Thanks for your kind reply, John. Let me try to explain simply how joint/actuators are coupled in my robot. There 6 groups of coupled joints per a hand and all groups of 2 joints are driven by 2 motors and transform matrix(2x2 or 3x2) from joint angle/velocity/torque to motor angle/velocity/torque can be expressed in terms of some ratios and vice versa. How can I express this relationship in URDF? Should I implement some supporting classes specific to my robot similar to PR2's SimpleTransmission, WriteTransmission, and PR2GripperTransmission? It may be helpful to understand how the PR2-specific transmission element is designed? - Yoonsoo 2010/10/14 John Hsu > Hi Yoonsoo, > URDF does not support coupled joints. Custom transmissions should most > likely be able to do what you have described. pr2_mechanism_modelhas some examples and documentation on how transmissions are used in PR2. > How are the joint/actuators coupled in your robot? > Thanks, > John > > On Tue, Oct 12, 2010 at 11:02 PM, Kim, Yoonsoo wrote: > >> Hi, >> >> My robot is composed of various coupled joints for dexterous hands, in >> which M joints are driven by N motors. >> >> I tried to find out how to express coupled joints in URDF but couldn't >> according to URDF XML reference. >> What I only found was PR2-specific element. Can this >> element express coupled joints and relationship between >> joints and actuators? >> >> If the element can't express coupled joints, any suggestion to do that >> will be appreciated. >> >> TIA >> >> - Yoonsoo >> >> >> _______________________________________________ >> ros-users mailing list >> ros-users@code.ros.org >> https://code.ros.org/mailman/listinfo/ros-users >> >> > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > >