Research And Application Of Online Inspection And Quality Monitoring System Based On Statistical Process Control

In this thesis, combining with the Guangxi Science Research and Technology Development Program “Development and application of the key parameters on-line monitoring system for large-size loaders during assembling process based on the cycle time”, developed the online inspection and quality monitoring system based on SPC. The system could achieve a lot of functions such as online inspection of the key assembly process parameters, storage and read test data from the database, statistical analysis of test data, draw control charts, control charts anomaly pattern on-line identification and statistical process diagnosis. The system improves the quality consciousness of related operations personnel and strengthens the management of the enterprise. What’s more, it improves the quality of production on the key station and improves the economic efficiency and market competitiveness of enterprises. The main contents are as follows:Firstly, some research is done on the theory and basic principles of SPC. During this period detailed study the mass distribution, process capability index, process control charts and other commonly used tools in SPC. Then depth analyzed SPC control chart theory, abnormal patterns and their application methods. And research how to implement SPC in quality monitoring.Secondly, through the demand analysis of the whole system, develop the overall scheme and the framework of the system. And design the system platform interface. In addition, three key technologies used system was introduced in detail such as data-capture technology, sensor error correction technology and control charts anomaly pattern fast identification.Thirdly, detailed design the online inspection subsystem of the pollution of the oil filter. At first develop the overall inspection scheme of the subsystem. Then introduce the grading standards of the international oil pollution. And plant model selection for components such as particle sensor, hydraulic pump, PU hose and flow control valves. At last verify the reliability of the system through field testing.Fourthly, detailed design the online inspection subsystem of rim bolt tightening torque. At first o develop the overall inspection scheme of the subsystem. And give the flow chart of system testing. Then design the detect control device and made it installed. At last verify the reliability of the system through field testing.Finally, achieve the initial application that the SPC quality monitoring strategy to loader assembly key process parameters. Illustrate the SPC application of the rims bolt tightening torque test data applied in the system platform: calculate statistics and control limits and draw the mean range control chart for analysis. And quickly identify the possible abnormal patterns of the control chart. Then quickly identify the possible abnormal patterns of the control chart. In the end, according to the identified abnormal pattern, combining with process capability index and other related parameters, provide some possible problems in the production process. And give some suggestions for improvement.