Fault diagnosing method of observing injection timing based on characteristic parameters of waveform of rail pressure

Abstract

The invention discloses a fault diagnosing method of observing injection timing based on characteristic parameters of waveform of rail pressure. The fault diagnosing method comprises the following steps: firstly sampling a rail pressure signal, and processing the sampled rail pressure signal, so that a balance point of the pressure drop of the rail pressure and average rail pressure, which correspond to each cylinder of a diesel engine, are obtained; secondly observing the injection timing based on the characteristic parameters of the waveform of the rail pressure, and then calculating an injection timing observing model according to the average speed of the diesel engine corresponding to each cylinder of the diesel engine so as to obtain an observed injection timing; finally, diagnosing a fault of the injection timing based on the observed injection timing, diagnosing a fault of the injection timing of an fuel injector of each cylinder of the diesel engine through comparing the observed injection timing with pre-setting injection timing set in advance, and outputting a fault condition of the injection timing of the fuel injector of each cylinder of the diesel engine. Tests prove that the fault diagnosing method disclosed by the invention has a good fault diagnosing effect on the injection timing of the fuel injector in the practical application.

Description

technical field [0001] The invention belongs to the technical field of internal combustion engine control, relates to a high-pressure common-rail fuel injection system of a diesel engine, and is a fault diagnosis method for a high-pressure common-rail fuel injection system of a diesel engine, in particular to a high-pressure common-rail fuel injection of a diesel engine based on the observation of rail pressure waveform characteristic parameters Diagnosis method for injection timing faults of system injectors. Background technique [0002] The internal combustion engine is the model with the highest thermal efficiency, the best energy utilization rate, and the most energy-saving model among the various power machinery currently being industrialized. It has been widely used in power generation, irrigation, ship power, vehicle power, etc. The advantage in power is the most obvious, and the global trend of "internal combustion engine" in vehicle power has been formed. [0003]...

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Problems solved by technology

[0006] Foreign research on fault diagnosis of high-pressure common rail systems is still in the confidential stage, while domestic research on fault diagnosis of high-pressure common rail systems is still in its infancy. The existing public high-pressure common rail system fault diagnosis technologies are often aimed at specific actuators and sensors. , such as the fault diagnosis of injector solenoid valve, high-pressure oil pump solenoid valve and rail pressure sensor, etc., the performance fault diagnosis method of high-pressure common rail system based on rail pressure waveform characteristics is still rare

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