Lidar Based Auto Docking

General autodocking package for ROS based robots. hehe. :) Note: your dock must have the same cross sectional dimensions as the fetch charging dock.stl file. Front face is 300mm long, Each side is 100mm long, at 45 degree angle

Setup/Installation

• Firstly, clone this package into your catkin/src folder using git clone.

• Next, use catkin_make to compile the package.

• Once the package has been compiled, open auto_dock.launch(which is located in the launch folder) and modify the remap statements as neccessary.

• to="scan" (scan could be replaced by the name of your laserscan topic ie. laser_scan)

• to="cmd_vel" (cmd_vel could be replaced by a custom name for sending velocity commands ie. dock_cmd_vel)

• Next, in the params folder, open docking_parameters.yaml and tune the parameters as neccessary. Detailed descriptions of the parameters can be found in the same document.

• The docking program subscribes to the topic battery_voltage of type std_msgs/Float32 to obtain the current batteries charge state in (Volts). Do ensure you have a source to publish to this topic.

• To run the autodock program, type roslaunch fetch_open_auto_dock auto_dock.launch

General Testing

• To test the docking program without having to publish to battery_voltage and set the far goal parameters, drive/place the robot about 1 metre away from the dock with the robot pointing towards it and run the following lines:

• roslaunch fetch_open_auto_dock auto_dock.launch

• Followed by rosrun fetch_open_auto_dock dock_on_button.py

• To test the undocking program by itself (warning: robot will reverse and spin 180 degrees) run the following lines:

• roslaunch fetch_open_auto_dock auto_dock.launch

• rosrun fetch_open_auto_dock undock_on_button.py

General Notes

• It is recommended to place the near goal about 1-1.5 metres away from the dock and have the robot point towards the dock.
• Obstacle avoidance is not implemented here. Ensure dock area is clear before docking robot.