Smart PID control method

Abstract

The invention discloses a smart PID control method. The theoretical system for setting the three gain parameters of the PID controller is established through the speed factor zc. Not only the problemof setting the three gain parameters of traditional PID is solved effectively, global stability and strong anti-disturbance capability specialty are provided. The control method has wide application value in the fields of power, machinery, chemical industry, light industry and so on.

Description

technical field [0001] The invention relates to a nonlinear uncertain system control method, in particular to a PID control method. Background technique [0002] For more than half a century, the classical control (cybernetics) method based on the frequency domain design method and the modern control (model theory) method based on the time domain design method have developed independently and formed their own methodological systems. In the practice of control engineering, the error between the control target and the actual behavior of the controlled object is easy to obtain and can be dealt with appropriately. Therefore, the prototype of the control strategy of "eliminating error based on error", that is, the PID controller in the actual It has been widely used in the field of industrial control. For practical control engineering problems, since it is usually difficult to give a "description of internal mechanism", the control strategy given by modern control theory based o...

AI Technical Summary

Problems solved by technology

However, the development of science and technology has put forward higher requirements on the accuracy, speed and robustness of the controller, and the shortcomings of PID control have gradually emerged: although PID control can ensure system stability, the dynamic quality of the closed-loop system is sensitive to PID gain changes

This shortcoming leads to an irreconcilable contradiction between "rapidity" and "overshoot" in the control system. Therefore, when the operating conditions of the system change, the gain of the controller needs to change accordingly, and this is also the result of various improved PID The original motivation of control methods such as adaptive PID, nonlinear PID, neuron PID, intelligent PID, fuzzy PID, expert system PID, etc.

Although various improved PID can improve the adaptive control ability of the system by online tuning the controller gain parameters, however, the existing PID control is still powerless for the control problems of nonlinear uncertain systems, especially the anti-disturbance ability is poor

In addition, the principle of PID control is to weight and sum the past (I), present (P) and future (change trend D) of the error to form a control signal, although effective control can be applied as long as the three gain parameters of PID are reasonably selected, however , the error and the integral and differential of the error are three physical quantities with completely different properties, and the control signal obtained by weighting and summing the three physical quantities with different properties lacks basic common sense

Because of the inherent irrationality of PID, experts, scholars and engineers engaged in control theory and control engineering at home and abroad have been working hard on the tuning of PID parameters for nearly a century, but so far, they have not found A solution with simple model structure, easy parameter tuning, good dynamic quality, high control precision and strong anti-disturbance ability

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