Self-learning method for dpf differential pressure sensor

Abstract

The invention belongs to the technical field of engines and particularly relates to a self-learning method for a DPF differential pressure sensor. The self-learning method for the DPF differential pressure sensor comprises the following steps of detecting the state of an engine and judging whether a vehicle stops or not; continuously and repeatedly acquiring the measured values of the differentialpressure sensor if the vehicle is under a stop condition; averaging the measured values acquired repeatedly; conducting pressure limiting processing on the average value to guarantee that the averagevalue is from the differential pressure upper-limit value to the differential pressure lower-limit value; storing the average value into an EEPROM of the vehicle; and correcting the measured value ofthe differential pressure sensor according to the average value in the traveling process of the vehicle. Through the self-learning method for the DPF differential pressure sensor, a measuring characteristic curve of the differential pressure sensor can be effectively corrected, the measuring precision of the differential pressure sensor is improved, and the traveling safety is improved.

Description

technical field [0001] The invention belongs to the technical field of engines, and in particular relates to a self-learning method for a DPF differential pressure sensor. Background technique [0002] At present, the DPF differential pressure sensor of the Euro VI product is installed in the exhaust gas environment. On the one hand, long-term high-temperature exhaust gas will affect the output of the sensor characteristics. On the other hand, aging or water will appear after a long period of use. The entry of steam, etc. will also cause the zero point of the DPF differential pressure sensor to drift, which will affect the measurement deviation of the DPF differential pressure sensor. When the differential pressure measurement deviates, it will lead to a deviation in the differential pressure carbon load calculated by the DPF. If the measured pressure difference is too large, the calculation of carbon load will be too large, which will lead to frequent regeneration of DPF, ...

AI Technical Summary

Problems solved by technology

[0002] At present, the DPF differential pressure sensor of Euro VI products is installed in the exhaust gas environment. On the one hand, long-term high-temperature exhaust gas will affect the output of the sensor characteristics. On the other hand, aging or water will appear after a long period of use. The entry of steam, etc. will also cause the zero point of the DPF differential pressure sensor to drift, affecting the measurement deviation of the DPF differential pressure sensor

When the differential pressure measurement deviates, it will lead to a deviation in the differential pressure carbon load calculated by the DPF

If the measured pressure difference is too large, the calculation of carbon load will be too large, which will lead to frequent regeneration of DPF, which may increase the fuel consumption of the engine; if the measured pressure difference is too small, the calculation of carbon load will be too small, The carbon load inside the DPF is too large, and there may be a risk of burning the DPF when the DPF is regenerated

At the same time, due to the inaccurate pressure difference measurement, it will bring great difficulty to the relevant diagnosis of DPF, which will lead to false or no error report of DPF diagnosis, which does not meet the requirements of regulations and affects the safety of driving.

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