search

hku-mars / FAST_LIO

A computationally efficient and robust LiDAR-inertial odometry (LIO) package
GNU General Public License v2.0
2.78k stars 936 forks source link

IMU offset on Livox Horizon and loosing track #108

Closed mohsenhadadi closed 2 years ago

mohsenhadadi commented 2 years ago

Hi everyone When I use Fast-Lio for Livox Horizon mounted at a 90 degrees perpendicular to my IMU's Y axis ,I encountered the following errors that I have attached. Please explain a little more about the parameters that I highlighted , I only encounter such a problem when I change livox angle related to my IMU angle downwards among Y axis , anybody can help me solving this problem??

config2 scan Untitled

XW-HKU commented 2 years ago

Why dont you use insider IMU of horizon and trouble yourself.

mohsenhadadi commented 2 years ago

Thanks for your response, but even when I use livox internal IMU and turn livox downward around Y axis the same problem will occur

XW-HKU commented 2 years ago

Thanks for your response, but even when I use livox internal IMU and turn livox downward around Y axis the same problem will occur

make sure there is no degeneration when you turn lidar downward.

mohsenhadadi commented 2 years ago

What do you mean by degeneration? Why when I change its location and direction due to my IMU in other axises rather than Y, it is fine and I don't have any error. But when misalignment is around Y and 90 degrees downward this problem happens , Can you please explain degeneration for me

XW-HKU commented 2 years ago

Thanks for your response, but even when I use livox internal IMU and turn livox downward around Y axis the same problem will occur

WHAT DO YOU MEAN "turn livox downward around Y" when you use internal imu ???????

mohsenhadadi commented 2 years ago

Look I have tried 2 different setups: 1st: using horizon + Fast Lio+ external IMU

2nd: using horizon and its internal IMU + Fast Lio

In both situation when livox is looking downward from my multirotor I get errors and generated points are not in correct position But if I install It in forward looking position on my multirotor every thing is fine

XW-HKU commented 2 years ago

If lidar is facing only one big surface like ground. It cannot locate itself.

mohsenhadadi commented 2 years ago

It was an interesting point Thank you so much for taking the time to help solve my problem

mohsenhadadi commented 2 years ago

Excuse me, I had a few more questions, can you help me? Why should scan_line in Horizon config. File be 6 while horizon is not a linear LiDAR and it has a wide non-repetitive pattern? And what about other parameters in the mapping file except extrinsics , do we need really to change them?

XW-HKU commented 2 years ago

Excuse me, I had a few more questions, can you help me? Why should scan_line in Horizon config. File be 6 while horizon is not a linear LiDAR and it has a wide non-repetitive pattern? And what about other parameters in the mapping file except extrinsics , do we need really to change them?

Actually the line number is not used in the livox lidar handler function.

mohsenhadadi commented 2 years ago

Thank you so much