which perceive it as complicated, expensive and high-risk.

Its early applications were in capital-intensive and technically sophisticated industries, such as microelectronics, cars and steel, where every system was a one-off, developed by suppliers working in collaboration with the users.

'The technology has now reached the stage where we are talking about an adaptation exercise to apply machine vision in new sectors,' Mr Smith says.

The ERA project is sponsored by the Department of Trade and Industry and involves 15 or so manufacturers, including Hygena, Parker Knoll, Layezee Beds and Ercol Furniture. Suppliers of machine vision systems that are members of the UK Industrial Machine Vision Association will also take part.