Method and device for correcting measured value of DPF differential pressure sensor and storage medium

[0033]Because the DPF differential pressure sensor works in a high temperature environment for a long time, the aging of the sensor itself and the accumulation of water in the gas intake pipe of the sensor will affect the output of the sensor, causing the measurement value of the differential pressure sensor to drift and increase the measurement error. If the measured value of differential pressure is too large, the estimated value of carbon load will be too large, resulting in frequent regeneration of DPF and increased fuel consumption; if the measured value of differential pressure is too small, the estimated value of carbon load will be small, and the The actual value of the carbon load is larger than the estimated value, and the DPF may be at risk of burning due to excessive carbon loading during regeneration. At the same time, due to the drift of the measured value of the differential pressure sensor, it brings great difficulty to the related diagnosis of DPF (overload, fi...

[0044] The embodiment of the present invention introduces a method for correcting the measured value of a DPF differential pressure sensor, such as figure 2 As shown, the specific steps of the correction method are as follows.

[0045] S1. Obtain the measured value of the current differential pressure sensor and the current average temperature of the DPF.

[0046] S2. Obtain the basic value of differential pressure correction from the correction model according to the current average temperature of the DPF, where the correction model is a function related to the average temperature of the DPF and the basic value of differential pressure correction.

[0047] S4. Obtain the carbon loading of the DPF, and obtain a correction coefficient according to the carbon loading of the DPF.

[0048] S5. Multiply the basic value of the differential pressure correction and the correction coefficient to obtain the differential pressure correction value;

[0049] S6. The current measured val...

[0054] like image 3 As shown, the embodiment of the present invention introduces the method for obtaining the correction model in the first embodiment or the second embodiment, and realizes the self-learning and updating of the correction model, and the specific steps are as follows.

[0055] S21. Detect whether the engine speed is zero.

[0056] When it is detected that the engine speed is zero, the detection operation is stopped, and step S22 is executed.

[0057] If the detected engine speed is not zero, it does not act, and continues to detect the engine speed.

[0058] The detection action in this step is generally to perform detection after the vehicle is stopped and turned off, which can reduce the frequency of detection.

[0059] S22, record the measured value of the differential pressure sensor and the average temperature of the DPF.

[0060] Generally speaking, the engine speed is detected after each stop. When the engine speed is detected to be zero for the firs...