The site is read-only. Please transition to use Robotics Stack Exchange
| ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange |
 | 1 | initial version |
Did you publish an inverted tf for you laserscanner like suggested here: http://ros.org/wiki/gmapping#Parameters (note for ~inverted_laser)?
The patch you applied removed code that was explicitly added to handle upright laserscanners, that report the scans in an inverted order. Ticket: https://code.ros.org/trac/ros-pkg/ticket/4984
My guess would be a problem with your transform that does not reflect the correct (upside-down) position of your laserscanner. The sign of the angle_increment should only be used to check the scan-order (clockwise or ccw), but not to determine if the laser is inverted.
| | 2 | No.2 Revision |
Did you publish an inverted tf for you laserscanner like suggested here: http://ros.org/wiki/gmapping#Parameters (note for ~inverted_laser)?
The patch you applied removed code that was explicitly added to handle upright laserscanners, that report the scans in an inverted order. Ticket: https://code.ros.org/trac/ros-pkg/ticket/4984
My guess would be a problem with your transform that does not reflect the correct (upside-down) position of your laserscanner. The sign of the angle_increment should only be used to check the scan-order (clockwise or ccw), but not to determine if the laser is inverted.
I think i have found the problem why our solution didnt work for you. In line 541 of slam_gmapping.cpp the plain scan.angle_min is used. To get valid results with an upside-down scanner you should use the transformed angle_min from line 338. I am however not sure if this will break mapping for scanners which are not centered (angle_min == -angle_max) but are rotated along the z-axis (for example are looking to the left side of the robot).
| | 3 | No.3 Revision |
Did you publish an inverted tf for you laserscanner like suggested here: http://ros.org/wiki/gmapping#Parameters (note for ~inverted_laser)?
The patch you applied removed code that was explicitly added to handle upright laserscanners, that report the scans in an inverted order. Ticket: https://code.ros.org/trac/ros-pkg/ticket/4984
My guess would be a problem with your transform that does not reflect the correct (upside-down) position of your laserscanner. The sign of the angle_increment should only be used to check the scan-order (clockwise or ccw), but not to determine if the laser is inverted.
Update (18.11.2011): I think i have found the problem why our solution didnt work for you. In line 541 of slam_gmapping.cpp the plain scan.angle_min is used. To get valid results with an upside-down scanner you should use the transformed angle_min from line 338. I am however not sure if this will break mapping for scanners which are not centered (angle_min == -angle_max) but are rotated along the z-axis (for example are looking to the left side of the robot).
Update (25.11.2011): I have uploaded a bag file and our gmapping launchfile here. These are the results: pre-patch and post-patch-5250
When you post your bag, I will try to implement my suggested solution from the last edit. Maybe we can get it to work under all circumstances.
ROS Answers is licensed under Creative Commons Attribution 3.0 Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
