ROS Answers: Open Source Q&A Forum - RSS feedhttps://answers.ros.org/questions/Open source question and answer forum written in Python and DjangoenROS Answers is licensed under Creative Commons Attribution 3.0Wed, 17 Jun 2015 04:36:08 -0500URDF coefficients of friction mu1 and mu2 questionhttps://answers.ros.org/question/12178/urdf-coefficients-of-friction-mu1-and-mu2-question/Can someone explain what these coefficients of friction mean? From looking at this tutorial it says that `"Here mu1 and mu2 are the friction coefficients of the wheels."`
[http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension](http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension)
However, when looking at the PR2 urdf for the wheels these coefficients are fairly large (`100.0`). That seems extremely high for a coefficient of friction.
The coefficient of rubber on dry concrete is `0.6-0.85` for example.
Thanks in advance!Thu, 01 Dec 2011 09:11:48 -0600https://answers.ros.org/question/12178/urdf-coefficients-of-friction-mu1-and-mu2-question/Comment by Mehdi. for <p>Can someone explain what these coefficients of friction mean? From looking at this tutorial it says that <code>"Here mu1 and mu2 are the friction coefficients of the wheels."</code></p>
<p><a href="http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension"></a><a href="http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension">http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension</a></p>
<p>However, when looking at the PR2 urdf for the wheels these coefficients are fairly large (<code>100.0</code>). That seems extremely high for a coefficient of friction.</p>
<p>The coefficient of rubber on dry concrete is <code>0.6-0.85</code> for example.</p>
<p>Thanks in advance!</p>
https://answers.ros.org/question/12178/urdf-coefficients-of-friction-mu1-and-mu2-question/?comment=211518#post-id-211518It really starts to get annoying with all those deleted Gazebo ROS tutorials with no replacement link...,Wed, 17 Jun 2015 04:36:08 -0500https://answers.ros.org/question/12178/urdf-coefficients-of-friction-mu1-and-mu2-question/?comment=211518#post-id-211518Answer by Wim for <p>Can someone explain what these coefficients of friction mean? From looking at this tutorial it says that <code>"Here mu1 and mu2 are the friction coefficients of the wheels."</code></p>
<p><a href="http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension"></a><a href="http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension">http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension</a></p>
<p>However, when looking at the PR2 urdf for the wheels these coefficients are fairly large (<code>100.0</code>). That seems extremely high for a coefficient of friction.</p>
<p>The coefficient of rubber on dry concrete is <code>0.6-0.85</code> for example.</p>
<p>Thanks in advance!</p>
https://answers.ros.org/question/12178/urdf-coefficients-of-friction-mu1-and-mu2-question/?answer=18222#post-id-18222My best guess is that the numbers were chosen very high to make sure the wheels could never slip, even though the numbers do not make any sense in the physical world.Wed, 14 Dec 2011 09:27:14 -0600https://answers.ros.org/question/12178/urdf-coefficients-of-friction-mu1-and-mu2-question/?answer=18222#post-id-18222