frc-2019-jetson

Team Arctos 6315's 2019 Jetson TX1 code. Made with help from @mincrmatt12.

            

Thank you to our generous sponsors:

This code runs on an NVIDIA Jetson TX1 and communicates with the roboRIO via NetworkTables. It is capable of detecting the relative position, direction and orientation of the target to within 2% error and has an MJPEG camera stream on port 1180. The code is written in C++ with ROS.

Build Environment

NVIDIA Jetson TX1 (preferred), Ubuntu 16.04 LTS (preferred) or Ubuntu 18.04 LTS. ROS Kinetic is only available on Ubuntu 16.04; use Melodic on Ubuntu 18.04.

To Build

Setup

• bash ./install_ros.sh for Ubuntu 16.04 or bash ./install_ros_melodic.sh for Ubuntu 18.04 if ROS is not installed
• bash ./build_setup.sh for Ubuntu 16.04 or bash ./build_setup.sh for Ubuntu 18.04
• source /opt/ros/kinetic/setup.bash for Ubuntu 16.04 or source /opt/ros/melodic/setup.bash for Ubuntu 18.04

Build

• catkin build

To Run

• source devel/setup.bash
• roslaunch bot bot.launch

Usage

NetworkTables

The program communicates with the roboRIO via the table roborio-jetson.

Table Entry	Modified By	Type	Purpose
vision-online	Jetson	boolean	Used to indicate that vision initialization is complete.
vision-enable	roboRIO	boolean	If set to true, vision mode will be enabled. The camera exposure will be lowered.
enable-success	Jetson	boolean	Indicates whether the vision enable operation was successful.
shutdown	roboRIO	boolean	If set to true, the Jetson will execute shutdown -P now and gracefully shut down.
horizontal-angle	Jetson	double (degrees)	The horizontal direction of the centre of the target relative to the centre of the camera. A negative angle means that the target is to the left and vice versa.
angle-offset	Jetson	double (degrees)	The horizontal angle difference between the centre of the camera and the hatch placement angle.
x-offset	Jetson	double (inches)	The left-right distance offset of the target.
y-offset	Jetson	double (inches)	The forwards-backwards distance offset of the target.
restart-server	roboRIO	boolean	If set to true, the camera server will be restarted.

Camera Streams

Once the program has started, there will be 2 camera streams available at once on port 1180:

• /stream?topic=/main_camera/image_raw
• /stream?topic=/secondary_camera/image_raw

You can also append additional options to the stream, such as quality, width and height. For example:
http://10.61.35.19:1180/stream?topic=/main_camera/image_raw&quality=25&width=640&height=360
will give you the main camera stream (Jetson at IP 10.61.35.19), with quality at 35% and dimensions 640x360. The stream is in MJPEG, so you can view it directly from the SmartDashboard.

Additionally, calling the service /vision_processing_node/publish_processed with data true will activate two more streams:

• /stream?topic=/vision_processing_node/thresholded_image
• /stream?topic=/vision_processing_node/identified_targets These streams are only updated when vision is active, and contain the image after thresholding, and the identified targets, respectively.