Novel Smith mutual coupling PI cooperative control theory method of time delay system

Abstract

In a large time delay process, information feedback is not timely, so that a controller based on feedback information is powerless for systems of the kind. Aiming at the control problem of a large time delay system, the invention provides a novel Smith mutual coupling PI cooperative control theory method, which is mainly characterized by and innovative in the steps of: constructing a Smith nominalpredictor according to nominal parameters of a time delay object; forming a time-delay-free inertia system by combining the Smith nominal predictor with a time-delay object; originally designing an SMCPI cooperative control force model; setting a central speed factor according to a nominal time constant and time delay; and analyzing global robust stability of an SMCPI control system. The numerical simulation results show that the control method provided by the invention can obtain good dynamic quality and steady-state performance under the condition that various model parameters have time-varying perturbation, thus the novel Smith mutual coupling PI cooperative control theory method is an effective control method and has wide application value in the field of time-delay system control.

Description

technical field [0001] The invention relates to a control method of a time-delay system, in particular to a new method of Smith Mutual Coupling PI (SmithMutual Coupling Proportional-Integral, SMCPI) cooperative control theory. Background technique [0002] Time lag widely exists in industrial processes such as petroleum, chemical industry, metallurgy, nuclear reactor, and wastewater treatment. These industrial processes can often be simplified as one or more first-order plus-purity lag systems. Due to the existence of the time lag phenomenon, the system has been in invalid output during the time lag period (assuming that the invalid output is y=0), therefore, during the time lag period, the tracking error e 1 =y d -y=y d It is always at the maximum value, and it is easy to cause large overshoot, long response time, and even oscillation or instability of the entire system due to integral saturation, which brings great challenges to the design of the time-delay system contr...

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Problems solved by technology

However, the stability domain margin obtained by this method has only a small appropriate range, and is very sensitive to the control performance of the time-delay system, and a small change in the stability domain (such as 0.005) may cause system instability

In addition, the response speed of this method is very slow. For the controlled object with a delay time τ=60s, it takes about 6000 seconds to enter a stable state

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