Week 3.2 - 2R Robotic Arm Challenge

%% Define link lengths of the 2R robotic arm

L1 = 10; % Length of first link

L2 = 7; % Length of second link

%% Define joint angles for animation

% theta1 and theta2 represent the angles of the first and second joints respectively

numFrames = 120; % Number of frames in animation

% Generate angles smoothly from 0 to 90 degrees

theta1 = linspace(0, pi/2, numFrames); % Joint 1 angle in radians

theta2 = linspace(0, pi/2, numFrames); % Joint 2 angle in radians

%% Initialize figure for animation

figure;

axis equal;

%%If you don't set limits (xlim and ylim), MATLAB will automatically adjust the axis limits based on the data plotted

%This can Cause, Unstable or Shifting Viewport, Arm going out of view, Inconsistent Scaling.

% In my case, when, I forgot to set limits, MATLAB resized the plot dynamically, Making it Zoom in/ out.

xlim([-L1-L2, L1+L2]);

ylim([-L1-L2, L1+L2]);

xlabel('X Position');

ylabel('Y Position');

title('2R Robotic Arm Forward Kinematics Animation');

grid on;

hold on;

% Create video writer object to save animation

v = VideoWriter('2R_Robotic_Arm.mp4', 'MPEG-4');

v.FrameRate = 120;

open(v);

%% Animation loop

for i = 1:numFrames

% Calculate Joint Positions using Forward Kinematics

x0 = 0; y0 = 0; % Base of robot

x1 = L1 * cos(theta1(i));

y1 = L1 * sin(theta1(i));

x2 = x1 + L2 * cos(theta1(i) + theta2(i));

y2 = y1 + L2 * sin(theta1(i) + theta2(i));

% Plot the arm

cla; % Clear previous frame

plot([x0, x1], [y0, y1], 'r-', 'LineWidth', 3); % First link

hold on;

plot([x1, x2], [y1, y2], 'b-', 'LineWidth', 3); % Second link

plot(x0, y0, 'ko', 'MarkerSize', 8, 'MarkerFaceColor', 'k'); % Base

plot(x1, y1, 'go', 'MarkerSize', 8, 'MarkerFaceColor', 'g'); % Joint 1

plot(x2, y2, 'bo', 'MarkerSize', 8, 'MarkerFaceColor', 'b'); % End Effector

% Update figure and capture frame

drawnow;

frame = getframe(gcf);

writeVideo(v, frame);

end

% Close video writer

close(v);

%% Errors: Forgot to set the limits ( explained at the code part _ Xlim & Ylim . Also attached a mp4 file.

% output