ROS2 compatibility mode

[Samahu]

Related Issues & PRs

• foxy's ROS2 foxy compatibility mode #149
• resolves Homologation of ouster client for ROS / ROS 2 support #8
• resolves Plans for ROS2? #50
• resolves Publishing pointclouds in os_sensor frame is misleading #33
• resolves Low performance ROS2 Humble Beta #63
• partially addresses Do you plan to release APT packages for the ROS2 Rolling driver? #69
• related Delay on lidar scans #76
• related Pointcloud partially flickering (incomplete) in rviz. #110
• incorporates add option for data frame #127
• related Frame Rate Drop #137
• related corrupt scans #144

Summary of Changes

• Build compatibility mode with Steve Macenski's implementation of Ouster driver for ROS2
• Combine the functionality of os_sensor and os_cloud into a single node/component named os_driver
• Retain the os_sensor and os_cloud for backward compatibility and also still be able to record the raw packets
• Add unit tests around the ThreadSafeRingBuffer
• Add an option to select the frame of reference when publishing point cloud and use lidar_frame by default
• Provide topic mapping that is compatible with Steve Macenski's Ouster ROS2 driver
  • Provide support for parsing Steve's Ouster ROS2 yaml format
    • Partially support proc_mask handling (all flags supported excluding the IMG)
  • Create and utilize an RVIZ config file that immediately maps to the topics of the community driver
• Add the ability to publish sensor_msgs::msg::LaserScan
  • Added a scan_ring parameter to enable picking a specific ring.
• Add ability to override QoS settings
• Factored out the functionality of OusterImage and integrate into OusterDriver same as os_cloud

Performance Comparison

Still in the process of running a full benchmark but in general the current data shows the following:

• Improved overall performance over the current mainline driver when using the new os_driver node (a reduction in CPU utilization by 30%)
• Improved overall performance and stability over the community driver when using os_driver node (a reduction in CPU utilization by 15-20%)

TODOs

• Provide topic mapping that is compatible with Steve Macenski's Ouster ROS2 driver
• Provide support for parsing Steve's Ouster ROS2 yaml format
  • Support the proc_mask parameter
• Add an option to use select the frame_id for published point clouds between os_lidar and os_sensor.
• Hook up the implemented ThreadSafeRingBuffer to minimize packets drop in case the processing thread falls behind.
  • Add units around the ThreadSafeRingBuffer
  • Reduce the number of synchronization objects needed
• Add the ability to publish sensor_msgs::msg::LaserScan
  • Configurable ring (De-scoped)
• Configurable QoS (allow system default qos)
• Factor out the functionality of OusterImage and integrate into OusterDriver same as os_cloud (De-scoped)

Validation

Old Interface Maintained

The three launch commands should be fully preserved under the new changes

# regular launch
ros2 launch ouster_ros sensor.launch.xml    \
    sensor_hostname:=<sensor host name>
# record
ros2 launch ouster_ros record.launch.xml    \
    sensor_hostname:=<sensor host name>     \
    bag_file:=<optional bag file name>      \
    metadata:=<json file name>              # optional
# replay
ros2 launch ouster_ros replay.launch.xml    \
    bag_file:=<path to rosbag file>         \
    metadata:=<json file name>              # optional if bag file has /metadata topic

Single Node (os_sensor+os_cloud+os_image)

To use the new combined node os_driver run the launch file driver.launch.py as shown below but please find the driver_config.yaml and adjust to match your sensor settings:

ros2 launch ouster_ros driver.launch.py

Single Node (Compatibility Mode)

To have the same topic names as the community driver use driver_launch.py launch file instead, this launch file points to the community_driver_config.yaml and it should work seamlessly except for the IMG option of proc_mask parameter (all flags should work as expected)

ros2 launch ouster_ros driver_launch.py

proc_mask flags

• When running in a single node test enabling \ disabling individual flags for the proc_mask.
  • For example enable only the IMU, SCAN, IMG and PCL.
  • Watch that only the specific message of the enabled message type actually gets published

Alternate QoS settings

• Test enabling \ disabling the use_system_default_qos
  Note that when setting use_system_default_qos to true RViz won't be able to display the point cloud by default. You would need to select /ouster/points topic and adjust the policy to be reliable.

Alternate PointCloud frame

• Test altering point_cloud_frame between os_lidar and os_sensor
  Altering between the two should be clearly reflected in the the rendered point cloud in RVIZ

Sensor Lifecycle Management

• Connect the sensor, then invoke the /ouster/reset service

  ros2 service call /ouster/reset std_srvs/srv/Empty

  • Watch point cloud update pauses for couple of second while the sensor restarts then the node resumes normally.
• Connect to the sensor, open the sensor configuration change and apply any change except the udp_lidar_profile.
  • Watch the os_driver node detects the change and re-adapts accordingly.
• Connect to the sensor, open the sensor configuration change and change the udp_lidar_profile.
  • Watch the sensor, generates few errors and then performs successfully re-activates itself.

[kairenw]

😍