Method and system for diagnosing open-circuit fault of digital circuit

Abstract

The invention provides a method and a system for diagnosing an open-circuit fault of a digital circuit. According to the method and the system, a digital signal output module is connected with a digital signal acquisition module, so as to selectively output a high level or a low level according to the actual state of the current circuit; the digital signal acquisition module is connected with a digital signal fault diagnosis module, so as to acquire a digital signal voltage value; when the digital circuit is short-circuited to a power supply, the acquired voltage value is equal to the voltage of the power supply; when the digital circuit is short-circuited to the ground, the acquired voltage value is equal to 0 V; when the digital circuit is in open circuit, the acquired voltage value is equal to one second of the voltage of the power supply; the digital signal fault diagnosis module performs comparative diagnosis on the output voltage value and standard voltage values under five conditions of high level, low level, short circuit to the power supply, short circuit to the ground and open circuit and judges whether the current digital input circuit has an open-circuit fault or not. After the digital circuit is diagnosed by utilizing the method and the system, various fault modes of the digital circuit can be recognized, the open-circuit fault of the digital circuit can be clearly and accurately reported, and the defect that open-circuit diagnosis cannot be performed on a traditional digital circuit is effectively overcome.

Description

technical field [0001] The invention relates to a hybrid vehicle digital circuit fault state diagnosis technology, in particular to a digital circuit open circuit diagnosis method and system. Background technique [0002] Hybrid electric vehicles include multiple functions such as idling start and stop, energy recovery, and acceleration boost. In order to realize these functions, the vehicle controller often needs to use digital circuits to obtain critical signals, such as brake pedal signals. The status diagnosis of the digital circuit is essential in the hybrid power system, and the traditional pull-up / pull-down digital circuit cannot diagnose the circuit open circuit. Contents of the invention [0003] In order to solve the above problems, the present invention proposes a method and system for diagnosing open-circuit faults of digital circuits in hybrid electric vehicles. By comparing the voltage value of the current digital input, the fault state of the digital circuit...

AI Technical Summary

Problems solved by technology

[0002] Hybrid electric vehicles include multiple functions such as idling start and stop, energy recovery, and acceleration boost. In order to realize these functions, the vehicle controller often needs to use digital circuits to obtain critical signals, such as brake pedal signals. The status diagnosis of digital circuits is essential in hybrid power systems, and traditional pull-up / pull-down digital circuits cannot diagnose open circuits

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