Slam gmapping tutorial troubleshooting

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One more thing: when I downloaded the provided .bag file from Willow Garage and tried playing it, this is what happened:

    $ rosbag play basic_localization_stage.bag
[ INFO] [1311183994.765718223]: Opening basic_localization_stage.bag

Waiting 0.2 seconds after advertising topics... done.

 Hit space to toggle paused, or 's' to step.
 [RUNNING]  Bag Time:     34.600000   Duration: 0.000000 / 1239670987.745222    
 [RUNNING]  Bag Time:     34.600420   Duration: 0.000420 / 1239670987.745222   
 [RUNNING]  Bag Time:     34.703970   Duration: 0.103970 / 1239670987.745222    
 [RUNNING]  Bag Time:     34.872898   Duration: 0.272898 / 1239670987.745222

...etc. It ran until bag time hit 126, then this message came up:

 [RUNNING]  Bag Time:    126.300712   Duration: 91.700712 / 1239670987.745222   
 [RUNNING]  Bag Time:    126.400910   Duration: 91.800910 / 1239670987.745222   
 [RUNNING]  Bag Time:    126.510560   Duration: 91.910560 / 1239670987.745222    
 [RUNNING]  Bag Time:    126.600720   Duration: 92.000720 / 1239670987.745222  
 [FATAL] [1311182318.849101157]: Time is out of dual 32-bit range

I went ahead with the next few steps in the tutorial anyway, and generated a partial map off the data from WG, below.

(not sure what's going on with the picture there - I'll try to get it up somehow)

Any enlightenment?

Thanks,

-Khiya

I've found a partial solution: I do not have a fully functional robot yet - I was assuming I could just set up slam_gmapping with a Hokuyo URG-04LX laser ranger and an ASUS EeeBox running ROS. That means I had not set up my /tf or /odom nodes. I'm not sure why this caused trouble, but apparently it did. As a temporary fix, I used this launch file to initialize the laser before I ran through the steps in slam_gmapping tutorial:

 <launch>
    <node pkg="hokuyo_node" type="hokuyo_node" name="scan">
    <param name="port" value = "/dev/robot/laser" />
    <param name="max_ang_degrees" value="90" />
    <param name="min_ang_degrees" value="-90" />
    <param name="frame_id" value="base_scan" />
    </node>

    <node pkg="tf" type="static_transform_publisher" name="hokuyo_static_tf_publisher" args="0 0 0 0 0 0 1 base_link base_scan 50" />

    <node pkg="tf" type="static_transform_publisher" name="odom_static_tf_publisher" args="0 0 0 0 0 0 1 odom base_link 50"/>

</launch>

All I did in this file was set up a static identity transform from base_link to base_scan, and from odom to base_link. The dual 32-bit error did not appear, thankfully, but another problem did happen: In the terminal running slam_gmapping, this warning appeared when I played back the bag file:

[WARN] [1312405487.766138148]: TF_OLD_DATA ignoring data from the past for frame /odom at time 1.31241e+09 according to authority /play_1312405475737786833
Possible reasons are listed at 
[ WARN] [1312405487.768969562]: TF_OLD_DATA ignoring data from the past for frame /base_scan at time 1.31241e+09 according to authority /play_1312405475737786833
Possible reasons are listed at 
[ WARN] [1312405487.780878676]: TF_OLD_DATA ignoring data from the past for frame /odom at time 1.31241e+09 according to authority /play_1312405475737786833
Possible reasons are listed at

and then nothing, so I don't know where 'Possible reasons' are listed. After that, when I ran the map_saver function, it began but I received a 'Waiting for map' message that did not end until I canceled the process.

There must be something else that's obvious, I'm just missing it. Can anyone spot it?

Thanks,

Khiya