Research On Coordination Technology Of Digital Measurement Assisted Wing-Fuselage Docking

Aircraft assembly is the key technology of aircraft development,and it plays a great role in aircraft manufacturing.Large component docking is one of the main parts of aircraft assembly,therefore the quality of large component docking determines the aircraft performance,manufacturing cost and cycle to a great extent.The conventional assembly method,which is inefficient and difficult to guarantee assembly precision or quality,can’t meet the demand of higher efficiency and lower cost of modern aircraft manufacturing.The digital assembly method of aircraft component,which is integrated by digital measuring technology,flexible supporting and positioning teachnology,computer integrated control system and information management,promotes the assembly process by digitization,flexibility,automation and informationization.Thus,it improves the quality and efficiency of aircraft assembly.For the time being,the digital assembly method has been gradually applied into large component docking in china,but still taking conventional method as the main method,and this causes lots of problems in assembly quality coordination.Taking airliner wing-fuselage docking as the research object,the in-depth and systematic research is done on assembly characteristics,digital measuring field,pose and position calculation.The main achievements in this thesis are as follows:(1)The overall route of wing-fuselage docking is constructed.The assembly characteristics of wing-fuselage docking are defined,and on this basis,the measuring coordination route is established.The calculation method of tolerance of position and pose reference points is studied,and Monte Carlo simulation method is used to analyze the accuracy of components’ pose.(2)The construction method coupled with reference point layout and station planning of measuring field is proposed.In order to solve the existed problems in station planning of laser tracker,the interference detection and station layout are studied,and also the basic principle is presented.According to the principle of indirect adjustment,the error model of coordinate transformation parameters is built.Based on the error model,the relationship between measuring error and the precision of measuring field is analyzed,so as to the error of reference point layout.(3)The optimization method of measuring field is studied.By comparing five different layouts of reference points,the most optimized way--stereo layout is proposed.The gross error detection model of public reference points is built,as well as the coordinate correction expression.The validity and precision of the wing-fuselage docking measuring field are verified.(4)The coordination model of wing-fuselage docking is constructed by considering the accuracy of position and pose and mactching quality synthetically.The coordination model based on the pose and position accuracy,and the matching quality is separately constructed.In order to avoid the inferior solution of the coordination model of wing-fuselage docking,the particle swarm optimization(PSO)algorithm is adopted.The influence of inertia weight and population diversity on PSO is studied.Aimed at solving multi-constraint problem of the model,a new concept called constrained feasible region is proposed to change the selection mechanism of the global best particle.The simulation result proves that the improved PSO can increase the efficiency and precision of the model.The key technologies studied in this thesis are applied to C919 wing-fuselage docking.The verification results show that the achievements can effectively guarantee the accuracy of docking and improve the assembly quality.