Automated Painting for Aerospace, Challenges, Newer Technologies and Lessons Learned 2012-01-1855
Many Aerospace Manufacturers desire to automate their painting processes to improve quality, reduce coating and other materials usage, and reduce labor content. Automated Painting Systems have been developed for a number of industries, but are less common in Aerospace for a number of reasons, including 1) very large objects to paint with complex surfaces, 2) parts to be painted which are not located accurately or consistently, and 3) a (relatively) small number of parts to paint although often a very large variety of different parts. In developing and implementing automated painting systems, these challenges need to be overcome in robust and cost effective ways, and technologies have been developed and are being enhanced to deal with these challenges. This paper will address some of the most important technologies which are being used to facilitate implementation of automated painting systems.
The robotic systems to paint the very large objects such as wings, fuselages, stabilizers, or entire aircraft are more complicated manipulators with a variety of mechanical axes and the more complicated programming and motion control systems that go with them. In a typical implementation, a six axis painting robot is manipulated using a rail, a rotating column, and a z-lift. Programming of these multi-axis manipulators and robots is difficult to do by using conventional teach pendant techniques, but can be done with offline programming software. Vision systems and software are used to locate the parts in space and to apply offsets to the programmed motions.
Vision systems and software can also be used to automate the programming of aircraft component parts to provide the capability to paint 90%+ of the surfaces for a large variety of parts. An image of each part is taken, and key parameters are determined and input into a software algorithm which will determine the motion program for painting the part. In this way, thousands of different parts can be automatically painted without the programming of individual paths for each unique part.
Most aerospace painting is typically done with air atomized or high volume low pressure electrostatic guns. Electrostatic rotary atomizers have proven to be advantageous in automated painting sytems in optimizing transfer efficiency, appearance, and in reducing paint defects. Grounding of the parts is important and control of the painting parameters is critical to optimizing achieving the best results.
This paper will describe in detail the technical challenges, and some of the techniques and technologies used to accomplish these processes, and what lessons were learned during their implementation.