Method for detecting intermittent oscillation of industrial control circuits in online manner

Abstract

The invention discloses a method for detecting intermittent oscillation of industrial control circuits in an online manner. The method includes steps of (1), preliminarily acquiring a big window historical datum from each to-be-detected control circuit, processing the big window historical data and initializing detection systems; (2), acquiring a small window process datum from each to-be-detected control circuit in real time in an online manner, and updating the big window data by the aid of the small window process data; (3), combining the small window data with the original big window data, processing the small window data and the big window data and recombining the small window data with the big window data to obtain various frequency recombined sub-signals of the updated big window data; (4), computing monitoring statistics corresponding to the various recombined sub-signals and judging real-time detection results; (5), repeatedly carrying out steps (2), (3) and (4) and integrating all judgment results to obtain online detection results. The method has the advantages that intermittent and multi-period oscillation behavior of the industrial control circuits can be quantitatively detected by the aid of the method, compositions such as multiple-oscillation, intermittent oscillation and non-stationary signals in the intermittent and multi-period oscillation behavior can be differentiated from one another, and regular degrees and periods of various oscillation components can be acquired.

Description

technical field [0001] The invention relates to the field of performance evaluation in an industrial control system, in particular to an on-line detection method for intermittent oscillation of an industrial control loop. Background technique [0002] Modern industrial process equipment has the characteristics of large scale, high comprehensiveness, complex control, many variables, and long-term operation under closed-loop control. The common chemical production process in the industry often contains thousands of control loops, and these loops affect each other due to the coupling relationship. Due to the ubiquitous characteristics of controller over-tuning, external disturbance and non-linear operation of control valves in industrial control loops, oscillation behavior of control loops often occurs, which greatly affects the economic benefits and stability of industrial process equipment. [0003] Preliminary and accurate oscillation detection of industrial process equipme...

AI Technical Summary

Problems solved by technology

However, the detection method based on time-domain statistics of process data or autocorrelation function domain analysis has three shortcomings in industrial applications: 1. This method needs to have certain prior knowledge of the detection circuit or process, and some parameters are also determined according to experience; 2. For industrial processes with non-stationary and multiple oscillation cycles, it is impossible to realize fully automatic non-intervention detection, and it is necessary to design targeted filters for data stabilization processing and separation of oscillation components; 3. Most detection algorithms cannot quantitatively calculate the regularity of oscillation components

When there is intermittent oscillation behavior in the industrial process loop, only the essential time scale decomposition is simply performed, and the sub-signal components belonging to different frequency ranges are easy to mix with each other, which is extremely unfavorable for our oscillation detection; in addition, the irregular The peak perturbation of , when the perturbation has a large magnitude, it is likely to cause an inflated situation of the decomposition level of the essential time scale

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