Week 2- 2R Robotic Arm Challenge
To write a program in Matlab to simulate the forward kinematics of a 2R Robotic Arm
A robotic arm is mechanical arm with similar function to human arm,It consist of two kinematics pairs known as link 1 and link 2 with manipulator, this manipulator joined in link2 with rotating motion (robot arm) or linear displacement. the manipulator is also called as end effector and its analogos to human hand.
The robortics arm are used for
welding
painting
automotive robot solution
package industry
Diagram
Inputs
L1 = length of link 1
L2 = length of link 2
Theta 1 = angle made by link 1 with horizontal
Theta 2 = angle made by link 2 with horizontal
CODE
clear all
close all
clc
% inputs
%length of first arm
l1 = 1;
%length of second arm
l2 = 0.5;
%angle of first arm
theta1 = linspace(0,90,10);
%angle of second arm
theta2 = linspace(0,90,10);
% initiate the counter values
ct=1;
for i = 1:length(theta1)
THETA1 = theta1(i);
for j = 1:length(theta2)
THETA2 = theta2(j);
x0 = 0;
y0 = 0;
x1 = l1*cosd(THETA1);
y1 = l1*sind(THETA1);
x2 = x1 + l2*cosd(THETA2);
y2 = y1 + l2*sind(THETA2);
%plotting
plot([x0 x1], [y0 y1],[x1 x2], [y1 y2], 'linewidth',3)
axis([-0.5 1.5 0 1.5])
pause(0.03)
M(ct) = getframe(gcf);
ct = ct+1;
end
end
movie(M)
videofile = VideoWriter('forward_kinematics.avi');
open(videofile)
writeVideo(videofile,M)
close(videofile)
Output
The output of this program as come out with an animation video attached at below as link
Explanation
Theta 1 and Theta 2 has initial value to calculate the link2 with equation of finding THETA 1 THETA 2 by determining
the values, by using frame counting command 'ct' is initial at matlab
The posotion of the end points for each of the links are calculated using the equation
Link 1
start point = x0 = 0 , y0 = 0
end point = x1 = x0 + l1cos(theta1)
x1 = x0 + l1sin(theta1)
Link 2
end point = x2 = x1 + l2cos(theta2)
x2 = x1 + l2sin(theta2)
The graph is plotted using plot command, the 'getframe(gcf)' used to inside the second loop(controlling second link position)
to get current frame
The Movie 'M' command is used to play the video of plotting graph
The VideoWriter command create an empty videofile by name of 'forwardKinematics' in .avi formate and its stored in videofile
Result:
https://www.dropbox.com/t/J5kg2gf9G6GHmcVS
Above link is the animation of robotics kinematics arm
() [] , . '' * % ; = + - _