adding laser sensor to a robot for using gmapping

asked 2017-11-30 03:11:57 -0600

Henne gravatar image

Hello, I work with Naoqi Pepper and want to create a map(gmapping) with a lidar lite v3 laser sensor. I have written a driver and tf broadcaster for the lidar sensor to transform the laserscan to base_link of pepper. When i started gmapping, with my own laserscan topic and i move pepper around the room, then comes a error: Scan matching failed, using odometry; is the tf transformation wrong? I thought the transformation, which needs gmapping, is done by pepper's tf tree.

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i have the same sensor and i get the same error

marawy_alsakaf gravatar image marawy_alsakaf  ( 2017-11-30 06:33:21 -0600 )edit

This is a one-dimensional sensor, right? So you only get one single distance value. Is this correct? Are you rotating the sensor?

If not, this will not work for SLAM. There is just not enough Information and thus, the scan matcher will not score high enough, leading to this error message.

mgruhler gravatar image mgruhler  ( 2017-11-30 07:15:35 -0600 )edit

i thought i can move and rotate the robot and then the sensor picks up data for the map

Henne gravatar image Henne  ( 2017-11-30 07:38:35 -0600 )edit

i am rotating my lidar (using 3d printed mount with stepper motor) and receives the same error message

marawy_alsakaf gravatar image marawy_alsakaf  ( 2017-11-30 08:06:17 -0600 )edit

@Henne theoretically yes. But with just one reading, there is just not enough data for the algorithm to work properly. @marawy_alsakaf Do you then publish the Laserscan message after one sweep or still as single measurements? If it is the latter, there is not difference to using it fixed...

mgruhler gravatar image mgruhler  ( 2017-12-01 01:00:22 -0600 )edit

@mig i publish laserscans continuously, i get maps but they are not as expected

marawy_alsakaf gravatar image marawy_alsakaf  ( 2017-12-01 02:38:42 -0600 )edit

@marawy_alsakaf then please post a new question with more Information. Maybe also a sample what one of those scan Messages look like..

mgruhler gravatar image mgruhler  ( 2017-12-01 02:43:34 -0600 )edit
marawy_alsakaf gravatar image marawy_alsakaf  ( 2017-12-01 03:43:50 -0600 )edit