Electrical Harness Cabling

TECHNIA (formerly Intrinsys) were contracted to support the design and development of a major UK OEM’s vehicle electrical system. TECHNIA’s main objective in the project was to reduce design and development times, and associated cost of a new vehicle’s complete electrical cabling system by illustrating and designing out potential issues early on in the development process.

With a successful track record completing projects for market-leading clients in cutting-edge industries, TECHNIA is seen as expert providers of solutions within a life-like virtual environment. Engineering effectively without creating early physical products has enabled TECHNIA to facilitate prompt reviews and a streamlined change management process that’s enabled rapid modification implementation.

The Virtual Environment

The design was driven from the import of XML electrical schematics right the way through to harness-flattening.

TECHNIA used several CATIA V5 workbenches (e.g. Electrical Assembly Design, Electrical Harness Assembly, Electrical Harness Installation, Electrical Part Design, Electrical Wire Routing and Electrical Harness Flattening) to design the cabling systems in the most efficient manner. This was achieved by incorporating existing product design information to select routes, identify and avoid collisions and co-operate with defined services like tubing and HVAC.

Connectors were checked in conjunction with their mating socket to ensure there was enough room to install and remove retrospectively as required.

The XML schematic import was used to check that a continuous and appropriate path between connectors was possible and also to estimate the branch diameters throughout the harness. This was an important process as it confirmed that all connectors were present as specified in the initial schematics by the electrical design engineers and also allowed for the harness routing to be confirmed whilst providing key information to detail sections of the harness that would need to utilise formed bend radii where free space was limited.

This paired with the intelligent use of slack modes (Local slack, Branch total length and Branch percentage slack) and a full library of harness supports allowed for a well ordered, consistent and efficient solution to routing throughout the vehicle with minimal intrusion into the free space available.

Making the Most of Limited Space

In some instances the harness design needed to be adapted to work within a very constricted space envelope, as a result, a rectangular profiled cross section was used instead of the standard circular cross section. TECHNIA engineers worked closely with the vehicle designers to facilitate modifications to the chassis and body to accommodate and optimise cable routes, transit and access openings and the placement of grommets required to protect cabling through the vehicle.

Manufacturing and servicing processes were verified with human builder and the complete vehicle package. The combination of all vehicle systems and service routings ensured that cabling issues could be identified and eliminated with minimised cost early within the design process. Fully detailed and optimised harness drawings were produced for manufacturing, showing key details such as connector pinout and clip orientation aiding fitment for larger diameter sections of the harnesses.

Summary

TECHNIA provided a time and cost effective yet flexible solution, working collaboratively with the customer to meet their objective and provide the desired end result with the added ability to rapidly provide updates, new solutions and modifications as required as well as mechanical design support to aid the functional installation of electrical components.

Due to vehicle failure during testing TECHNIA had to make a number of very late changes that needed to be introduced in a very short timescale. This could be done as the design team had comprehensive 3D CAD data of the electrical harnesses paired with complete 3D vehicle and systems representations. This allowed TECHNIA to quickly and efficiently modify and communicate the changes to suppliers, without delay.