Fault diagnosis method of fault safety system

Abstract

The invention discloses a fault diagnosis method of a fault safety system, comprising the following steps: S1. determining parameter values such as an operation period P of the fault safety system, a turning period T of a dynamic signal, turning times N of the dynamic signal judged by a receiver, error accuracy shown in specification of a discrimination range in the case of single discrimination of the dynamic signal, and a time window T' of the dynamic signal after single discrimination, a duration time threshold G of a single burr signal and the like; S2. generating the dynamic signal with the turning period T, wherein the dynamic signal is generated by high-level and low-level alternate turnover; and S3. judging whether a fault occurs on the fault safety system via the receiver according to the continuous turning times N of the dynamic signal. In the invention, the dynamic signal is processed by a safe encoding strategy and then taken as a diagnosis basis for judging whether the fault occurs on the fault safety system, thus improving service reliability of the dynamic signal, and being beneficial to enhancing availability and safety of the fault safety system.

Description

Technical field [0001] The invention relates to the technical field of industrial control, in particular to a fault diagnosis method for a fail-safe system. Background technique [0002] With the development of large-scale integrated circuit technology, electronic components are increasingly used in the design of safety redundant systems. When the digital circuit fails, it will cause the level signal to have a fixed "0" or a fixed "1" error, but the specific "0" or "1" is not fixed, and the probability of occurrence is roughly the same. Therefore, whether "0" or "1" is used to indicate a module failure may bring potential safety hazards. [0003] If a dynamic signal that alternates between high and low levels is used instead of the above-mentioned level signal (TTL, CMOS, etc.), it can be distinguished from the “0” or “1” error of the output signal caused by the failure of the digital circuit. Therefore, in the design of safety systems, dynamic signals are often used to indicate ...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned patent proposes a dynamic signal identification method, which belongs to the most basic dynamic signal judgment method. It is impossible to judge whether a dynamic signal contains an interference signal, and it is easy to lead to misjudgment.

For safety systems, the conditions for the generation and judgment of dynamic signals should be very strict, and the existence or non-existence of dynamic signals cannot be easily judged, which may lead to wrong actions of fail-safe systems, which is very dangerous

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