How to Start the Project

The Project is developed on

• Ubuntu 18.04
• ROS melodic

#cd to the src directory, and make the python script executable
chmod u+x IK_Solver.py

#Redirect to ROS Workspace and start building process
catkin build
source ~/"ROS Workspace"/devel/setup.bash

#Launch the ROS Project
roslaunch delta_robot delta.launch

Project Roadmap

• Conduct concepts of ROS from tutorial, examples
• Implement the Ragnar Project, get familiar with ROS
• Investigate the Delta Robot Kinematic
• Design URDF of Delta Robot
• Move the Delta Robot in simulation rviz and observe its performance

Direct and Inverse kinematics

Inverse kinematics calculation (upper angles): For details see this pdf

Forward kinematics calculation (lower angles): For details see this pdf

Robot Operating System ROS

• A opensource framework for robotic applications
• A variety of tools and libraries are available
• Provides standard operating system services (device drivers, package management, hardware abstraction...)
• As modular as possible: gives robustness and versatility by developing complex robotic applications
• Three level of abstraction:
  • File system: Meta packages, packages, messages, services, repositories
  • Computation Graph: nodes, ROS master, server, messages, topics, services
  • Community: resources, distributions, ROS wiki, repositories

Design of URDF IRB360-3/1130 robot

More details about URDF and joints: http://wiki.ros.org/urdf/XML/joint#Elements

• base: base link of the ABB IRB 360-3/1130
• end_effector: end effector link
• Designed with 3 arms and only 1 arm is connected to end effector
• 3 upper arms: real geometry with length of 0.35m
• 6 lower arms: real geomatry with length of 0.8m

How to make the robot move

• The angles of joints states are calculated using inverse kinematics equations
• The angles degree and position of end effector are printed out
• Then sent to the URDF model via sensor_msgs/JointState message using joint_state publisher
• The motion of robot can be observed in Rviz

Limitation of URDF

• Closed kinematic chains cannot be simulated
• No universal joints in URDF, so we used coupled revolute joints
• Floating joints has 6DOF and can be used in URDF, but it cannot be controlled by joint_state_publisher, so we connected the end_effector with a dummy part

To Be Done

• Create Moveit! Package for the Robot using the URDF file, add collision properties
• Connect ABB Robot using ABB Controller