Vehicle fuel leakage detection method and detection system thereof

Abstract

The invention discloses a vehicle fuel leakage detection method and a detection system thereof. According to the detection method, the temperature T in an oil tank, the pressure P of a system, the fuel level V, the fuel RVP, the altitude information H and travelled distance S output by a vehicle control unit are input into a calibration function, namely D=f (V, P, T, RVP)+epsilon, so that a functional relation, namely D=f (T, P, V, RVP)+alphaS+betaH of the radius D of a leaking hole is obtained; and the functional relation of the radius D of the leaking hole is stored in an electric control unit (ECU), and therefore the vehicle fuel leakage is detected according to the functional relation of the radius D of the leaking hole by detecting the data of T, P, V, RVP, and D in real time. According to the leak detection method and the detection system thereof, both the influence of the temperature T in the oil tank, the pressure P of the system and an oil level V and the influence of the fuelRVP, the altitude information H and the travelled distance S are taken into account, so that the leakage detection precision is improved.

Description

technical field [0001] The invention belongs to the technical field of vehicle fuel evaporation leakage detection, and in particular relates to a vehicle fuel leakage detection method and a detection system thereof. Background technique [0002] There are three major sources of pollutants emitted by automobiles, namely exhaust gas, crankcase and fuel evaporation. Among them, the main component of fuel evaporative emissions is HC. In the face of increasingly severe environmental pressure, in order to prevent the pollution of fuel vapor to the atmosphere, GB18352.6-2016 (National VI regulations) have made more stringent regulations on evaporative emissions, and introduced the requirements for fuel evaporation system diagnosis. For traditional vehicles, the detection of the natural cooling process of the fuel evaporation system after the engine is turned off is low in cost but not high in accuracy; [0003] In the prior art, there is a device and method for fuel tank leakage d...

AI Technical Summary

Problems solved by technology

However, there are many factors affecting the pressure in the fuel tank, such as temperature, oil level and fuel RVP, etc., and the leakage of the fuel tank cannot be accurately judged only by the pressure change; the US patent proposes a leak detection method that combines the pressurization method and the decompression method , this method first measures the pressure change caused by the reference hole, and then measures the pressure change caused by the leak hole of the fuel tank, and judges the size of the leak hole by comparing the two measured pressures. The leak hole always exists, that is, the total gas outlet size in the system in this state is not the size of the reference hole, so the accuracy of the leak hole measured by this method is low, and it can only be judged whether the size of the leak hole is greater than 0.5mm or less than 0.5mm mm;

[0004] There is another system and method for leak detection of a fuel evaporation system, including a calibration reference system and a leak detection system. The method obtains a specific function through calibration data fitting, and calculates the Get the specific size of the leak hole, but there is still the problem of low fitting accuracy

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