FORWARD KINEMATICS OF A ROBOTIC ARM

FORWARD KINEMATICS OF A ROBOTIC ARM

AIM - To simulate forward kinematics of a 2-R robotic arm using MATLAB

OBJECTIVE

• Write a program to simulate the forward kinematics of robotic arm.
• Learn how to create a animation video in MATLAB.

GOVERNING EQUATIONS

(x0,y0) = Position of the base

Position of Link-1 (x1,y1)

x1= l1cosθ1

y1 = l1sinθ1

Position of Link-2 (x2,y2)

x2 = x1+l2cosθ2

y2 = y1+ l2sinθ2

PROGRAM CODE

EXPLAINATION

• First we put the input values i.e; length of both links

L1 = 1m

L2 = 0.5m

• Then we provide the theta values using the “linspace” command.
• Then we write the “For Loop” function so that for every value of 1 , rotates complete 90 degree.
• The loop repeats for all the 10 values of and plots a graph for each time.
• We provide the x and y axes limits .
• By using the “getframe” command we capture the graphs of each time and convert them into a single animation.
• Then we put the “movie(M)” command to convert the animation into a video file and then save it .

The saved video file extension also has to be specified ,in this case its”.avi”.s

% Program to show the forward kinematics of a 2-R Robotic Arm

% Inputs

l1=1;
l2= 0.5;

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 the arms of Robot
        
        plot([x0,x1],[y0,y1],[x1,x2],[y1,y2],'linewidth',5)
        axis([-0.1,1.5,0,1.5])
        
         pause(0.03)
         M(ct)= getframe(gcf);
         ct = ct+1;
    end
end
% Code for converting the plots into a video
movie(M)
videofile = VideoWriter('forward_kinematics.avi', 'Uncompressed AVI');
open(videofile)
writeVideo(videofile,M)
close(videofile)

ERRORS –

• Incorrect spelling of command “movie” and “VideoWriter”
• The Error was rectified by rewriting the correct spelling of the commands.

• Incorrect syntax of command

The error was rectified by changing the spelling of gct to gcf and then re-running the program.

• OUTPUTS- The following graphs represent the position of the links at different values of theta.

CONCLUSION- Hence, the simulation of the Robotic Arm is completed and the link is given below.

https://youtu.be/xuBYTu7GBwY