Research On Registration Technology On Large Aviation Components Based On Vision Measurement

The production and manufacturing level of large aircraft is the embodiment of national industry,science and technology and comprehensive strength,and the production and assembly quality of large aeronautical composite bearing components is an important guarantee for improving the safety and reliability of aircraft.In order to realize high reliability and low damage assembly connection of composite components,it is necessary to measure the surface dimension of large composite components with high precision,to reconstruct the surface features of its surface using the reverse reconstruction technology,carry out virtual assembly and predict the gap between the matching surface in advance,and provide the basis for the assembly and filling work.It not only can achieve the purpose of reducing assembly gap and stress,but also is an important basis for optimizing assembly process.Binocular vision measurement method has been widely used in aviation and aerospace fields due to its advantages of non-contact,high accuracy and high efficiency.In this paper,the binocular vision measurement method is used to measure large aviation components,and focuses on the research of the 3D data registration technology,aiming at the large size of the measured components and being blocked in some areas.The main research contents are as follows:(1)In view of the difficulty of automatic matching,low efficiency and poor field adaptability of points in traditional registration,a multi-ring coded point based on time is proposed,and is applied to the four cameras vision registration.According to the dynamic acquisition characteristic of the camera,the coded point is changed alternately of lighting and dimming with a certain frequency.The frequency of coded point is solved by sequence images acquired by cameras to decode the coded value,and complete the automatic matching of coded points.By comparing with the circular coded points,the correct decoding rate of the coded points proposed in this paper can reach 100%.Four cameras vision registration experiment is completed by using the multi-ring coded points,the registration accuracy can reach 0.015%.(2)In view of the three dimensional surface measurement of components which size is over 3m and cylinder parts,a large field of view binocular vision registration method based on laser tracker is proposed.The point error transfer model is established,and analyze the effect of the number and layout of public points in the calibration relationship between the global controlling coordinate system and the local coordinate system on the registration precision by simulation,to guides the layout of public points and achieves more than 0.2mm precision registration.(3)For the convenience of use,a binocular vision measurement system is designed and developed.All the hardware are integrated and connected,and the security equipment is added.The program of single picture acquisition and storage,real-time display,laser scanning and camera acquisition synchronization control are designed.Completing the design of software and hardware of the system,which can be delivered to the company.(4)On the basis of the above research,the precision verification experiment is carried out in the laboratory using the developed binocular vision registration measurement system.The experimental results show that the accuracy of the registration is up to 0.163 mm within 3m.The effectiveness and feasibility of the proposed methods and system are verified by measuring the wing wallboard and C beam of a certain type of aircraft in an aircraft factory workshop.