Create/Roomba odometry

Question

Hi,

I am thinking of getting a iRobot Create or a Roomba for a project which requires some no-so-bad odometry. I have gone through this thread and I have also noticed the following comment on turtlebot_node/roomba_sensor_handler.py

   114     # The distance and angle calculation sent by the robot seems to
   115     # be really bad. Re-calculate the values using the raw enconder
   116     # counts.

If I get a iRobot create I will get only the distance and angle which 'seems to be really bad' since iRobot create does not give out raw encoder counts.

I would like to know if this is still the case ? I prefer iRobot create since it is inexpensive and I don't need the vacuum function. Furthermore, It would be great if any of the users can give me some quantitative values on the odometry errors.

Gajan

p.s: Calling up iRobot support did not help at all :(

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Originally posted by gajan on ROS Answers with karma: 13 on 2012-04-16

Post score: 0

Answer 1

This was actually my comment :-). My problem was that odometry was actually really broken, i.e. it gave completely wrong values on the roomba. That's why the roomba driver uses the raw encoder values. I didn't try, but i expect the iCreate to give at least correct odometry values but maybe someone who owns one might want to confirm that.

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Originally posted by Lorenz with karma: 22731 on 2012-04-16

This answer was ACCEPTED on the original site

Post score: 1

Answer 2

NOTE: Create 2 and Roomba 500/600 firmware versions prior to 3.3.0 return an incorrect value for sensors measured in millimeters. It is recommended that you read the left and right encoder counts directly (packets IDs 43 and 44) and do the unit conversion yourself.
To determine the firmware version on your robot, send a 7 via the serial port to reset it. The robot will print a long welcome message which will include the firmware version, for example: r3_robot/tags/release-3.3.0.

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Originally posted by sonictl with karma: 287 on 2015-11-24

This answer was NOT ACCEPTED on the original site

Post score: 1