Research On Modeling And Predictive Control Of Double Tank Water Level Control System

Process automatic control plays an important role in modern industrial production,and liquid level control technology is widely used in process industry.In the actual industrial process,the cost and benefit of the plant and the production safety of each equipment are closely related to the control performance of the liquid level.In the liquid level control,the tank level is the most typical representative,which plays an important role in process control.Similar problems are often encountered in actual industrial production,so the study of tank liquid level has very practical significance.To ensure the safety and stability of the liquid level process control,it is important to establish a precise water tank model and develop advanced liquid level control strategies.Graphical techniques are widely used to aid the representation of dynamic system models,while linear graphs represent the internal relationships between components in a system.In this paper,the double-capacity water tank is taken as the controlled object,the water level of the water tank is the control quantity,and the mathematical model of the double-capacity water tank liquid level control system is established by using the modeling mechanism of the linear graph theory.The transfer function of the system is obtained based on the state space equation.The PID controller is designed and a large number of simulation experiments are carried out on the model.The output curves of the system performance indicators remain stable.Then the equivalent transfer method is used to verify the transfer function of the system,which proves the rationality of the model and provides an effective model for the dual-capacity tank system.This study has a good guiding significance for a class of systems with similar characteristics.Predictive control has been receiving much attention in the field of industrial control.Its main features are robustness,efficient processing of constraints,simple modeling and good control performance.In this paper,the predictive control algorithm is applied to the control of the liquid level of the double-capacity tank,and the mechanism model is linearized at the equilibrium point.The basic principles of predictive control and dynamic matrix control algorithms are studied,and the related computational flow of dynamic matrix control algorithms is analyzed.Through the Simulink simulation of MATLAB,the parameters of the DMC controller are designed without considering the interference and model mismatch and considering the model mismatch and interference effects.At the same time,through simulation analysis,the performance of DMC control and DMC-PID cascade control in system fastness,anti-interference and robustness are compared.