OS1 Example ROS Node

Contents

• ouster_ros/ contains sample code for publishing OS1 data as standard ROS topics

Operating System Support

• The visualizer has been tested on ROS Kinetic on Ubuntu 16.04
  • additionally requires ros-kinetic-pcl-ros, ros-kinetic-tf2-geometry-msgs and, optionally, ros-kinetic-rviz for visualization using ROS
• The visualizer has been tested on ROS Melodic on Ubuntu 18.04
  • additionally requires ros-melodic-pcl-ros, ros-melodic-tf2-geometry-msgs and, optionally, ros-melodic-rviz for visualization using ROS

Building the Sample ROS Node

• In the following instruction steps, /path/to/ouster_example is where you've cloned the repository
• Run the following command export CMAKE_PREFIX_PATH=/path/to/ouster_example
• Be sure to source the ROS setup script before building. For example: source /opt/ros/[kinetic_or_melodic]/setup.bash
• Build with mkdir -p myworkspace/src && cd myworkspace && ln -s /path/to/ouster_example ./src/ && catkin_make -DCMAKE_BUILD_TYPE=Release

Running the Sample ROS Nodes

• Make sure the OS1 is connected to the network and has obtained a DHCP lease. See section 3.1 in the accompanying software user guide for more details
• In each new terminal for each command below:
  • Make sure to source ROS environment with source /path/to/myworkspace/devel/setup.bash where /path/to/myworkspace is where the path to the workspace directory that was created when building the ROS nodes
• To publish ROS topics from a running sensor from within the ouster_ros directory:
  • Run roslaunch os1.launch os1_hostname:=<os1_hostname> os1_udp_dest:=<udp_data_dest_ip> lidar_mode:=<lidar_mode> viz:=<viz>where:
    • <os1_hostname> can be the hostname (os1-991xxxxxxxxx) or IP of the OS1
    • <udp_data_dest_ip> is the IP to which the sensor should send data
    • <lidar_mode> is one of 512x10, 512x20, 1024x10, 1024x20, or 2048x10
    • <viz> is either true or false. If true, a window should open and start displaying data after a few seconds
• To record raw sensor output
  • In another terminal instance, run rosbag record /os1_node/imu_packets /os1_node/lidar_packets
  • This will save a .bag file of recorded data in that directory
• To publish ROS topics from recorded data from withint the ouster_ros directory:
  • Run roslaunch os1.launch replay:=true os1_hostname:=<os1_hostname>
  • In a second terminal run rosbag play --clock <bagfile>
  • Note: os1_node reads and writes metadata to ${ROS_HOME} to enable accurately replaying raw data. By default, the name of this file is based on the hostname of the sensor. The location of this file can be overridden using the metadata:=<path_to_file> flag
  • If a metadata file is not available, the visualizer will default to 1024x10. This can be overridden with the lidar_mode parameter. Visualizer output will only be correct if the same lidar_mode parameter is used for both recording and replay
• To display sensor output using ROS tools (rviz):
  • Follow the instructions above for running the example ROS code with a sensor or recorded data
  • To visualize output using rviz, run rviz -d /path/to/ouster_ros/viz.rviz in another terminal
  • To view lidar intensity/noise/range images, add image:=true to either of the roslaunch commands above

Key bindings

key	what it does
o	Increase point size
p	Decrease point size
m	Cycle point cloud coloring by z-height / intensity / z-height plus intensity / range
c	Cycle color scheme for range image
shift c	Cycle color scheme for point cloud
v	Toggle color cycling in range image
n	Display ambient image from the sensor
r	Reset camera position
0 (zero)	Toggle parallel projection and reset camera
d	Cycle through fraction of the window height used for displaying range and intensity image

Mouse control

• Click and drag rotates the view
• Middle click and drag pans the view
• Scroll adjusts how far away the camera is from the vehicle