Turtlebot/Create doesn't move straight
When I keyboard-teleop my Turtlebot, it often shifts toward left, say a few degrees. Although this doesn't always happen, once it starts happening I have no idea how to correct that (e.g. rebooting both PC & iRobot Create didn't take effect). Calibration of odom & gyro was successful enough (but I think calibration doesn't matter since this happens even with teleop which I believe doesn't use IMU). I see neither significant amount of stuff stuck at wheels nor related info in the owner's manual available at irobot.com. Probably due to this, SLAM mapping is terrible.
Thanks.
Update) /odom returns some values, so I was wrong saying that odometry & gyro weren't used in teleop. And the value returned only shows displacement in x-direction which I interpret as the robot doesn't know at ROS level that it's shifting left. Now 3 out of 4 Turtlebots in our office show the same phenomenon.
Update-2) We found Create itself moves fairly straight by the embedded demo programs, with and without the toppings (= Turtlebot's structure). And Create even deviates when the Turtlebot's structure is removed but laptop still connected and controlled via teleop. These indicate that the root cause might lie somewhere in ROS software, its configuration or their combination.
