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1. Introduction
The chamfering process plays an important role in mechanical processing. Particularly, in the field of aerospace manufacturing, there are many special-shaped and thin-walled workpieces that need to be chamfered, such as aircraft skins and fuel storage tanks. The quality of the chamfering seriously affects the subsequent welding process. However, the special-shaped thin-walled workpieces often have complex and diverse structures within different sizes. Moreover, the thin-walled structures are easily deformed under the processing force. Therefore, in such applications, manual processing is currently used in most cases. However, the disadvantages of manual processing are apparent. On one hand, the manual processing is uncertain and the chamfering quality depends on the human experience. On the other hand, the manual work is inefficient and a large amount of dust is generated during the process, which threatens the health of the operators. Therefore, the development of automatic chamfering equipment for this field is of great significance for improving the quality and efficiency of chamfering.
Considering the large-size, complex-shaped and thin-walled workpieces, in this application, the robot manufacturing system is more suitable than computer numerical control machine tools because of the high flexibility and broad working range (Gao et al., 2016; Pan and Zhang, 2008). At the same time, because of these characteristics, robotic systems are also widely used in other areas of the aerospace applications, such as the painting of large aircraft (Wang et al., 2019) and on-orbit servicing missions (Liu et al., 2019). Although there are already some robot chamfering tools and strategies in existing research studies, these methods can rarely be applied due to the difficulties of processing special-shaped thin-walled parts. Two main difficulties are listed below:
Due to the special shape and diversity of the workpiece, it is difficult to position it during processing with high accuracy, and it is challenging to design appropriate and high-precision fixtures. Therefore, the workpiece has a relatively large position error, which brings great difficulties to the robot processing.
As the workpiece is thin-walled, it is prone to deform during the process.
Therefore, considering the above two problems and the high-efficiency requirement of the manufacturing system, this paper proposes a robot chamfering system. The system includes a measurement part and a processing part. In the measurement part,...