Project 1
AIM:
To deal with the development of a forward energy-based fuel consumption model of a conventional vehicle.
DESCRIPTION:
It is the Simulink model of the vehicle. It is modeled using a ‘Driver’ block, which is a basic PI controller that generates accelerator and brake pedal outputs to match the desired
and actual vehicle speeds. The ‘Controller’ block is the brains of the vehicle, representing the electronic controls units. 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. It consists of an ‘Engine’ connected to the ‘Automatic Transmission’ through a ‘Torque
Converter’. The output of the transmission is connected to the ’Differential’, which powers the ‘Wheels’, which provides the tractive force for vehicle acceleration. The longitudinal dynamics of the vehicle along with the road load are represented in the ‘Vehicle Dynamics’ block. The solver selected is ode3 with a fixed step size of 0.01 sec.
PROCEDURE:
a. Tabulate the fuel economy numbers (kmpl) for UDDS and HWFET cycle. This forms the baseline numbers for comparing with the future hybrid version.
b. Plot the time trace for engine, transmission input, transmission output and wheel speed on one plot.
c. Plot engine torque, engine power, fuel rate and fuel consumption using subplots.
d. Plot accelerator and brake pedal, gear command, vehicle desired and actual speed, vehicle distance using subplots.
e. Plot the engine operating points on the engine fuel map.
f. Write down appropriate brief comments on each of these plots, describing the vehicle behavior throughout the drive cycle.
g. Generate the plots for both drive cycles
MATLAB CODE:
%% Vehicle Parameters
M = 1500; % Vehicle weight [kg]
Cr = 0.015; % Rolling resistance coefficient
Rw = 0.35; % Rolling radius [m]
Cd = 0.33; % Drag coefficient
Af = 2; % Frontal area [m2]
rhoa = 1.225; % Air density [kg/m3]
Vwind = 0; % Wind velocity [kmph]
g = 9.81; % Gravitational acceleration [m/s2]
theta = 0; % Slope [deg]
myu_road_tire = 1; % Coefficient of friction between tire - road interface
%% Powertrain Parameters
FDR = 3.73; % Final Drive Ratio / Diff Ratio
DiffEff = 0.99; % Differential efficiency (assumed independent of operating conditions)
NumGear = 4; % Number of gears in transmission
TransGear = [1:NumGear]; % Transmission Gears
TransRatio = [3.06, 1.62, 1, 0.7]; % Corresponding Transmission ratios
TransEff = 0.90; % Transmission efficiency (assumed independent of operating conditions)
TC_SR = [0, .5, .6, .7, .8, .87, .92, .94, .96, .97, 1]; % Torque Converter Speed Ratio (Matlab default) -> TurbSpd/PumpSpd
TC_TR = [2.232, 1.5462, 1.4058, 1.2746, 1.1528, 1.0732, 1.0192, 1, 1, 1, 1]; % Torque Converter Torque Ratio (Matlab default) -> TurbTrq/PumpTrq
TC_Cf = 1e-4 * [.72558, .66322, .63463, .59042, .51331, .4144, .29287, .22444, .12186, .04386, 0]; % Torque Converter Capacity Factor (Matlab default) -> PumpTrq/PumpSpd^2 [Nm/rpm^2]
load Vehicle_Data/Engine_data_1_9L_Saturn_95kW
load Vehicle_Data/Trans_Shift_map
%% Driver Parameters
Kp = 10; % P gain for driver PI model
Ki = 1; % I gain for driver PI model
Drive_Cycle_Select = 1; % Drive cycle selection
% Drive cycle values in m/s
if Drive_Cycle_Select == 1
load DriveCycles/UDDS;
elseif Drive_Cycle_Select == 2
load DriveCycles/HWFET;
elseif Drive_Cycle_Select == 3
load DriveCycles/FTP;
elseif Drive_Cycle_Select == 4
load DriveCycles/US06;
elseif Drive_Cycle_Select == 5
load DriveCycles/NEDC;
elseif Drive_Cycle_Select == 6
load DriveCycles/WLTP;
end
time_end = cyc_time(end);
vel_end = cyc_vel(end);LOAD ALL THE VALUES IN THE WORKSPACE.
SIMULINK MODEL:
DRIVER UNIT:
DRIVER UNIT SCOPE:
CONTROLLER UNIT:
CONTROLLER UNIT SCOPE:
ENGINE CONTROL UNIT:
ENGINE CONTROL SCOPE:
IDLE SPEED CONTROLLER:
TRANSMISSION CONTROL UNIT:
SHIFT LOGIC:
SIMULINK FUNCTION:
BRAKE CONTROL UNIT:
POWERTRAIN SIMULINK MODEL:
ENGINE BLOCK:
ENGINE OUTPUT SCOPE:
TRANSMISSION:
TRANSMISSION SCOPE:
TORQUE CONVERTER:
TORQUE CONVERTER SCOPE :
DIFFERENTIAL:
WHEELS:
VEHICLE DYNAMICS:
SCOPE:
HERE WE CAN COMPUTE THE FUEL ECONOMY NUMBERS OF UDDS AND HWFET DRIVE CYCLES:
THE PROCESSING AND PLOTTING MATLAB CODE:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Skill-Lync -> Hybrid Drives Development
% Project 1 - Conventional Vehicle Model
% By - Ullekh Gambhira
% Description:
% The following file is to used 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_speed = out.Wheel_speed; % Wheel speed [kmph]
Eng_Fuel_rate = out.Eng_Fuel_Rate; % Engine Fuel Rate [%]
Veh_Desired_Spd = out.Veh_desired_spd; % Desired Vehicle Speed
%% 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]
%% Plotting Fuel Consumption vs Fuel Rate
figure(1)
hold on
grid on
plot(Time, Eng_Fuel_Consump, 'linewidth', 1, 'Color', 'k');
plot(Time, Eng_Fuel_rate, 'linewidth', 1, 'Color', 'r');
xlabel('fuel consumption')
ylabel('Fuel Rate')
xlim([0, Time(end)]);
legend('fuel consumption','Fuel Rate');
%% Plotting vehicle characteristics time trace Engine, Transmission Input, Transmission Output and Wheel Speed
figure(2)
hold on
grid on
plot(Time, Eng_Spd, 'linewidth',1, 'Color', 'g');
plot(Time, Trans_In_Spd, 'linewidth',1, 'Color', 'k');
plot(Time, Trans_Out_Spd, 'linewidth',1, 'Color', 'r');
plot(Time, Wheel_speed, 'linewidth',1, 'Color', 'b');
xlabel('Time [s]')
ylabel('Speed [rpm]')
xlim([0, Time(end)]);
ylim([0, 6000]);
legend('Transmission Input','Transmission Output','Wheel Speed','Engine Speed');
%% Plotting vehicle characteristics time trace accelerator
figure(3)
subplot(2,2,1)
plot(Time, Eng_Trq, 'linewidth', 1, 'Color', 'g');
xlabel('Time [s]')
ylabel('Torque [Nm]')
legend('Torque');
subplot(2,2,2)
plot(Time, Eng_Pwr, 'linewidth', 1, 'Color', 'k');
xlabel('Time [s]')
ylabel('Power [KW]')
legend('Engine Power');
subplot(2,2,3)
plot(Time, Eng_Fuel_rate, 'linewidth', 1, 'Color', 'r');
xlabel('Time [s]')
ylabel('Fuel Rate [%]')
legend('Fuel Rate')
subplot(2,2,4)
plot(Time, Eng_Fuel_Consump, 'linewidth', 1, 'Color', 'b');
xlabel('Time [s]')
ylabel('Fuel Consumption [Kmpl]')
legend('Fuel Consumption')
%% Plotting vehicle characteristics time trace accelerator
figure(4)
subplot(3,1,1)
hold on
grid on
plot(Time, Acc_Pdl, 'linewidth', 1, 'Color', 'k');
plot(Time, Brk_Pdl, 'linewidth', 1, 'Color', 'r');
ylabel('Pedal [%]')
xlim([0, Time(end)]);
legend('Accel','Brake');
subplot(3,1,2)
hold on
grid on
plot(Time, Veh_Desired_Spd, 'linewidth', 1, 'Color', 'k');
plot(Time, Veh_Spd, 'linewidth', 1, 'Color', 'r');
ylabel('Speed [rpm]')
xlim([0, Time(end)]);
legend('Vehicle Desired Speed','Vehicle Actual Speed');
subplot(3,1,3)
hold on
grid on
plot(Time, Gear_Cmd, 'linewidth', 1, 'Color', 'k');
xlim([0, Time(end)]);
xlabel('Time [s]');
ylabel('Gear');
%% 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');
[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]');
%p4 = plot(Eng_Spd,Eng_Trq,'.','color','k');
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)]);RESULTS:
FUEL CONSUMPTION VS FUEL RATE FIGURE(1):
PLOTS OF TIME TRACE FOR ENGINE, TRANSMISSION, INPUT, TRANSMISSION OUTPUT, AND WHEEL SPEED FIGURE(2).
PLOTS FOR TORQUE, ENGINE POWER, FUEL RATE, AND FUEL CONSUMPTION FIGURE(3):
HWFET DRIVE CYCLE:
FUEL CONSUMPTION VS FUEL RATE FIGURE(1):
PLOTS OF TIME TRACE FOR ENGINE, TRANSMISSION, INPUT, TRANSMISSION OUTPUT, AND WHEEL SPEED FIGURE(2).
PLOTS FOR TORQUE, ENGINE POWER, FUEL RATE, AND FUEL CONSUMPTION FIGURE(3):
RESULTS:
HERE WE CAN DEFINE ALL OF THE PLOTS.