Development Of Measurement System For Internal Dimension Of Rail Vehicle Body

As the key bearing part of the rail vehicle body,which can accommodate passengers or goods and install various mechanical and electrical equipment,its assembly and production quality has an important influence on the safety of the vehicle operation and the assembly quality of all parts inside the vehicle body.The rail vehicle body is mainly made up of four parts: end wall,side wall,underframe and roof.However,the influence of the positioning error and welding deformation of welding parts directly leads to the key dimensions and shape and position tolerance of the vehicle body after welding and assembly not in conformity with the manufacturing standards.Therefore,it is necessary to measure the key dimensions and shape and position tolerance of the rail vehicle body accurately and efficiently in the welding assembly process,and then provide data support for the adjustment of welding process quantity and welding parameters,and provide effective quality assurance for welding assembly production.In this paper,the digital detection and data storage technology of key dimensions is studied in view of the problems existing in the welding and assembly production of rail transit body,such as low efficiency and poor accuracy of key dimension detection,and the failure of automatic storage,analysis,tracking and sharing of test data.A set of automatic measurement of key dimensions of vehicle body is designed,which is suitable for the field operation of manufacturing measurement system.This thesis designs and builds the measurement system of the interior dimension of the rail vehicle body from three aspects: mechanical structure,measurement and control system and upper computer software system,as follows:(1)According to the measurement requirements of key dimensions inside the rail vehicle body,the whole structure of the measurement system is designed,and the mechanical transmission parts are calculated and checked.The static and modal analysis of the whole structure are carried out through the finite element simulation calculation,which verifies the structure reliability;the processing technology is optimized and the mechanical structure of the test system is built.(2)The design and construction of eight axis motion control and multi-channel data acquisition system are carried out.The mathematical model establishment and fuzzy PID algorithm of the two axis adaptive leveling platform of the measurement system are completed.The static and dynamic measurement accuracy and stability of the core sensor are studied and verified by the algorithm research and test.(3)The system integration of multi-axis motion control,multi-channel data acquisition,equipment status self-test,data analysis and processing is carried out,and the upper computer human-computer interaction software system is developed.The database system of measurement results and report output module are created,and the functions of the software system are verified.