Could not find a connection between 'map' and 'base_link' because they are not part of the same tree.Tf has two or more unconnected trees when I set TRAJECTORY_BUILDER_2D.use_imu_data to true

[zhouleiqiang]

Dear developer,

I am Leiqiang. Recently, I have been using your Cartographer for mapping. My approach involves using 2D point clouds and IMU data. However, I have encountered an issue. Specifically, when I set TRAJECTORY_BUILDER_2D.use_imu_data to false in the Lua configuration file, the algorithm runs normally (with a warning: "W0829 18:19:24.000000 6505 pose_extrapolator.cc:152] Queue too short for velocity estimation. Queue duration: 0 ms"). However, when I set TRAJECTORY_BUILDER_2D.use_imu_data to true, I get the error message "Could not find a connection between 'map' and 'base_link' because they are not part of the same tree. Tf has two or more unconnected trees." I'm unsure of the cause. I've tried various versions of Cartographer, and the issue persists. I'm unable to resolve it. Please help me out, and I'm looking forward to your response.

Best regards,
Leiqiang