Research On Control Method Of LPG Gas-electric Hybrid Bus Powertrain For Emission Performance

Hybrid electric bus, has become a hot spot of new energy vehicles in China. Inrecentyears, one of the most popular research directions is improving the control method ofpwertrainto increase vehicle performance. But the emission performance of current LPGhybrid electric bus, short as LPGHEB, can hardly meet the emission standards.Thispaperstudies the LPGHEB’s powertrain control method faced to reduce emission. So thisresearch has great significant.First of all, this paper introduced the problem that the present LPGHEB’s poor emissio nperformance and the research status about LPGHEB indomestic and foreign. Secondly,through theoretical and experimental methods, the present LPGHEB control method wasanalyzed and finded the short comings in terms of emissions. Then the rule between emissionand working condition of LPG engine was studied. Based on the rule, a control method,LPGHEB Powertrain Control Method based on Emission, short as LPCME, was designed.This control method consists of two parts. The first part is torque distribution control strategybased on Adaptive Fuzzy Inference System, short as ANFIS. The second part is PID control ofengine torque based on neural network. LPCME can reasonably allocate the engine and ISGmotor’s output torque, and overcome the problems of the engine torque control. Thirdly,According to the present LPGHEB’s powertrain structure, LPGHEB vehicle dynamicssimulation model was built. Based on the modle, computer simulation is carried out. Theresult shows that compared with the original LPGHEB’s control methods, ANFNP controlmethod can make LPGHEB’s CO emissions fell by 35.2%, NOx emissions fell by 41.0%, HCemissions fell by 29.3% in city working station. At last, the hardware in loop simulationplatform of the LPGHEB powertrain control system was developed based on the NationalInstruments.In conclusion, the paper through simulation and experiments to test the ANFNP controlmethod, conformed that this method could improve the emission performance of the LPGhybrid electric bus.