| The process control experimental device is an important carrier for students to understand the process object model and learn the design of the control system.However,most of the current experimental devices have the following problems:object measurement accuracy and mathematical model accuracy are not high,dynamic characteristics are slow,and it takes a long time to conduct an experiment;supporting software is not clear and intuitive enough,which is not conducive to algorithm research and control system design.In this thesis,an experimental device for quadruple-tank liquid level control system based on load cell is designed.The experimental device adopts the RS-485 serial communication mode,the peristaltic pump as the actuator,and is seamlessly connected to the Lab VIEW and MATLAB/Simulink host computer platforms,it has the characteristics of accurate liquid level measurement,high mathematical model accuracy,fast dynamic characteristics,and convenient control system design and operation.Then,the model predictive control system is researched on quadruple-tank experimental device.The main research contents are as follows:(1)Aiming at the problems existing in the current process experiment device,a quadruple-tank controlled object experiment device based on the load cell is designed.Then,based on the system identification method combining mechanism analysis and experimental data,a multivariate mathematical model of the system is established.Finally,the design problem of model predictive control is studied for the minimum phase and non-minimum phase of the system under different structures.(2)According to the step response model of the quadruple-tank and the principle of the multivariable DMC algorithm,a constrained MPC control system based on output feedback is designed.Then,aiming at the nonlinear problem of the controlled object of the quadruple-tank,a multi-model adaptive predictive control algorithm based on output feedback is proposed based on the DMC algorithm,and the experimental research is carried out in the experimental device.Finally,based on S7-400 PLC and PCS 7 industrial control platform,using CFC programming configuration tool and APL advanced algorithm library,the MPC control of the quadruple-tank is realized and verified on the experimental device.(3)According to the state space model of the quadruple-tank and the principle of the MPC algorithm based on the state space,a state feedback MPC control system is designed.Then,on the basis of state feedback MPC,a multi-model predictive control algorithm based on state feedback is proposed,and the experimental research is carried out in the experimental device.The results show that the system has good control performance. |
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