Evaluation of Fuel Economy and Emissions Reduction for a Motorcycle With Automatic Idling-Stop Device

In an attempt to improve the fuel economy and reduce the exhaust emissions of motorcycles, some manufactures have developed commercialized motorcycles equipped with automatic idling-stop and go (AISG) functionality. Even though research efforts devoted to the idling-stop strategy have demonstrated its effectiveness, motorcycles equipped with the AISG device are not popular because the general public still has some concerns about them. This paper aims to evaluate the benefits and feasibility of a commercialized motorcycle with AISG functionality with regard to the public's concerns about fuel economy and emission problems during engine restart transients. In order to verify the accuracy of the analytical results and control for variable driver characteristics, a motorcycle chassis dynamometer was used to recreate the urban driving pattern. Furthermore, the feasibility of fuel-saving and emissions improvement by adjusting fuel-injection signal of the engine control unit (ECU) during engine restart operation was also evaluated. The experimental results showed that the addition of the fuel-injection modulation plus idling-stop strategy can improve the fuel economy rate by up to 12.2% and reduce carbon monoxide (CO) emission by up to 36.95% in comparison with the non-idling stop case.