PID control method based on stability coefficient multivariable strong coupling time-delay system

Abstract

The invention provides a PID (Proportion Integration Differentiation) control method based on a stability coefficient multivariable strong coupling time-delay system, which comprises the following steps of: firstly, designing a compensator for the multivariable strong-coupling system in a frequency domain based on an RCGA (Remote Control Grid Array) to realize system decoupling, and processing the time-delay effect of each sub-loop by utilizing a Pade approximation method; then determining PID controller parameters for each sub-loop of the decoupled system on the basis of a stability coefficient, and finally applying the PID parameters of each sub-loop to a PID controller of an original multivariable system inserted into a compensator. The PID controller designed by the method can meet design requirements in multiple aspects of robust stability, output performance and the like; and meanwhile, the requirements of low order and easy realization can be met. The unknown parameters in the controller are solved through the given stability coefficient, so that understanding is facilitated, and the method has a high reference value for parameter determination of other system controllers. Simulation analysis proves that the designed system can give consideration to response characteristics and robustness at the same time, and the design process is simple and easy to implement.

Description

technical field [0001] The invention relates to the technical field of multivariable system control, in particular to a PID control method for a multivariable strongly coupled time-delay system based on a stability coefficient. Background technique [0002] Many industrial control devices (such as heavy oil fractionation towers in the petroleum industry, multi-product distillation towers for separating ethanol-water mixtures in chemical systems, heat exchangers in the natural gas industry, etc.) are usually between controlled variables such as temperature, liquid level, and pressure. Interaction and different phenomena (such as information, energy transmission time) cause time delays. These strong coupling, time-delay effects will affect the performance of the system, resulting in very poor system response. [0003] In the chemical industry, liquids are pumped from one storage tank to another and stored. Liquid levels in these tanks need to be controlled at all times, and ...

AI Technical Summary

Problems solved by technology

The time lag of paper basis weight quantitative measurement and the coupling of multiple valve quantitative control seriously affect the uniformity of paper basis weight distribution, resulting in the deterioration of paper appearance and physical properties

[0004] Existing control methods, such as inverse Nyquist array method, multivariable simplified decoupling Smith predictive controller design, multivariable system internal model control design method, etc., on the one hand, may be difficult to deal with the strong coupling effect of multivariable systems complicates the design of controllers, which are made more difficult in the presence of time delays

On the other hand, concepts are often complex and difficult to understand, and controllers are difficult to implement

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