VERSA-BOT V 1.0 – A SHOP -FLOOR MOBILE MANIPULATOR

Goals of the Project:

• Modelling the Versa-BOT in the SolidWorks software with 7 degrees of freedom.
• Exporting the 3-D model into URDF.
• Moving the mobile manipulator URDF to the Ubuntu OS to work with ROS 2.
• Spawning the robot in the Gazebo environment in an empty world like did in project 1.
• Including LIDAR in the robot and RViz visualization of the sensor.
• Creating an algorithm for controlling the robot in the gazebo environment.

3.2. Dimensions of the Robot

MOBILE BASE

Property	Measurement
Length	762.00 mm
Width	381.00 mm
Height	157.85 mm
Wheelbase	304.80 mm
Wheel Radius	108.00 mm

MANIPULATOR

Property	Measurement
Arm Base Length	100.00 mm
First Link Length	190.50 mm
Second Link Length	190.50 mm
Third Link Length	328.93 mm
Radius of the Link	38.00 mm
End-Effector	Vacuum Gripper

9.2 Control Method - Open-loop Controller

The control method employed for robot operation is an open-loop controller. This type of controller facilitates the operation in the Gazebo environment, enabling the robot's vacuum gripper—the end-effector—to pick up a can effectively.

Control Flow

The sequence of operations is as follows:

• Initial Movement:

  • For the initial 5 seconds, the robot is set to a velocity of 3m/s.
  • Then, it accelerates to 6 m/s for the subsequent 3 seconds.

• Arm Articulation:

  • Post linear motion, the robotic arm executes a predefined joint angle trajectory, tracing the path of an arc.
  • A time function halts the arm after 2 seconds, ensuring a smooth transition.

• Gripper Engagement:

  • As the arm ceases motion, the vacuum gripper activates to secure a coke can.

• Reverse Motion:

  • The robot then reverses at a speed of 3 m/s for 5 seconds, followed by 6 m/s for the final 3 seconds.
  • During this time, the gripper maintains its hold on the Coke can.

• Gripper Disengagement:

  • The grip is released after the reversal is complete, marking the end of the operation.

This systematic approach, merging articulated manipulation with linear movement, showcases the robot's capability to execute a pick and place task with precision and efficiency.