2R Robotic Arm Challenge

AIM: To write a MATLAB code to simulate the forward kinematics of a 2R Robotic Arm.

Stepwise explanation of the code:

• Firstly, the input variables like length of links 1 and 2, i.e., l1 and l2 are allocated.
• And the values of theta 1 and theta 2 are allocated.
• Using for and nested for loops, various coordinates of the two links such as [x0, y0], [x1, y1], and [x2, y2] are found out using the basic trigonometric equations.
• Later, the plots are plotted using plot() syntax.
• Finally, a movie is created using movie() syntax.

Program code:

%robotic arm
clear all
close all 
clc

%inputs
theta1 = linspace(0,120,10); %theta1 = 1:120 degrees
theta2 = linspace(0,90,10); %theta2 = 1:90 degrees
l1 = 2.5; %length of link 1
l2 = 1.5; %length of link 2

ct =1;
for i = 1:length(theta1)
    THETA1 = theta1(i);
    for j = 1:length(theta2)
        THETA2 = theta2(j);
        x0 = 0; %base of robotic arm is fixed
        y0 = 0;
        x1 = l1*cosd(THETA1); %end coordinates of link 1
        y1 = l1*sind(THETA1);
        x2 = x1+l2*cosd(THETA2); %end coordinates of link 2
        y2 = y1+l2*sind(THETA2);
        
        plot([x0 x1],[y0 y1],[x1 x2],[y1 y2],'linewidth',3)
        axis([-2 5 0 6])
        pause(0.03)
        M(ct) = getframe(gcf);
        ct = ct+1;
    end
end
   %to create a movie
   movie(M)
   videofile = VideoWriter('forward_kinematics.avi');
   open(videofile)
   writeVideo(videofile,M)
   close(videofile)
        

OUTPUT/ANIMATION:

https://drive.google.com/file/d/10MI_084bdwh8ECrrlmBcSoLGxOqwyLsK/view?usp=sharing

CONCLUSION:

This MATLAB code simulates the forward kinematics of a 2R Robotic arm. The input arguments can be varied in order to fix the length of the links and also the angles of the links with respect to the x axis. Another link of the Robotic arm can also be added by adding the 4th coordinates and also another for loop.