The sub-assembly construction areas, each with a number of robots, were simulated completely as part of the digital planning process

The Vectra project has been only two years in the planning and has seen massive development at Opel's two plants in RÜsselsheim, Germany, and Ellesmere Port, UK. The planning for the manufacture of the new Vectra has been ambitious, with TMS Produktionssystme, TMS-South Africa, The Design Group and Delmia working together, systematically using 3D layouts and computer simulations to enhance production capability. With so many people involved from diverse disciplines, the Delmia simulation environment proved to be a highly efficient means of communication, capable of displaying technical situations in an objective way that was easy for all concerned to understand.

Sub-assembly construction

The sub-assembly construction areas, each with a number of robots, were simulated completely as part of the digital planning process. The aim of these virtual trial runs was to define the robot movements that would be needed in practice. The robots perform tasks to a high standard of precision, such as joining body elements by welding, and then moving the processed panels and stampings smoothly from one workstation to the next. Naturally, it is essential for all the robot movements to be performed without the risk of collisions occurring.

Nick Stanford, a simulation manager at Design UK, explained that his office had worked on the Front Wheelhouse Robotic Cell, while Design South Africa worked on the Rear Wheelhouse. This included the design, simulation and Off-Line Programming (OLP). Design UK and Design South Africa also undertook the simulation and OLP of the front floor. "Opel provided an initial cell concept, while Design proved the efficiency of the cell and the reachability of the robots at the same time as designing the tooling. Much of the cell programming took place off site, allowing the programming of 102 robots prior to installation and commissioning. The simultaneous engineering culture of the project was essential, with decisions and changes being made by the hour. Great use was made of the internet in order for the work in progress to be shared between Design UK, Design South Africa, TMS-South Africa and TMS Produktionssystme."

Managing the project

The expertise of the large European manufacturing concern TMS Produktionssystme was called on to manage this project. TMS has many years' experience in the automotive industry and it was eager to try the new Delmia technology. TMS Produktionssystme worked closely with the TMS-South Africa office that in turn called on Design South Africa, Design Automation and Design UK to assist with a por-tion of the design and the simulation and automation requirements.

With the average weld taking just four seconds, the reachability and clearance tolerance figures had to be utterly trustworthy

Design, the global engineering services company, had never used Delmia systems before, but as Opel specified that Delmia was to be the standard environment for the OLP of all its robots on the virtual production line, the company decided to give Delmia's IGRIP and UltraSpot a try. Nick Herrmann, Design UK's managing director, explained: "It is fair to say we were reluctant, but we benchtested IGRIP and UltraSpot and found them to be superior simulation tools."

Reachability and clearance

It is a manufacturing truism that the shorter the cycle times, the more equipment is required for the cell. Accessibility can then prove to be a problem, but IGRIP was able to verify clearances between 1-5mm. With the front and rear wheelhouse robotic cells completing 66 jobs an hour and with the average weld taking just four seconds, the reachability and clearance tolerance figures had to be utterly trustworthy.

Dave Kupferman, the director of Design Automation in South Africa, commented, "This is the biggest project combining both simulation and OLP we have ever attempted and we simply would not have been able to undertake it without the many useful facets that Delmia gives us. Even experienced eyes can analyze a robot cell and believe it will perform, but as IGRIP configures each and every point, robot singularities soon become glaring."