Engine misfire coordinated diagnosis method for hybrid electric vehicle

Abstract

The invention provides an engine misfire coordinated diagnosis method for hybrid electric vehicle. When the EMS determines that the engine is suspected of misfire, the EMS judges whether the engine speed is in the area A where misfire can be diagnosed normally. If so, the EMS performs misfire fault diagnosis. When the engine misfire is diagnosed, the vehicle enters the fault mode, the EMS cancelsthe engine suspected misfire notification, and the instrument displays the misfire fault; and when the engine misfire occurs, the vehicle enters the fault mode. If not, the EMS sends a suspected engine misfire message to the HCU, the HCU judges whether the current vehicle satisfies the condition of entering the engine speed pull-up mode, If yes, the HCU controls the vehicle to enter the engine speed pull-up mode and sends the information that the engine speed has been pulled up to the EMS after the engine speed pull-up reaches the requirement. After that, the EMS diagnoses the misfire fault, otherwise the HCU sends the message that the vehicle cannot enter the engine speed pull-up mode to the EMS, and the EMS does not diagnose the misfire. The method of the invention is simple and feasible, and can improve the accuracy of misfire diagnosis.

Description

technical field [0001] The invention relates to the control field of hybrid electric vehicles, in particular to a coordinated diagnosis method for engine misfires of hybrid electric vehicles. Background technique [0002] With the development of science and social progress, environmental and energy problems have become prominent, and hybrid vehicles have gradually become the focus of the new energy industry. Engine misfires, oil shortages, and poor compression on HEVs can all lead to engine misfire failures, which, once engine misfire failures occur, will result in reduced performance and increased emissions. Engine misfire types include: single misfire, continuous misfire, and multiple misfires. Single misfire refers to the phenomenon that the misfire cylinder sometimes works normally and sometimes misfires during the working process of the engine; continuous misfire refers to the continuous occurrence of misfire in the misfire cylinder; multiple misfire refers to the simu...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the defects of the prior art, the present invention aims to provide a coordinated diagnosis method for hybrid vehicle engine misfire, which is simple and feasible, and solves the problem of hybrid vehicles by coordinating HCU (i.e. vehicle controller) and EMS (i.e. engine management system). When the engine misfires, the crankshaft speed is affected by the speed regulation torque applied by the motor, resulting in inaccurate misfire diagnosis

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