The traditional use of simulation software in aerospace manufacturing applications has been as a pre-production tool for the validation of tool paths and the generation of robot programs. Once the process has been proven via simulation, the data is then transferred to the machine or robot and the production process executed. This is a linear approach in which the virtual and real systems are operated independently and in a serial manner.
The current capabilities of offline programming (OLP) and simulation systems when combined with appropriate hardware in a flexible manufacturing environment now allow them to be used right at the heart of a manufacturing process, as an integral part of the manufacturing route.
In a flexible manufacturing cell such as that developed at the University of Nottingham for the automated assembly and riveting of large aerostructures, a key driver is the need to reduce or eliminate complex and costly jigs and fixtures for part positioning. The use of simple non-precise support structures results in variation in the spatial relationship between the robot and the part or assembly. These variations are inherent in the nature of the parts, as a result of the additive manufacturing process and from the use of robots.
The part position and orientation variation must be measured and accounted for in the robot program and the combination of a non-contact real-time metrology system and an OLP system linked together in a flexible cell allows this to happen as part of the manufacturing process. This results in a much closer coupling between the virtual part of the manufacturing process and the real part.
This paper will describe the embedding of the simulation system at the heart of the robotic assembly and riveting cell at the University of Nottingham and will outline the ways in which the capabilities of the simulation system can be utilized to produce an innovative and highly flexible manufacturing system for the production of aerospace assemblies with significant geometrical variations.