Simulation test method and device for on-board diagnostics (OBD) function of diesel engine after-treatment system

Abstract

The invention discloses a simulation test method and device for an on-board diagnostics (OBD) function of a diesel engine after-treatment system. Various faults of a selective catalytic reduction (SCR) and diesel particulate filter (DPF) after-treatment system are summarized, fault features are extracted, and a set of virtual instrument-based electronic simulation test system for an OBD fault diagnosis function of the SCR and DPF system is established through the fault features, so that simulation of partial faults of the SCR and DPF system can be realized, and then the rapid test of the OBD fault diagnosis function is completed. In the process of development, acceptance and evaluation of an OBD diagnostic algorithm of the diesel engine after-treatment system, a large number of test verification work and test resources are reduced, and the development progress is improved. In addition, the method and device can well solve the problems that in an actual test environment, certain OBD faults are not easy or impossible to produce, so-called fault injection is supposed to be performed by a hardware-in-the-loop system, and immeasurable damage to a vehicle or an engine can be caused.

Description

technical field [0001] The invention relates to a simulation test method and device for the OBD function of a diesel engine post-processing system, which belongs to the test and development technology of the OBD fault diagnosis function of the heavy-duty diesel vehicle post-processing system. Background technique [0002] On-board diagnostic system (OBD) is an online fault diagnosis system used to control vehicle emissions. It can effectively monitor the over-limit of vehicle emissions caused by aging, component damage or other reasons during the use of the after-treatment system of the vehicle. When a fault occurs, compared with the routine maintenance and regular annual inspection of the vehicle, the OBD system can prompt more quickly so that it can be repaired as soon as possible. The OBD system cannot directly measure the emission value of each pollutant in the exhaust gas, but needs to monitor the components related to the emission, and establish a certain correspondenc...

AI Technical Summary

Problems solved by technology

In the process of development, acceptance and evaluation of the OBD fault diagnosis function of the diesel engine aftertreatment system, a lot of test verification work is required, the workload is huge, and a lot of time is required, which will seriously affect the development progress

If the test verification is carried out on the engine bench or the whole vehicle, it will consume a lot of test resources, require huge manpower, material resources and financial resources, and the development progress will be greatly affected

In addition, in the actual test environment, some faults are not easy or cannot occur, and it is difficult to verify the OBD fault diagnosis function of the post-processing system, which will seriously affect the development progress

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