% part 3 of the mini project
% Prabir Barooah, March 20, 2009

clear all
%conversion: 
mph2mpersec = 0.44704; %m/sec

m = 1300; %kg
b = 42926.2; %N/volt
a = 150.91; %30.17; % N/m^2 s^2 

v_0 = 60*mph2mpersec;
theta_0 = a*v_0^2/b

%% part 1
%for running simulink model 'car_nonlinear'
theta_1 = theta_0;
theta_2 = theta_0+0.3;
% step time is alraedy specified as 10 sec, 
% so just run the simulink model:
% I use a matlab command 'sim' to run simulink from 
% matlab script:
sim('car_nonlinear');

figure
subplot(211);
plot(tout,v);
set(gca,'fontsize',18);
xlabel('t (sec)');
ylabel('v(m/s)');

subplot(212);
time =[0 10 10.00001 20];
theta = [theta_1 theta_1 theta_2 theta_2];
plot(time,theta);
set(gca,'fontsize',18);
xlabel('t (sec)');
ylabel('\theta (Volt)');


%% part 2
p= 2*a*v_0/m
k = b/m