Materials Pre-computer Control System Design Of The Grinding Process

The highly effective and reliable running of mine pre-mill, which includes crushing and grinding and is an effective machine to achieve the goal of more crushing and less grinding, affects the mine production safety and the economic efficiency significantly. The working condition of mine pre-mill is extremely complex, and there are many factors which affect the impact of ore's pre-grinding. It is necessary to design an effective computer control system to improve the crushing and grinding efficiency and automation level of the pre-mill, which has a preferable value of research and prospect of application.The goal of thesis is to design an automatic control system to satisfy the granularity production request, reduce consumed power and make the automatic control of material production process of pre-mill come true. The main work is as follows:(1)The system functions and the implementation methods of the pre-mill computer control system are defined and the control model of the pre-mill's main working parameters(such as the work load, the feeding and the working speed of main motor etc.) is built through analyzing the pre-mill system's principle and its performance technology.(2)According the control demand of pre-mill, two two-dimensional fuzzy controllers are designed to control the system with fuzzy control theory. The design process of the fuzzy controllers which are developed by fuzzy logic toolbox of MATLAB is particularly introduced, and the simulative study of control system of pre-mill is carried out under simulation environment of SIMULINK.(3)The hardware, hardware circuit and software are designed through the analysis of the structure and control requirements of the pre-mill control system. On the model selection of hardware of the system, CPU224 of S7-200 PLC produced by Siemens Company is chosen as the main control unit, EM235 and EM232 expansion units, INVT transducer and displacement sensor etc. are chosen. On the software design of the system, the programming process is accomplished with STEP7-Micro/WIN4.0, and the design and debugging of remote monitoring system are accomplished with MCGS.(4)According to the working current of main motor and the signal of discharge size, using the fuzzy control theory to implementing real-time on-line monitoring for pressure of rolling millstone at work, clearance of the discharge gate, working current of main motor, discharge size, the speed of main motor and the feeding.(5)The field experiment about this computer control system of pre-mill's material shattering process is carried out. The experimental result shows that the system is reliable to implement remote monitoring and protect the system's safety, improves the working stability and quality of the products, and satisfies the request of the computer control system by the pre-mill.The thesis innovates in the design technique of control system of pre-mill crushing process of material. There are great social and economic efficiencies for saving energy and improving output of grinding. Therefore, there is a broad perspective in application about this designed control system.