Hi Yoonsoo,<br>URDF does not support coupled joints.  Custom transmissions should most likely be able to do what you have described.   <a href="http://www.ros.org/wiki/pr2_mechanism_model">pr2_mechanism_model</a> has some examples and documentation on how transmissions are used in PR2.<br>

How are the joint/actuators coupled in your robot?<br>Thanks,<br>John<br><br><div class="gmail_quote">On Tue, Oct 12, 2010 at 11:02 PM, Kim, Yoonsoo <span dir="ltr">&lt;<a href="mailto:yesarang.kim@gmail.com" target="_blank">yesarang.kim@gmail.com</a>&gt;</span> wrote:<br>


<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Hi,<div><br></div><div>My robot is composed of various coupled joints for dexterous hands, in which M joints are driven by N motors.</div>


<div><br></div><div>I tried to find out how to express coupled joints in URDF but couldn&#39;t according to URDF XML reference.</div>
<div>What I only found was PR2-specific &lt;transmission&gt; element. Can this &lt;transmission&gt; element express coupled joints and relationship between joints and actuators?</div><div><br></div><div>If the element can&#39;t express coupled joints, any suggestion to do that will be appreciated.</div>



<div><br></div><div>TIA</div><div><br></div><font color="#888888"><div>- Yoonsoo</div><div><br></div>
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