Project 1
Title
Project 1 deals with the development of a forward energy-based fuel consumption model of a conventional vehicle.
Aim:
1] Build a Simulink model using blocks and complete the vehicle model.
23 Writing scripts in MATLAB to load all the variables required for running the Simulink model.
3] Tabulate the fuel economy numbers (kmpl) for UDDS and HWFET cycles.
4] Plot the time trace for the engine. transmission input, transmission output, and wheel speed on one plot.
5] Plot engine torque and engine power. fuel rate and fuel consumption using subplots.
6] Plot accelerator and brake pedal, gear command, vehicle desired and actual speed, and vehicle distance using subplots
7] Plot the engine operating points on the engine fuel map.
8) Generate the plots for both drive cycles
9] Study of Conventional vehicle Simulink model and creates graphs.
Conventional Vehicle:
Conventional vehicles use an internal combustion engine fueled by gasoline or diesel to power the wheels, in this the heat engine uses the principle of heat release through the combustion of a fuel with an oxidizer in a combustion chamber to create expanding gases that push against a piston creating force and torque output.
In this vehicle, the engine converts chemical energy stored in the fuel into heat which is used to produce useful work. Typically use fossil fuels like petroleum (petrol and diesel).
The most popular type of engine used in this system is 4 strokes reciprocating engine. The engine in-cylinder process can be represented by ideal thermodynamic cycles such as the Otto cycle and the Diesel cycle. Otto cycle is an ideal cycle that describes the cycle process for a spark-ignited SI engine, and the Diesel cycle is the ideal cycle that describes the cycle process for a compression ignited Cl engine
Energy and performance of the vehicle
In this system, the power demand on the wheel needs to be instantly supplied by the powertrain. In another word the power coming from the powertrain dictates the power demand on the wheels (as per performance viz, acceleration, speed, etc is determined by it
Conventional powertrain efficiency:
The engine generates power by converting chemical energy stored into mechanical energy through the process of combustion. This process of energy conversion also has efficiency and the energy input is in the form of fuel consumption.
- Instantaneous fuel consumption is given as
It deals with the modeling of multi-domain systems through the use of a unified approach based on an ordinary differential and algebraic equation describing the static and dynamic effects.
Each system has are two generalized variables
1] Efforts:- It is a generalized force variable, ex- torque, force, voltage, heating value.
2] Flow:- It is the generalized flow/velocity variable. ex:- velocity, current, mass flow rate.
MATLAB scripts:
Used to load all the variables required for running the Simulink model and for post-processing. The drive cycle selection is also done here. Before running the Simulink vehicle model, run this initialization script.
ts see Simulink model of a conventional vehicle,
1.9L ADVISOR database developed by NREL, USA. The transmission shift map and controller took Matlab/Simulink example database.
developed capability to simulate the vehicle's different cycles like HWFET, FTP, etc.
"Project1_InitFile.m" Matlab variables required Simulink post-processing. cycle selection is also done here. Before running the Simulink vehicle model, this initialization script
DRIVER MODEl:
scope result:
CONTROLLER
The 'Controller' block is the brain of the vehicle, representing the electronic controls units. It is based on the driver inputs, it generates desired engine torque, desired transmission gear, and desired brake torque. These inputs are fed to the 'Powertrain' block which represents the drivetrain of the vehicle.
ENGINE CONTROLER UNIT:
Transmission Control Unit
In this unit, we create a steady flow variable state for controlling of gears of the vehicle in ascending and descending order with respect to time, speed, distance, and is
SHIFT LOGIC:
ideal speed controller
BRAKE CONTROL UNIT:
SCOPE RESULTS FROM CONTROLLER:
3] PowerTrain:
The powertrain encompasses every component that converts the engine's power into movement. This includes the engine, transmission, the driveshaft, differentials, axles; basically anything from the engine through to the rotating wheels.
n this model we used the map-based model to model the fuel consumption of the engine. It is based on maximum Torque and minimum torque from the controller, and then it saturated torque and gives output then saturated torque and speed map give fuel consumption takes the speed and torque then the output goes into saturated than its integrated.
In these models, we take engine torque, and gear selector from the controller for transmission of gear ratio. The ratio is multiplied by transmission input torque and then the transmission efficiency positive torque and negative torque give transmission input speed. In this case, the torque converter connects the engine to the transmission it is part of the transmission. It basically engines dynamics and that is decoupled.
ENGINE:
scope:
TRANSMISSION:
SCOPE RESULTS:
Differential
In this taking input is the transmission output than it's going to the differential ratio multiplied by the output and input torque then meet axle torque. The axle torque is lower than the transmission torque and the differential ratio.
In this model, we take the axle torque from the differential and brake torque from the controller, it is subtracted and multiplied by rolling radius and velocity then we meet the tractive force from the axle and brake torque, and the wheel speed is met using velocity.
WHEELS:
scope
vehicle dynamics:
scope:
FOR UDDS cycle:
a. Time Vs Speed: In this, the speed is increasing continuously.
Aerodynamic Drag: Drag increase when the power increase.
c. Rolling resistance: It also increases when power is increased wrt time
d. Total Power = aerodynamics drag + rolling resistance + inertial resistance
CONCLUSION: The increase in Power causes an increase in the forces with respect to time (Drag force, Rolling resistance, Total power)
2. HWFET Drive Cycle:
a. Time vs Speed: Speed is continuously increasing wrt time.
b. Aerodynamic Drag: Drag increases when the power increase
c. Rolling Resistance: Resistance decreases wrt time.
d. Total Power = Aerodynamic Drag + Rolling Resistance + Inertial Resistance
CONCLUSION:
By comparing both decisions we use the UDDS cycle for better fuel consumption and the emission of a vehicle is a better way.
Now for creating Plots we use MATLAB closing will give down:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Skill-Lync -> Hybrid Drives Development
% Project 1 - Conventional Vehicle Model
% By - Harshavardhana G
% Description:
% The following file is to use with the Initialization file and Simulink
% results for post-processing of the data.
% The file is incomplete has some examples of how the data is imported
% into a readable format, data analysis and plotting examples.
% Based on the project task, use commands in a similar format as given
% below, to analyse the data and generate required plots.
% You can change variable names if desired
%% Post-Processing File
% File for post-processing the Conventional vehicle simulation model data
%% Renaming variables
Time = out.tout;
Acc_Pdl = out.Acc_Pdl; % % Accelerator pedal [%]
Brk_Pdl = out.Brk_Pdl; % % Brake pedal [%]
Gear_Cmd = out.Gear_Cmd; % % Transmission gear
Trans_In_Spd = out.Trans_In_Spd*30/pi; % % Transmission input speed [rpm]
Trans_Out_Spd = out.Trans_Out_Spd*30/pi; % % Transmission output speed [rpm]
Eng_Trq = out.Eng_Trq; % % Engine brake torque [Nm]
Eng_Spd = out.Eng_Spd*30/pi; % % Engine speed [rpm]
Eng_Fuel_Consump = out.Eng_Fuel_Consumption; % Engine fuel consumption [g]
Veh_Dist = out.Veh_Dist/1000; % % Distance traveled by vehicle [km]
Veh_Spd = out.Veh_Spd*18/5; % % Vehicle speed [kmph]
Wheel_Spd = out.WheelSpd; % % Wheel Speed [kmph]
Velocity = out.Velocity; % % Velocity in [m/s]
Eng_Fuel_Rate = out.Eng_Fuel_Rate; % Engine Fuel Rate
%% Data Analysis
Eng_Pwr = Eng_Spd*pi/30*Eng_Trq/1000; % Engine brake power [kW]
rho_petrol = 0.7197; % Density of petrol [kg/L]
kmpl = Veh_Dist(end)/(Eng_Fuel_Consump(end)/1000/rho_petrol); % Fuel economy [kmpl]
Wheel_spd = Wheel_Spd.Data(:,1);
%% Plotting vehicle characteristics Trans Input & Output Speed and Wheel Speed wrt Time
figure ('Name','Trans Input & Output Speed and Wheel Speed wrt Time')
hold on
grid on
plot (Time, Trans_In_Spd, 'linewidth', 1, 'color', 'black');
plot (Time, Trans_Out_Spd, 'linewidth', 1, 'color', 'red');
plot (Time,Wheel_spd, 'linewidth', 1, 'color', 'blue');
ylabel('Speed [rpm]');
xlabel('Time [sec]');
xlim([0, Time(end)]);
ylim([0, 5000]);
legend('Trans Input','trans Output','Wheel Speed');
title('Trans Input & Output Speed and Wheel Speed wrt Time');
%% plotting vehicle characteristics time trace to Engine speed, Engine Torque, Engine power, and Engine Fuel Rate, Engine Fuel Consumption
% Data Conversion from Double Timeseries
Eng_spd = Eng_Spd.Data(:,1); % Engine Speed
Eng_trq = Eng_Trq.Data(:,1); % Engine Torque
Eng_pwr = Eng_Pwr.Data(:,1); % Engine Power
Eng_fuel_consumption = Eng_Fuel_Consump.Data(:,1); % Engine Fuel Consumption
Eng_fuel_rate = Eng_Fuel_Rate.Data(:,1); % Engine Fuel Rate
Veh_dist = Veh_Dist.Data(:,1); % Vehicle Distance
Veh_spd = Veh_Spd.Data(:,1); % Vehicle Speed
% Plotting Engine speed, Engine Torque and Engine power
figure ('Name','Engine speed, Engine Torque and Engine power')
subplot(3,1,1)
plot(Time,Eng_spd,'linewidth',1,'color','yellow');
xlabel('Time [sec]');
ylabel('Speed [kmph]');
legend('Engine Speed');
title('Speed wrt Time');
grid on
subplot(3,1,2)
plot(Time,Eng_trq,'linewidth',1,'color','black');
xlabel('Time [sec]');
ylabel('Torque [Nm]');
legend('Engine Torque');
title('Torque wrt Time');
grid on
subplot(3,1,3)
plot(Time,Eng_pwr,'linewidth',1,'color','blue');
xlabel('Time [sec]');
ylabel('Power [kW]');
legend('Engine Power');
title('Power wrt Time');
grid on
% Plotting Engine Fuel Rate and Engine Fuel Consumption
figure('Name','Engine Fuel Rate and Engine Fuel Consumption')
subplot(2,1,1)
plot(Time,Eng_fuel_rate,'linewidth',1,'color','green');
xlabel('Time [sec]');
ylabel('Fuel Rate [%]');
legend('Engine Fuel Rate');
title('Fuel Rate wrt Time');
grid on
subplot(2,1,2)
plot(Time,Eng_fuel_consumption,'linewidth',1,'color','red');
xlabel('Time [sec]');
ylabel('Fuel Consumption');
legend('Engine Fuel Consumption');
title('Fuel Consumption wrt Time');
grid on
%% Plotting Fuel Economy Vs Engine Fuel Consumption
figure('Name','Engine Fuel Economy vs Engine Fuel Consumption')
plot(Eng_fuel_rate, Eng_fuel_consumption,'linewidth',1,'color','black');
ylabel('Fuel Consumption');
xlabel('Fuel Rate [%]');
legend('Fuel Economy vs Fuel Consumption');
title('Engine Fuel Economy vs Engine Fuel Consumption');
grid on
%% Plotting vehicle characteristics of Acc. & Brake Pedal, Trans Input & Output Speed and Gear Command wrt Time
figure ('Name','Acc. & Brake Pedal, Trans Input & Output Speed and Gear Command wrt Time')
subplot(3,1,1)
hold on
plot(Time, Acc_Pdl, 'linewidth', 1, 'Color', 'black');
plot(Time, Brk_Pdl, 'linewidth', 1, 'Color', 'red');
ylabel('Pedal [%]')
xlim([0, Time(end)]);
legend('Accel','Brake');
title('Acceleration & Brake Pedal wrt Time');
grid on
subplot(3,1,2)
hold on
plot(Time, Trans_In_Spd, 'linewidth', 1, 'Color', 'black');
plot(Time, Trans_Out_Spd, 'linewidth', 1, 'Color', 'red');
ylabel('Speed [rpm]')
xlim([0, Time(end)]);
ylim([0, 6000]);
legend('Trans Input','Trans Output');
title('Trans Input and Output Speed wrt Time');
grid on
subplot(3,1,3)
plot(Time, Gear_Cmd, 'linewidth', 1, 'Color', 'black');
xlim([0, Time(end)]);
xlabel('Time [s]');
ylabel('Gear');
title('Gear Command wrt Time');
grid on
%% Plotting gear command vehicle distance with actual speed
figure ('Name','Vehicle distance and Actual speed wrt Gear Command')
subplot(2,1,1)
plot(Veh_spd,Gear_Cmd,'linewidth',1,'color','black');
xlabel('Speed [rpm]')
ylabel('Gear')
title('Gear Command wrt Vehicle Speed')
grid on
subplot(2,1,2)
plot(Veh_dist,Gear_Cmd,'linewidth',1,'color','blue');
xlabel('Distance [km]')
ylabel('Gear')
title('Gear Command wrt Distance')
grid on
%% Plotting engine operating points on engine fuel map
figure('Name','Engine Operating Points');
hold on
grid on
title('Engine Operating Points','fontsize',12);
p1=plot(Eng_map_spd*30/pi,Eng_max_trq,'linewidth',2,'color','r');
p2=line([Eng_map_spd(end)*30/pi Eng_map_spd(end)*30/pi],[0 Eng_max_trq(end)]);
set(p2,'linewidth',1,'linestyle','--','color','k');
p3=line([Eng_map_spd(1)*30/pi Eng_map_spd(1)*30/pi],[0 Eng_max_trq(1)]);
set(p3,'linewidth',1,'linestyle','--','color','k');
xlabel('Engine Speed [rpm]');
ylabel('Engine Torque [Nm]');
legend([p1 p3],{'Max Curve','Operating Points'});
axis([Eng_map_spd(1)*30/pi Eng_map_spd(end)*30/pi 0 Eng_map_trq(end)]);
figure('Name','Fuel Consumption Map');
hold on
grid on
p1=plot(Eng_map_spd*30/pi,Eng_max_trq,'linewidth',2,'color','r');
p2=line([Eng_map_spd(end)*30/pi Eng_map_spd(end)*30/pi],[0 Eng_max_trq(end)]);
set(p2,'linewidth',1,'linestyle','--','color','k');
p3=line([Eng_map_spd(1)*30/pi Eng_map_spd(1)*30/pi],[0 Eng_max_trq(1)]);
set(p3,'linewidth',1,'linestyle','--','color','k');
[c,h] = contour(Eng_map_spd'*30/pi,Eng_map_trq,Eng_fuel_map');
clabel(c,h);
xlabel('Engine Speed [rpm]');
ylabel('Engine Torque [Nm]');
title('Engine Fuel Consumption Map [g/s]');
legend([p1 p3],{'Max Curve','Operating Points'});
axis([Eng_map_spd(1)*30/pi Eng_map_spd(end)*30/pi 0 Eng_map_trq(end)]);
UDDS Cycle:
1) Plotting vehicle characteristics time trace transmission IN/OUT and Wheel Speed:
In this graph, transmission input and output will fluctuate up and down with increasing speed and time.
Plotting vehicle characteristics time trace to Engine speed, Engine Torque, and Engine Power:
Plotting vehicle characteristics for Engine Fuel Economy vs Engine Fuel Consumption.
In this, the engine fuel consumption is suddenly increasing as increasing fuel economy but if fuel economy is constant then the fuel consumption is also constant.
Plotting vehicle characteristics time trace Acceleration & Brake Pedal, Transmission IN/OUT Speed and Gear Command wrt Time:
Plotting vehicle characteristics for Engine Fuel Consumption Map:
HWFET CYCLE
Plotting vehicle characteristics for Engine Fuel Consumption Map:
CONCLUSION: The plotting of different cycle parameters using Simulink model