Match And Optimize Of Bus Powertrain Based On The Driving Cycle Method

Bus, as a fast and efficient transport tool in the city, is also one of the urban airpollution sources. Vehicle and engine plants are facing the dual pressures both fromthe pursuit of energy saving and good vehicle dynamic.The bus driving cycle need to be considered for doing bus power train matching,which has a great influence on the bus emissions and fuel economy;. Under differenttraffic conditions, the performance of vehicle such as power, economy and emissionsare different, due to different driving characteristics. So it is a critical problem toensure engine working area under the fuel economic zone as often as possible whenthe match working do, which can make the engine, has a good expression.City bus usually has a special driving cycle, because it is driven under a givenregion. So first of all, a local bus driving cycle should be built when matchingengine and transmission. Then a lot of surveys such as the speed of vehicle, rotatespeed of the engine and gear using condition are needed to be done for the setting ofdriving cycle.Statistics of vehicle resistance torque and speed in common use should be done,which can also know the engine favorite working zone. If this zone deviate theengine fuel economic area, power train parameters should be adjusted to achieveconsistency.A vehicle model is built in CRUISE and the secondary development ondriving cycle has been done. To verify the model accuracy of vehicle and drivingcycle, fuel economy characters and dynamic are simulated.Associate iSIGHT and CRUISE together for the simulation and optimization,which set gear ratio as design variables and engine power as constraints.Multi-objective genetic algorithm on fuel economy and dynamic is used for the lessfuel.