CN-122014446-A - Fault detection method and device and vehicle

CN122014446ACN 122014446 ACN122014446 ACN 122014446ACN-122014446-A

Abstract

The application relates to a fault detection method and device and a vehicle, and relates to the technical field of vehicles. The fault detection method comprises the steps of obtaining a pressure time domain signal of an air inlet manifold under the condition that the operation duty ratio of an electromagnetic valve is larger than a duty ratio threshold value, extracting a target frequency domain signal with preset frequency from the pressure time domain signal, wherein the preset frequency is the control frequency of the electromagnetic valve, and determining whether a pipeline to be detected in at least one desorption pipeline is in a desorption flow fault state according to the signal amplitude of the target frequency domain signal. The application avoids the problems of hardware cost increase, installation and maintenance difficulty rise caused by installing the special flow sensor, and reduces hardware cost and maintenance cost on the premise of ensuring the timeliness and reliability of desorption flow fault detection.

Inventors

JING JUNCHAO
HUANG WEISHAN

Assignees

极光湾(宁波)智能科技有限公司
极光湾科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (10)

1. A fault detection method, characterized in that it is applied to a vehicle, the vehicle includes an engine and a carbon canister, the carbon canister is connected with an intake manifold of the engine through at least one desorption pipeline, an electromagnetic valve is disposed between an air outlet of the carbon canister and the at least one desorption pipeline, the fault detection method includes: Acquiring a pressure time domain signal of the air inlet manifold under the condition that the operation duty ratio of the electromagnetic valve is larger than a duty ratio threshold value; Extracting a target frequency domain signal with preset frequency from the pressure time domain signal, wherein the preset frequency is the control frequency of the electromagnetic valve; and determining whether a pipeline to be detected in the at least one desorption pipeline is in a desorption flow fault state according to the signal amplitude of the target frequency domain signal.
2. The fault detection method of claim 1, wherein the at least one desorption line comprises a low pressure line and a high pressure line, wherein the low pressure line is connected between the canister and the intake manifold, the high pressure line is connected between the canister and an intake end of a supercharger, and an exhaust end of the supercharger is connected with the intake manifold; before the acquiring the pressure time domain signal of the intake manifold, the fault detection method further includes: acquiring ambient pressure and intake pressure of the intake manifold; under the condition that the air inlet pressure is smaller than the ambient pressure, determining the low-pressure pipeline as the pipeline to be detected; and under the condition that the air inlet pressure is greater than or equal to the ambient pressure and is smaller than the preset pressure, determining the high-pressure pipeline as the pipeline to be detected.
3. The fault detection method according to claim 1, wherein the extracting a target frequency domain signal of a preset frequency from the pressure time domain signal includes: Performing discrete sine function counting based on the preset frequency and a preset period, and determining a sine phase angle, wherein the preset period is an updating period of a sine function counter of discrete Fourier transform; determining a cosine phase angle by performing phase shift processing on the sine phase angle; and determining a real component and an imaginary component in a complex representation of the target frequency domain signal from the pressure time domain signal, the sine phase angle and the cosine phase angle.
4. A fault detection method according to claim 3, wherein said determining said real component and said imaginary component in said complex representation from said pressure time domain signal, said sine phase angle and said cosine phase angle comprises: Determining an imaginary part instantaneous value according to the pressure time domain signal and the sine function value, and determining a real part instantaneous value according to the pressure time domain signal and the cosine function value, wherein the sine function value is a function value determined based on the sine phase angle, and the cosine function value is a function value determined based on the cosine phase angle; And integrating the imaginary part instantaneous value and the real part instantaneous value to obtain the imaginary part component and the real part component.
5. The fault detection method of claim 3, wherein prior to said determining whether the line to be detected is in a desorption flow fault condition based on the signal amplitude of the target frequency domain signal, the fault detection method further comprises: Determining an initial amplitude of the target frequency domain signal according to the imaginary component, the real component and a preset integration time window; compensating the initial amplitude according to an ambient pressure compensation coefficient and/or a duty cycle compensation coefficient, and determining the signal amplitude; The ambient pressure compensation coefficient is a coefficient determined based on the ambient pressure in the preset period, and the duty cycle compensation coefficient is a coefficient determined based on the operation duty cycle of the electromagnetic valve in the preset period.
6. The fault detection method according to any one of claims 1 to 5, wherein the determining whether the pipeline to be detected is in a desorption flow fault state according to the signal amplitude of the target frequency domain signal includes: acquiring an amplitude average value of at least two signal amplitudes within a preset duration; Under the condition that the average value of the amplitude is larger than or equal to an average value threshold value, determining that the pipeline to be detected is not in a desorption flow fault state; Under the condition that the average value of the amplitude is smaller than the average value threshold value, determining that the pipeline to be detected is in a desorption flow fault state; wherein the average value threshold corresponds to the pipeline to be detected.
7. The fault detection method according to any one of claims 1 to 5, wherein the determining whether the pipeline to be detected is in a desorption flow fault state according to the signal amplitude of the target frequency domain signal includes: acquiring at least two signal amplitudes within a preset duration; Determining a target number of target amplitudes in at least two signal amplitudes, wherein the target amplitudes are amplitudes greater than an amplitude threshold in the at least two signal amplitudes; under the condition that the target quantity is larger than or equal to a quantity threshold value, determining that the pipeline to be detected is not in a desorption flow fault state; Under the condition that the target quantity is smaller than the quantity threshold value, determining that the pipeline to be detected is in a desorption flow fault state; wherein the amplitude threshold corresponds to the pipeline to be detected and/or the quantity threshold corresponds to the pipeline to be detected.
8. The fault detection method according to any one of claims 1 to 5, wherein the fault detection method further comprises, before extracting a target frequency domain signal of a preset frequency from the pressure time domain signal: Acquiring a pressure value of a pressure time domain signal of the intake manifold; Under the condition that the pressure value is smaller than a pressure threshold value, determining that the at least one desorption pipeline is in a desorption flow fault state, and stopping executing the step of extracting a target frequency domain signal with preset frequency from the pressure time domain signal; And under the condition that the pressure value is greater than or equal to the pressure threshold value, continuing to execute the step of extracting a target frequency domain signal with preset frequency from the pressure time domain signal.
9. The utility model provides a fault detection device, its characterized in that is applied to the vehicle, the vehicle includes engine and carbon tank, the carbon tank through at least one desorption pipeline with the intake manifold of engine is connected, the gas outlet of carbon tank with be provided with the solenoid valve between the at least one desorption pipeline, fault detection device includes: the acquisition module is used for acquiring a pressure time domain signal of the air inlet manifold under the condition that the operation duty ratio of the electromagnetic valve is larger than a duty ratio threshold value; The extraction module is used for extracting a target frequency domain signal with preset frequency from the pressure time domain signal, wherein the preset frequency is the control frequency of the electromagnetic valve; And the determining module is used for determining whether the pipeline to be detected in the at least one desorption pipeline is in a desorption flow fault state according to the signal amplitude of the target frequency domain signal.
10. A vehicle, characterized by comprising: a memory; Processor, and A computer program; wherein the computer program is stored in the memory and configured to be executed by the processor to implement the method of any one of claims 1 to 8.

Description

Fault detection method and device and vehicle Technical Field The present application relates to the field of vehicle technologies, and in particular, to a fault detection method and apparatus, and a vehicle. Background With increasingly stringent global emissions regulations, hybrid vehicles have become an important technological path for achieving energy conservation and emission reduction. The fuel evaporation emission control system needs to ensure that the fuel vapor trapped by the carbon tank can be reliably led into the engine for combustion, so as to avoid leakage pollution. Therefore, effective monitoring of the desorption flow of the carbon tank becomes a key link for meeting the mandatory diagnostic requirements of regulations. At present, the monitoring of the desorption flow of the carbon tank in the industry mainly depends on the addition of a direct flow sensor in a desorption pipeline, however, the direct addition of the sensor can increase hardware cost, further increase later maintenance cost, and is difficult to be widely applied to mass production vehicles. How to reliably detect the desorption flow failure of an engine without adding a sensor for directly collecting the flow becomes a problem to be solved. Disclosure of Invention In order to solve the technical problems, the application provides a fault detection method, a fault detection device and a vehicle, which can improve the timeliness and reliability of desorption flow fault detection on the premise of not increasing hardware cost and maintenance cost. The application provides a fault detection method which is applied to a vehicle, the vehicle comprises an engine and a carbon tank, the carbon tank is connected with an air inlet manifold of the engine through at least one desorption pipeline, an electromagnetic valve is arranged between an air outlet of the carbon tank and the at least one desorption pipeline, the fault detection method comprises the steps of obtaining a pressure time domain signal of the air inlet manifold under the condition that the operation duty ratio of the electromagnetic valve is larger than a duty ratio threshold value, extracting a target frequency domain signal with preset frequency from the pressure time domain signal, wherein the preset frequency is the control frequency of the electromagnetic valve, and determining whether a pipeline to be detected in the at least one desorption pipeline is in a desorption flow fault state according to the signal amplitude of the target frequency domain signal. In some technical schemes of the application, at least one desorption pipeline comprises a low-pressure pipeline and a high-pressure pipeline, wherein the low-pressure pipeline is connected between a carbon tank and an air inlet manifold, the high-pressure pipeline is connected between the carbon tank and an air inlet end of a supercharger, an air outlet end of the supercharger is connected with the air inlet manifold, before a pressure time domain signal of the air inlet manifold is acquired, the fault detection method further comprises the steps of acquiring ambient pressure and air inlet pressure of the air inlet manifold, determining the low-pressure pipeline as a pipeline to be detected under the condition that the air inlet pressure is smaller than the ambient pressure, and determining the high-pressure pipeline as the pipeline to be detected under the condition that the air inlet pressure is larger than or equal to the ambient pressure and smaller than the preset pressure. In some technical schemes of the application, extracting the target frequency domain signal with preset frequency from the pressure time domain signal comprises the steps of performing discrete sine function counting based on the preset frequency and a preset period, determining a sine phase angle, wherein the preset period is an updating period of a discrete Fourier transform sine function counter, determining a cosine phase angle by performing phase offset processing on the sine phase angle, and determining a real component and an imaginary component in complex expression of the target frequency domain signal according to the pressure time domain signal, the sine phase angle and the cosine phase angle. In some technical schemes of the application, determining real component and imaginary component in complex expression according to pressure time domain signal, sine phase angle and cosine phase angle comprises determining imaginary component instantaneous value according to pressure time domain signal and sine function value, and determining real component instantaneous value according to pressure time domain signal and cosine function value, wherein sine function value is a function value determined based on sine phase angle, cosine function value is a function value determined based on cosine phase angle, integrating imaginary component instantaneous value and real component instantaneous value, and obtaining imaginary component a