Week 2- 2R Robotic Arm Challenge

Aim: Write a program in Matlab to simulate the forward kinematics of a 2R Robotic Arm,as shown in the video.

1. Create an animation file of the plot.

Inputs:

l1 = 1.4 meters

l2 = 0.8 meters

theta1 = (0,90) 10 values in degress

theta2 = (0,90) 10 values in degress

x0 = 0

y0 = 0

x1 = l1*cosd(theta1)

y1 = l1*sind(theta1)

x2 = x1+l2*cosd(theta2)

y2 = y1+l2*sind(theta2)

Objective of the Project:

To study the forward kinematics links of a robotic arm at different position and different angles to understand the working of a robotic arm.

Body of the content:

% forward kinematics of a 2R robotic arm manipulator
clear all
close all
clc

% inputs
l1 = 1.4;
l2 = 0.8;
theta1 = linspace(0,90,10);
theta2 = linspace(0,90,10);
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([-0.1 1.5 0 1.5])
         pause(0.3)
         M(ct) = getframe(gcf);
         ct=ct+1;
        
        
    end
        
        
end

movie(M)
videofile = VideoWriter('forward_kinematics.avi','Uncompressed AVI')
open(videofile)
writeVideo(videofile,M)
close(videofile)

Explanation of the program:

1. First we define the length of the robotic arm l1 and l2 respectively.

2. Assign values to theta1 and theta 2 using linspace command.

3. After that use for loop command for link 1 and theta1.

4. Again use for loop command for link 2 and theta2.

5. After that define the co-ordinates of the robotic arm.

6. Then plot all the co-ordinates.

7. All figures are assigned to a value M one at a time using ct followed by terminates for loop.

8. movie command is used to combine all the figures saved in the M file to make an animate and saving in .avi extension.

Report: Animation link

https://youtu.be/g3Gxyf_lmOo

Conclusion: A pratical functioning of the robotic arm are experienced through simulating the forward kinematics in a Matlab.