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Reduction of overall drag to improve aircraft performance has always been one of the goals for aircraft manufacturers. One of the key contributors to decreasing drag is achieving laminar flow on a large proportion of the wing. Laminar flow requires parts to be manufactured and assembled within tighter tolerance bands than current build processes. Drilling of aircraft wings to the tolerances demanded by laminar flow requires machines with the stiffness and accuracy of a CNC machine while having the flexibility and envelope of an articulated arm. This paper describes the development and evaluation of high accuracy automated processes to enable the assembly of a one-off innovative laminar flow wing concept. This project is a continuation of a previously published SAE paper related to the development of advanced thermally stable and lightweight assembly fixture required to maintain laminar flow tolerances.

The ability to adapt to rapidly evolving market demands continues to be the one of the key challenges in the automation of assembly processes in the aerospace industry. To meet this challenge, industry and academia have made efforts to automate flexible fixturing. LOCOMACHS (Low Cost Manufacturing and Assembly of Composite and Hybrid Structures) - a European Union funded project with 31 partners - aims to address various aspects of aero-structure assembly with a special attention directed to the development of a new build philosophy along with relevant enabling technologies. This paper aims to present the results on the developed wing box build philosophy and the integration of automated flexible tooling solutions into the assembly process. The developed solution constitutes the use of synchronized hexapods for the assembly of front spar to upper cover whereas another hexapod was developed to install a rib by using of a force feedback sensor.

One way assembly of aero structures has the potential to significantly reduce build times. One of the solutions, which goes towards achieving this philosophy, is the use of a ‘C’ clamping automated drilling system. The Manufacturing Technology Centre has developed and manufactured a ‘C’ clamping automated drilling unit to overcome many of the limitations of current designs, which prevent their use on a broader range of structures. The drilling unit addresses issues with access, size and weight restrictions as well as economic factors. This technical paper will present the outcomes from the design and manufacture of the drilling unit that is to be used within restricted access areas, as either a hand held device or as a robotic end effector free from any cables or hoses, allowing full and unhindered articulation of any robot motion. The device’s services: power, tool lubrication, swarf extraction and control systems have been designed to be embedded, rendering it a standalone unit.

Industrial robots are extremely good at repetitive tasks. They exhibit excellent repeatability, making them ideal candidates for many tasks. However, increasing use of CAD based offline programming highlights the fact that industrial robots are generally not accurate devices. Several approaches have been used to compensate for this deficiency. Robot calibration is well established and factory calibrated robots are available from most industrial robot manufacturers. This can improve the spatial accuracy of robots to figures better than 1mm which is adequate for most robot processes in use today. Improvements in accuracy beyond this point can be achieved if the working range of the robot is constrained in some way. For example, limiting a robot to working in a single plane or restricting the robot to a reduced work volume can contribute to significant improvements in accuracy. However, for applications requiring high accuracy without these constraints some additional control is needed.

The increasing global demand for commercial aircraft creates many new challenges in manufacturing including an increased need to maximize the automation of manufacturing processes. The purpose of this research is to develop the understanding of leading edge assembly processes using robot mounted tooling and an automated fixture with advanced process monitoring. Within this research real-time process monitoring data is acquired from an assembly operation and processed into an open cloud environment enabling advanced data analytics. Implementation of advanced analytics utilising process data could be developed for the use of machine learning algorithms which can lead to superior fault finding. The aim of this research is to improve product quality, reduce cost and increase process knowledge, enabling the potential for maximized online and offline process feedback.

There is the need to strive towards more advanced aircraft with the use of materials such as composites, and a desire to improve efficiency by achieving and maintaining laminar flow over a large proportion of the aircraft wing. Due to the high tolerances required to achieve laminar flow, the manufacturing processes and tooling will have to be revaluated to enable successful manufacture in a production environment. A major influence in achieving the key characteristics and tolerances is the assembly fixture. This paper details the design and manufacture of a carbon fibre based assembly fixture, required for a one-off build of an innovative leading edge wing concept. The fixture has been designed and optimised in order to make it adaptable, reconfigurable, and suitable for lifting as well as being thermally stable whilst maintaining laminar flow tolerances.