Quality Magazine

Laser Tracking Transforms Efficiency

July 1, 2006
A helicopter manufacturer improves production line efficiency with the implementation of laser tracker measurement systems.

One of the world's leading helicopter manufacturers, Eurocopter has improved production line efficiency by up to 70% in just a few years with the implementation of two laser tracker measurement systems from Leica Geosystems.

Eurocopter, formed in 1992 by a merger of the helicopter divisions of Aerospatiale-matra (France) and DaimlerChrysler Aerospace (Germany), is today a wholly owned subsidiary of European Aeronautic, Defense and Space Company (EADS), one of the three largest aerospace groups in the world. The EADS Group includes the aircraft manufacturer Airbus, the world's largest helicopter supplier Eurocopter and the joint venture MBDA, the international leader in missile systems.

According to Reinhold Grosskopf, head of workshop development, the deployment of the two laser trackers for quality assurance purposes at Eurocopter's production plant in Donauwörth, Germany, has changed technical measurement procedures. "We do not only produce helicopters, we are also the main supplier for the Airbus industry, in particular for the A-380," Grosskopf says. "Our employees have to cope with a huge work and maintenance turnover with the manufacture of doors and doorways for the Airbus assembly operations. These problems can only be solved in a goal-oriented way with a flexible measurement system such as the Leica Laser Tracker."



Added Versatility

A laser tracker is an industrial measurement system used for manufacturing validation and inspection applications in manufacturing and engineering. This technology brought versatility to the technical measurement procedures at Donauwörth. This mobile device enabled Eurocopter to perform direct measurements during manufacturing. In other words, a part no longer has to be temporarily removed from the production line and moved to the fixed examination location of a stationary coordinate measuring machine (CMM).

Used specifically by the aerospace industry, the Leica LTD800 laser tracker is made up of a high-speed tracking 3-D laser interferometer and precision angular encoders that deliver a measuring rate of up to 3,000 points per second, with a measurement distance up to 40 meters, or 131 feet, when used with a corner cube reflector. The laser tracks strategic checkpoints via reflector targets residing in small circular slots designed into tooling, or reflector targets lodged in off-the-shelf nests that have been applied to assemblies. Its precision measurement capabilities enable aerospace manufacturers to validate designs, build-and-inspect, confirm close tolerance work, perform alignments and part mating, and capture 3-D coordinate data on-the-fly.

At Eurocopter, a laser tracker is used most frequently for the construction of large assembly devices. Slipways previously had to be built in modular fashion within the CMM prior to subsequent assembly. This can now be done completely during the building process, right in the place where they will later be needed. Examples are the large devices built for the transport helicopter NH-90, which are 7 meters long, 3 meters wide and 4 meters high.

Even the baseframe is measured with a laser tracker, so technicians have few problems with retrospective changes. These simply can be added to the existing systems, without the need to involve the construction department again. This particular laser tracking application at Donauwörth has resulted in time savings of at least 70%.



Error Compensation

Another application is the new robot facility at Eurocopter. With the help of the laser tracking, the quality of error compensation can be measured precisely. The Laser Tracker checks whether the robot really has drilled and milled with the same precision as a numerical control machine.

The laser trackers also play a key role during the examination of Airbus doors, as virtually every door has different specifications. If the door in the fixture is closed, the positions of so-called doorstops have to be measured, an additional criterion for interchangeability and a further quality requirement for Eurocopter's French partners.

Measurement of doorstop positions, which are located behind the door lining, are carried out with the LTD800 laser tracker in combination with the wireless, armless Leica T-Probe equipped with Renishaw sensors. The walk-around T-Probe is a handheld device that operates without cords or cables. The probe allows engineers and metrologists to carry out measurements with six degrees of freedom and the ability to measure inside deep parts.

The T-Probe is one of two technological enhancements to the laser tracker product line. The second product is a new high-speed hand scanner-the Leica T-Scan. This product enables operators to digitize complex surfaces and large objects easily and quickly with precision, all without data post-processing. The laser tracking systems, combined with wireless probing and rapid noncontact scanning, has introduced a level of portable data acquisition technologies that capture, visualize and process spatial data on the shop floor.

Powered by technologies such as laser tracking, Eurocopter is reaping payback in greater productivity and product quality. "The Laser Trackers have proved their worth for us," Grosskopf adds. "We especially value the precision, the long-term stability and the customer support. What is particularly impressive in practical terms is the time savings we have been able to achieve thanks to the flexibility of the tracker system."



QUALITY Tech Tips

-The laser tracker is comprised of a high-speed tracking 3-D laser interferometer and precision angular encoders that deliver a measuring rate of up to 3,000 points per second.

-The T-Probe allows engineers and metrologists to carry out measurements with six degrees of freedom and the ability to measure inside deep parts.

-The laser tracking systems, combined with wireless probing and rapid noncontact scanning, has introduced a new level of portable data acquisition technologies.