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Extensive use of virtual design and digital manufacturing throughout the product development process
High-End Automotive Industry: Case Study
Recently I attended a presentation by an Aston Martin Director, describing their approach to product development. It centred on the extensive use of virtual, or digital engineering throughout the product development process.
Aston Martin, a high performance automotive manufacturer, perhaps most famous for supplying the cars James Bond drives, have developed an approach driven by the use of advanced computer aided design and computer aided engineering. And it appears to be highly effective!
They term their new product development activities a ‘product creation process’, as it is holistic covering many disciplines and stages. Like other development processes it includes decision gates, milestones and distinct phases. It is however highly customised and importantly all stages are recreated digitally, in a virtual world – from project start to final preparation for production.
Systems engineering is used throughout with requirements being captured and verified through testing – again all digitally. Car assemblies and subassemblies are developed and tested virtually. CAD readiness levels describe how developed virtual parts and assemblies are.
All digital development activities are run against a scheduled project plan. CAD project engineers will meet and discuss progress against the plan. Likewise manufacturing and production engineers will be concurrently developing and organising bills of materials and gearing up for production, again against the plan. Remember this is all digital, but it is treated in exactly the same way as traditional physical product development and production activities.
Detailed checking takes place for CAD components and assemblies in virtual space. Clearances are checked to ensure they are in tolerance and to recommended specifications. Likewise any potential clashes are designed out. Virtual fly through models show what the extremes of any tolerances look like on the actual vehicle, for example on gaps and split lines between panels.
Service engineers will also check how the vehicle will be maintained, all in the virtual environment. Access for tools and routines can be refined and checked. Likewise production engineers will review and decide on body assembly fixtures and best component holding and moving positions, including the position of robots and any automation. The digital environment enables this to be optimised. Virtual jigs and fixtures are developed and will be physically manufactured later.
Ergonomics are reviewed and refined digitally. This includes using anthropometric data to check male and female sight lines, ride height comfort, arm and console rests, elbow room etc.
Digital reviews are carried out with score cards to check compliance. The digital Engineering Change Order system tracks changes and modifications. Engineers hold daily wash-up meetings, just as in the physical world. Score cards use colours to track progress, with all actions being stepped through according to predefined processes, led by project engineers. Practical questions are asked about the location of tooling and correct kitting for bills of materials.
CAD review meetings take place with cross-functional teams
of engineers looking at large projections of the digital vehicle. Here the CAD
model can be built up, flown through, orientated, cut away etc depending on
what is under review.
High-End Automotive Industry - Computer Aided Engineering (CAE) Analysis
Analysis conducted through Computer Aided Engineering (CAE) drives down the number of digital and physical prototypes required. In this way it speeds up time to market. At set points in the product development process the CAD model is frozen and CAE analysis, takes place to test components and assemblies against performance specifications.
CAE analysis takes place to test a range of features, these include:
Thermal management where the temperatures are mapped on the model and engineering decisions are made to mitigate any risks posed. An example is ducting excessive heat away, perhaps to atmosphere, from parts bonded together where the adhesive may start to break down above a certain temperature. Airflow and cooling are modelled on the virtual car using computational fluid dynamics (CFD).
Aero-acoustics are used to analyse sound as air moves across the windscreen, wing mirrors, door windows, wipers etc. Turbulent air is analysed using CFD with the goal of mitigating the impact through design changes.
Sound Quality analysis uses CAE to simulate the characteristics of exhaust noise. The analysis looks at resonance. The aim is to tune the sound to what is perceived as desirable, working to a specification. Refinements to the exhaust system are modelled and retested.
Body stiffness and bending feature CAE to analyse bending, stiffness and torque on the chassis and complete car. Modelling highlights different loadings and the resonance they produce, depending on driving conditions and terrain. Exaggerated movement on CAD models show how the forces act on the car frame. Stiffness is desirable so braces are added and modelled to test rigidity.
Crashworthiness involves proving-out the impact of different types of crash in a virtual environment. There is very close correlation between virtual and physical crash testing when the CAD simulation and real life videos run side-by-side. Virtual testing is considerably cheaper. Crash models are refined over time to increase accuracy. Crashes are modelled for a range of scenarios including front, side, rear and glancing impacts. Additionally occupant and pedestrian protection is modelled including crumple zone testing. Airbag testing also takes place, all done virtually.
Aerodynamic testing involves using CFD to look at airflow, drag coefficients, turbulence and drag on the whole vehicle as well as various parts of the car such as wings and wheels.
High-End Automotive Industry - Future Enhancements & Further Facts
An area for improvement in virtual product development would be better understanding and tracking of mass as the car goes through the development stages. Where is weight added as the assembly builds up and can it be kept on track according to the plan? Tracking costs through development is a similar discipline.
Most deep CAE analysis is conducted in-house although some work is outsourced. The IP lies in the significant internal work.
Siemens TeamCentre is the principle CAD package, although up to 20 specialist CAE packages are used along with other software covering ERP and engineering changes. The ERP system brings the CAD and BOM production data together.
A future aim will be to speed up the CAE analysis loops derived from CAD models at various stages of the development process.
Clay models are still used! They are ¼ size and are used to mock-up and create surface CAD data.
The engineering change management system uses a colour coded arrangement which varies depending on the status of the change after a proposal is submitted.
Finally the company future looks in safe hands with a highly regarded graduate development scheme. Here successfully applicants move around different parts of the business for 12 months, as well as potentially getting CAD training. They will then work closely with experienced project engineers and are soon immersed in core work with many soon acquiring responsibilities for parts or features within of the car.
The extensive use of digital data is central to the way the business goes about product development. This is typical for many automotive manufacturers and as so, impacts smaller businesses in the supply chain. Engineers and SMEs who understand it stand a great chance of benefitting commercially and personally.
In summary, it was a informative and inspirational presentation.
Director, Advice Manufacturing