Transform failed

edit

Hello. I have a simple tf-tree (sorry, i have not enough point to download picture). May be it is available here.

If no: tf-tree is map -> odom -> base_link -> lazer. When i launch file with gmapping, not always there is an error:

Transform failed during publishing of map_odom transform: Lookup would require extrapolation into the future. Requested time 1436451359.820962500 but the latest data is at time 1436451359.720510500, when looking up transform from frame [base_link] to frame [odom].

It happens not always. But when after this file i launch the other contais hector_exploration_node, hector_exploration_planner and hector_costmap, it happens every time.

I changed the use_sim_time parameter: if it is false, there is the error, else there isn't error, but the navigation part(second launch file) only starts and doesn't work (freezes). I did this diagnostic. It works properly.

Edit:

Fist launch file:

<launch>

<node pkg="bot" type="tf_sender.py" name="tf_sender"> </node>

<node pkg="bot" type="vel_sender.py" name="vel_sender"> </node>

<node pkg="hokuyo_node" type="hokuyo_node" name="lidar"> </node>

<node pkg="robot_state_publisher" type="robot_state_publisher" name="robot_state_publisher"/>

<node pkg="hector_mapping" type="hector_mapping" name="gmapping"> </node>

<node pkg="turtlesim" type="turtle_teleop_key" name="teleop"/> </launch>

Second:

<launch>

<!--node name="static_tf0" pkg="tf"

type="static_transform_publisher" args="2 0 0 0 0 0 /map /base_link 100"/-->

<node pkg="hector_exploration_node" type="exploration_planner_node" <br=""> name="hector_exploration_node" output="screen"> <rosparam file="$(find hector_exploration_node)/config/costmap.yaml" command="load"/> <rosparam file="$(find navigation_car)/costmap_common_params.yaml" command="load" ns="global_costmap"/> <rosparam file="$(find navigation_car)/costmap_common_params.yaml" command="load" ns="local_costmap"/> <rosparam file="$(find navigation_car)/local_costmap_params.yaml" command="load" ns="local_costmap"/> <rosparam file="$(find navigation_car)/global_costmap_params.yaml" command="load" ns="global_costmap"/> <rosparam file="$(find navigation_car)/base_local_planner_params.yaml" command="load"/> <rosparam file="$(find navigation_car)/minimal.yaml" command="load" ns="/costmap_node/costmap"/>

</node>

<node pkg="hector_exploration_controller" type="simple_exploration_controller" name="hector_exploration_controller" output="screen" respawn="true">
<remap from="/cmd_vel" to="/turtle1/cmd_vel"/> </node>

<node pkg="hector_costmap" type="hector_costmap" name="hector_costmap" output="screen" respawn="false">

<!-- Costmap parameters -->
<param name="use_elevation_map" value="false" />
<param name="use_grid_map" value="true" />
<param name="use_cloud_map" value="false" />

<param name="initial_free_cells_radius"

value="0.3" /> </node>

</launch>