A digital flexible assembly system is developed which is used to assemble one fuselage large component of a large aircraft. The laser tracking metrology system is the important part of the flexible assembly system. The metrology system is composed of three modules: laser tracking measurement module, data processing module, and real-time motion simulation module. The laser tracking measurement module is mainly completing the measurement functions of the laser tracker. Data processing module is the core module of the metrology system, and is responsible for all data computation and transmission in assembling and positioning the aircraft component. The real-time motion simulation module provides the three-dimensional scene simulation of the assembly to the users and gives the users a more intuitive understanding of the assembly process. This paper introduces the system structure and working principle of the developed metrology system which based on the laser tracker. The application of the metrology system and the flexible assembly system can greatly improve the assembly accuracy.

Flush air data system (FADS) have been successfully used on the nose tip of large manned/unmanned air vehicles instead of a traditional noseboom air data system. In order to integrate FADS with strapdown inertial navigation, high accuracy of angle of attack and sideslip is required. The estimated accuracy of angle of attack and sideslip in three types of FADS, which have different pressure ports layout, is compared using the nonlinear least squares theory. Evaluation function is provided to evaluate the accuracy of angle of attack and sideslip in different pressure ports layout. The results show that more sensors and radiation-type can provide high accuracy.