Animation of a 2R - robotic arm using Python

1.AIM: To simulate the forward kinematics of a 2R Robotic Arm

2.ASSUMPTIONS:

1. Assumption of the lengths of the two links, l1 and l2.
2. The initial co-ordinates of the base of the robotic arm (0,0) i.e the base of the robot arm is assumed to be at the origin.

3.OBJECTIVES:

1. To determine the various motions of the robotic arm and the manipulator in its workspace.
2. Create an animation file of the plot.

4.FLOW :

1. Assign values to the input variables.
2. Get the values of co-ordinates of the various link motion.
3. Plot the graphical representation of the robotic links and stitch the various plots and create an animation.

5.PYTHON CODE :

import math
import matplotlib.pyplot as plt

#input lengths 
l1=2
l2=1

n_theta=12      #no of values required in the range of 0 to 90 degree

theta_start=0          #start from
theta_end=math.pi/2    # end to

theta1=[]            #array to store all values for theta1
theta2=[]            #array to store all values for theta2

for i in range(0,n_theta):
	tmp=theta_start + i*(theta_end - theta_start)/(n_theta - 1) # to evaluate the minimum interval
	theta1.append(tmp)                                          # append all the values in theta 1
	theta2.append(tmp)                                          # append all the values in theta 2

# start point of link 1
x0=0    
y0=0
count=1 # count for the no. of images generated
for t1 in theta1:
	for t2 in theta2:

		#link 1 & link 2 common point
		x1= l1*math.cos(t1)
		y1= l1*math.sin(t1)

		#end point of link 2
		x2=x1+l2*math.cos(t2)
		y2=y1+l2*math.sin(t2)

		#increment the no. of images generated
		filename= str(count) + '.png'
		count=count+1

		#plotting data
		plt.figure()
		plt.plot([x0,x1],[y0,y1])
		plt.plot([x1,x2],[y1,y2])
		plt.xlim([0,3])                #setting the plot limits for x axis
		plt.ylim([0,3])                #setting the plot limits for y axis
		plt.savefig(filename)          #saving all the plots

6. OBSERVATION:

1. The multiple plots are extracted one by one and stitched together to form an animation.

7.CONCLUSION:

1. The animation depicts the various possible motions and the co-ordinates of the arm as well as the manipulator.
2. The final animation of the various plots of the two links is obtained by the image stitching process, and thus the animation is generated in MATLAB.
3. The Youtube animation which is uploaded on my channel is provided below: