Study On The Measurement Techniques In The Aerocraft Assembly Based On Articulated Arm Coordinate Measuring Machines

Aerocraft assembly is an important part in the field of spaceflight industry. The quality of the assembly has directly effect on controling the attitude and the orbit of the aerocraft. Aerocraft of certain type has a large size and complex shape, so the measurement of aerocraft assembly is a kind of large-scale measurement. Articulated arm coordinate measuring machine is a new type of coordinate measuring machines. It is flexible, light and convenient. Also it has high efficiency and can take measure directly when the object measured has a complex shape or some points in the covert area. So it is significant to study aerocraft assembly measurement by articulated arm coordinate measuring machine and develop a special software.First, the thesis expound the current development of the aerocraft assembly and the principle of the common coordinate measuring systems. Also analyze the components, principle and the character of the articulated arm coordinate measuring machine. In the view of the character of the object measured, the thesis put forward a method to get coordinates by articulated arm coordinate measuring machine and CAM2 software. Then the methods of building coordinate system and the projects of the angle and length measurement are studied in the thesis.Second, the space line fitting method and the least-square model are deduced, and expound the method of dealing with the special problems. For space circle fitting, the thesis converts the nonlinear equations into the linear equations and get the least squares result by using generalized inverse matrix. And the thesis also introduces some calculation methods of parameters such as the angle, distance, vector projection and so on.Later, the special software developed in VB6.0 platform and analyze the modules of read and write, compensation of probe's radius and so on. The software has friendly interfaces and output the measurement results in a way of "one key type". And this software can make the measurement more convenient.Finally, the contrast experiments between special software and CAM2 are carried with the measurement values and validate measurement plans and the software achieved the expected purposes, which has laid a good foundation for the follow-up work.