The fuselage of the aircraft is assembled from tens of thousands of parts/components, divided into large parts, including the fuselage (front, middle, rear), wing, tail, landing gear, operating system, power unit and so on. Usually, these parts are huge in size and are manufactured in different factories. Finally, the combination of high-efficiency and high-precision control methods has always been the main subject of exploration by aircraft OEMs.
With the development of technology, digital manufacturing is widely used to represent modern aviation manufacturing technology, and it mainly presents the following characteristics:
Diluted TOOLING and strengthened EQUIPMENT;
Diluted the concept of physical standard work, and strengthened the process of digital transfer;
Dilutes the definition of static manufacturing and reinforces the concept of dynamic manufacturing;
Lighten the awareness of rigid tooling and strengthen the application of flexible tooling;
Diluted the traditional tooling design method and strengthened the tooling design ideas under the new technology;
Diluted the characteristics of professional tooling manufacturing and strengthened the scope of multi-field participation;
The practice of serial design has been diluted, and the program of concurrent engineering has been strengthened.
For aircraft assembly, in addition to the conventional formwork assembly method, with the development of laser tracking technology, the aviation main engine factory began to research and utilize the aircraft flexible assembly technology based on MAA measurement auxiliary assembly technology.
Profile assembly technology
As the most direct control means of the assembly relationship in the assembly process of the aircraft, the accuracy and interchangeability of the frame size play an extremely important role, directly affecting the process and time period of the later assembly.
The laser tracker combines the angle of the target point, the distance measurement and the real-time tracking. The horizontal and vertical angle measurement and the distance measurement are combined, and the three-dimensional coordinates of the mirror core are uniquely determined. With the measurement range of tens of meters or even hundreds of meters, it is currently used in the aerospace industry for the measurement of fixtures and profiles for component assembly, and it is not necessary to build scales and adapter plates; to achieve large-scale tooling on-site assembly and measurement without decomposition It realizes the weekly inspection of digital process equipment, which is convenient for digital retrieval and traceability.
Flexible Assembly - Measurement Auxiliary Assembly Technology
Through the three-dimensional digital definition of aircraft products and the application of digital technology such as design and manufacturing synergy, the development of aircraft structural assembly to digital assembly is promoted, and automated flexible assembly is realized, thereby improving production efficiency and assembly quality. Advanced aerospace manufacturing companies have adopted digital laser tracking and positioning technology during the installation of aircraft frames. In the total assembly line unit, the "Measurement Auxiliary Assembly" system was introduced. A measurement system consisting of a laser or photogrammetric subsystem, computer-aided measurement system, "bestfit" optimization software and a specially designed graphical user interface that can be used in aircraft assembly phase (such as a fuselage or wing-to-body docking) The traditional process problems related to the assembly and positioning of large-scale body parts. The combination of these technologies has the advantages of no-frame assembly, faster assembly processes, reduced rework and wear and tear.
MAA measures auxiliary assembly. There are three main systems in its implementation: measurement system, positioning system with six degrees of freedom measurement, and operation and simulation software system. Among them, the laser tracker is responsible for the measurement link, the positioning system is responsible for moving the assembled components under the guidance of the laser tracker, and the computer system is responsible for the motion guidance and feedback calculation. Under this system architecture, a laser tracker is used to monitor and direct the positioning of the positioning system by tracking multiple reflective targets that are fixed to the moving parts.