Loop Technology bring automation into wing boxes with new robotic arm

Loop Technology has developed a new type of robotic arm to deliver high accuracy automation including sealing and inspection inside aircraft wings and other confined spaces. It is the result of a four-year ATI grant funded R&D project with Spirit AeroSystems that concluded in September 2022.

Assembly inside confined spaces such as wing boxes is a major challenge for aerostructure manufacturers. These processes have remained a manual task due to the gap in the market for an automated solution with a high degree of accuracy, a relatively high payload, and suitable reach in order to replace the use of hand tools.

Robotic arm accessing confined space with sealant tool

Loop Technology has developed a seven-axis, robotically-controlled, articulated positioner called Bravura to address this gap. It can be used with an industrial robot to automate sub-assembly operations including sealing and inspection inside wing boxes, and has the potential for other applications such as nut-running and swaging. The system has a reach of 1100mm and can manipulate tooling end effectors up to 5kg in weight.

“Bravura extends the possibilities of end of arm tooling by adding six degrees of freedom in a compact form factor with high torque motors, continuous rotation, and a unique path planning solution” says Ross Horrigan, Technical Director at Loop Technology. “Although Bravura is an articulated robot in its own right, it is typically deployed as end of arm tooling for a larger robot. To insert Bravura smoothly and accurately into a wing box, we use the kinematic coupling capabilities of the Bravura controller to move all thirteen axes simultaneously.”

The primary project, OptiComp (Optimised Composite Wings and Aerostructures), was led by Spirit’s Belfast facility to ensure the UK aerospace industry is positioned as a global leader in the design, development, and production of large complex aerostructures (particularly wings).

Similar technology to target this application has been developed in the past such as snake-arm robots. However, unlike snake-arm robots that can be disadvantaged by low stiffness and compromised accuracy due to being cable-driven, Bravura uses frameless servo motors paired with high ratio harmonic gearboxes for high power density drive units to operate with high precision.

In addition to the end of arm positioner, Loop Technology has also developed a complementary toolkit of end of arm tooling with built-in vision for use in space restricted areas.