Automating for better manufacturing?

It’s advanced process control (APC), Jim, but not as we know it! A little company with representation in the UK and the US, going by the ridiculous name of Curvaceous Software, may be changing the face of APC before our very eyes. And when industry realises, this little acronym could at last fall into common engineering parlance way beyond the originating ‘big ticket’ process industries. APCs deliver their benefits by improving the consistency of plant (and in the future, factory) operations. Model-based and predictive, multi-variable, multi-constraint and adaptive, they adjust process variables already under automatic regulatory control in the face of even subtle deviations (from feed or mechanical changes, etc), but taking a holistic view of all relevant plant. More stable operations mean less product variability which, in turn, mean plants capable of being driven closer to the limit, yielding better throughput and quality. The problem with APC has been nothing to do with its abilities, which are well documented and excellent, but everything to do with its cost, timescale and complexity. Petrochemical plant and refinery managers have long accepted 18 month implementations of APC systems costing small fortunes. They’ve done so because when APC is up, it lets them run massively expensive continuous plants so much more predictably that it’s paid for itself in short order. In discrete manufacturing? Examples abound: Agip Petroli increased profitability at its Sannazzaro refinery by 3% with an AspenTech DMCplus multi-variable controller, achieving ROI in eight months. Similar Honeywell Hi-Spec technology was responsible for upgrading APC at Sasol Synthetic Fuels’ cold separation and methane reforming units in South Africa, leading to improved stability and product quality as well as reduced emissions. All well and undeniably good there. In these industries, huge volumes and highly automated and energy consuming production plants justify the investment in time, effort, fees and temporarily reduced throughput (as masses of data is collected to build successful model controllers, mimicking their behaviour). But how do you transfer this even to hybrid plants like food and beverage, much less discrete manufacturing? The clue is in the model-building and problem visualisation. Make that an order of magnitude simpler and definition of, for instance, multiple machine controls and shopfloor operations need no longer take months and a team of consultants, but weeks or perhaps days – with operators delivering the goods. Enter Gerrards Cross-based Curvaceous. “We came across this new application of parallel co-ordinate maths that lets you visualise and manipulate many variables simultaneously and highlight relationships between them by working geometry in ‘n’ dimensional space,” explains UK managing director Dr Robin Brooks disarmingly. “Users ... get a simple graphical display of many more variables and observations than they could possibly have worked with before.” And the point: with this tool, models simulating plant and machinery operations can be built intuitively, from history data and best practice. You choose your objectives – consistency of operations against whatever criteria matter most – and the APC model will achieve what human operators and/or automation simply cannot. It’s not been sold into discrete manufacturing yet, but it could be, and it could detect and alert on subtle changes, including those resulting from, for example, drifting machine set-ups, cumulative tolerancing, tool wear and so on. “It’s got very good prospects,” says Brooks. “We’ve got a wallpaper printer interested, for example.” Hardly massive plant. “It’s quite a complex process of depositing PVC solution onto paper, baking and squirting inks. And you’ve got to get it right – defects are easy to see when they’re on a wall! Our system will enable operators to maintain unmatchable consistency.” At its most basic level, what we have here is the potential to improve on what’s currently the accepted norm in terms of machine maintenance and set-ups. At the moment, a five user license for the software tool costs £35,000, but Brooks says lower cost versions are on the horizon. If so, the doors could well open for APC in manufacturing. Time to take another look?