Increased use of composite materials in aircraft construction reduces weight and cuts fuel burn. That’s beneficial for the environment, but the structural complexity of composites necessitates new inspection regimes to verify quality during manufacture as well as for early detection of product degradation throughout the service lifespan. These inspections use ultrasonic techniques such as ’guided waves’, but are labourintensive. Clean Sky’s CRO-INSPECT project is developing a collaborative hybrid work cell whereby human diligence is complemented by robotic efficiency, paving the way for competitive industry processes in European aeronautics.
The trend towards automation in industrial processes is irrefutable, driven by cost savings, quality assurance and business efficiencies. But robotic processes have their limitations, especially when it comes to inspecting aeronautical components manufactured in composite materials. The complex structure of composites – combined with the intricate geometry of many aircraft components – means that human judgment is key to ascertaining the integrity of a part as it undergoes ultrasonic inspection, whether it’s during the production process or later, through its operational life. And by the standards of today’s industry processes, such inspection processes are very labour-intensive.
What if the laborious human role could be complemented with, and accelerated by, the efficiency of robotics? That’s the premise behind Clean Sky’s 36-month CRO-INSPECT project, which kicked off in December 2016. It’s already making significant strides towards proving its viability as a powerful concept for aeronautical inspections for the future – one that leverages the productivity of European aerospace skills, bringing competitive advantage to Europe’s aviation sector.
”The objective of CRO-INSPECT is to have a collaborative robotic solution because the inspection of aircraft components is, in some areas, almost impossible to automate – the idea is to have a more optimised and higher quality level of inspection” says Loreto Susperregi, Researcher at the Spanish research alliance IK4-Tekniker, the Primary Coordinator for the Clean Sky CRO-INSPECT project. Also supporting the project are inspections solution provider Tecnatom, as well as Lortek, which is responsible for the ultrasonic ’guided waves’ technology which is used for the detection of defects in composites.
Tekniker is using a specific aileron designed by SAAB for the mock-up and for the validation of the solution, but once the process is fully fledged it will be applicable to numerous other aircraft components.
”Today in the aircraft sector where they’re manufacturing big parts inspection is very expensive because you have to mount a big infrastructure, so our approach is to use a small mobile manipulator that moves around the part and performs the inspection. If we are able to demonstrate that we can carry out inspections using this kind of solution it will be a more economical and more flexible solution” says Susperregi. ”There are some areas of aileron inspection that cannot be automated with robotics, so the aim is to employ a collaborative robot which uses a mobile manipulator, a type of robotic arm. The idea is to provide more flexibility for inspections solutions, enabling inspection of different ailerons while human operators are safely working around the robot ” says Susperregi.
To ensure safety the system is equipped with several sensors in order to detect the proximity of humans and will stop or reduce the speed accordingly, depending on the distance, because apart from providing the functionality – in this case, the inspection of the aileron – the system uses an ultrasonic tool. So the technologies in development at CRO-INSPECT focus both on the control of the platform that automatically performs the inspection operation, as well as on the safety behaviours that are required in order to avoid any risk to the people working around the robot.
Key to the viability of the project is the human element, both from the point of view of manoeuvrability and fine motor skills as well as from the perspective of analytical skills, says Susperregi: ”The aircraft industry is quite manual compared to other Industries, and for good reason. Human dexterity is very difficult to achieve with robots today. For operations that require human dexterity you need the integration of the human in the loop, and from an analytics point of view, human supervision is critically important in the inspections processes. As a general principle, if we’re talking about repetitive activities without too much added value then probably a robotic solution will replace humans, but if we’re talking about activities that require reasoning, common sense, and supervision – then I hardly see the replacement of the human by any robotic solutions”.
In terms of progress, the CRO-INSPECT team say that they are working towards producing ”functional prototypes where we can validate the technological approach that we have decided upon. We need to determine whether the configuration of the mobile platform with the robotic arm is flexible enough to provide a solution for the intended inspection activities. We will be finishing in August 2019 and the road map is to produce several prototypes at TRL6/7. In fact, we are building the mockup of the solution here at Tekniker, and now we are mainly involved in the integration of the mobile plat form with the arm” adds Suspereggi.
In the context of Clean Sky’s drive to foster the technologies that will bring competitive advantage to European aviation and benefit its citizens, CRO-INSPECT is a key initiative in that bigger picture of nurturing efficiencies as well as industrial leadership in Europe’s mobility ecosystems:
”CRO-INSPECT will contribute to a process optimization in terms of manufacturing timing; cost-efficient process (-7% of the inspection costs) and to an increased quality of the inspection. From an economic impact point of view, this means reducing the overall manufacturing costs, thus making European aeronautics more competitive”, says Elena Pedone, Clean Sky’s Project Administrator for PIPS. ”In addition, this technology could be spilled over to other economic sectors that use also composite materials, such as Wind Energy, and/or Ship-building, making the European Industry globally more competitive.
”Finally from the environmental point of view this means a reduction of the CO2 and NOx emissions resulted from the manufacturing process, thus contributing to the ACARE goals.”