Confusion about TF Odom to Base_footprint
So I have some confusion about transformation between odom and base_footprint. I am using turtlebot_gazebo turtlebot3_house,launch. After I ran this launch file, I checked the TF frame view. I find that the only transform is odom->base_footprint.
My understanding is: odom frame and base_footprint should both be the position of robot. Why this tf exist? Can someone explain this? Thanks in advance!
Below is /odom topic
zhefan@zhefan-OMEN-by-HP-Laptop-17-an0xx:~$ rostopic echo -n1 odom
header:
seq: 4454
stamp:
secs: 148
nsecs: 500000000
frame_id: "odom"
child_frame_id: "base_footprint"
pose:
pose:
position:
x: -3.0000338659
y: 1.00008570224
z: -0.00100139306072
orientation:
x: -9.64725127562e-06
y: 0.00385309683028
z: 0.00067114823324
w: 0.999992351527
And this is tf:
transforms:
-
header:
seq: 0
stamp:
secs: 38
nsecs: 700000000
frame_id: "odom"
child_frame_id: "base_footprint"
transform:
translation:
x: -3.00002305648
y: 1.00002237871
z: -0.00100139296313
rotation:
x: -7.72369546136e-06
y: 0.00385310031639
z: 0.000171801496723
w: 0.999992561994
---