PID control algorithm of multivariable ARX-Laguerre model

Abstract

The invention relates to a PID control algorithm of a multivariable ARX-Laguerre model, which is used in a fractionating tower control system, and comprises the steps of after a controlled object is selected, further selecting a Laguerre function pole; carrying out on-line identification on parameters of the multivariable ARX-Laguerre model by using actual input and output of the controlled object; combining the two to obtain a prediction model, then obtaining the output of the prediction model, and correcting the output of the prediction model according to the actual output of the controlled object; setting a set value, obtaining a reference trajectory according to the set value, and subtracting the corrected prediction model output from the reference trajectory to obtain an error; obtaining a new performance index by adding an FOPID control reconstruction performance index formula; substituting the error into the performance index, and performing minimization processing to obtain an optimal control increment; and accumulating the optimal control increments to obtain an optimal control quantity, inputting the optimal control quantity into the system again, and repeating the operation to perform rolling optimization until the prediction model is approximate to an actual system.

Description

technical field [0001] The invention relates to a FOPID predictive control algorithm based on a multivariable ARX-Laguerre model, belonging to the field of nonlinear control of fractionation towers. Background technique [0002] Fractionation tower is an important separation and purification device, which is widely used in petrochemical, pharmaceutical and chemical industries. It is the main energy-consuming device in the chemical industry, and its energy consumption accounts for about 40% to 50% of the total energy consumption, but its energy conversion rate can only be maintained at a low level of 5% to 10%, resulting in extremely Big energy waste. And its irreplaceability has also led to the search for more advanced control methods to improve the control effect of the fractionation column has become the focus of research. [0003] Fractional-order PID control is a control method extended on the basis of traditional PID control, and the order of integral and differential...

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Problems solved by technology

[0005] The present invention proposes a FOPID predictive control based on a multivariable ARX-Laguerre model in order to make up for the shortcomings of the traditional FOPID control for the poor control accuracy of complex systems, and to solve the shortcomings of the model predictive control algorithm based on intelligent control theory in the fractionation tower control. algorithm

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