Week-4 Challenge WOT Condition Part-2

• Hardware-in-the-loop (HIL) engine control design

• Vehicle-level fuel economy and performance simulations

The lookup tables, developed with the Model-Based Calibration Toolbox™, are functions of injected fuel mass, F, engine torque, T, engine speed, N, and engine temperature, Temp_Eng.

Input Command Setting	Input Engine Temperature Parameter Setting	Lookup Tables
Fuel mass	off	ƒ(F,N)
	on	ƒ(F,N,TempEng)
Torque	off	ƒ(T,N)
	on	ƒ(T,N,TempEng)

The block enables you to specify lookup tables for these engine characteristics:

To bound the Mapped CI Engine block output, the block does not extrapolate the lookup table data.

Mapped Motor:-

The Mapped Motor block implements a mapped motor and drive electronics operating in torque-control mode. The output torque tracks the torque reference demand and includes a motor-response and drive-response time constant. Use the block for fast system-level simulations when you do not know detailed motor parameters, for example, for motor power and torque tradeoff studies. The block assumes that the speed fluctuations due to mechanical load do not affect the motor torque tracking.

Dynamic Model:-

The spark ignition engine premixes the fuel with air before admitting the mixture into the cylinder of the device. Various mechanical and electrical system have been developed to carry out this mixing. The fuel mixture is then compressed before being ignited with an electrical spark. In some more complex engines there is a pre-ignition chamber where a fuel-rich mixture is ignited first, with this ignition then spreading into the main cylinder. The precise fuel and the composition of the air–fuel mixture will influence performance parameters such as the efficiency and the level and type of engine emissions.

Compression of SI Mapped & Dynamic Model:-

In mapped model all the data's are assigned by look up table that are insterted by user. The look up table gives the data of velocity, power and the time duration of velocity passed through engine system. It is very short process time condition system and derived with drive cycle.

Flow of power and accleration are intiate with look up table that will in the form of spreadsheet table. Where data's are taken in flow process and results may generated by the lookup table.

DYNAMIC ENGINE

This model works based on engine behaviour and gives the input that will based upon the running conditions of the flow. whereas velocity is rasied or lowerd by the actual conditions and speed of vehicle will varies in obserbtion of engine working system. Time taken for running simulation is too long when compared with mapped engine.

In dynamic model actual torque and fuel flow are adjusted by the engine characterstics condition.

Type		Implementation
Mapped	CiMappedEngine SiMappedEngine	Model uses a set of steady-state lookup tables to characterize engine performance. The tables provide overall enginecharacteristics, including actual torque, fuel flow rate, BSFC, and engine-out exhaust emissions.
Dynamic	CiEngine SiEngine	Model decomposes the engine behavior into engine characteristics that are separated into lower-level components. By combining components in this way, the models capture the dynamic effects.

SI MAPPED ENGINE:-

OUTPUT PLOTS

PROCEDURE FOR CHANGE THE MODEL TYPE:-

METHOD-1

In HEV vehicle model there should be a two type of engine, motor and generator set up are defined and they are mapped and dynamic. The mapped test is data created by the own excel sheet data or drive cycle data.

Time taken for mapped test is so less than time taken for dynamic test so the mapped engine are used for drive cycle flow of process.

Here the model can be changed by either mapped or dynamic condition. By changing the model into mapped to dynamic there are two methods are followed,

In method 1- we want to change the engine system as mapped SI Engine to dynamic (SI Engine).Select the SI engine (dynamic) and and click model explorer to open the file of model explorer dialogbox.

Model explorer dialogbox is opened and various data's are present in that dilaogbox . Block data types are present in that table and engine setup are also mentioned in that table.

Now the engine model is changed as SI Engine from the Mapped SI engine and simluation should be run to plot output values of velocity, motor, torque, battery capacity , state of charge,(SOC) and fuel consumption.

METHOD-2

In Method-2 the engine system are changed from mapped SI engine to Dynamic SI engine by right click the engine system that you want to change the model and various options are shown in that box.

Select the subsystem and model reference option the three option will shown in that option. click convert to option and select variant subsystem. That sholud be explained through screenshot are given below-

Now variant subsysytem is selected in main menu and click variant Manager that is shown below-

Variable manager dialog box is opened and some data's are appeared in that table, the different models are also shown in that dialogbox right click the model which you want to change. Now click set as label model active choice and the model will be change by SI engine (dynamic). That dialogbox is shown below-

Now the engine model is changed as SI Engine from the Mapped SI engine and simluation should be run to plot output values of velocity, motor, torque, battery capacity , state of charge, (SOC) and fuel consumption.

Motor:-

By changing the motor from mapped to dynamic the same methods are followed as, by the changing engine system of mapped to dynmaic. Two methods are acting on changing the mapped to SI motor that are explained in enigne systems.

Generator:-

Same process of changing the motor from mapped to dynamic is also followed for generator system. Two methods are acting on changing the mapped to SI generator that are explained in enigne systems.

CASE-2:-

2. How does the model calculate miles per gallon? Which factors are considered to model fuel flow?

Fuel efficiency is a form of thermal efficiency, meaning the ratio from effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile.

Fuel consumption is a more accurate measure of a vehicle's performance because it is a linear relationship while fuel economy leads to distortions in efficiency improvements.

Explanation:-

In this model the fuel consumption are calculated in miles per gallon through performance calculation block in visualization. That performance calculations block are shown as below-

The performance calculations block calculate the mileage and consumption of fuel taken in distance. That can be calculated by three characterstics they are given below-

• Vehicle speed
• Fuel Volume Flow
• Battery Power

Battery Power:-

In first step the battery power unit is converted from W to KW by dividing 1000 and output values are obtained. That output of power KW is now converted into KW/h to US EPA(standard) by dividing with the value of 33.7. The output values from the KW/h is coverted into second by dividing the value with 3600.

Therefore output value are obtained as kws/USgal. And that value is converted for volume of fuel flow so that output is multiplied by 0.00378541 as the result of m^3 per gal is obtained.

Fuel Volume Flow:-

By adding the two inputs of 0.00378541 and the value of fuel volume flow the output is obtained. And that output is integrated through integration block for getting an m^3. The ouput is now converted into Litre for calculate the fuel consumption of vehicle.

Vehicle Speed:-

Vehicle acceleration speed is also depends the fuel consumption and to calculate mileage per distance . The input of vehicle speed is splited by two equvalent values and product the values and again take square root of values from the output of product that will gives the same answer. But the only way to negelecting the negative terminals this step is followed.

Now integrate that output values and results will be in meter(m). To convert the m to km for distance 100. 1/1000/100 is proceed by conversion of distance. The output values are now entered in the saturation block for intitate the lower limit value of distance during the acceleration.

The output value of fuelvol flow and vehicle speed is now multiplied and dividing in the other same block where the results gives L/100km calc.An output shows the mileage for distance of 100km.

Conversion In Miles Per Gallon:-

The Same process is followed for the US gal also but after finding the m^3 in the fuelvolflow the m^3 will changed into US gal by product of the value 264.172 and saturation block is intitate to lower limit of distance during acceleration. In vehicle speed derivation also changed after the integration of speed as m. To convert the unit as m to mile by product the value of 0.000621371.

Then after converting the units an output value of fuelvol flow and vehicle speed is now multiplied and dividing in the other same block where the results gives US MPG CALC. That shows the vehicle miles per gallon in US standard.That flowdiagram is shown below-

Model Fuel Flow:-

Fuel flow plot is obtained from the vehicle engine system by clicking the engine setup there are many flow is opened by that dialogbox and plot the graph which observation is needed.

In this flow the fuel mass flow is intiated with the form of lookup table , Engine speed (RPM) and Torque (Nm) is noticed during the flow of fuel that will accelerates the vehicle.

Here the engine speed is rasied by the flow of fuel it will also increased the torque so that distance travel of vehicle is raised during the fuel flow. The velocity of vehicle is increased or decreased by the accleration of vehicle.

Battery Flow:-

Battery flow represents the power transmission from the battery to motor and that flow of power will increase the vehicle speed and distance travel of vehicle. Certain amount of cell is filled in battery that will based on the capacity of battery power.

It will transmit the power upto the capacity of battery and it will drained after energy level of battery. Recharging conditions are done during the deacceleration of vehicle.

CASE-3:-

3. Run the HEV ReferenceApplication with WOT drive cycle. Change the grade and wind velocity in the environment block. Comment on the results.

By Taking the HEV model reference the model is opened and drive cycle is changed as WOT that flow diagram are given below-

The results of the WOT drive cycle are derived by individual plots that are shown as-

PLOT-1 (TRACE VELOCITY, TARGET ACTUAL mph)

In this plot the velocity is raised by the torque for certain limit of speed and power is transformed by accleration force. The maximum velocity attain by the vehicle through plot is 60mph.

Then speed of vehicle is driven in constant speed. when deacceleration is acted the SOC is raised by recharging an battery.

PLOT-2 (ENGINE SPEED, MOTOR SPEED)

Here the plot initiate speed of motor and engine speed by RPM. The supply of power from the battery is observed and distributed by control system that power is generated to the motor.

The maximum speed of the motor is intiate in this plot.

PLOT-3 (ENGINE TORQUE, MOTOR TORQUE)

This plots shows the engine torque, motor torque and the generator torque of vehicle. The raise of velocity in vehicle at initial stage is driven by this supply of torque.

Velocity range to attain the maximum torque is applied for this system . An battery supplies the power to motor and that conversion of energy is transmitted into torque.

PLOT-4 (BATTERY CURRENT(A))

A battery capacity of the vehicle is varied depends upon the drive cycle of engine system. In this plot shows that the engine starts and battery power is also generated so graph points are increased in intital point.

The torque is produced by battery so the level of power transmission is high in that state when it reaches maximum velocity limit it will interchange the engine system and battery becomes low on that stateflow. when the gear shifted is happen the torque will raise again so that portion power transmission become high.

PLOT-5 (BATTERY SOC)

The State Of Charge refers to the recharging condition of battery during an deacceleration process. Here the plot shows that same system battery flow is rasied while supplying the power and it will low by insufficient power when it raise again during the deacceleration process.

PLOT-6 ( FUEL ECONOMY)

This plot shows the fuel consumption of vehicle per distance. This calculates the mileage of vehicle during the acceleration of vehicle.

CHANGE IN GRADE AND WIND VELOCITY IN THE ENVIRONMENT BLOCK:-

In this condition the grade is denoted as 10 and the wind velocity is denoted as 30 in environment block that changes are shown as given below-

Reslt:-

• By changing the grade and wind values in the default model some changes are obtained in results they are shown as below-
• plot-1:- In the plot 1 the torque of vehicle to obtain the velocity will be low when compared to default model velocity. The maximum speed obtain in this state condition is 50mph.
• Plot-2:- In this plot engine speed and motor speed are getting high compared with the default model because the grade value is denoted and that gradeability of vehicle is obtained. To archive the speed the motor will take more power to run the generator.
• Plot-3:- Torque is raised in this system due to wind energy is applied in this model so frictional force will get more pressure by this condition hence torque of vehicle is more than comparing with default model.
• Plot-4:- Battery current supply is also high by giving the more power to torque the battery power is transmitted to torque and that should be passed to genertator. some times the generator is acting as recharging system of battery
• Plot-5:- State of charge is not possible in the intial state by the continous acceleration of vehicle and raise in torque the SOC is not acting for some point when the slope portion is obtained and torque will reduce then constant power will acted that portion state of charge will acting.
• Plot-6:- Fuel economy is very high in this drive condition due to the wind and gradeability. The torque is gradually increased so that fuel consumption is also became high.

CASE-4:-

4. Keeping all other parameters same, compare the simulated results of hybrid and pure electric powertrains.

Hybrid Electric Vehicle

The Hybrid Electric vehicle the initial torque is obtained from the battery for the certain speed limit and it will interchange into IC engine after attains the limited speed.

In hybrid vehicle velocity reaches the maximum level in short duration of time. By increasing the torque using the battery, the recharging process of battery is done during de-accleration.

This model shows that parallel conditions is applied in hybrid vehicle and the transformation of power is acted by battery. During the IC engine power generation process to vehicle the motor acts as a generator for battery.

Result:-

PURE ELECTRIC POWERTRAIN:

The electric vehicle reference application represents a full electric vehicle model with a motor-generator, battery, direct-drive transmission, and associated powertrain control algorithms. Use the electric vehicle reference application for powertrain matching analysis and component selection, control and diagnostic algorithm design, and hardware-in-the-loop (HIL) testing.

Result:-

CONCLUSION:-

COMPARISON OF HYBRID WITH PURE ELECTRIC POWERTRAIN:-

• The drivetrain loss for EV vehicle is more than the HEV vehicle. Whereas the power loss in EV vehicle is less than that of HEV vehicle.
• Therefore the EV vehicle is more efficient than the HEV vehicle because an battery used for Electric vehicle is Lithium ion which has low discharge rate than the battery used for HEV Nickel metal hybrid battery
• In hybrid vehicle the emission is obtained and the fuel consumption rate is high. whereas the Electric Vehicle release the 0% of emission this will grade as suitable for environmental condition.
• Therefore all simulations are done and models are extracted for comparing the HEV and EV.