Tau robot platform for laser welding next generation, extra-large aerospace and automotive structures (e-Tau)

Laser welding is a high throughput, low distortion, fully automated joining method, already used by aerospace and automotive industries for several decades to fabricate structures from fuselage sections to car bodies. The requirements on the welds in such structures, depending on the application in question, can be very demanding: strength, resistance to fatigue, resistance to corrosion, aesthetics etc.

Laser welding takes place at high speed and results in very small welds. This, coupled with the demands placed on the welds, renders even small imperfections unacceptable. Meeting this quality challenge is always difficult. This is becoming more so, as structures needed for safer and more energy-efficient aircraft and mass-electrification of road transport become larger and more intricate. This currently limits the broader uptake of laser welding, which would otherwise be an attractively productive manufacturing technique.

This is compounded by the fact that laser welding requires precise setup. Welding can prove intolerant to small gaps between parts, or small positioning errors between the laser beam and those parts. Gaps and errors can result from problems upstream, with inadequate material controls, incorrect part placement, and poor fixturing, as well as distortion-induced part movement during welding. Such problems are further exacerbated in larger structures made out of thin materials.

Cost-effective, flexible, and accurate beam manipulation over a large working area is essential, as is a capability for intelligent real-time adjustments in the beam during welding. This requirement is not currently well served by industrial robots, nor alternative manipulators such as scanners or gantries.

The e-Tau project will develop, test and validate a novel precision laser welding system, facilitating a step-change in the quality of larger aerospace and automotive welded structures:

* By developing cutting-edge high precision parallel kinematic machine (PKM) Tau robot manipulation
* That works with advanced laser beam wobbling optics
* Integrated with intelligent quality assurance and control sensors
* Then demonstrating the application of that system to the fabrication of large wing skin structures for the aerospace sector, and assembly of a range of automotive parts for e-mobility
* Along with an accompanying digital twin system, to visualise and quantify production applications with throughput and cost information.

With this, e-Tau will unlock, for manufacturing as a whole:

* Improved tolerance to part placement and fit-up for laser welding.
* Improved - and maintained - weld quality.
* Increased productivity and reduction in repairs and scrap.

Reduced and potentially eliminated need for expensive and time-consuming post-weld NDT.