Metrology-assisted robotic processing of aerospace applications

Modern aerospace structures tend to consist of large numbers of geometrically complex structural components which by their very nature tend to suffer from significant levels of physical distortion and are thus difficult to assemble. One solution to this problem is to use large complex jigs which physically control the shape of the parts. These jigs are usually loaded using either direct manual labour or manual labour assisted by cranes or lifting devices. The use of manual operations represents a significant health and safety risk and increased likelihood of damaging components during assembly. The application of automation in the processing of such structures has so far been confined to small product specific cells owing to difficulties in pre-defining and fixing the exact geometry and positioning of parts within the work volume. The use of specially designed jigs, fixtures and aids such as drilling templates can be adapted to support automation but are expensive, have long manufacturing lead times and cannot be economically modified for use on other aircraft types. The paper proposes a solution to the above problems using standard industrial robots and an advanced control and non-contact metrology systems. The developed methodology is generic and has been evaluated and demonstrated in a number of different applications. The application described in this paper is the assembly of regional jet fuselage panels. Results are presented along with an analysis of the accuracy and repeatability of the system and its elements.