Modelling Fuel Cut Off Controller on CNG Engines Using Fuzzy Logic: A Prototype

Abstract

Compressed Natural Gas (CNG) is an alternative solution to the limited availability of fossil energy. CNG use's advantages include high octane value, applicable to vehicles requiring large power, cost-effectiveness, and lower emissions. However, applying the old CNG kit leaves emission problems and fuel wastage during deceleration. Although numerous studies have been carried out with numerous variables to improve engine performance and emissions, reports regarding deceleration interventions are still limited. Therefore, this study proposes enhanced modeling to optimize the fuel cut-off controller by applying fuzzy logic by controlling the throttle valve position based on the input sensor of the engine. Engine dynamics, fuel characteristics, and intake systems are considered strictly in the development of the control system to obtain more precise results that refer to the complete combustion process. The designed model has advantages over previous studies, which focused on achieving CNG AFR stoichiometry to improve fuel economy by using the fuel cut-off method during deceleration. The results showed that fuel savings could be increased during deceleration by cutting off fuel flow to the engine. This can be seen from the increase in AFR ± 57% and decrease ± 38% - 67% in CNG flow rate during deceleration which is promising to be widely applied. In the future, the proposed model could be used as part of the vehicle component in optimizing the fuel consumption that will support green technology sustainability