hyrbid_automata

HybridAutomata with Go To Goal, Obstacle Avoidance and Follow Wall modes governed by SlidingModeSwitch for Differential Drive Robot in ROS Gazebo.

Getting started

Prerequisites

• ROS Melodic with Gazebo-9 (Desktop-Full Install)
• Python 2.7 with numpy
• Control Of Mobile Robots: Geogia Tech is a prerequisite for understanding the process of how this project works or you can visit this blog to get a quick crashcourse.

Installing

• Clone the repository to the local machine
• Place the repository folder in /your/machine/catkin_ws/src
• Navigate into catkin_ws folder and open terminal.
• Type catkin_make and press enter.
• Make sure your .bashrc file (located in Home Folder) has these lines added in them: source yourpath/ros/melodic/setup.bash source yourpath/catkin_ws/devel/setup.bash
• After catkin has completed making the workspace, ROS should be able to locate your new rospackage dd_bot. To check it, type in terminal rospack find dd_bot. This should print out the location of the dd_bot folder. If the rospackage location is not displayed, please contact the collaborators.

Simulating an Induced Mode Control

• Open a terminal and type roslaunch dd_bot gazebo.launch. A Gazebo world should be loaded with a differential robot surrounded by a blue colored disc (Laser Sensor visualiztion) and a wall obstacle around it.
• Open another terminal inside the folder by entering command cd /your/machine/catkin_ws/src/hybrid_automata/dd_bot and type python induced_mode.py.
• The robot will start to move from current position to (5,5) as per default value. To change the desired position, open induced_mode.py and make changes in line 18 accordingly. *hybrid_automata.py has all the constants and configuration parameters defined for the Python controller design. *The folders urdf and config collectively constitute the model specifications for the physics engine of simulator. A good way to understand about editting them is following ROS Gazebo tutorials here or follow up my blog for a crashcourse NOTE : If anything is logged in red color while running any of the above commands, there has been some error. Contact collaborators in such case with the log messages.

Known issues

• Could not load controller 'right_wheel_controller' because controller type 'effort_controllers/JointVelocityController' does not exist.
  Instal ros-control package for ros-melodic
  sudo apt-get install ros-melodic-ros-control ros-melodic-ros-controllers
• [REST.cc:205] Error in REST request
  Check this Gazebo Answers thread

Built with

• SolidWorks - 3D CAD model
• ROS Meloidc - ROS control node
• Gazebo 9 - Simulation environment
• Python 2.7 - Python interface for easy UI

Authors

• Aniket Sharma

Acknowledgements

Hearty thanks to Georgia Tech for putting up and amazing walkthrough course on controlling mobile robots. Dr. Magnus Egerstedt has done a brilliant job in explaining each concept part by part and compiling them in the big picture with real world demonstration of each part. I definitely recommend completing that course for control system enthusiasts.