Show low frequency when recording rosbag or echoing /ouster/points topic & Artifact of ROS driver

[SangHunHan92]

1. Show low frequency when recording rosbag or echoing /ouster/points topic with ROS2 galactic driver When I launch ouster driver with ros2 launch ouster_ros driver.launch.py, lidar pointcloud showing with rviz2 shows a sufficiently high frequency (probably 20hz) [Fig 1].

However, if I record or echo /ouster/points topic, lidar frequency is significantly slower. [Fig 2] When I stopped record or echo, the original frequency is restored.

Surprisingly, ROS noetic driver doesn't have this problem at all. Both record and echo work well at 20hz.

During this process, I checked the data transfer amount with iftop, but there was no change. (Constant at about 60Mb) Changing resolution of the pointcloud also doesn't work: even the lowest 512x10 doesn't solve the issue. What's the solution for ROS2 galactic?

2. Show Artifact when running ROS driver When I launch ouster driver, lidar pointcloud in rviz show line artifact [Fig 3]. This issue shows either ROS and ROS2 driver.

(Examples of ROS noetic)

(Example of ROS2 galactic)

But, this artifact doesn't show in OusterStudio [Fig 4].

Platform (please complete the following information):

• Ouster Sensor? OS-1-32-U
• Ouster Firmware Version? 2.5
• ROS version/distro? ros2 galactic, ros noetic
• Operating System? Linux ubuntu 20.04 focal
• Machine Architecture? amd64
• git commit hash (if not the latest).

[andre-nguyen]

Is this possibly the same issue as #240 and #272 ? Have you tried https://github.com/ouster-lidar/ouster-ros/pull/302 or #320 ?

[Samahu]

@SangHunHan92 what @andre-nguyen said, most likely it is the same problem. For ROS[noetic] if you can pull #319 and see if that helps your situation or wait till it gets merged.

[Samahu]

I just noticed that you mentioned you were under ROS[galactic] so the PR that @andre-nguyen referenced is the right one