Re: [ros-users] Navigation stack : Error : Aborting because …

Shanker,

On Tue, Nov 30, 2010 at 6:24 PM, shankerk <shankerkeshavdas@gmail.com>wrote:

>
> Hi Eitan,
>
> In response to your question of whether I was publishing /initialpose, I
> am.
> It looks like this:
>

> header:
>  seq: 49665
>  stamp:
>    secs: 1291167633
>    nsecs: 17403000
>  frame_id: /map
> pose:
>  pose:
>    position:
>      x: 0.0
>      y: 0.0
>       z: 0.0
>    orientation:
>      x: 0.0
>      y: 0.0
>      z: 0.0
>       w: 1.0
>  covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
> 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
> 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

>

Just publishing an initialpose message isn't enough for amcl to figure out
where the robot is. You need to try and give it a reasonable close guess as
to the robot's actual position to start with. Technically, there's a way to
configure amcl to use a lot of particles that would allow amcl to solve this
"kidnapped robot" problem for you, but its computationally intensive, takes
a fair amount of time, and its doubtful that you have amcl configured to do
this. The message that you're publishing will just place the center of the
robot in the lower left corner of the map, meaning much of the robot will
actually be off the map.


>
> In response to your suggestion of using just localization and the joystick
> to tele-operate, I move the robot around, but I do not see any change in
> the
> topic /amcl_pose. It stays at the same value as /initialpose (all zeros).
>

Are you sure that laser scans, map, and odometry information are all going
into amcl correctly. You'll need all three for it to do anything.

Hope this helps,

Eitan


>
> Hope this is of some diagnostic help.
>
> Thanks
> Shanker
> --
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