How to use nebula sensor driver?

[LuZhishan]

I am trying to launch a robosense Helios-16P lidar with nebula. But there are many params I don't understand, so I want to kown how to change these params to my lidar?

[LuZhishan]

I set data_port to mosp_port in rslidar_sdk and gnss_port to difop_port . Then I get a strange point cloud

so how to salve this problem?

[LuZhishan]

new bag with log
bag.zip

[mojomex]

Thank you for the Rosbag. It uncovered a bug that was introduced in a recent Nebula update, which I currently PR'ed a fix for:

• fix(robosense): include DIFOP packets in record/replay functionality tier4/nebula#213

Without this fix, not all necessary information was recorded from the sensor.
Could you either wait until the fix is merged, or use the Nebula branch from the PR and record
/robosense_packets and /robosense_info_packets?

Sorry that this process is more tedious than expected 🙇

[LuZhishan]

I used your breach fix/robosense-packet-replayand got a bad result

[robosense_ros_wrapper_node-1] [WARN] [1730337443.635416077] [robosense_ros_wrapper_node.DecoderWrapper]: Missed pointcloud output deadline
[robosense_ros_wrapper_node-1] [ERROR] [1730337447.535254476] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337448.035473985] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337448.536937740] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [WARN] [1730337448.635467733] [robosense_ros_wrapper_node.DecoderWrapper]: Missed pointcloud output deadline
[robosense_ros_wrapper_node-1] [ERROR] [1730337449.038271755] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337449.538812553] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337450.038929406] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337450.539662253] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337451.040745835] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337451.542259173] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337452.042564248] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337452.543023233] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337453.043222176] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337453.544886532] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [WARN] [1730337453.635567471] [robosense_ros_wrapper_node.DecoderWrapper]: Missed pointcloud output deadline
[robosense_ros_wrapper_node-1] [ERROR] [1730337454.046113433] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337454.547474920] [robosense_ros_wrapper_node]: Packet(s) dropped
[robosense_ros_wrapper_node-1] [ERROR] [1730337455.048625140] [robosense_ros_wrapper_node]: Packet(s) dropped

fix.zip
Here is the new bag,and there is no packets msg.

[LuZhishan]

pcap.zip
Here is a pcap file, maybe it is useful to you

[mojomex]

Hi, I'm sorry to get back to you only now. I had a look at the PCAP, and it seems that our decoder supports only Helios-32. For Helios-16, the elevation angle is calculated differently.

We currently do not have any contributors with a Helios-16, but we would be open to collaborate with you if you have the time and resources to make a PR to Nebula 🙇
It looks like everything besides the elevation angle correction works as expected. If you are interested, please have a look at Helios-16's User Manual for a possible implementation.

[LuZhishan]

@amc-nu Could you please help me with this problem?

[polurik]

Hello, Mr LuZhishan, I want to integrate vlp-16 Lidar to autoware.universe. I am using single_lidar_sensor_kit package along with the vehicle model sample_vehicle
I am unable to get even the point cloud. can you please help me by telling the steps you followed to get the point cloud in the first place?i followed the procedure in the following page:
https://autowarefoundation.github.io/autoware-documentation/main/how-to-guides/integrating-autoware/creating-vehicle-and-sensor-model/creating-sensor-model/

[mojomex]

Hi, please refer to the Nebula documentation for details on how to configure for your sensor.
Also be sure to look at the logs from Nebula, as it reports any connection or configuration errors.

[polurik]

Dear Mrmojomex,
I installed nebula node using the link:
https://github.com/tier4/nebula
I have built the node. It was successful.I used the following command to launch:
ros2 launch nebula_ros velodyne_launch_all_hw.xml sensor_model:=VLP16.

the node starts fine. How do I see the point cloud from here?

[mojomex]

Hi, you can use a tool like RViz2, Foxglove or Lichtblick to visualize ROS2 topics, including pointclouds.
Please refer to one of the below:

• RViz2 guide
• Foxglove (account required) with ROS2 bridge

[LuZhishan]

@mojomex There is another bug in nebula driver with Helios. The time stamp of pointcloud is wrong.
Use Sensor Time doesn't seem to be effective. I tested it using 2024.8 and the latest code, and the results were the same

[polurik]

nikhil0353
—
Today at 10:36 AM
Hi Iu, I am integrating sensors (Lidar VLP16 and an IMU) to autoware. universe. For Lidar I am using nebula package.
there are two nebula packages(one in src/sensor_component/external/nebula and another in src/sensor_kit/sample_sensor_kit_launch/common_sensor_launch/nebula_node_container_launch.py

I used the stack in the main branch. IS it ok to use that ?or is it recommended to use some other version?

I am facing the following issues
1- The nebula folder on src/sensor_component/external/nebula path publishes
/velodyne_packets
/velodyne_points

But the sensing pipeline does not seem to work. the nebula node in the following path seem to launch the sensing pipeline(as per the details in the launch file). But this process is not happening.
path of the folder: src/sensor_kit/sample_sensor_kit_launch/common_sensor_launch/nebula_node_container_launch.py

So my understanding is this is how the topics are getting modified after moving through each stage of sensing pipeline:
velodyne_points -->pointcloud_raw_ex----->self_cropped/pointcloud_ex------->mirror_cropped/pointcloud_ex------>rectified/pointcloud_ex------->pointcloud_before_sync

But I am not even getting ros2 topic echo top/pointcloud_raw_ex

Can you please help?
I will greatly appreciate your support

[mojomex]

Hi,
Nebula is the sensor driver (decoding incoming LiDAR packets, publishing LiDAR diagnostics etc.) while the sample_sensor_kit is what defines what sensors and which preprocessing pipeline are configured.

Please refer to the Autoware tutorials (especially the sensor kit) section for how to set this up correctly.

If you're only using one LiDAR you could have a look at single LiDAR sensor kit which is also included in default Autoware.