Challenge

Week 2- 2R Robotic Arm Challenge

SSwapnil Oak13 Apr 2022

Objective : - Write a Program in Matlab to Simulate the Forward Kinematics of a 2R Robotic Arm.
Step-wise explanation of the Code.
Create an animation File of the plot.

Robotic Arm:-
robotic arm is type of mechnaical arm , similar function of human arm.arm link such as manipulator are connectred by joints allowing either rotational motion or translational displacement. Calculating postion and orientation o the end effector in the terms of joint variables is called forward kinematics.

Inputs:-
Length of the link (L1) = 1;
Length of the link (L2) = 0.5;

Co-ordinates of X & Y

( X0,Y0)

Starting point of link 1 it is in fixed postion
X0 = 0
Y0 = 0

( X1,Y1)

Ending Point of the link 1 is the starting point of link 2.angle between base and link 1 is angle theta1

So X1 & Y1 will be,
X1 = L1*cosd( theta1)
Y1 = L1*sind(theta1)

(X2,Y2)
Ending Point of angle between link 1 & link 2 is represnted by angle theta 2

So X2 & Y2 will be,

X2 = X1+L2*cosd(theta2)
Y2 = Y1+L2*sind(theta2)

Code :-

% Forward Kinematics of a 2R Robotic Arm

clear all

close all

clc

% Inputs

L1 = 1;

L2 = 0.5;

% Angle Between the Links

theta1 = linspace(0,70,40);

theta2 = linspace(0,70,40);

ct=1;

for i=1:length(theta1)

THETA1 = theta1(i)

for j = 1:length(theta2)

THETA2 = theta2(j)

% x y co-ordinates start point of the link 1

X0 = 0;

Y0 = 0;

% x y co-ordinates of the End point of the link 1

X1 = L1*cosd(THETA1);

Y1 = L1*sind(THETA1);

% x y co-ordinates of the End point of the link 2

X2 = X1+ L2*cosd(THETA2);

Y2 = Y1+ L2*sind(THETA2);

% Plotting

plot([X0 X1], [Y0 Y1], [X1 X2], [Y1 Y2],'linewidth',3)

% Plotting x and Y axis Co-ordinates

axis([-0.1 1.5 0 1.5])

pause(0.01)

M(ct) = getframe(gcf);

ct = ct+1;

end

movie(M)

videofile = VideoWriter('forward_kinematics.avi','Uncompressed AVI');

open(videofile)

writeVideo(videofile,M)

close(videofile)

Explanation Of Code :-

Matlab started with clear all , close all , clc command
input value of theta 1 & theta 2 is determined with linspace command
initialize the counter command using ct
for moving robotic arm using for loop.
The value of 'i' is going to change from 1 to the length of theta 1 & the value of 'j' is going to change from 1 to the length of theta 2. this original values assigned with THETA1 & THETA2. loop counter variables are used to access perticular value, So the link 1 & link 2 changes the postion with respect to theta 2.
enter the co - ordinates
enter the values ([X0 X1],[Y0 Y1],[X1 X2],[Y1 Y2])
pause command used for the speed of animation.
used getframe command individual value
using movie command to create movie & with the help of video file command uncompressed avi file ganerated.
video open and closed with respect to open & closed command.

Animation :-

https://youtu.be/iTravqCWfz0

Errors :-

1) Incorrecet used of '='

Overcome Error 1 : - by ommite the '=' sign

2) Undifined Plotting Function

overcome Error 2 :- adding % sign

Week 2- 2R Robotic Arm Challenge

Ship work like this
in your own course.

Talk to a career counsellor

Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.