% Program 5.8
% RR robot arm
% Dynamics 
% Newton-Euler equations of motion
% the program uses the function: RRrobot(t,x) 
% the function is defined in the program RRrobot.m

clear; clc; close;

t0 = 0;  tf = 10; time = [0; tf];

x0 = [-pi/18; 0; pi/6; 0]; 

[t,xs] = ode45(@RRrobot, time, x0);

x1 = xs(:,1); 
x2 = xs(:,2);
x3 = xs(:,3); 
x4 = xs(:,4);  

subplot(2,1,1),plot(t,x1*180/pi,'r'),...
xlabel('t (s)'),ylabel('q1 (deg)'),grid,...
subplot(2,1,2),plot(t,x3*180/pi,'b'),...
xlabel('t (s)'),ylabel('q2 (deg)'),grid

% [ts,xs] = ode45(g,0:1:5,x0); 
% [ts,xs]