Challenge

Week 3.2 - 2R Robotic Arm Challenge

KKamesh Entoorbaskar27 Mar 2025

Aim

To simulate the forward kinematics of a 2R Robotic arm

Objective

To understand and implement forward kinematics for a 2R robotic arm.
To visualise the motion of the robotic arm as the joint angles change.
To generate an animation of the arm's movement and save it as a videofile.

Methodology

Define the length of the two links.
Generate a range of angles for each joint.
Compute the position of the robotic arm’s joints using trigonometric calculations.
Plot and animate the robotic arm’s motion frame by frame.
Capture and save the animation as a video file.

Code

% Code to simulate the forward kinematics of a 2R Robotic Arm

clear all

close all

clc

% Length of the arms

l1 = 1;

l2 = 0.5;

% Angle of the arms with respect to the x-axis

theta1 = linspace(0,90,10);

theta2 = linspace(0,90,10);

% Setting Up counter for figures

ct = 1;

% For loop for providing the angles of link 1 with respect to the x-axis

for i = 1:length(theta1)

THETA1 = theta1(i);

% For loop for providing the angles of link 2 with respect to the link 1

for j = 1:length(theta2)

THETA2 = theta2(j);

% The base of the robotic arm

x_0 = 0;

y_0 = 0;

% The position of the first joint

x_1 = l1*cosd(THETA1);

y_1 = l1*sind(THETA1);

% The position of the second joint end

x_2 = x_1 + l2*cosd(THETA2);

y_2 = y_1 + l2*sind(THETA2);

% Figures for each frame

figure(1)

% Creating links

plot([x_0,x_1],[y_0,y_1],[x_1,x_2],[y_1,y_2],'LineWidth',3)

% Axis limits for better visualization.

axis([-0.1 1.5 0 1.5])

pause(0.03)

% Captures the current frame and stores it in M for animation.

M(ct) = getframe(gcf);

ct = ct+1;

end

% Creating a movie using the saved frames

movie(M)

% Creating a video file named Forward_Kinematics.avi using the frames

% stored

videofile = VideoWriter('Forward_Kinematics.avi','Uncompressed AVI')

open(videofile)

writeVideo(videofile,M)

close(videofile)

Errors faced while programming

An issue arose where link two was getting longer and longer, eventually reaching the same length of the first link. After a step-by-step line check of the code, it was discovered that the length of link two was mistakenly used for the y-coordinate of the end of link one. Correcting this mistake ensured accurate link positioning and proper simulation.

Additionally, when creating figures, using a counter to store individual frames resulted in multiple figures being created, leading to increased execution time. By changing it to figure(1), the process became more efficient, reducing unnecessary figures and making it easier to access and update the figure during simulation.

Results

The simulation successfully visualises the movement of the 2R robotic arm as the joint angles vary. The trajectory and motion of the end effector demonstrate the expected kinematic behaviour. The captured frames are compiled into an animation, stored as a video file.

https://youtu.be/9eoSNlF9ugA

Week 3.2 - 2R Robotic Arm Challenge

Aim

Objective

Methodology

Code

Errors faced while programming

Results

Ship work like this
in your own course.

Talk to a career counsellor

Aim

Objective

Methodology

Code

Errors faced while programming

Results

Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.