Accurate, repeatable automotive measurement ensures premium quality production

Audi Sport wanted to improve the productivity, accuracy and reliability of its automotive measurements. It chose Hexagon solutions to verify component dimensions, from cubing models to individual parts, and to check fit and finish on car bodies throughout production. Audi Sport can now be confident it is producing the highest-quality finished vehicles.

With historic brands like “quattro”, Audi Sport GmbH is one of the most respected names in high-tech, high performance motoring. Founded 40 years ago, Audi Sport’s range contains parent Audi AG’s fastest and most exclusive models, from the compact Audi RS 3 to the all-electric RS e-tron GT.Around 600 people manufacture the e-tron GT family at Audi Sport’s 300,000-square-metre Böllinger Höfe base, a few kilometres from Audi’s giant Neckarsulm production facility in Heilbronn-Franken, Germany. Final Assembly of the Audi RS 6 Avant GT* also takes place at Böllinger Höfe. Three assembly stations were specially set up for this exclusive limited edition of 600 units. In total, Audi employs over 15,000 people in the region.

Premium quality is the foundation of the Audi Sport brand; the flagship R8 was built almost entirely by hand. The final Audi R8 rolled off the line at the close of the first quarter of 2024.The plant’s strengths – precision, perfection, passion and love of detail – continue with the e-tron GT. Customers expect these prestigious vehicles to be produced to the highest standards, with perfectly-fitted components and narrow, uniform panel gaps. Audi Sport wanted to enhance the productivity and performance of its measurement systems right across its vehicle design, prototyping and manufacturing processes. It chose a range of Hexagon metrology solutions that verify the dimensions of critical parts and help assure the highest fit-and-finish standards, from new product development and component manufacture through to assembly on the production line and final quality control.

A complete solution, from measurement to data handling

Audi Sport’s measurement toolkit includes a Hexagon Measuring Arm, Lecia Absolute Tracker AT960, Absolute Scanner AS1 and NEXTSENSE CALIPRI systems for non-contact flush-and-gap measurement. Audi Sport installed its first CALIPRI systems in 2018 and then added two more systems to support the pre-series production of the RS e-tron GT. It also runs the evaluation software for the CALIPRI C14 and CALIPRI CB20. “At the Böllinger Höfe site, we use several systems from Hexagon,” says Roberto Paduano, Team Coordinator, Audi Sport. “These include the CALIPRI systems, several articulated measuring arms, and a photogrammetry system.”

Measuring flush and gap in production

In vehicle production, Audi Sport relies on handheld CALIPRI C14 devices for in-process measurement of flush and gap. Featuring sophisticated laser-light-section technology with the patented CALIPRI Principle, the CALIPRI C14’s sensor captures the profile’s 2D contour from different perspectives, looking both deeply into the gap and along the complete folded edge to exactly capture the gap geometry. The C14 offers a simple, accurate and reproducible way to measure automotive flush and gap: inline, near-line or off-line. Many automotive OEMs use the C14 to measure dozens of vehicle profile types, including the fit between the car body and doors, bonnet, boot, bumpers, headlights and many other components.

“We capture gap measurements on the raw car body, evaluate them after the paint process, and continue assessing them on the finished vehicle,” says Roberto. “We have colleagues trained on the C14 who perform various daily measurements on the car body and in specific areas of finished vehicles. The goal is to achieve optimal dimensional allowances in the bodywork so that we ultimately produce compliant, high-quality finished vehicles.”

The C14’s high accuracy and repeatability helps assure Audi Sport’s experts that all measurements are correct. “This repeatability gives us confidence in our daily work,” states Roberto. “Another advantage is that the C14 systems are mobile and location-independent, which means we can use them flexibly wherever needed, they are not restricted to a single location,” adds Daniele. “They’re also quite compact and convenient.”

Automatic measurement with the CALIPRI CB20

Audi is currently trialling the automated, robotic CALIPRI CB20 flush-and-gap measurement system for 100% inspection of car bodies. It can be fitted to standard industrial robots and cobots on body-in-white production lines and also used for final assembly. “Essentially, the CALIPRI CB20 is the automated version of the C14, and we are now testing it in our measurement cell,” says Daniele. “We use the data it captures to perform a geometric analysis of the vehicle.”

The CALIPRI CB20 system used at Audi Sport Features patented CaliBreeze technology, letting it make accurate, repeatable measurements on challenging surfaces with poor reflectivity like glass or plastic, highly reflective chrome or very light-absorbing deep black finishes.

“Its ability to apply a thin layer of water vapour to transparent surfaces is a big advantage, particularly on headlights and taillights,” explains Daniele. “That makes them matte, creating optical contrast so that the laser can measure them effectively. The system is highly accurate, reliable and provides consistent repeatability in measurements.”

“Especially on our sports vehicles, we have many carbon parts with a top layer of clear coat,” says Roberto. “The CB20’s vaporisation technique is helpful here. It also successfully handles the challenge of gap measurements around the windscreen and A-pillar where the laser moves from reflective to transparent surfaces and back again.”

Dependable measurement with superior support

The CALIPRI C14 systems on the assembly line at the Böllinger Höfe facility are used particularly intensively. So having rock-solid support for any questions or issues is vital.

“We receive solid support from Hexagon for all the products we use here,” says Roberto. “We rely on their measurement systems to help us assure quality during production and we are satisfied with their quick response time to any questions we have.”