Redundancy TF baselink -> lidar and baselink -> imu ?

[pbrandschutz]

In the file params.yaml one needs to set the following params:

• frames/odom: <odom_frame>
• frames/baselink: <baselink_frame>
• frames/lidar: <lidar_frame>
• frames/imu: <imu_frame>

Out of this frames, one knows about the transformation between baselink -> lidar and baselink -> imu

In the file dlio.yaml one needs to set the following params:

• extrinsics/baselink2imu/t
• extrinsics/baselink2imu/R
• extrinsics/baselink2lidar/t
• extrinsics/baselink2lidar/R

The first 2 params describe the transformation baselink -> imu and the second describes the transformation baselink -> lidar

Is there a reason, why i need to define both?
Because with the provided frames the TF is known. Also, if there is a non-fixed joint between baselink and imu/lidar, using the hardcoded transformations would lead to issues.

Thanks