Knowledge is power

The latest ‘knowledge-based’ design software, which incorporates expert rules and best practice parameters, is being incorporated into processes from Formula 1 car production to mould-making.

The key to expert software, or ‘knowledgeware’, lies in converting rules and know-how about materials, techniques, performance and geometry into an easily accessible, embedded format. This is becoming increasingly important as companies move towards design-to-order – and more and more non-CAD users wish to impact on design programmes at the earliest stage.

These packages promise to take the headache out of many tricky or time-consuming practices by turning ‘tacit’ knowledge into implicit. Knowledge is commonly incorporated into the software as a graphic or textual ‘wizard’.

EDS (formerly UGS/Unigraphics) introduced Wave technology a couple of years ago, combining parametric design with knowledge-based capture of geometric rules. Together these techniques offer controlled and automated change throughout a product design programme. Wave can also drive change through a chain of in-process manufacturing models, with the associated drawings and CAM data being updated automatically.

‘Wave helps improve the communication of design criteria within an organisation and along the supply chain,’ says Neil McLeod of EDS. ‘It allows each group to work within published constraints in the knowledge that their designs will integrate safely into the overall product.’

Unigraphics originally introduced a series of Process wizards and assistants in its Version 16, then brought in Knowledge Driven Automation and Knowledge Fusion with Version17. These encapsulate knowledge of specific engineering disciplines to automate and accelerate the design process.

Specialist packages, such as Mold Wizard for automating plastics injection mould design, Progressive Die Wizard, Gear Engineering Wizard and Strength Wizard for finite element analysis, enable non-experts to handle sophisticated applications. The Process Wizards and Assistants run in parallel with design development, enabling concurrent engineering.

Jaguar Racing uses Wave to accelerate the development of its wind-tunnel models. Parts are created as flexible templates which can be modified in minutes. Steve Nevey, Jaguar Racing CAE manager, explains: ‘We have to go through numerous repetitions, as subtle differences can have a significant impact on performance.’ For example, design of the Jaguar ‘smile’ (where the front wing dips in the middle) and its angle of attack can be changed with ease. As the knowledge-based geometry in Wave is associative, the model knows automatically how to maintain parameters and constraints for the slot gap and aspect ratio of the wing. Wave’s parametrically driven design facility can drive design changes automatically, which frees the designer to concentrate on other features.

EDS’s Knowledge Fusion enables users to develop their own company-specific applications.

Audi has cut design time for the definition of body panel press tools by a third, and made up to 50 per cent time savings in other areas. Airbus is now looking to use Catia knowledgeware to expand its scope across the process from design to wing manufacture, and then through the product’s lifecycle.

Valeo is employing Catia knowledgeware that can automatically handle a variety of bulkhead and windscreen angle designs to automate the design of windscreen wipers. Paper-process machinery manufacturer Valmet is to build special templates to automate the design process as it moves from mostly 2D to 3D design with Catia Version 5.

Peter Marley, Catia product marketing manager, says: ‘Knowledgeware helps automate the process for a lot of repetitive design tasks. The designer can concentrate on being innovative rather than just problem-solving. This makes for more efficient design and better product optimisation.’

Marley considers that knowledge-based design is fundamental to the next stage of design development. He claims that most CAD designs will become generative, knowledge-based and associative. This means features will be able to be pulled out from a design catalogue and automatically adapted to the product context.

Design-to-order will become truly ‘accessible’ using knowledge-based solutions. This is already being demonstrated by Krebs Engineering in the US, which is using Catia V5 to design cyclonic separators. Customers specify key parameters by volume, materials and space available. Templates do 70 per cent of the design work.

The wizard concept is gaining ground in specialist design software, too. Delcam has developed packages for both mould and electrode design. Powershape includes the PS Mouldmaker module, a wizard for mould assembly modelling, and PS Electrode is for electrode design. Two new wizards are under development – one for injection mould cooling channels, the other for designing slides in components containing an undercut.

Delcam marketing manager Peter Dickin also recognises growing demand for embedded knowledge within CAD packages. ‘Wizards help people through the toolmaking design exercise. But we’re still a long way from being able to create a mould automatically as most large ones require non-standard components.’ He considers that that may be an advantage, as it means ‘you can step out of the automated design process at anytime and tweak it to get the result you want’.

CoCreate recently introduced Mould Design Module for OneSpace Designer, following the earlier success of a Sheet Metal Module. Each module has a knowledge database that features wizards and a facility to add further items according to individual customer know-how. These modules were developed in close partnership with Trumpf for the sheet metal module, and Canon for the mould module. New modules for plastics design and very large assemblies are due this year.

Specialist applications

Geoff Hedges, CoCreate’s solution marketing manager, says: ‘We can bring a lot to specialist areas like moulding, sheet-metal and plastics. But it will be far more difficult to tackle general engineering rules, as software design tools can be used for such a broad range of applications.’

PTC offers two main knowledge-based engineering products. A methodology based on Behavioural Modelling was introduced last year, which analyses product designs or brings together different virtual prototypes for product optimisation.

Product manager Chad Jackson considers that there are two different levels of knowledge engineering. ‘The first is to interrogate a CAD model with questions about the properties of the solid model. The second is to set functional or conditional ‘what if’ rules,’ he says.

Cycle manufacturer Cannondale uses behavioural modelling to design rear suspensions with 30 iterations in one day, where previously five iterations took three days. Arizona-based Space Systems Loral employs behavioural modelling to optimise design of satellite solar panels so that they expand in relation to thruster deployment in space. Designing and testing of the system once took four weeks. Knowledge engineering enables test and set-up in 30 minutes.

Looking ahead, Jackson is convinced that sharing of CAD knowledge will become enterprise-wide, rather than limited to the engineering and design offices. ‘New web-enabled concepts like Wildfire will offer greater connectivity between CAD and non-CAD users.’

It is clear that in today’s e-enabled world complex engineering design knowledge, like other areas of expertise, will no longer be limited to those ‘in the know’.