Design And Development Of The Simulation System For Grinding Process Control Based On METSIM Software

Grinding process is a critical procedure of mineral process, and its running qualities, such as ore granularity, are extremely important for the productivity and quality improvement. It is of comprehensive and complicated characteristics of nonlinearity, large time-delay, slow time-varying and so many other key engineering parameters which cannot be detected online. It is dramatically significant and difficult to study the control algorithms and the optimization algorithms techniques for grinding process. In order to decrease the costs and risks of practical debugging, how to establish a control simulation system of grinding process for engineering in laboratory is an issue which has great practical value. But the present grinding modules used in grinding process simulation system is based on academic hypothesis,which is hard to accepted by the industrial circles,while the modules based on METSIM, provided by equipment manufactures through experimental verification, are much more accurate and can be accepted by the industrial circles,so the simulation result is much more convincing.This paper is supported by National 973 Program "Basic Research of Complex Manufacturing Process for Integrated Control Theory and Technology" of State Key Laboratory of Synthetical Automation for Process Industries in Northeastern University, where control simulation experiment platform of grinding process is designed and developed based on METSIM software.The details are as follows:(1) The grinding process model based on METSIM software is designed and developed. Taking advantage of the abundant model library of commercial METSIM software, and taking certain two stage grinding process as the object, we built the simulation model based on METSIM software. To fulfill the dynamic simulation of the grinding process, the DDE dynamic data link interface is configured based on the requirements of control layer.(2) The basic control loop based on Rockwell software is designed and developed. Aiming at the ore feeding, water feeding of ball mill, overflow concentration loop of spiral classifier, and pumping concentration loop of cyclone, we developed the PID control system.(3) The monitoring platform system of grinding process based on RSView32 is designed and developed. We designed the function and structure of the process monitoring system, and also the upper computer monitoring system. With the model and trend configuration, the PID parameters can be adjusted online and the process data can be displayed synchronously.(4) Data communication interface software of grinding process based on EXCEL VBA is designed and developed. We designed the structure of data communication interface and developed the software based on DDE-OPC data communication mechanism, with the communication software, we can fulfill the closed loop control of the whole grinding process.(5) The simulation system is debugged and run on computer platform. To verify the practicability and availability of the whole system, we designed several experiments,and carried out the control experiment for grinding process.