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How does Hector_mapping and Gmapping do if the robot is on the slope?

asked 2014-03-05 22:36:50 -0600

Yuichi Chu gravatar image

Hello everyone! I have made both hector_mapping and Gmapping work well on the ground , but I got some problems when the robot is on continuous slope of 20 degrees.How does the two algorithms work at this situation?Can they fuse the roll and pitch with the laser data automously and I just need to publish data of roll and pitch ?Or do I need to run other nodes,such as robot_pose_ekf ?

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answered 2014-03-05 22:42:21 -0600

dornhege gravatar image

Within certain limits this can work. Did you set up your robot like this?

As always with SLAM it depends on the environment. As long as your sloped world can be interpreted as a 2D map you have a chance of that working. If your laser is not leveled the transition from flat ground to sloped ground may be tricky.

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Actually, I don't see the problem, yet. There are transforms for the robot base relative to its horizontally oriented projection over ground and to the map, transforms for the laser relative to the robot base etc. Shouldn't hector_mapping be able to make use of these transforms?

Hendrik Wiese gravatar image Hendrik Wiese  ( 2014-03-05 23:12:08 -0600 )edit

Yes, if the robot is setup like that. However, if you drive up a slope and the environment completely changes at a certain height it becomes problematic.

dornhege gravatar image dornhege  ( 2014-03-06 00:23:26 -0600 )edit

Thank you very much for answering,dornhege. I set in the launch file. I plan to set odom_frame equals to base_footprint ,and base_footprint equals to base_stablized,and use the hector_imu_attitude_to_tf to add the transform from base_stablized to base_link.

Yuichi Chu gravatar image Yuichi Chu  ( 2014-03-06 00:32:39 -0600 )edit

are there any problems with the tf setting?And would you please give me some advice about how to calculate the height between base_footprint and base_stablized ?

Yuichi Chu gravatar image Yuichi Chu  ( 2014-03-06 00:34:46 -0600 )edit

Why are you going to calculate the height between base_footprint and base_stabilized? Isn't that something that a sensor of some kind should measure?

Hendrik Wiese gravatar image Hendrik Wiese  ( 2014-03-06 01:11:32 -0600 )edit

I think that depends on the definition of what base_footprint should be. Is that at zero height relative to the robot or at zero height in the world. SLAM with 6-dof pose estimation would probably include the height offset in the map->odom transform.

dornhege gravatar image dornhege  ( 2014-03-06 22:39:52 -0600 )edit

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Asked: 2014-03-05 22:36:50 -0600

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Last updated: Mar 05 '14