Virtual manufacturing from beginning to end

DaimlerChrysler is pioneering the development of a single application to cover all aspects of design, development and manufacturing. Virtual manufacturing will allow a vehicle and the plant to be designed and built virtually - with full simulation and visualisation

By Janet I Priestap, DaimlerChrysler

Time to market is critical to success in manufacturing, particularly in the fast-moving automotive industry. Using pre-release versions of the software, DaimlerChrysler Technical Center Auburn Hills has worked closely with Dassault Syst弇es to develop a version of the CATIA CAD/CAM/CAE/PDM system that creates a seamless union between product development and manufacturing. DaimlerChrysler is aiming for a single integrated design and engineering system covering all aspects of the product creation process - from end to end.

What is CATIA?

CATIA stands for computer-aided 3D interactive application. It is a series of integrated software products that are used in all aspects of the product creation process, from concept through to planning for after-sales service.

Using innovative methods and CATIA as an end-to-end virtual manufacturing tool supports DaimlerChrysler in meeting its time, cost and quality corporate objective of 'getting better new cars to market faster and at lower cost'.

Designers anywhere in the supply chain can be sure that the data they are using is the latest. Suppliers are fully integrated in the process and have access to corporate data. Paper is minimised as a means of communication. Engineers at all stages are involved earlier than ever before, helping to shorten the development cycle.

Product, process and plant

DaimlerChrysler divides the virtual manufacturing process into three domains: product, process and plant.


Product. This domain covers the design of the vehicle itself, but also includes all data and data links throughout the product life cycle. This is the application for which CATIA is most commonly used by other manufacturers in the automotive industry.
Process. DaimlerChrysler Auburn Hills is investigating using CATIA to carry out virtual design of the manufacturing process, including the assembly processes, offline programs and control code used to manufacture the product.
Plant. The final step in the virtual manufacturing process is to design the plant (resources and physical facility) in which the vehicle will be built. Here, too, DaimlerChrysler is experimenting with the use of a single software tool to model whole plants.

Product domain

Product development - the design of individual parts of vehicles - is the primary application area for CATIA. DaimlerChrysler has been an industry leader in developing and integrating digital mock-up tools into processes. This process has been extended to full design-in-context, which includes the definition of welding features, adhesive features and assembly tolerancing. DaimlerChrysler has pioneered this technology and is the only company with seven 'paperless' cars on the market, starting with the 1998 Dodge Intrepid. Developed entirely without conventional drawings, they will be joined by an eighth paperless car when the PT Cruiser is introduced.

DaimlerChrysler Auburn Hills and partners have teamed with Dassault Systemes to develop an advanced virtual product modelling environment for CATIA called Virtual Product Modeler (VPM) from Enovia, a Dassault company. The environment offers a number of new features, including synchronisation between various applications, integrated bills of material, release management, nesting of multiple levels of an assembly in overlay structures, and an intuitive interface.

Process domain

The process domain covers the various steps involved in detailed planning of the manufacturing process:


Assignment of resources, optimisation of work flow
Linking multiple processes
Simulation, collision checking

DaimlerChrysler is pioneering work on the potential use of CATIA for virtual design of the manufacturing process. The vision is of a tool that will allow simulation and visualisation of the entire manufacturing process of a vehicle or other complex product, using the same interface and data from the product domain. This integrated virtual manufacturing approach allows product and process development - and even plant development - to run largely concurrently. Associative links in VPM can be used to jump from the product definition to the process that will manufacture it.

Any station can be outsourced to a supplier without any problem, as all DaimlerChrysler's first-tier suppliers and many second-tier suppliers have adopted CATIA and have access to those parts of the corporate database relevant to their projects.

Process model

The process model is managed in CATIA as a set of actions. Any changes to the product since it was last reviewed are automatically outlined to the engineer. Links between the product and the process can be used as a visualisation tool to identify and check sequences.

Weld allocation, for example, can be undertaken and optimised using VPM. Typically, in vehicle manufacture a process engineer has to allocate some 2,000 spot welds between some 120 workcells. VPM supports the engineer by identifying which welds could be allocated to which workcells, allowing problems to be identified nearly a year ahead of tooling construction.

Simulating the process

With the manufacturing process defined, VPM can now send product, resource and weld allocation to the Integrated Graphics Robot Instruction Program (IGRIP) for validation of cycle times. The simulation checks accessibility (for example, of weld locations) and automatically adjusts the robot's position where necessary. This approach means that interferences are detected long before tool cutting, and often before finalising tool design.

Finally, when a path has been verified to be collision-free, the detailed robot program can be created and downloaded to the robot controller on the plant floor.

In the past, translation between the native CAD system and the simulation system has been an inhibitor of truly simultaneous engineering. By combining CATIA, the process modeller, IGRIP and VPM, DaimlerChrysler will be able to achieve greater levels of concurrent engineering.

Plant domain

The final link in the virtual manufacturing chain is the plant domain. And it is here that DaimlerChrysler's vision is boldest: the aim is to simulate assembly based on a complete digital mock-up of the plant, including the product and process data, all developed concurrently.

This approach has multiple benefits. Through simulation and visualisation with live product and process data, it allows earlier and more effective optimisation of plant and process design, and thus it supports faster launches. The virtual approach allows bugs to be identified and eliminated long before going to implementation, which results in lower costs, better production facility utilisation, and shorter time to market.

This is not science fiction: DaimlerChrysler is beginning to apply these tools. In a trial program, conceptual design of a new 1million sq ft Jeep plant has been undertaken concurrently using CATIA and conventional design on Bentley workstations. Cost savings of approximately US$3m to $4m (about Euros3m to 4m) are expected by the end of the project.

The future

Taking the lead in the industry, DaimlerChrysler is pioneering the development of an integrated design system throughout the product creation process, to achieve dramatic reductions in system cycle time, cost, investment, and launch curves, as well as improvements in product quality, function and performance.

DaimlerChrysler is working toward forming a single system with a familiar, intuitive, Internet-style interface throughout. This development will continue to help the company achieve its goal of getting new models to market faster at lower cost.

Author

This article is an edited version of a speech originally presented by Janet I Priestap of DaimlerChrysler at the DaimlerChrysler Innovation Symposium, held on 10-11 November 1999 in Stuttgart, Germany. Janet I Priestap is supervisor, plant solutions, DaimlerChrysler. She is responsible for the implementation and integration of the virtual plant into the CATIA environment.

Additional information and news from DaimlerChrysler are available on the Internet at: www.media.daimlerchrysler.com
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