Week 2- 2R Robotic Arm Challenge

simulate the forward kinematics of a 2R Robotic Arm

clear all
close all
clc

%inputs
l1 = 1
l2 = 0.5

%angle 1 and angle 2
a1=linspace(0,90,10);
a2=linspace(0,90,10);

%for loop for generating sucessive lines
ct=1;
for i = 1:length(a1)
    A1 = a1(i);
    for j = 1:length(a2)
        A2 = a2(j);
       
        %coordinates

%hinged coordinates
x0 = 0;
y0 = 0;

%first link coordinates
x1 = l1*cosd(A1);
y1 = l1*sind(A1);

%coordinates in 2 links 
x2 = x1 + l2*cosd(A2);
y2 = y1 + l2*sind(A2);

%plotting

plot([x0 x1],[y0 y1],[x1 x2],[y1 y2],'linewidth',3)

%fixed axis to fix the grid
axis([-0.1 1.5 0 1.5])
pause(0.03)


%storing frame in array by getframe code
M(ct) = getframe(gcf);

ct=ct+1

    end
    
end


%accessing and saving video file
movie(M)
videofile = VideoWriter('roboticarm.avi','Uncompressed AVI');
open(videofile)
writeVideo(videofile,M)
close(videofile)

1. the first step of the code is to clear the screen and close all previous programs
2. Then providing input values for both links (length and angles in this case)
3. now to get successive output values to generate the plot we start for loop
4. in which 2 variables were assigned for different links (for loop length(angle) shows the number of values specified earlier in inputs)
5. after for loop is generated We add coordinates (calculated using the geometry of line figure of robotic arm)
6. After all 3 points coordinated have been assigned we plot the graph using plot command giving the line some width
7. axis is been fixed
8. after frames have been saved by frame code and Variable M is assigned for frames which are saved
9. for accessing and saving video file M the Videowriter command is used and name of file is assigned which is then opened

errors faced

1. As matlab commands are case sensitive many times after run it failed to execute, for eg I wrote videowriter command which is wrong later came to know with the help that it was VideoWriter
2. syntax errors as due to typing mistakes, non assigned variables were also there
3. underdefined variables

Screen shot of output at time of executing

Animation video of Robotic arm

https://youtu.be/JConmfCIups