Industrial control system multi-loop oscillation causality analysis method based on improved CCM

Abstract

The invention discloses an industrial control system multi-loop oscillation causality analysis method based on an improved CCM. The method comprises the following steps: calculating mutual informationbetween every two oscillation circuit process output signals to be analyzed to perform feature selection, a loop signal pair with a relatively high correlation degree is reserved; removing noise andperiodic terms by using EMD and DFA methods; calculating a cross mapping index of the reconstructed sub-signal pair under different time delays by using a CCM method; preliminarily judging the authenticity of the causal relationship according to the positive and negative of the optimal time delay, then the cross mapping indexes of each target sub-signal pair corresponding to the optimal time delayunder different sample lengths are calculated, judging whether convergence occurs according to the convergence threshold, and finally obtaining the final causal relationship network of the oscillation circuit, so that the oscillation propagation path is determined and the oscillation source is positioned. According to the method, the oscillation propagation path in the industrial control system can be rapidly and accurately diagnosed, the oscillation source can be positioned, and a new thought is provided for fault diagnosis of the oscillation circuit of the industrial control system by usinga causal analysis method.

Description

technical field [0001] The invention belongs to the field of fault diagnosis of industrial control systems, in particular to an improved CCM-based multi-loop oscillation causality analysis method for industrial control systems. Background technique [0002] About 30% of industrial control loops have oscillatory faults due to controller overtuning, valve stickiness, external disturbances, and process nonlinearities. Oscillation is one of the main causes of control performance degradation in industrial control systems. Continuous oscillation increases the wear and tear of industrial equipment, reduces product quality, seriously affects factory production efficiency and even creates potential safety hazards. There may be thousands of loops in a large-scale industrial control system. Due to the mutual influence and high coupling between the loops, the oscillation of any one of them may be transmitted to other loops of the system, eventually leading to global oscillation. [00...

AI Technical Summary

Problems solved by technology

In particular, some oscillating signals are similar to periodic sinusoidal signals. There is often a phase difference between sinusoidal signals, and it is often impossible to directly determine the specific lag information between the two based on the phase difference, thus reducing the accuracy of causal analysis.

Periodic signals may also make signals similar and synergistic, which interferes with causal analysis

In addition to periodic signals, unwanted noise, which is almost unavoidable in industrial processes, can also have an impact on causal analysis

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