# Revision history [back]

### Tf timout with multiple machines

Hi! I try to get the navigation stack running on my robot. I've got ROS running on the robot and on an PC used for visualization in Rviz and, if possible, for calculation like gmapping.

Nodes i need: odometry_publisher; base_control; tf_broadcaster; rviz; gmapping; depth_to laserscan; freenect(kinect); move_base.

I tried to distribute the nodes on the two PC in so may different combinations. But i allways get the same problem:

When i start all the nodes on my robot like: Odometry_publisher, freenect(kinect) and base_control everything looks good. Then i start the rest of the nodes on the other PC.

In rviz it needs one minute until the laser scan in shown( before it tells that there is no transform from base_link to map). even if the laser scan is not visible in rviz, gmapping is building map After that minute all of my nodes work fine. the is tha map made by gmapping and all the sensordata is published.

BUT: Starting the Navigation stack produces that Warning and does nothing afterwards:

 [ WARN] [1532685774.079683838]: Timed out waiting for transform from base_link to map to become available before running costmap, tf error: Lookup would require extrapolation into the past.  Requested time 1532685692.802003361 but the earliest data is at time 1532685767.757000016, when looking up transform from frame [base_link] to frame [map]. Transform returned after 0.100864 timeout was 0.1.


btw i does make no change where the master runs I think my time is completely messed up. anyone an idea how to fix that?

thanks you so much!

### Tf timout with multiple machines

Hi! I try to get the navigation stack running on my robot. I've got ROS running on the robot and on an PC used for visualization in Rviz and, if possible, for calculation like gmapping.

Nodes i need: odometry_publisher; base_control; tf_broadcaster; rviz; gmapping; depth_to laserscan; freenect(kinect); move_base.

I tried to distribute the nodes on the two PC in so may different combinations. But i allways get the same problem:

When i start all the nodes on my robot like: Odometry_publisher, freenect(kinect) and base_control everything looks good. Then i start the rest of the nodes on the other PC.

In rviz it needs one minute until the laser scan in shown( before it tells that there is no transform from base_link to map). even if the laser scan is not visible in rviz, gmapping is building map After that minute all of my nodes work fine. the is tha map made by gmapping and all the sensordata is published.

BUT: Starting the Navigation stack produces that Warning and does nothing afterwards:

 [ WARN] [1532685774.079683838]: Timed out waiting for transform from base_link to map to become available before running costmap, tf error: Lookup would require extrapolation into the past.  Requested time 1532685692.802003361 but the earliest data is at time 1532685767.757000016, when looking up transform from frame [base_link] to frame [map]. Transform returned after 0.100864 timeout was 0.1.


btw i does make no change where the master runs I think my time is completely messed up. anyone an idea how to fix that?

thanks you so much!

### Tf timout timeout with multiple machines

Hi! I try to get the navigation stack running on my robot. I've got ROS running on the robot and on an PC used for visualization in Rviz and, if possible, for calculation like gmapping.

Nodes i need: odometry_publisher; base_control; tf_broadcaster; rviz; gmapping; depth_to laserscan; freenect(kinect); move_base.

I tried to distribute the nodes on the two PC in so may different combinations. But i allways get the same problem:

When i start all the nodes on my robot like: Odometry_publisher, freenect(kinect) and base_control everything looks good. Then i start the rest of the nodes on the other PC.

In rviz it needs one minute until the laser scan in shown( before it tells that there is no transform from base_link to map). even if the laser scan is not visible in rviz, gmapping is building map After that minute all of my nodes work fine. the is tha map made by gmapping and all the sensordata is published.

BUT: Starting the Navigation stack produces that Warning and does nothing afterwards:

 [ WARN] [1532685774.079683838]: Timed out waiting for transform from base_link to map to become available before running costmap, tf error: Lookup would require extrapolation into the past.  Requested time 1532685692.802003361 but the earliest data is at time 1532685767.757000016, when looking up transform from frame [base_link] to frame [map]. Transform returned after 0.100864 timeout was 0.1.


btw i does make no change where the master runs I think my time is completely messed up. anyone an idea how to fix that?

thanks you so much!