LEYLAND Trucks’ latest 18 tonne truck prototype has rolled off the production line, having been designed entirely with the use of advanced simulation and Virtual Reality (VR).

Leyland’s design team, which is responsible for the design of both the DAF LF and Foden range of trucks, approached VR specialists, Virtalis, three years ago.  Ian Cure, Leyland’s CAD system manager, explained: “We were using PTC’s Pro/ENGINEER, but we needed to do more than just model.  We wanted to see a whole vehicle on the screen, and be able to move around it to discuss particular design issues, as we would have done using the traditional physical mock-up approach.  The sheer size of the ProEngineer models means that viewing a complete vehicle was nearly impossible to achieve.  However, converting the ProEngineer data into PTC’s DIVISION Mockup resulted in file sizes just a 20th of the original model.  This meant that suddenly everything became easy to manipulate and visualise.  An added bonus of using DVMockup, was that one also had the ability to work in true 3D mode.  When our then engineering director saw what design benefits Virtalis clients were achieving using 3D projection systems, he gave the VR project the immediate green light.”

Previously, like most in their industry, the Leyland Design Team built physical mock-ups of trucks it was designing.  This was to ensure the parts fitted together as the designers intended and to be certain there were the requisite clearances during the manufacturing process.  Doug Holmes, the lead engineer of Leyland’s Configuration Group, said: “Even though we employed a full-time engineer to keep the physical model as up-to-date as possible, there was necessarily a lag between when the changes were made and when we could see the implications of those changes.  Now we have instant feedback.  Not only that, but we can share the design with our manufacturing colleagues.  All their doubts melted away when they realised that they could see the model, review it and use the DVMockup tools to rehearse the various manufacturing processes.”

Providing customers with a truck to match their particular requirements has led to Leyland having a very complex bill of materials.  This is because the number of possible truck permutations is almost limitless.  Trucks are tailored for different operating conditions; a seven tonne vehicle, for example, can have a choice of six different wheelbases, two different engines, four different gearboxes and 300 rear axle ratios.  Using VR to link Leyland’s designers with its manufacturing engineers has helped to cut both design rework and time-to-market.

Doug Holmes said: “With Virtalis’ help we were able to build up the entire manufacturing process stage by stage.  They installed a passive stereo system, which allowed us to carry out design reviews with our manufacturing colleagues weekly.  As we were able to work on how the design was to be built at the same time as the design itself, the manufacturing engineers quickly realised the advantages to them and their team on the production line.”

The change from physical static build to VR stage-by-stage build was radical for Leyland Trucks.  Two days before the new truck variants were scheduled to go down the production line, workers from the shop floor were shown the model and taken through the 40 stage manufacturing process.  This familiarised them with the new parts and their new roles in a single session.

Ian Cure commented: “One of the our operatives spotted one part being added out of sequence, so a last minute change was effected.  On the big day, everything went smoothly, as everyone knew what to expect.  We were even able to drive the first prototype off the production line.  Such was the success in the removal of physical prototypes in the design process, it was reported to the main PACCAR Board as a significant event in Leyland’s manufacturing history.  Since then, we have had a flood of internal visitors to view our ongoing VR initiatives.  We like to think that we’re number one in VR within the PACCAR group.  We are very proud of this achievement and we believe it is the way forward.”

Andrew Connell, technical director at Virtalis, concluded: “Leyland have become VR evangelists.  More people are being trained in Virtual Mockup techniques and they are investigating the world of immersive VR and touch and force feedback, so they can train at manufacturing and servicing their new designs and the upgrading of their system to a digital environment.  Now the momentum is building and they can see what can be achieved with this technology, they are realising the myriad uses of VR in design, manufacturing, maintenance and marketing.”