Fractional-order PID controller parameter optimizing and setting method based on closed-loop reference model

Abstract

The invention discloses a fractional-order PID controller parameter optimizing and setting method based on a closed-loop reference model. The method comprises the steps that S1, an ideal closed-loop reference model is selected, and the cut-off frequency omega c and the order alpha of the ideal closed-loop reference model are selected according to the control performance requirements of a system; S2, according to a transfer function expression of the closed-loop system and by combining with the ideal closed-loop system model H(s) and a fractional order PID controller model Gc(s), an ideal control object model (shown in the description) is derived; S3, the frequency domain response characteristics of an unknown controlled object model Gp(s) are obtained, so that the ideal control object model (shown in the description) and Gp(s) are identical in response when omega = 0 and omega = x, and a function relation of kp, kd and mu when omega = omega x is calculated; S4, by optimizing and identifying parameters in the ideal form of an unknown object (shown in the description), so that the unknown object (shown in the description) is close to the actual object Gp(s) in frequency domain response index in a cut-off frequency range, frequency domain response error indexes are established, the error indexes are optimized (shown in the description) when 0 < mu < 2, and finally parameters of a fractional-order controller are obtained. The fractional-order PID controller parameter optimizing and setting method utilizes an identification method of the system to rapidly obtain controller parameters and meanwhile can also ensure best approximation of the ideal reference model.

Description

technical field [0001] The patent of the present invention relates to the field of fractional-order PID control, in particular to a method for optimizing and setting parameters of fractional-order PID controllers based on a closed-loop reference model. Background technique [0002] The fractional order PID controller was proposed by Professor I. Podlubny, and its general format is abbreviated as PI λ D. μ , it has a concept and analysis method similar to integer-order calculus, and at the same time it is more universal and applicable than traditional integer-order PID. Due to the introduction of fractional orders of differential and integral, the controller adds two adjustable parameters, the performance adjustment range of the system becomes larger, and better control effect is expected to be obtained. But at the same time, it also increases the difficulty of controller design and parameter tuning. [0003] In recent years, fractional-order PID controllers have gradually...

AI Technical Summary

Problems solved by technology

Although the fractional-order PID controller tuning method has been studied to some extent, there is still a lack of fast and effective de

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