Design And Development Of The Teaching Experiment Platform Of Decoupling Control For The Two-Airflow Mixing Process

Many control loops have coupling effects in industrial processes,making the conventional single-loop controller less effective and even difficult to put into automatic operation.Multivariable decoupling control is an effective control strategy to solve the above problem.However,the introduction of multivariable decoupling control in the teaching of automation emphasizes more on mathematical theory,so the coupling and decoupling control problem has always been the difficulty and focus in automation teaching.With the support of the project of Liaoning Province Metallurgical Comprehensive Automation Engineering Laboratory,the two-way air mixing process is taken as a physical object,and a multivariable decoupling control experiment platform has been designed and developed that is highly consistent with the industrial environment.Based on this platform,decoupling control and identification experiments with multivariable strong coupling are carried out under industrial environment,which can help students to deepen the understanding of multivariable decoupling control,so as to improve the teaching effect.The main work of this paper is as follows:(1)On the basis of a detailed overview of the development of the existing process control experimental teaching platform and the problem of multivariable decoupling control,the air mixing process is taken as the controlled object.The teaching experiment requirements of multivariable decoupling control system platform are analyzed in detail to help teaching experiments.(2)The system architecture of multivariable decoupling control teaching experiment platform composed of two air-mixed controlled objects,instruments and implementing agencies,PLC control system,monitoring computer and model computer is designed.The functional modules related to teaching experiment are designed,which can carry out teaching experiments such as transfer function matrix identification,relative gain matrix identification,decoupler design and decoupling control operation,and can carry out comparison experiments of various decoupling control algorithms.(3)Based on the Siemens S7-300 PLC,SIMATIC WinCC and MATLAB GUI software,the air mixing process decoupling control platform software was developed.The PLC process control and monitoring software was completed by using Siemens industrial control software.Use MATLAB to develop a model computer software for complex computing tasks(transfer function Matrix identification,decoupler design)and use OPC method to realize data communication between PLC system and model machine software.(4)A series of experiments were carried out on the air mixing decoupling control experiment platform.The experiment results show that the platform has the advantages of highly simulating industrial scene environment,being intuitive and easy to understand.It is also safe and reliable,convenient and flexible,playing a catalytic role to decoupling control teaching.