<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en-gb">
	<link rel="self" type="application/atom+xml" href="https://pybullet.org/Bullet/phpBB3/app.php/feed/topic/13319" />

	<title>Real-Time Physics Simulation Forum</title>
	
	<link href="https://pybullet.org/Bullet/phpBB3/index.php" />
	<updated>2021-11-21T15:37:51+00:00</updated>

	<author><name><![CDATA[Real-Time Physics Simulation Forum]]></name></author>
	<id>https://pybullet.org/Bullet/phpBB3/app.php/feed/topic/13319</id>

		<entry>
		<author><name><![CDATA[wlsrbs82]]></name></author>
		<updated>2021-11-21T15:37:51+00:00</updated>

		<published>2021-11-21T15:37:51+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=43713#p43713</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=43713#p43713"/>
		<title type="html"><![CDATA[Doubled Centrifugal Term of Joint Reaction Forces]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=43713#p43713"><![CDATA[
Hi,<br><br>Firstly, thanks for your PyBullet engine. I am happy to use your engine for my works.<br><br>For using PyBullet as a mechanical system design tool, I am on the verification phase currently.<br>I tested 1 DOF rotating bar with some mass for very simple case study.<br>I observed that centrifugal force from PyBullet is twice result from commercial CAE software.<br>(HyperWorks MotionSolve and Autodesk Inventor Built-in Dynamic Simulation)<br>More clearly, my setting is like this, for example.<br>mass = 1kg, COM from center of rotation = 2m, constant rotating speed = 1 rad/s<br>Although 2N is expected from centrifugal force, I got the 4 N as a related reaction force from getJointState of PyBullet. <br>For another very complex case of 6DOF, most of the results was quite similar to those from commercial software.<br>But centrifugal force case has definitely double value when PyBullet is used. <br><br>My system is Windows 10 and is currently up to date with pybullet-3.1.7. I have attached the urdf and motion input in question.<br>For my simulation, I used POSITION CONTROL and zero dampings.<br>Could you give some advices of what might be wrong? or is there any isssue of reaction force calculation?<dl class="file"><dt><span class="imageset icon_topic_attach"></span> <a class="postlink" href="https://pybullet.org/Bullet/phpBB3/download/file.php?id=1887">Simple Model.urdf.zip</a></dt></dl><br /><dl class="file"><dt><span class="imageset icon_topic_attach"></span> <a class="postlink" href="https://pybullet.org/Bullet/phpBB3/download/file.php?id=1886">1DOF GDT.csv</a></dt></dl><p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=14156">wlsrbs82</a> — Sun Nov 21, 2021 3:37 pm</p><hr />
]]></content>
	</entry>
	</feed>
