Research On High-precision Measurement And Visual Assembly Technology For Large Parts Butting

In the product manufacturing field of large-size products,such as aviation,aerospace,ships and other fields,the key to ensuring the shape accuracy of large-size products lies in the assembly accuracy of large-size products.It is of great significance to improve the manufacturing quality by improving the assembly shape inspection level of large-size parts.Therefore,high precision,quality and reliability have always been the persistent goals pursued by measurement researchers.At present,the important part of digital assembly of large-size products is measurement aided assembly technology.However,the commonly used digital measurement aided assembly technology cannot meet the requirements of highprecision docking measurement for various reasons with the continuous improvement of assembly accuracy requirements for new large-size products.This thesis offers a new multidevice hybrid docking measurement method.After the i GPS laser tracking measurement guides the global attitude alignment of large-size components,a local high-precision fusion sensing measurement system is introduced to compensate the local errors of the joint parts,and a high-precision measurement platform is established for the assembly process of docking of large-size components.At the same time,the visual evaluation method based on the docking measurement program can reduce the number of docking pre-assembly,and improve the docking reliability.The contents are as follows:(1)Design a multi-device hybrid automatic docking measurement program and determine the basic pose parameters and measurement technology requirements of docking large-size components.According to the docking process,the measurement principle and measurement flow are determined,the composition of the measurement system and the functional structure of the measurement software are defined.(2)Build a high-precision docking measurement network and analyze the uncertainty of the measurement network.Under the docking network,a unified measurement reference system is established,and the pose conversion relationship of each subsystem in docking assembly is clarified,which provides data basis for subsequent docking drive.By establishing the uncertain measurement model of each measurement system,the measurement uncertainty of the measurement network is analyzed,and the layout of the measurement network is defined.(3)By combining the docking target model of the component with the spatial position information of the process ball head of the locator,the docking attitude adjustment parameter is planned and the docking uncertainty is analyzed.Based on the target pose and current pose after global pose alignment and local pose error compensation of the moving parts,the 6-DOF motion platform pose adjustment platform is calculated to obtain the the docking attitude adjustment drive.By establishing the docking uncertainty model,the docking uncertainty is analyzed.(4)Compile a visual evaluation tool to pre-evaluate the feasibility of the assembly program,and visually assist the construction of the pose measurement network of large-size components before docking to ensure the measurement accuracy,avoid errors exceeding the set threshold,and improve the reliability of intelligent assembly of large-size components.