| Ceramic Auto-Hydraulic Press is the key equipment for compression molding of ceramic tile.However,the problems of low compression efficiency,large pressure shock and poor repetitive control precision in ceramic press restrict the development making ceramic tile thinner.The electro-hydraulic control system is the core part of ceramic hydraulic press.The control performance of compression process directly influences the production efficiency and the quality of ceramic tile.This topic comes form the technical plan project of Fuzhou City "the Development of Accurate Close-loop Monitoring and Control System for Large Tonnage Automatic Press"and cooperates with Fujian Haiyuan Automatic Equipments Co.,Ltd.In this paper,a ceramic hydraulic press manufactured by the above company is the research object.In order to mastering the operating law and improving the rapidity,stationarity and control precision to adapt the development making ceramic tile thinner,the modeling,simulation,testing and control strategy optimized research on its electro-hydraulic control system is carried out.In this paper,the operate mode and motion flow designed for satisfying the compression technology of ceramic tile,the structure and working principle of ceramic press are firstly analyzed.In addition,the working principle and status of electro-hydraulic control system during each motion of compression process is analyzed.The kinetics control model of main cylinder in the key stage of ceramic compression process is built based on electro-hydraulic control theory to analyze the impact on performance by several important parameters.The simulation models of critical hydraulic components such as kinds of cartridge valves and constant pressure variable axial piston pump are established and verified the correctness based on AMESim.The continuous motion system simulation model of compression process system is built and dynamically analyzed so that the relationship between the control signals of valves and critical performance parameters included of pressure in two chambers of main-cylinder and displacement during compression process is acquired.The real-time monitoring system of ceramic hydraulic press is designed.The correctness of simulation model is verified by using the monitoring system testing the operating data.Using Simulink to create control module that combines the verified AMESim model into co-simulation platform that used to research the control strategy for improving the performance of main cylinder moving down process.According to the characteristics of the ceramic powder load,fuzzy control strategy is put forward to improve the control precision and operation efficiency in compression process because the traditional control method could cause the unstable compression performance and poor parameters adaptability.The innovation of this paper is completely establishing the simulation model that can simulate continuous motions in compression process according to the real working condition of ceramic hydraulic press and creating the monitoring system to verify the reliability of model in production experiment.The strategy that could improve the performance of the two key stages included main cylinder moving down and low-pressure compression is respectively put forward.The research of this paper improves the operating efficiency,stability and control precision in compression process essentially and promotes the design and optimization for electro-hydraulic system of ceramic press.The research production has practical value for engineering application. |
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