ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange
Ask Your Question
0

Hector_Slam mapping Hokuyo [closed]

asked 2012-08-31 03:07:02 -0500

Tirgo gravatar image

updated 2014-01-28 17:13:30 -0500

ngrennan gravatar image

Hello

I'm trying to create something similar to this http://www.youtube.com/watch?feature=player_embedded&v=F8pdObV_df4, but i'm not able to create constant good maps.

I'm using hector slam with the hokuyo URG-04LX and an imu for roll/pitch.(so no odometry) Some (indoor) maps are perfect, but if i try it again the map sometimes drifts and the position in rviz becomes weird.

So my question is: Hector_slam creates its own odometry right? Or do i have to add odometry for proper map results? Or is my laser scanner to weak for hector, so that i need something like hokuyo UTM-30LX?

Thx for your response

edit retag flag offensive reopen merge delete

Closed for the following reason the question is answered, right answer was accepted by Tirgo
close date 2016-04-08 04:49:17.205694

1 Answer

Sort by ยป oldest newest most voted
1

answered 2012-08-31 03:25:38 -0500

Well Hector is able to work without any odometry support. In such a case Hector uses the laser data only to calc. its location in respect to the map. As long as the laser data are meaning full hector will work well in this mode, i.e. the range, noise, updated rate and vehicle speed stay within some bounds. For example, the hokuyo URG-04LX has a range of 4-7m (if i remember correctly) which means your environment should not have spots larger the 4-7m free space. As rule of the thump you can say that at least 50% of the beams should stay within half of the max range. Therefore your outdoor conditions are easily violating this rule of the thump.

Hope this helps.

edit flag offensive delete link more

Comments

Hello thx for your response. So basically i have to avoid spots with over 4-7 meter free space. That would explain the broken maps. Are there any tricks to work around? Or other stacks like hector_slam which could work? Because 4-7 meter is even indoor not that much.

Tirgo gravatar image Tirgo  ( 2012-08-31 04:00:05 -0500 )edit

hector slam can handle slam without any odom param, I can understand when the robot do the linear move, but think about this situation, if the robot just do rotation in the same place, the hector slam can know the rotation accurate? and if it is a round spheric environment, I don't think hector c

bredzhang gravatar image bredzhang  ( 2015-12-17 22:02:04 -0500 )edit

Depends on your hardware and the enviroment, but yes it can also handle rotations. If you have a short range laser scanner or an enivorement without many charactaristica you are running into problems.

Tirgo gravatar image Tirgo  ( 2016-04-08 04:49:00 -0500 )edit

Question Tools

Stats

Asked: 2012-08-31 03:07:02 -0500

Seen: 1,864 times

Last updated: Aug 31 '12