For the PR2, there is the very nice pr2_calibration stack available (http://www.ros.org/wiki/pr2_calibration). It would be extremely useful to have a generalized framework for calibrating arbitrary robots, or at least providing building blocks for doing that. Is there already something like this available? If not, are there plans for doing that?
Originally posted by Stefan Kohlbrecher on ROS Answers with karma: 24361 on 2011-02-19
Post score: 5
Hi Stefan,
A Warning:
All of the API's internal to the pr2_calibration stack are unstable and definitely could change. This code hasn't been API reviewed, and it definitely isn't as clean as many of our released and reviewed stacks. Although calibrating another robot is possible, it is definitely not a supported use case.
The techniques used in the pr2_calibration stack should port to any robot consisting of tilting lasers, monocular cameras, and stereo cameras. However, (as Dejan probably will agree), using the pr2_calibration stack on another robot will require significant reconfiguration. To get a feel for how much work must be done, the full configuration for calibrating the PR2 is in the pr2_calibration_launch package. This consists mostly of yaml files and roslaunch files for capturing data, running the optimization, and generating a calibrated URDF. Porting these files to a new robot isn't trivial, but it is also significantly less work than writing a calibration pipeline from scratch.
If you do go down the path of porting pr2_calibration_launch to your robot, please keep me in the loop, and I can try to provide advice along the way. Maybe Dejan can help too :-)
A Generalized Calibration Pipeline
Building a generalized calibration pipeline could definitely be a great benefit to the community. However, at Willow Garage, we currently don't have the resources to dedicate towards making the pr2_calibration stack more portable.
Originally posted by vpradeep with karma: 760 on 2011-02-24
This answer was ACCEPTED on the original site
Post score: 6
Hi Stefan,
I had my high-hopes to port pr2_calibration stack to our TUM-Rosie robot but then stopped working with it after we got our PR2. I have however quite an extensive private email conversation with Vijay where he helped me understand the design of pr2_calibration stack. If you want I could send it to you.
On the other side, I have to say that I do not really understand why there is no more interest into generalization of the mentioned stack from ROS community given that 60+ robots are now running on ROS, it is really convenient to use it and essentially also solves one of the elementary issues one has with every robot.
cheers, D.
Originally posted by dejanpan with karma: 1420 on 2011-02-19
This answer was NOT ACCEPTED on the original site
Post score: 5
Comment by Stefan Kohlbrecher on 2011-02-19:
Hi Dejan. As we're switching robots to ROS, I'm in the process of evaluating what the remaining "weak points" are (multi-robot comms and calibration are high on the list). I'm not sure I'll get around to looking into them in the next few months myself, so any other takers are welcome :) regards S.