Mass manufacturing of products, such as aluminium plate, requires millions of Euros worth of investment every year, and aluminium plate producers naturally seek to maximise the productivity and profitability of rolling mills.

Now scientists at the universities of Reading and Leicester in the UK have teamed up with Alcoa to develop new state-of-the-art ‘fused expert system’ that has shown through plate rolling trials how mills could work at optimum performance levels.

Dr Will Browne of Reading’s School of Systems Engineering, together with professor Ian Postlethwaite and Dr Liqun Yao from Leicester, created the system that fuses the human and computer knowledge of a rolling mill and uses that combined understanding to produce high quality plates of aluminium – potentially saving manufacturers millions of Euros. The system is described in the latest issue of Engineering Applications of Artificial Intelligence.

“The UK is one of the world leaders in metals production, but, for supervisory and plant-wide control systems, it had lost ground by failing to embrace new technologies,” said Postlethwaite. “This project redressed this situation through the development of a generic knowledge-based system for supervisory control of rolling mills,” added Browne.

Aluminium plates used in the manufacture of aeroplanes and ships, for example, are produced by passing an initial aluminium slab through a giant mangle – a four-high rolling stand - many times so that it is flattened into a thin final plate. A large number of factors may affect the quality of the final plate – the number of passes, plate temperature, plate width, and so forth – and as much background knowledge as possible is needed to ensure that the plates are near perfect, with no waves.

“With even the most advanced supervisory control system, not all plant knowledge is fully utilised,” said Browne. “However, our new system makes a much improved use of both the human knowledge of the plant and technological data. It predicts and diagnoses quality problems before and during rolling and this leads to superior product shape and shape prediction, and improved explanations of product quality defects, coupled with suggested remedy actions. Ultimately, the development of this knowledge-based system can improve the operational efficiency of plants manufacturing hot band aluminium plate by increasing productivity and yield."

The Engineering and Physical Sciences Research Council-funded research followed on from groundbreaking work by the University of Leicester and involved the combining of knowledge-elicitation and data-mining techniques to develop the fused expert system. Knowledge-elicitation involves establishing important facts and heuristics (rules of thumb) from plant experts, while data-mining is the process of analysing data, often utilising advanced artificial intelligence techniques, in order to identify patterns or relationships.

“The fusion of these two techniques produced an expert system that successfully rolled aluminium plate without significant shape defects,” said Browne. “The methodology is transferable to all the other plate alloys and it is applicable to many other industrial problems. The system could be used in many areas of industrial processing, such as drink cans or wallpaper and we hope that, with the aid of industrial sponsorship, we will be able to take the technology even further forward,” he concluded.

Safety buses poised for growth

Meanwhile, the relatively small global market for distributed/remote I/O (DRI/O) using safety buses/networks is about to enjoy a period of higher growth according to a recent study from Venture Development Corporation (VDC).

Launched in 1971, VDC (www.vdc-corp.com) is an independent technology market research and strategy consulting firm that specialises in a number of industrial, embedded, component, retail automation, RFID, AIDC, datacom/telecom, and defence markets.

Its new study Industrial Distributed/Remote I/O: Global Market Demand Analysis and User Requirement Analysis, 4th Edition, indicates that safety buses/networks accounted for 1.3 per cent of global DRI/O shipments in 2005 and forecasts 2010 shipments to be 2.3 per cent. That will be a rise in value from US$42.1 today to US$99.4 in 2010.

Distributed/remote I/O for use in PLC system applications had the highest utilisation of safety buses/networks. On the other end of the spectrum, only a fractional share of products for PC-based systems are equipped with safety bus capabilities.

“PLC system applications are the most attractive for safety buses,” says VDC analyst Jake Millette. “This is due to the high level of shipments for equipment and machinery in discrete manufacturing compared to process controls. The development and promotion of safety buses by PLC suppliers such as Siemens has also led to a greater adoption.”

In 2005, PROFIsafe accounted for the largest share of the overall market and of distributed/remote I/O for use with DCSs and PLCs. This lead is expected to be held in 2010. AS-i Safety at Work accounted for the second largest share of the overall market in 2005 and either led or was among the leaders for each product type. However, DeviceNet Safety, just barely behind AS-i Safety at Work in 2005, is forecast to take second place by 2010.

VDC’s study concludes that the safety bus/network arena will become more crowded in coming years: “Ethernet/IP Safety is close to release and the Safetybus p Club is developing its SafetyNet protocol. These reflect the general trend to Ethernet solutions in the safety bus/network market.”