Today, the electronic elements in a car—including everything from headlights to power steering to airbag deployment systems—represent nearly a quarter of the vehicle's overall cost. The cabling required to connect these elements has also increased correspondingly. As a result, the average automobile wire harness now holds more than 1000 cables, making it one of the most expensive car parts. The aerospace industry faces similar but even greater challenges. For example, a helicopter's electrical system may contain more than 20,000 wires, while a large commercial jet could have almost 100 miles of wiring.
In addition to meeting electrical requirements, automotive and aerospace design teams must allow for the impact of wiring on mechanical aspects of a design. Because the cabling and wire harnesses are among the heaviest parts of the vehicle, their weight must be distributed appropriately.
Each year, automobile and aerospace manufacturers design new models that contain more electronics subsystems, requiring more integration, earlier on. To support these developments, cables must carry more signals at a higher frequency, with greater power.
Until recently, the design of cable and wire harness systems was a completely manual process. But the increased complexity of the systems and business factors, such as shortened design times and the growing role of outside suppliers, have forced a change: The design process is now done electronically. Designers of these systems now require design tools with the same level of sophistication traditionally found in chip and board design.
The automobile and aerospace industries have begun widespread adoption of software tools that address the entire wire harness life cycle, from concept through manufacturing and support. Software design tools make it possible to design and analyze complex systems much more quickly and accurately than the manual methods. But beyond that, they also add productivity enhancements to the design process. Another factor driving the adoption of electronic design tools is virtual prototyping. To save time and money, automakers and aerospace manufacturers are increasingly using virtual prototyping instead of building real prototypes.
In addition, automated design tools provide data management capabilities. For every car design, there are multiple variations that affect the requirements for the cabling and wire harness. Aircraft pose an even greater challenge due to the large number of systems and configurations possible. Data management is the key to ensuring the accuracy of a product's design and documentation.
To continue the process of adding new technology features to cars, automobile manufacturers plan to transition from today's 12-V electrical system to a 42-V system. With the first new 42-V vehicles scheduled for release in 2003, the major automakers are looking to their suppliers to adapt to the new system as well. Suppliers that can make the transition with minimum added cost and disruption will have an advantage.
Today, the automation of cabling and wire harness design must keep up with the present technical complexity of automobile and aerospace designs and meet time- and cost-saving requirements. In the future, data-centric tools that address the entire wire harness lifecycle will facilitate continued technical innovation, while boosting time- and cost-saving design efficiencies even further.