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

Abstract

A large time delay process is difficult to control, and the fundamental reason is that information feedback is not timely, so a controller based on feedback information is powerless for the system. Aiming at the control problem of a large time delay system, the invention provides a novel method of the Smith auto-coupling PI (SACPI) cooperative control theory independent of a controlled object model. According to the invention, the method comprise the steps: on the basis of an early invention, constructing a Smith nominal predictor according to nominal parameters of a time delay object, and setting a speed factor according to a nominal time constant and nominal time delay. Theoretically, the SACPI control system is not only globally asymptotically stable, but also has good parameter perturbation robustness. Numerical simulation results show that under the condition that various model parameters have time-varying perturbation, the control method can obtain good dynamic quality and steady-state performance, and therefore, the method is an effective control method and has a high 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 Auto-Coupling Proportional-Integral (Smith Auto-Coupling Proportional-Integral, SACPI) cooperative control theory. Background technique [0002] Time lag widely exists in industrial processes such as petroleum, chemical industry, power grid, 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 Always at the maximum value, 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 time-delay system con...

AI Technical Summary

Problems solved by technology

However, the speed factor of the intelligent PI compound control method is set by the integral step, which is difficult to grasp in practical applications; the speed factor of the damping intelligent PI control method and the predictive intelligent PI control method are jointly adjusted by the system time constant and the dead time. Effectively improves the practicability, however, it is sensitive to the perturbation of the delay time, and the speed factor needs to be corrected, which brings certain difficulties to the practical application

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