A method and system for safely collecting input signals by taking two out of two

Abstract

The present invention provides a method and system for safely collecting input signals by taking two out of two. The method comprises the steps of self-checking before logic unit 1 and logic unit 2 collect signals, and then logic unit 1 and logic unit 2 judge the collection circuit according to the self-checking results. Whether the hardware of the first and the second acquisition circuit is faulty, if it is faulty, it will lead to the safety report error. If there is no fault, the output unit will output the input signal, the protection circuit one and the protection circuit two will receive the input signal respectively, and then the acquisition circuit one will receive the input signal from the protection circuit one. The input signal is collected from the second circuit, and the input signal is collected from the second protection circuit by the second collecting circuit. The invention uses the self-checking function to detect the failure of the input hardware circuit; uses the two-out-two safety input system to improve the safety of the safety input circuit system; uses the multi-frequency pulse excitation dynamic acquisition to improve the anti-interference ability; Real-time detection of hardware circuit failures ensures timeliness and improves readability.

Description

technical field [0001] The invention belongs to the technical field of rail transit industrial control, and in particular relates to a method and a system for safely collecting input signals by taking two out of two. Background technique [0002] In the safety input system in the field of rail transit industrial control, fixed-level input acquisition or 1010 fixed-frequency single-dynamic pulse sequence acquisition methods are generally used, but these two acquisition methods have defects. The defects are: 1) When electromagnetic interference is introduced by the external environment, the fixed level signal will fluctuate, causing the input system to collect the wrong level signal; 2) When the acquisition hardware circuit fails, such as a short circuit of the signal line or Open circuit, the system cannot detect the fault and eliminate the fault in time. The disadvantage of using 1010 fixed single dynamic pulse sequence acquisition is that 1) all acquisition channels use th...

AI Technical Summary

Problems solved by technology

[0002] In the safety input system in the field of rail transit industrial control, the method of fixed-level input acquisition or 1010 fixed-frequency single dynamic pulse sequence acquisition is generally used, but these two acquisition methods have defects, and the fixed-level input acquisition method The disadvantages are: 1) When electromagnetic interference is introduced from the external environment, the fixed level signal will fluctuate, causing the input system to collect the wrong level signal; 2) When the acquisition hardware circuit fails, such as a short circuit in the signal line or Open circuit, the system cannot detect and eliminate faults in time

The disadvantage of adopting 1010 fixed single dynamic pulse sequence acquisition is that 1) all acquisition channels adopt the pulse excitation sequence of the same frequency, which is easily interfered by adjacent acquisition channels; When coupling strings, because the same frequency pulse excitation is used, the signal of the input channel is confused

During the operation of rail transit trains, the safety input system is mainly used to collect the information of the train passenger door switch, train stop position information, train turnout information, signal light information, etc. According to these information, the driver (train control center) controls the start and stop of the train, Opening and closing doors, train running speed, train scheduling, etc., if the acquisition signal is wrong or the acquisition signal is chaotic, it will cause wrong operation of the train control, which may lead to major traffic accidents such as train rear-end collision, which seriously threatens people's lives property safety

Images