Could not find a connection between 'lidar_link' and 'base_link' because they are not part of the same tree.Tf has two or more unconnected trees.

[120ccz]

我在运行lio-sam时的tf tree如下图所示：

报错内容为：
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.600528833] [lio_sam_imuPreintegration]: Could not find a connection between 'lidar_link' and 'base_link' because they are not part of the same tree.Tf has two or more unconnected trees.
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.662496183] [lio_sam_imuPreintegration]: Lookup would require extrapolation at time 1711012939.249872, but only time 1711012939.600189 is in the buffer, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.723478771] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.249872 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.785574438] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.846604469] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.910756994] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012940.033550766] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012940.033828606] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]

[120ccz]

My tf tree while running lio-sam is shown in the following figure:

The error message is:
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.600528833] [lio_sam_imuPreintegration]: Could not find a connection between 'lidar_link' and 'base_link' because they are not part of the same tree.Tf has two or more unconnected trees.
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.662496183] [lio_sam_imuPreintegration]: Lookup would require extrapolation at time 1711012939.249872, but only time 1711012939.600189 is in the buffer, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.723478771] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.249872 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.785574438] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.846604469] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012939.910756994] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012940.033550766] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]
[lio_sam_imuPreintegration-3] [ERROR] [1711012940.033828606] [lio_sam_imuPreintegration]: Lookup would require extrapolation into the past. Requested time 1711012939.552636 but the earliest data is at time 1711012939.600189, when looking up transform from frame [base_link] to frame [lidar_link]

[mbed92]

Exactly the same issue here. LIO-SAM (ros2 branch) constantly tries to output TF between odom and base_link, no matter what.

[yanjingang]

@120ccz 请问这个问题解决了吗？我也遇到了相同的问题，多谢～