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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.

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.