A Matlab Program to simulate the forward kinematics of a 2R Robotic Arm

Aim:- A Matlab Program to simulate the forward kinematics of a 2R Robotic Arm.

Objectives:-

• To write a program in Matlab to simulate the forward kinematics of a 2R Robotic Arm.
• Creating an animation file of the plot.
• In this, we consider a 2R Robotic Arm and we need to calculate the position of link 1 and link 2.

Programming using MATLAB:-

clear all
close all
clc

% A matlab program to simulate the forward kinematics of a 2R Robotic Arm
% Creating an animation file of the plot
% So In this we will consider a 2R Robotic arm which has two links with
% two lengths L1 & L2 and angles theta1 & theta2.
% The calculations and inputs are as follows:-
% The inputs are
% Lenghts
L1 = 1;
L2 = 0.5;
% Angles
theta1 = linspace(0,75,10);
theta2 = linspace(0,75,10);

ct=1;
% Creating the loop
for i = 1:length(theta1)
    THETA1 = theta1(i);
    for j = 1:length(theta2)
        THETA2 = theta2(j);
        % Co-ordinates
        x0 = 0;
        y0 = 0;
        % To Calculate the position of the Robotic arm
        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(0.04)
        M(ct) = getframe(gcf);
        ct=ct+1;
    end
end

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

Output:-

https://youtu.be/ISDi0RZDWx8

Explanation:-

• Forward kinematics refers to the use of the kinematic equations of a robot to compute the position of the end-effector from specified values for the joint parameters.
• So First we have taken the required inputs, lengths, angles and Co-ordinates.
• Then we used a counter command for incrementing or decrementing by a specific step value in every iteration of a loop.
• Then we created a loop for making the plot animate.
• After that we created a plot for the Robotic Arm.
• And then we paused the code and created frames in order to animate the plot according to the frames.
• Then we wrote a program to create a movie.

Errors and how to overcome them:-

• I got an error with the plot and I got only one link showing in the plot because I gave larger values to the L1 & L2. So the value must be smaller in order to get the graph.
• I got an error in the plotting after typing 'linewidth' because I forgot to avoid apostrophe after typing 'linewidth'.

Screenshot of my errors:-

Conclusion:-

So, In this we successfully calculated and simulated the forward kinematics of a 2R Robotic Arm and created an animation file of the plot.