Wire harness

Starting point and motivation

Producing a main wire harness automatically in its current form would not be economical at all. The main reasons for this are as follows:

• There is too much variety in the components
• Too much intermeshing/interweaving in large wire harnesses
• Lack of a pinning convention
• The cables are too long

The excessively long cables could be prevented by adjustments to the production machines. On the other hand, the large variety of parts, the extensive intermeshing and the lack of a pinning convention are obstacles to automation that need to be reduced or eliminated.

The fact that the number of different components is continuously increasing inevitably leads to an increase in the variety of parts. One reason for this is the significant increase in functions without any convention regarding the use of standardised, modular connectors by the function providers.

Any additional or new function (e.g. ADAS) triggers a chain reaction of further process steps. At least one additional control unit, several sensors with new digital interfaces and various actuators are needed to control and network the components. All components require fail-safe connections to each other and must guarantee a constant power supply. At the moment,

“Just connect it the way it comes”

is the credo that manufacturers follow today. This results in an extremely intertwined set of lines with an unmanageable variety of parts and processes that stifles any attempt at automation at the outset.

What is needed now are approaches and concepts that lead to a reduction in the variety of parts and processes (focus of phase 1), enable/promote automated production by removing the intermeshing (focus of phase 2) and thus provide an innovative solution for the on-board electrical system of tomorrow.

Current working focuses

One current focus of the work being carried out is the analysis of the causes of intermeshing in the electrical system. Starting with a variety of hypotheses concerning the causes, these causes will be examined in greater detail after an evaluation of the possible ways forward. One likely way forward will be to draw up a standard interface to modularise the on-board electrical system and the resulting energy and data interfaces to be standardised. >

Outlook

In the future, interface concepts for a sensible division of the wire harness into production modules will be developed. This division into sub-scopes reduces the complexity of the individual, much smaller wire harness modules. However, the possibility of reproducing today’s level of variance should not be disregarded. The complexity is shifted from a single-piece wiring harness into a) smaller partial scopes and b) their combinatorics with each other. The solution approaches developed for division into partial scopes are to be evaluated on the basis of their feasibility with all parties involved and then combined into a uniform concept.

The next step is to compare the underlying interconnection paradigm of automotive wire harnesses with that of IT and consumer electronics. The extent to which paradigms and technologies that may deviate from the current automotive state of the art can be borrowed from the IT and consumer product environment needs to be assessed.