Fuzzy PID control instrument and control method

Abstract

The invention provides a fuzzy PID control instrument and control method. The method comprises the following steps: obtaining a real-time sampling value; according to the real-time sampling value and a set value, calculating to obtain an actual deviation EPC, and according to a preset proportion gain P, calculating to obtain a deviation scope EP; if the actual deviation EPC is beyond the deviation scope EP, correcting a preset PID parameter by use of a fuzzy control algorithm until the actual deviation EPC is within the deviation scope EP; and if the actual deviation EPC is within the deviation scope EP, calculating to obtain a control output value by use of a PID algorithm. According to the invention, fuzzy dynamic control and the PID algorithm are combined together so that the response speed of automation control is improved, and at the same time, it can be ensured that over-regulation and under-regulation conditions do not occur in the rapid rising process of a measured amount; and furthermore, the stable period of an automatic control process is also shortened, the method can be better applied to complex working condition environments with changeable measured amounts, and the efficiency of automatic control and the control effect are substantially improved.

Description

technical field [0001] The invention relates to the field of automatic control, in particular to a fuzzy PID controller combined with a fuzzy algorithm and a PID algorithm and a control method. Background technique [0002] PID controllers are widely used in the field of industrial automation control. They are mainly used to complete fixed-point control of collected physical quantity signals such as temperature, pressure, liquid level, and flow in industrial environments, replacing traditional manual experience value judgments and adjustments to production processes. Inaccurate judgment of artificial experience value, unsatisfactory control effect and other problems. A general PID controller mainly includes: an acquisition module, ADC, MCU, display module, and output control module. The acquisition and analog-to-digital conversion of industrial signals are completed through the acquisition module and ADC, and the PID mathematical operation is completed through the program al...

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Problems solved by technology

[0004] The PID control technology of the above scheme only uses the fuzzy algorithm to obtain the correction value of the PID parameters. Although this control method using only the fuzzy algorithm can quickly make the controlled object reach the expected set value and the response speed is fast, its overshoot Large, large control error, low precision; and another existing PID control technology only uses the PID algorithm to obtain the correction value of the PID parameters, although the accuracy is improved, the error is small, the overshoot is small, but its response speed is slow, Affect the efficiency of automatic control; further, the above two PID control methods are only suitable for relatively stable working conditions, and some parameters are changeable, such as temperature, pressure, liquid level and other parameters will continue to change due to frequent switching equipment The complex working environment, its control efficiency is low, the stability period is long, and the control effect is not ideal

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