Development And Implementation Of MES For Automobile Parts Assembly Workshop

For the increasingly market competition,automobile manufacturing enterprises generally use strict quality control standards and means to deal with the diversification of the production process under the drive of the aim to downsize for efficiency and manufacture flexibly.At present,the discrete manufacturing mode was adopted by most automobile parts manufacturing enterprises to manufacture their products.Under this circumstances,production process flow will always be changed according to the customer’s different orders.It has become a hot issue for the automobile enterprises on how to respond to the quick changes of process flow and the strict management of production process Based on the analysis of features on automobile manufacturing enterprises,a manufacturing execution system(MES)concerning on the production process data collection and process control was developed.The application of the system could realize the transparent monitoring of manufacturing process,prevent bad workpieces from circulation on the production line,and regulate the process flow and operation of employees.PLC communication technologies,as the key method,were adopted to realize real-time data acquisition in this paper.The main frame design of the MES for discrete manufacturing,data acquisition technology and monitoring technology of production process were studied.The main contents of the dissertation are as follows:(1)In terms of MES main frame,the modular design concept was adopted to construct the system functional module on the basis of customer requirements analysis of each process of manufacturing.Client/Server frame was used to build the system,and a sensible database structure was established according to data requirements of the enterprise.(2)In the aspect of data collection,the communication between PC and PLC under the condition of the multi-protocol was integrated by parsing the FINS protocol,MC protocol and OPC principle,which could realize the reading and writing data about production process parameters and equipment status data on PLC in real time.Moreover,the data collection work under the multi-protocol condition was wrapped into a background service,which is independent of the server and the client,and could avoid the interference from the misoperation of the client while data acquiring in real-time.(3)By using object-oriented programming method and optimized database access technology,the main function modules such as permission level setting,working procedure setting and basic information query were developed.(4)The possible improper operation modes during product processing was analyzed,and the exception handling mechanism and the early-warning dictionary were established.The conditional combination of different early warning contents and production status was provided,which could lock the working device and give a warning when the illegal data and operations were captured.