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can hector_slam be used to create 3D models?

asked 2016-02-16 13:22:12 -0600

chukcha2 gravatar image

Hello, Does hector_slam create only 2D maps or can it be used to created 3D models as well? My data comes from a Velodyne LiDAR and I need to create a 3D model of the object that is being scanned. I am looking for the right tool to use and was not sure if hector_slam could create 3D models. If it can't and you can recommend something else, please do so :) Thank you.

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answered 2016-02-17 01:28:59 -0600

hector_slam performs localization only in 2D, but if you combine that information with IMU data (for roll and pitch) and additional data about the z position (from prior knowledge, odometry or other sensors), it can be used for 3D mapping. This approach is used for building a 3D octomap-based map via mapping with known poses using a RGB-D sensor with our autonomous USAR robots as visible in this video.

Depending on your accuracy requirements, sensor motion and scale of environment other solutions might be worth a look. See for instance this recent video made using a Velodyne HDL-64e. ethzasl_icp_mapping also uses libpointmatcher and you could try that.

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Thank you Stefan. It is not immediately clear from the video the quality of the 3D model, the resolution, etc. but I will look into libpointmatcher and ethzasl_icp_mapping. I am specifically interested in mounting VLP-16 on a drone and scanning a small building with a couple cm or better resolution.

chukcha2 gravatar imagechukcha2 ( 2016-02-17 11:08:01 -0600 )edit

Hi, I'm doing something similar as you are up to. I first tried using lpm/ethzasl_icp_mapping but was disappointed by the high percentage of points that you have to filter out to get it running in realtime. I found configuring it quite hard. Please let me know if you're better at tweaking params :)

jodafo gravatar imagejodafo ( 2016-02-29 07:15:47 -0600 )edit

Also, I implemented a point to plane algo that doesnt rely on kd trees for surface normal approximation and src/tar point association. It seems to be _a_lot_ faster (>20iter, 100%pts) than lpm and doesnt deteriorate with map size . I'll try to write up the approach and release code end of next month

jodafo gravatar imagejodafo ( 2016-02-29 07:33:18 -0600 )edit

@jodafo, I haven't had a chance to try it yet. But please let me know of your results :)

chukcha2 gravatar imagechukcha2 ( 2016-03-02 15:34:42 -0600 )edit

Our team is also working on 3D SLAM by modifying some existing 2D SLAM algorithm such as hector_slam, gmapping and MRPT icp-SLAM. We are not sure whether we can successfully modify hector_slam because it seems hard to add IMU data to it, neither is gmapping. Hope to see any of your progress :)

Clack gravatar imageClack ( 2016-03-03 03:11:25 -0600 )edit

Hi Clack, how much work have you done ? have you been successful in modifying hector_slam to get a 3D SLAM ?

hashim gravatar imagehashim ( 2016-04-10 02:25:39 -0600 )edit

We've mainly focused on building a 2D SLAM system recently. However one of our teammates planned to convert 2D point cloud to 3D using data obtained by IMU. He will have this done in maybe one month. I will inform you as soon as we have a progress. And we are also curious about your idea :)

Clack gravatar imageClack ( 2016-04-10 06:07:32 -0600 )edit

I mean the 3D point clouds are based on 2D ones obtained by the laser scanner. And IMU data are used to build a transform relationship between 2D and 3D.

Clack gravatar imageClack ( 2016-04-10 06:11:22 -0600 )edit
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answered 2016-06-27 05:38:43 -0600

hashim gravatar image

updated 2016-06-28 05:22:26 -0600

i was successful in generating a 3D map of the indoor environments (somewhat rough). I have used hector_localization and hector_mapping for localizing my robot in a 3D environment and octomapps for generating the maps. hector_localization is provided with imu messages and poseupdate topic from the hector_mapping node. Thanks to Stefan for providing the file which is linked in this answer

http://answers.ros.org/question/22401...

https://www.youtube.com/watch?v=REdjz...

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Can you please email me at ateator@jhfletcher.com ? I am interested in a setup much like yours and would like to see your cose / ask you questions.

ateator gravatar imageateator ( 2016-06-27 07:44:43 -0600 )edit

@ateator, if possible, can you keep this correspondence public so that others can benefit from it too? ;) @hashim, did you use an IMU in your setup?

chukcha2 gravatar imagechukcha2 ( 2016-06-27 13:09:54 -0600 )edit

yes i have used imu in the setup, but i am thinking of writing a blog or something like this on it. first see the video, there are some errors but they can be removed using a better hardware

hashim gravatar imagehashim ( 2016-06-28 05:09:12 -0600 )edit

I've generated fairly accurate 3D maps of indoor environments using hector_mapping, hector_imu_attitude_to_tf, and octomap_server using a laser scanner, ultrasonic range finder for altitude, and an IMU for orientation.

Icehawk101 gravatar imageIcehawk101 ( 2016-06-29 08:29:11 -0600 )edit

Well, icehawk, is there any way we could get copies of some of your files? Possibly over email?

ateator gravatar imageateator ( 2016-06-29 09:40:34 -0600 )edit

@Icehawk101, how do you use a range finder for measuring altitude? And yes, it would be great to see the maps you were able to generate.

chukcha2 gravatar imagechukcha2 ( 2016-06-29 12:32:34 -0600 )edit

I have the ulrasonic sensor facing down to determine the range between the prototype and the ground, then I built a node that takes the pose estimate from hector_mapping, adds the height as a z value for the pose, then publishes a transform from base_footprint->base_stabilized

Icehawk101 gravatar imageIcehawk101 ( 2016-06-29 13:01:31 -0600 )edit

I am trying to do a similar setup, can you guide me on how to interface hector_slam with octomap 3D?

kumar12 gravatar imagekumar12 ( 2017-10-23 17:00:02 -0600 )edit

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Asked: 2016-02-16 13:22:12 -0600

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Last updated: Jun 28 '16