Week 2- 2R Robotic Arm Challenge

% program in Matlab to simulate the forward kinematics of a 2R Robotic Arm

% Input Parameters 

% Length of 1 st arm 

l1 = 1

% Length of 1 st arm 

l2 = 2

% Angle maee by 1 st arm with Horizontal 

theta1 =  linspace(0,90,10);

% Angle maee by 2 nd arm with Horizontal 

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);
        
        plot ([x0 x1],[y0 y1],[x1 x2],[y1 y2],'linewidth',3);
        axis([0 4 0 4]);
        pause(0.03)
        M(ct)=getframe(gcf);
        ct = ct + 1;
        
    end
end

movie(M)
videofile = VideoWriter('forward_kinematics_2R_Rbotic_Arm.avi','uncompressed AVI');
open(videofile)
writeVideo(videofile,M)
close(videofile)

Result Movie 

Google Drive Link

Location as Mentioned - Skill Lync Challenges > Week 2 - 2R Robotic Arm Challenge > Movie 

Week 2 - 2R Robotic Arm Challenge

Report 

1. Code Execution Explanation 

l1 = 1 

 Length of 1 st arm Stored as l1 = 1

l2 = 2

 Length of 2 nd arm Stored as l2 = 2

Angle made by 1 st & 2nd arm with Horizontal

theta1 = linspace(0,90,10)

theta2 = linspace(0,90,10)

Results in formation 1*10 Matrix as Shown 

theta1 & theta2=

0 10 20 30 40 50 60 70 80 90

Now 

In for Loop 

for i = 1:length(theta1)

i stores 1st value of theta1 as 0 and calculate For THETA1 = theta1(i) i.e THETA1 = theta1(0)

now for i = 0 

2nd for loop executed 

for j = 1:length(theta2)

j stores 1st value of theta2 as 0 and calculate For THETA2 = theta2(j) i.e THETA2 = theta2(0)

now for stored values of 

THETA1 & THETA2

Following co-ordinates get calculated 

x0 = 0;
y0 = 0;

x1 = l1*cosd(THETA1);
y1 = l1*sind(THETA1);

x2 = x1 + l2*cosd(THETA2);
y2 = y1 + l2*sind(THETA2);

The cycle repeats for 10 values with calculating co-ordinates for x0 x1 x2 y0 y1 y2 by storing 10 values of j from theta 2

similary aginst every 1 single value of THETA1, 10 values of THETA generated and Co - ordinares are calculated 

and 100 Positions recorded with varying co ordinares for  ([x0 x1],[y0 y1],[x1 x2],[y1 y2])

Plot a graph aginst this 100 positins with linewidth 3

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

Fix Axis Limits for ease of understanding 

Fix X Axis limits from 0 to 4

Fix y Axis limits range from 0 to 4

axis([0 4 0 4])

to visualise the plot 

generate counter ct =1

and increment the couter after excecution of for loop by 1 i.e ct + 1

Pause the code in order to smooth execution and display of plot 

the animation of the 100 positions Displayed 

2. Errors Faced 

1. Unrecognised Function l1cosd(THETA1)

 Steps taken to overcome 

Multiplication sign were missing 

corrrected as 

l1cosd*(THETA1)

2. Plot Were Distinct 

Steps Taken to Overcome

Plot was mentioned wrong as

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

Corrected as 

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

3. Filename invalid 

Stesps to oversome

A space observed in file name hence removed

4. Excuted Completely without errors