clear all; 

Exercise 1.2 - Modeling of a Robot

In this exercise you will model a Universal UR3e robot from given DH parameters.

Please store your solutions in the predefined variables!

Task description:

Given the DH parameters of a UR3e Robot:

Link	a [m]	alpha	d [m]	theta
1	0	pi/2	0.15185	0
2	-0.24355	0	0	0
3	-0.2132	0	0	0
4	0	pi/2	0.13105	0
5	0	-pi/2	0.08535	0
6	0	0	0.0921	0

The base and the coordinate frame of the first joint are identical!

Answer all the questions and store your solution in the correct variable

Task 1

1. Setup the robot structure and use the data format "column"
2. Define bodies, name them body_1, ..., body_n
3. Define joints, name them joint_1, ..., joint_n

Use the following variables to store your solution:

• robot (name of your robot)
• bodies (name of your variable containing the bodies)
• joints (name of your variable containing the joints)

  robot = [];
  bodies = []; 
  joints = []; 
  

You can check your work by clicking the Run:

check_exercise('1-2-1')

Checking exercise 1-2-1: Variable Structure

Checking variables:

Checking Variable robot
[OK] robot is of type rigidBodyTree

Checking robot data format
[OK] Correct data format

Checking Variable bodies
[OK] bodies is of type cell

Checking Variable joints
[OK] joints is of type cell

checking body elements
checking joint elements

Task 2

1. Link the DH parameters to the corresponding joints.
2. Link the joints to their bodies.
3. Add the bodies to the robot

   DH=[
      %a       alpha       d       theta
      0        pi/2        0.15185  0;
      -0.24355 0           0       0;
      -0.2132  0           0       0;
      0        pi/2        0.13105 0;
      0        -pi/2       0.08535 0;
      0        0           0.0921  0;
       ]
   

Add your code here:

You can check your work by clicking the Run:

check_exercise('1-2-2')

Task 3

1. Define the gravity to be in negative Z direction with a magnitude of \(9\ldotp 81\;\frac{m}{s^2 }\) (see figure above)
2. Set the home position for joints 1, 3 and 5 to \(\frac{\pi }{2}\)

Add your code here:

You can check your work by clicking the Run:

check_exercise('1-2-3')