| Current Friction Stir Welding (FSW) systems are not suitable for low production runs or in situations where fluctuations in supply tolerances are expected. This is due to the fact that FSW systems do not have control systems that are flexible enough to handle the inherent variations that are found in many real world manufacturing processes. Theoretically a system could be outfitted with multiple sensors and new control systems could be developed for each type of variation and situation, but this is neither economical nor possible as FSW is not understood well enough. Generally a human operator is better suited to react to variations or unique situations than a machine; however, human operators will not necessarily perform as well as a machine with precision and consistency for known conditions. To address this, a shared control system was developed. The shared control system was based on a material flow model as well an interface, both presented in this dissertation. To evaluate the material flow model, several tests were carried out by butt welding 5083-H111 aluminum plates with gaps up two millimeters machined into the mating surfaces. These welds were performed on both a CNC mill and an industrial robot. The test showed good correlation between the predicted and measured results (typically within +/- 20%). To test the interface, 5083-H116 aluminum plates with gaps up to 2.5 millimeters wide were butt welded using a shared control strategy. Using the interface and a gap compensation routine based on the model, the strength of the welds was greatly increased. |
