much translation error

[kimjh7669]

Hello. I have to calibrate imu(vectornav or xsens) and velodyne 16 to collect data.
Thank you for providing such a great calib tool.

I have a question about translation calib.
The imu and lidar were translated only along the y-axis about 20cm on the wooden bar, and the rest were fixed in parallel.
First, I launched ros_calib_init.launch to calculate rotation extrinsic and i was able to get quite good matrix.
Then, I launched linkalibr_ouster_vectoranv.launch to calculate final matrix.
At the result, the rotation matrix part is also bad, and the translation part is also bad.

• I_T_L_init.txt result

  0.997439 0.00637283 0.0712354 0
  0.0033876 -0.999114 0.041949 0
  0.0714397 -0.0416003 -0.996577 0
  0 0 0 1

• I_T_L_final.txt result

  -0.386475 -0.411896 0.825214 -0.559896
  -0.723331 -0.419749 -0.548273 1.4327
  0.572215 -0.808797 -0.135714 -3.28511
  0 0 0 1

• Another Question

Failed to find match for field 'ring'. Failed to find match for field 't'. Time taken for deskewing: 0.00407839 [s] [Propagation] successfully propagated [Update] successful updateScan2Scan [Update] successful updateScan2GlobalMap [ INFO] [1672722624.107535293]: Lidar scan no: 918 [ INFO] [1672722624.107562742]: No of lodom: 914 [ INFO] [1672722624.109466388]: No of imu measurements: 4 Failed to find match for field 'ring'. Failed to find match for field 't'. Time taken for deskewing: 0.00496578 [s] [Propagation] successfully propagated [Update] successful updateScan2Scan [Update] successful updateScan2GlobalMap [ INFO] [1672722624.138625378]: Lidar scan no: 919 [ INFO] [1672722624.138680511]: No of lodom: 915 [ INFO] [1672722624.141287681]: No of imu measurements: 4 Failed to find match for field 'ring'. Failed to find match for field 't'. Time taken for deskewing: 0.00486684 [s] [Propagation] successfully propagated [Update] successful updateScan2Scan [Update] successful updateScan2GlobalMap [ INFO] [1672722624.162236239]: Lidar scan no: 92 [ INFO] [1672722624.162261841]: No of lodom: 916 [ INFO] [1672722624.163941929]: No of imu measurements: 4 Failed to find match for field 'ring'. Failed to find match for field 't'. Time taken for deskewing: 0.00520134 [s] [Propagation] successfully propagated [Update] successful updateScan2Scan [Update] successful updateScan2GlobalMa [ INFO] [1672722624.187217560]: Lidar scan no: 921 [ INFO] [1672722624.187252278]: No of lodom: 917 [ INFO] [1672722624.189091669]: No of imu measurements: 4 Failed to find match for field 'ring'. Failed to find match for field 't'. Time taken for deskewing: 0.00448751 [s] [Propagation] successfully propagated [Update] successful updateScan2Scan [Update] successful updateScan2GlobalMap [ INFO] [1672722624.236811719]: Lidar scan no: 922 [ INFO] [1672722624.236841774]: No of lodom: 918 [ INFO] [1672722624.238453383]: Reached end of bag [ INFO] [1672722624.238477978]: Kalman Filtering took : 55.9863 [s] Writing KF calibration result to: /media/hdd/ros/imu_lidar_calib/230103/I_T_L_final.txt [ INFO] [1672722624.238812911]: Translation [in m]: -0.559896 1.4327 -3.28511 [ INFO] [1672722624.238831509]: Euler Angles [in deg]: 103.903 55.6102 133.176

Is the "Failed to find match for field 'ring' or 't'." critical to calib? how can I do for remove this warning?

THX!