Turtlebot SLAM map building problems
I have some problems building a map with my Turtlebot. I run the calibration (0.85 for the gyro and 0.93 for odom) multiple times and followed the instructions in the tutorials for starting gmapping. The map looks like a set of scans scattered around, also the orientation shown in rviz is not consistent with where the robot is going.
To me it seems like there is either a problem with the odometry/gyro or the localization is not working properly. The gyro seems to work (I see the values changing when rotating), do I need to change anything in the config files (except the odo/gyro cal values)? I should also mention that I am using all the turtlebot hardware except the Kinect mounting hardware. I made my own mounting pole but the kinect is located approximately at the same place as with the standard turtlebot.
As recommended I did the tests in http://www.ros.org/wiki/navigation/Troubleshooting and it seems like there is something wrong with the odometry, but only while turning, moving straight seems to be fine. The gyro seems to output good values (see plots) and the calibration was done multiple times. Have a look at the following link for a few screenshots and some more details.
I did a 180 degree turn and the /odom orientation (yaw) measured 176.8 degrees, however the /robot_pose_ekf/odom orientation (yaw) measured only 60.4 degrees. So that leads me to believe it is either the gyro or something wrong with the EKF.
Also, following is the calibration output (removed a few repeated lines to make the post shorter):
[INFO] [WallTime: 1324939496.895343] ... imu drift is -0.621943 degrees per second
[INFO] [WallTime: 1324939497.197380] Still waiting for imu
[INFO] [WallTime: 1324939497.499277] Still waiting for scan
[INFO] [WallTime: 1324939497.801215] Aligning base with wall
[INFO] [WallTime: 1324939498.103249] Still waiting for imu
[INFO] [WallTime: 1324939498.405232] Still waiting for scan
[INFO] [WallTime: 1324939545.778987] Odom error: 2.295941 percent
[INFO] [WallTime: 1324939545.780867] Imu error: -32.801991 percent
[INFO] [WallTime: 1324939546.090230] Still waiting for imu
[INFO] [WallTime: 1324939546.392098] Still waiting for scan
[INFO] [WallTime: 1324939546.996119] Aligning base with wall
[INFO] [WallTime: 1324939548.270806] Still waiting for imu
[INFO] [WallTime: 1324939548.573036] Still waiting for scan
[INFO] [WallTime: 1324939560.870167] Odom error: -11.098675 percent
[INFO] [WallTime: 1324939560.872639] Imu error: 19.686330 percent
[INFO] [WallTime: 1324939561.178241] Still waiting for imu
[INFO] [WallTime: 1324939561.480022] Still waiting for scan
[INFO] [WallTime: 1324939561.782138] Aligning base with wall
[INFO] [WallTime: 1324939565.640311] Still waiting for imu
[INFO] [WallTime: 1324939565.942336] Still waiting for scan
[INFO] [WallTime: 1324939573.806552] Odom error: 6.987265 percent
[INFO] [WallTime: 1324939573.808156] Imu error: 35.610160 percent
[INFO] [WallTime: 1324939574.111180] Still waiting for imu
[INFO] [WallTime: 1324939574.413042] Still waiting for scan
[INFO] [WallTime: 1324939574.715408] Aligning base with wall
[INFO] [WallTime: 1324939577.046587] Still ...