No localization with Livox Lidar

[WeilongXia]

Thanks a lot for opening source such a great work, but when I run the code, I found that the odometry output pose has always been the origin and has not changed. I have checked the data topics of lidar and imu, and there is nothing wrong. The frequency of lidar is 10Hz, and the frequency of imu is 200Hz. What are the possible reasons for the above case? Looking forward to your reply~

[kennyjchen]

Yeah I haven't tested Livox support out since I don't have any data. Think you could upload a bag for me to play around with? Thanks!

[WeilongXia]

This is the dataset of Livox-mid360: https://1drv.ms/u/s!AjkIEg1kWUNeiAIZHIDBTzXmtHqf?e=cWek2u
And the extrinsic between the Lidar frame and IMU frame is

[Joosoo1]

Yes, it seems that we are experiencing the same problem, may I ask if you are using it as a navigation for robots? Drones or unmanned vehicles?Maybe we can communicate that i have recently encountered some difficulties.

[WeilongXia]

Yeah I 'm going to use it as a localization module for drones, and maybe we can use the g-mail to communicate: xiawl0524@gmail.com

Yes, it seems that we are experiencing the same problem, may I ask if you are using it as a navigation for robots? Drones or unmanned vehicles?Maybe we can communicate that i have recently encountered some difficulties.↳

[Joosoo1]

ok, after my test, livox-mid360 can run DLIO successfully, just change the point cloud publishing form "xfer_format" to "2" in livox_ros_driver2, then it can run DLIO successfully. DLIO can be run successfully, as follows:

[Joosoo1]

But the results do not seem to be very good, odom data z-axis jitter will be relatively large, may be due to the reason of not tuning parameters, but also may be due to the built-in imu noise is too large, the follow-up we can exchange about how to make it better and more stable, in addition, I am also intended to apply it to the top of the drone, used as navigation and positioning.

[WeilongXia]

Thanks to your reply, the dimension of the acceleration data from the build-in imu in Livox MID-360 is g(gravity) instead of m/s^2, maybe you should multiply the data with a constant value like 9.8?

[Joosoo1]

Thanks to your reply, the dimension of the acceleration data from the build-in imu in Livox MID-360 is g(gravity) instead of m/s^2, maybe you should multiply the data with a constant value like 9.8?

ok,i will try!If you have better results, please let me know too!

[WeilongXia]

I have tried to set xfer_format t o 2, and the result seems great!

[Joosoo1]

wow! Your results look great, the position estimation is accurate and the built point cloud map has no drift, but my results are as bad as ever, still with a large offset on the z-axis, can you share your configuration parameters file? Also, about the z-axis, my livox has a z-axis accel bias of -5, while yours is 0. I think there is something wrong here.

[kennyjchen]

Hi @WeilongXia and @Joosoo1 -- thanks for the great discussion you two have started here. Looks like the Livox branch is working! It just needs to be published in the standard format.

Yeah something is definitely wrong if the IMU biases are that large. Have you checked your extrinsics? That's typically an issue, especially since the convention for IMU and LiDAR are different.

Edit: it's working, but deskewing is not (note the deskewed points: 0 in the terminal screenshots above). Looks like a per-point timestamp issue with Livox sensors.

[kennyjchen]

@Joosoo1 Yes, change the units of the accelerometer to m/s^2 as per the advice above.

Could someone record me a dataset in the new xfer_format? Thanks.

[Joosoo1]

Well, it's true that because of the acceleration units, it has to be m/s^2 for it to work well.
I provide the dataset：https://1drv.ms/u/s!AiyqJY-cvK5varx4IwdfshuTfeE?e=TtbAdI
pointcloud_topic:/livox/lidar
imu_topic:/livox/imu (the acceleration unit is g, so you need to modify the code in DLIO)
The parameters are:
! livox-mid360 (built-in imu) extranet

[dxdydz3dt]

Can you translate in English Please!. I am trying to run Livox but its not working

[Joosoo1]

Can you translate in English Please!. I am trying to run Livox but its not working
You can take a look at this: #5 (comment)

It is necessary to additionally convert the acceleration units of the /livox/imu topic output to m/s^2,then the DLIO will work well, of course all this needs to be under the source code of the livox branch.