Why is RosAria PointCloud and LaserScan mirrored?

asked 2019-11-12 02:37:45 -0600

fendrbud gravatar image

updated 2019-11-13 05:25:56 -0600

Is there a reason why the pointcloud and laserscan readings from rosaria (when running MobileSim) is mirror in relation to eachother when observing in RVIZ? It seems like the pointcloud (flat squares) is correctly oriented in relation to the simulation in MobileSim while the laserscan (boxes) are mirrored. Why is this?

pointcloud and laserscan illustration

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Please attach your image directly to the question, so we can keep things self-contained.

I've given you sufficient karma to do that.

gvdhoorn gravatar image gvdhoorn  ( 2019-11-12 03:01:18 -0600 )edit

Thank you, corrected now.

fendrbud gravatar image fendrbud  ( 2019-11-12 03:12:38 -0600 )edit
1

Are you sure your transforms are properly set?

It is like you are publishing the Pointcould in a frame and the laser scan in another frame with a different transformation.

Weasfas gravatar image Weasfas  ( 2019-11-12 04:15:04 -0600 )edit

I believe the OP is using one of the .xacros from the MobileRobots/amr-ros-config repository (#q335375), so I would assume those are OK, but perhaps there is some configuration that needs to be updated.

gvdhoorn gravatar image gvdhoorn  ( 2019-11-12 10:16:03 -0600 )edit

I Indeed use the urdf from MobileRobots/amr-ros-config. Specifically this one which I believe should be correct, right?

fendrbud gravatar image fendrbud  ( 2019-11-12 14:06:23 -0600 )edit

I don't see any mention of a laser scanner or anything about sensors in that .urdf. Did you add something yourself? Or how did you 'attach' the laserscanner to the robot model?

gvdhoorn gravatar image gvdhoorn  ( 2019-11-12 14:21:03 -0600 )edit

The transformation between the base_link and laser_frame is published by RosAria (see the image I added to the original post).

fendrbud gravatar image fendrbud  ( 2019-11-12 14:28:38 -0600 )edit

The transformation between the base_link and laser_frame is published by RosAria

that could be, but that does't mean it necessarily correct.

If you visualise the TF tree in RViz (add the display), does it have the expected orientation?

From your RViz+rosaria screenshot it looks to me like the entire robot is 'backwards'. Does rosaria require any configuration? Perhaps you need to tell it which model Pioneer you have and what sensors are mounted and how?

I've never used rosaria or these robots though, so I could be wrong.

gvdhoorn gravatar image gvdhoorn  ( 2019-11-13 01:29:56 -0600 )edit

I uploaded another picture showing the frames in rviz which to me seems to be correct. However, the TF tree in the left panel does not show the expected tree and it seems like there is some kind of bug since the "odom" tab between "Tree" and "base_link" is invisible.

When using MobileSim I explicitly tells it that it should simulate a Pioneer LX robot ($MobileSim --robot pioneer-lx), specifically this Aria/params/pioneer-lx.p.

edit: line 135 in the file mentioned specifies that the laser is flipper (LaserFlipped true; Laser_1 is upside-down.)

fendrbud gravatar image fendrbud  ( 2019-11-13 05:36:07 -0600 )edit