METR4202

This is the source code for the 2022 METR4202 team project, hosted on GitHub. Clone it with

$ git clone https://github.com/Ethan1023/METR4202.git

Package dependencies and RPi setup are all listed in a very nice repository.

Setup and Launch

After cloning this project, a few steps are necessary before it will run. First, source ROS Noetic using:

$ source /opt/ros/noetic/setup.bash

Camera setup

Running the Ximea camera requires a reasonably lengthy setup and calibration, as documented in UQ-METR4202/metr4202_ximea_ros.

Assuming this has been done, and the correct camera IDs are used specified in the ximea_ros and ximea_colour, the only necessary modification is adding the following line to ximea_ros/launch/ximea_aruco.launch:

        <arg name="fiducial_len" value="0.028"/>

Add this line under the last existing argument within the <include> tags. The value of this argument should be set to the side length (in meters) of the ArUco tags that will be used.

Finally, if not done already, run the following command after each boot to disable the USB memory limits:

echo 0 | sudo tee /sys/module/usbcore/parameters/usbfs_memory_mb

As a final note, the accuracy of the camera is highly dependent on all of zoom, focus and aperture, as well as lighting conditions. Assuming the zoom and focus are reasonably well set and the lighting conditions are sufficient, if the camera is having trouble detecting ArUco tags, this may suggest the aperture is too large.

Beware that there is a trade-off here, as reducing the aperature too much may result in inconsistent colour detection. This is best tuned experimentally by trial and error in the environment where it will be used.

Dynamixel Setup

Follow the procedure here, using the config in configs/ in this repository

Make and launch

Make the project by changing into the catkin_ws directory (or moving the entire project into ~/catkin_ws/src if not there already).

$ cd ~/catkin_ws && catkin_make && source ./devel/setup.bash

Start the ROS master:

$ roscore

Now in a new terminal, the project can be launched using:

$ roslaunch metr4202 project.launch

The nodes will start printing to the terminal, and two camera views will pop up. Change the camera view to colour by activating the first camera view and hit spacebar. The robot is now ready to sort and throw your luggage!

ROS Details

Consists of components of a ROS package, including

• Launch files in launch/
• Python scripts in scripts/
• Custom messages in msg/
• Dependencies in package.xml
• Build information in CMakeLists.txt

Launch files

• project.launch
• detection.launch
• control.launch

Current nodes

• state_machine
• joint_controller
• box_transform
• colour_detection
• gripper

Other

• Dynamixel config for https://github.com/UQ-METR4202/dynamixel_interface can be found in configs/
• Ximea camera calibration can be found in configs/