2R ROBOTIC ARM SIMULATOR (PYTHON)

AIM: TO SIMULATE THE FORWARD KINEMATICS OF A 2R ROBOTIC ARM USING PYTHON

INTRODUCTION: A manipulator/end effector movement determines the workspace where the robotic arm can be applicable. Our motive is to animate the movement of the robotic arm with the subsequent relative motion between the two-comprising links.

OBJECTIVE:

• Write a program to simulate forward kinematics of a 2R Robotic Arm
• Animating and creating a movie from the plots/figures obtained from the program

INPUTS:

(x0, y0) = starting point of link1

(x1, y1) = endpoint of link1 / starting point of link 2

(x2, y2) = endpoint of link 2

l1 = length of the link attached to the base

l2 = length of the link between the first link and the end effector

theta1 = angle made by link 1 with x-axis

theta2 = angle made by link 2 with x-axis

PROGRAM:

import math
import matplotlib.pyplot as plt

# Inputs
l1 = 1
l2 = 0.5
n_theta = 10

theta_start = 0
theta_end = math.pi/2

theta1 = []
theta2 = []

# Creating an array of values of theta and retaining them
for i in range(0,n_theta):
	tmp = theta_start + i*(theta_end-theta_start)/(n_theta-1)
	theta1.append(tmp)
	theta2.append(tmp)

x0 = 0
y0 = 0

# Defining counter variable
ct = 1
for t1 in theta1:
	for t2 in theta2:
		# Link 1, Link 2 connector
		x1 = l1*math.cos(t1)
		y1 = l1*math.sin(t1)

		# Coordinates of the manipulator
		x2 = x1 + l2*math.cos(t2)
		y2 = y1 + l2*math.sin(t2)


		# Naming the figures using the counter variable and saving them in '.png' format
		filename = str(ct) + '.png'
		ct = ct + 1

		# Plotting figures and saving them with particular filename
		plt.figure()
		plt.plot([x0,x1],[y0,y1])
		plt.plot([x1,x2],[y1,y2])
		plt.xlim([0,2])
		plt.ylim([0,2])
		plt.savefig(filename)

ANIMATION: The Link for the animation has been mentioned below –

https://youtu.be/A23ECfexhBM

CONCLUSION: A practical scenario regarding the functioning of the robotic arm and its workspace has been experienced by simulating the forward kinematics with a program in Python.