Week 2- 2R Robotic Arm Challenge

https://youtu.be/An4N-vXRK40

%program for forward kinematics of 2R robotic arm manipulator animation
clear all
close all
clc

%input 
%length of the arm
l1 = 1;             
l2 = 0.5;          


%Angle of of both links with respect to horizondal axis
theta1 = linspace(0,90,10);
theta2 = linspace(0,90,10);

%program
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 1.7 0 1.7])


pause(0.03)


M(ct)=getframe(gcf)
ct=ct+1;     
end 
end


movie(M)
videofile = VideoWriter('2Rarmmechanism.avi','uncompressed AVI');
open(videofile)
writeVideo(videofile,M)
close(videofile)

REPORT

First of all the input should be provided.

%length of the arm

l1 = 1;

l2 = 0.5;

%Angle of of both links with respect to horizondal axis

theta1 = linspace(0,90,10);

theta2 = linspace(0,90,10);

By using the command 10 values for theta will be calculated, which is in between 0 to 90 degree .

ct=1

Counter plot will be addesd to plote plot induvidualy

Plot can be generated manually but it is a tedious work , to make it automatic we will use for loop funtion(to repeat action again and again).

for i=1:length(theta1)

Value of i wiil change from 1 to length of theta1,length(theta1) is nothing but all the 10 theta value between 0 to 90 which is generated by the linspace command.

THETA1=theta1(i);

THETA1 is a variable (that contain only one variable only), where theta 1 is an array (contain 10 value from 0 to 90)

i is the loop counter which determine how many times the for loop get excicuted.

second loop is required because of the 10 position of theta1 , theta2.

for j=1:length(theta2)

THETA2=theta2(j);

Then we have to provide the point equation for calculation value .

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)

By this comand plot will generated, in that specific width and colour .

axis([-0.1 1.7 0 1.7])

This commandis used for fixing the work area in the graph .

M(ct)=getframe(gcf)

This command is used for making the plot in an animated form.

ct=ct+1;

Is a forloop increment excecution.

movie(M)

videofile = VideoWriter('2Rarmmechanism.avi','uncompressed AVI');

open(videofile)

writeVideo(videofile,M)

close(videofile)

In order to make the animation to avi vdeo formate we use the above commants

NB: It is very important to note that the comments are case sensitive

ERRORS

When i excecute the ct=ct+1 before the M(ct) the above error occures.

Error 2 : unable to save as video in the system due to the case sensitivity of the

videofile = videowriter('2Rarmmechanism.avi','uncompressed AVI');

open(videofile)

writevideo(videofile,M)

close(videofile)

result:

Unrecognized function or variable 'videowriter'.

Error in arm_manipulator (line 48)
videofile=videowriter('2Rarmmechanism','uncompressed AVI');