Research On Engine Speed Control Methods For Extended-range Electric Vehicles

With the dramatic increase in the number of cars, the environmental pollutionissues brought by automotives can’t be ignored anymore.In the process of designingand developing for automotives, improving fuel efficiency and reducing pollutionemissions are the primary considerations.As we know, conventional fossil-fuelledautomotives have only one energy source, in the different road conditions, theautomotives have to work in the different operating points. Due to the intrinsiccharacteristics of engine, it has lower efficiency and higher emissions when it workunder the condition of low motion or small load. In the view of the limitation ofconventional fossil-fueled vehicles, this paper focuses on the speed control problem ofthe internal-combustion-engine(ICE) systems for the extended-range electricvehicles(E-REV).Extended-range electric vehicles have two operating modes: electric-only modeand extended-range mode. An E-REV can shut down the ICE during the electric-onlymode in which the batteries power the electric motors which drive the vehicles so thatthe E-REV can achieve zero-emission. For meeting the requirements of high-speeddriving and long endurance, the extended-range mode is proposed. In this mode,ICEis started and offers the kinetic energy for generator which powers the electric motorto drive the vehicle. E-REV achieves higher fuel economy than conventional vehicledue to the capability of recovering energy during braking, what’s more an HEV canavoid low-efficiency operating points of the ICE by first storing excess power in thebatteries. The performance of E-REV can satisfies people’s demand in the urban. Thepower split is to be made during vehicle operation comprises a new control task, whichis often referred to as the energy management problem which can optimize theefficiency and emissions of ICE.To design the engine speed control strategies accurately, in the second chapter webuid the engine mathematical model for speed controlling on the basis of acknowledgethe engine operation.Then the simulation models are built under the environment ofMatlab/simulink. For verifying the accuracy of the model, we set the model parametersbased on a6-cylinder4-stroke spark ignition engine model in the enDYNA, thencompare the model with the model in the in enDYNA. enDYNA model consists of fourmodules, namely the Engine, MOTION, Cooling Basic and ECU. enDYNA is acomplete engine model based on the practical physical model and some of the engineruntime map data which offers real-time simulations model for developing the controlsystems of engines. What’s more enDYNA offers numerical simulations in Matlabwhich is convenient for developing the algorithm of engine control an ECU. EnDYNA has a high global recognition and reliability in the automotive field.Based on the model has been built above,in the third we design the fuzzy PIDcontroller and then show the simulation results and analysis. However the controlperformance is not well when the load torque changes. After adding the fuzzy controllerbefore the PID controller, the three parameters of PID can be adjusted real time.Thefuzzy PID controller has a better performance comparing with PID controller.In theforth section,we propose model prediction controller to adjust throttle angleautomatically so that the engine speed can track the expectations. In the different workconditions, comprehensive analysis are given to compare the advantages anddisadvantages of the two control methods.