Technical Paper
Study of OBD stageII Misfire Detection System for Small Motorcycles
2020-01-24
2019-32-0511
In recent years, the shift to Fuel Injection (FI) system for motorcycles has been accelerated in response to the enhancement of exhaust emission regulations and the improvement of fuel efficiency for global environmental protection. In addition, On Board Diagnostics (OBD) was introduced to inform users of vehicle abnormalities and failures and prevent from emission failure in the market. OBD stageII requires enlargement of requirements and threshold detection. Seven items are presented in the EU5, Bharat Stage 6 (BS6). The misfire detection in small motorcycles has several problems. First, for the small motorcycle, a single-cylinder engine is the main and its combustion behavior cannot be compared with other cylinders. Consequently, it is difficult to detect misfire. For misfire detection, we focused on the difference in crank angular velocity during combustion stroke between normal combustion and misfire.