Instructions for AGV SIM TASK

Catkin Workspace

Create a catkin workspace through the following commands

mkdir –p ~/catkin_ws/src
cd ~/catkin_ws/src
catkin_init_workspace
cd ~/catkin_ws/
catkin_make
source ~/catkin_ws/devel/setup.bash
echo "source ~/catkin_ws/devel/setup.bash" >> ~/.bashrc

To ensure your workspace is properly set up, check for the ROS_PACKAGE_PATH using the following command. You must see the current directory similar to

echo $ROS_PACKAGE_PATH

/home//catkin_ws/src:/opt/ros/noetic/share:/opt/ros/noetic/stacks

Cloning the current repository

All the executables and folders are to be placed in src/ and catkin_make every time you modify the src/ folder. Hence, navigate to the src/ folder and clone the required repositories & dependencies as follows:

cd ~/catkin_ws/src
git clone https://github.com/tharun-selvam/sim_task_agv.git

Dependencies

git clone https://github.com/nilseuropa/realsense_ros_gazebo.git

git clone https://github.com/issaiass/realsense2_description.git

sudo apt-get install ros-noetic-teleop-twist-keyboard ros-noetic-urdf ros-noetic-xacro ros-noetic-rqt-image-view  ros-noetic-robot-state-publisher ros-noetic-joint-state-publisher-gui

Before moving on to launching the setup, navigate to the root of the workspace and make the workspace

cd ~/catkin_ws
catkin_make

Use the commands in the following section to launch the bot.

Running Gazebo Simulations

In terminal 1,

roslaunch tortoisebotpromax_gazebo tortoisebotpromax_playground.launch

Running RViz Visualization

Open another terminal (terminal 2)

roslaunch tortoisebotpromax_description display.launch

You may change the Rviz configuration by adding topics for generating maps, visualization purposes, etc.,

Teleoperation of the bot

In terminal 3

rosrun teleop_twist_keyboard teleop_twist_keyboard.py

and follow the instructions in the terminal for teleoperation. Note: Use keyboard commands while being in the terminal for publishing the control commands.

You may subscribe to the needed sensor feedback and publish your control commands through corresponding rostopics via subscribers and publishers. To list down all rostopics, use

rostopic list

Getting the TortoisebotProMax Running

Here's a quick overview of the launch files that need to be initiated to get the robot running in autonomous/manual mode:

1. bringup.launch: Initiates the necessary hardware nodes and state publishers on the robot. Launching this script will get you:

• Teleop control
• Lidar visualization
• Wheel odometry
• Imu data
• State publishers
• Internal PID control Here's the command line:

roslaunch tortoisebotpromax_firmware bringup.launch pid:=true

(Note: You can turn PID off simply by changing the argument to pid:=false)

2. server_bringup.launch: Initiates necessary localization tools for autonomous navigation Launching this script will get you:

• Cartographer Node Initialization
• Laser-based odometry Here's the command line:

roslaunch tortoisebotpromax_firmware server_bringup.launch

3. tortoisebotpromax_navigation.launch: Initiates the autonomous navigation for exploration as well as localization modes Launching this script will get you:

• Cartographer Based Mapping/Localization
• Move base navigation tools Here's the command line:

roslaunch tortoisebotpromax_navigation tortoisebotpromax_navigation.launch exploration:=true

Note:

• exploration:true enables the robot to move in SLAM mode. It can autonomously navigate in the environment while creating the map for the same.
• exploration:=false mode sets the robot in localization mode. It spawns itself in the map you provide and navigates within the space.
• When in localization mode, you can provide the map file by:

roslaunch tortoisebotpromax_navigation tortoisebotpromax_navigation.launch exploration:=false map_file:/"location of your map file"

Task

After launching the above setup,

1. You will need to visualize the lidar point cloud in Rviz. (Take a screenshot of Rviz as proof)
2. Teleoperate, scan the AruCo markers and store the corresponding waypoint information and robot's pose.
3. Generate an occupancy grid-based map ( You may use established algorithms by mentioning) while teleoperating with the bot.
4. Finally, drive the robot autonomously through a sequence of waypoints stored.

General Useful references

1. ROS Tutorials -http://wiki.ros.org/ROS/Tutorials
2. Rviz User guide -http://wiki.ros.org/rviz/UserGuide

Some useful tips

• Try reading on launch files, ros params, urdf files to get an idea of the code base
• Learning about urdf files also exposes you to learn about Gazebo and Rviz which really helps
• As you might have realised by now, there aren't many video tutorials on ROS. So you have to learn by going through the documentation
• Google WHATEVER error you face and go through every link and comment on stackoverflow