Software plays vital role in Land Rover designs

Improved design development workflow, enabled by ICEM software, has resulted in reduced costs and improved quality at Land Rover.

Improved design development workflow, enabled by ICEM software, has resulted in reduced costs and improved quality at Land Rover.

Integrating ICEM Surf into the overall body and interior design development process for the all-new Land Rover Discovery and Range Rover Sport has enabled Ford's Land Rover unit to reduce late design changes, cut tooling development costs and reach its quality targets.

NIAIS, otherwise known as the Detroit Motor Show, is traditionally the first on the calendar of the major annual motor industry events.

As such, it attracts most of the leading automotive manufacturers, who use it as a platform to introduce their latest offerings and to demonstrate some of their forward design thinking.

For example, the 2005 NIAIS was used by Ford Premier Automotive Group member, Land Rover, to showcase three new vehicles.

Probably the most eagerly awaited of these new Land Rover products at the show was the Range Rover Sport.

Inspired by the Range Stormer concept car shown at the 2004 event, the Range Rover Sport sees Land Rover entering the performance segment of the SUV market for the first time with its very own 'Sports Tourer'.

Also new on the Land Rover stand was the Range Rover for 2006.

Incorporating some refreshed exterior styling, this is the first significant update to the award-winning Range Rover since the current model's introduction in March 2002.

The third vehicle that was new to the 2005 Detroit event was the international award-winning Land Rover Discovery 3.

Roomier yet externally not much bigger than the outgoing Discovery, the new Discovery 3 features a spacious cabin packed with clever stowage locations, as well as either five or seven comfortable seats.

The exterior design is distinctively Land Rover.

With its minimalist, modern design approach, there is no chance of confusing the Discovery 3 with any other vehicle on the road.

The body is a combination of steel, much of which is high-strength grade, and aluminium.

An innovation here is Land Rover's all-new integrated body-frame.

This is a new vehicle architecture that combines the torsional rigidity, car-like handling and refinement of a monocoque (or unitary) body with the strength and versatility of a traditional ladder-frame, as used on many SUVs.

So, unlike most bodies attached to separate platforms, the Discovery 3 body is a key part of the vehicle structure.

This gives it its uniqueness, its stiffness and its strength.

Computer-aided design, high-strength steel and a sophisticated hydro-forming production technique combine to deliver this new technology, allowing a lighter weight, cleverer shapes and much tighter tolerances.

An integral part of the computer-aided design process for both the Land Rover Discovery 3 and the Range Rover Sport was the ICEM Surf surface modelling, surface analysis and design visualisation software suite from ICEM .

The software played a vital role not only in the design process in terms of the development of the Class A surface data required for the manufacturing process, but also by enabling an improved design data workflow.

This allowed the engineers downstream of the design phase to start their own development processes much earlier than is usual, with the result that fewer late design changes were required and development costs were reduced.

The Land Rover Discovery 3, as well as the Range Rover Sport, is a completely new vehicle.

Both vehicles use Land Rover's T5 platform.

From its external body panels right down to the interior switches, everything on the Discovery 3 is a new design.

And unusually in the automotive industry, everything was designed internally by Land Rover's design team in the UK.

Everything that the customer can see, right down to the window buttons and door handles, with the exception of the seat cushions, was designed internally with the aid of ICEM Surf.

The development process followed a more or less typical pattern - but with some significant differences from earlier development programmes at Land Rover.

With the surfacing engineers working alongside and in parallel with the designers and clay modellers, the starting point was a surface model generated with ICEM Surf from a 3D scan of the early 'styling theme' clay model.

This was little more than a 'picture model', with no packaging or feasibility data.

The next step, therefore, was to add package data, such as the glass planes, occupancy information, engine points, wheel envelopes and 'door shut lines'.

Some of these data, such as the engine points, came from the Catia solid modelling CAD/CAM system used by Land Rover's engineering department.

This marked the first step in what would become a constant two-way flow of design data between ICEM Surf and Catia throughout the vehicle's development process.

With the basic package data added to this early surface model, the surfacing engineers were then able to redefine the styling model over the engineering hard points, using ICEM Surf.

These redefined model data were then used to drive changes to the clay model for styling review and further refinement.

Again, this was a two-way process, with the ICEM Surf model data being used to drive changes to the clay that were required from an engineering feasibility viewpoint, while changes to the clay required by the stylists were scanned and re-imported into ICEM Surf for the digital surface model to be updated.

During this two-way styling development process, before the project had reached the 'stop clay' or design freeze stage, the clay model was the 'master'.

From stop-clay onwards, the ICEM Surf digital surface model was the master model.

From here on in, everything was done in the digital world.

However, even before the stop-clay stage had been reached, the early surface model data created with ICEM Surf had been pre-released to the manufacturing engineers working on the Catia engineering CAD/CAM system for use in the tooling development process.

Key to this was the ability that ICEM Surf gives to quickly create high quality surface data and to drive these surfaces back onto the clay in a two-way process.

This meant that even before the design freeze stage had been reached, Land Rover's designers knew they had a database that captured the design intent and was also sufficiently robust in terms of engineering feasibility for the manufacturing engineers to be able to begin tooling development.

This early availability of high quality surface model data enabled Land Rover's manufacturing engineers to undertake engineering feasibility analysis in order to determine, at a very early stage in the design development process, whether or not the surfaces were feasible from a manufacturing standpoint.

Any problems that were identified - maybe a surface that did not conform to a minimum curvature and which could therefore lead to problems with the press tool - were then passed on to the surfacing engineers so that the necessary remedial actions could be taken, before a design had been signed off.

Apart from enabling early engineering and manufacturing feasibility analysis, another key reason for having available a robust digital surface model at an early stage in the vehicle development process was to help drive Land Rover's 'Virtual Series' process.

One of Land Rover's aims is to reduce to an absolute minimum the number of physical prototype vehicles that need to be built during the development process.

The Virtual Series process can be likened to a 'virtual factory' in which the Land Rover engineering department fully engineers a vehicle in the virtual world and produces what is commonly known as a digital mock-up.

However, to be able to produce this digital mock-up, Engineering needs surface model data that is fairly robust in terms of engineering feasibility and design intent, early on in the development process - in fact, even while the clay is still being developed.

On the Discovery 3 and Range Rover Sport, that meant that while the styling detail was still being refined, Land Rover's surfacing engineers had already developed a surface model that included engineering and packaging information, such as glass planes, door shut lines and panel interfaces.

Using ICEM Surf, they were therefore able, at various points in time, to release to the engineers working on Catia a full set of design data relating to the exterior of the vehicle.

This data was released in what is known as 'car line', meaning that it represented the individual body panel components in their assembled condition.

Engineering was then able to incorporate this surface model data into the digital mock-up to identify any issues and then feed these back up the process chain.

This Virtual Series process usually involves four 'loops' before production release of the data.

Each time, any issues that trigger a surface model design change are dealt with in ICEM Surf.

In the early stages of the Discovery 3 and Range Rover Sport development projects, before stop-clay, the modified surface model data were then used to drive changes to the clay.

Any changes after stop-clay were dealt with in the virtual world using ICEM Surf's surface modelling, real-time rendering and design visualisation facilities.

All of this required reliable data exchange capabilities between ICEM Surf and the Catia engineering CAD/CAM system.

This capability is also key to Land Rover's 'optical quality' process, which brings together designers, surfacing engineers, manufacturing engineers and quality audit personnel, among others, for detailed virtual design reviews.

Using ICEM Surf to create photo-realistic visualisations, in real-time, of a combination of ICEM Surf surface model design data and Catia engineering design data, the optical quality process enabled the team to visually examine door shut-line gaps, surface profiles, panel interfaces and see-through conditions to ensure the required level of quality, both from a visual and from an engineering viewpoint.

The great majority of issues that arose during the Land Rover Discovery 3 and Range Rover Sport design development projects were dealt with in the virtual world, using ICEM Surf as far as the design of the body and interior trim surfaces was concerned.

By the time it came to release of the surface data to production, the design development team was therefore confident that the visually important aspects of the design, such as surfaces continuity, surface reflections, door shut lines, component interfaces and see-through conditions, as well as the engineering and manufacturing feasibility aspects of it, would deliver a high quality vehicle.

However, this did not mean that no physical models were required.

In addition to some individual components along the way, two full-scale models of the Discovery 3 and Range Rover Sport were built: a 'feasibility cube' fairly early in the process and before final production release, the 'function cube'.

With their bodies and interiors machined from the ICEM Surf surface model data, these function cubes, accurate to 0.2mm across the whole car, are precise models of the final vehicles, complete with all of the customer-visible components in their final finish.

And as good as the virtual world is, they are still really the only way to ensure that the final vehicle has the 'quality feel' for which Land Rover strives.

The improved workflow enabled by ICEM Surf through its data exchange capabilities with the Catia engineering CAD/CAM system, together with the ability it gave the surfaces development team to generate high quality surface data and make it available to downstream design and manufacturing teams early in the development process, resulted in far fewer physical prototypes of components being required than would otherwise have been the case.

More importantly, by being able to release ICEM Surf surface model data, as it evolved, directly into the tooling development process, late design changes were avoided.

This enabled Land Rover to ensure that before any tooling was laid down, the designs were technically feasible and accurately represented the final design of the vehicle's various body and interior components.

This, in turn, resulted in a major reduction in the tooling development and production costs.

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