TY - GEN
T1 - Self-motion in spatial parallel mechanisms with more than three legs
AU - O'Brien, John F.
AU - Jafari, Farhad
AU - Wen, John T.
PY - 2005/12/1
Y1 - 2005/12/1
N2 - Parallel mechanisms frequently possess an unstable type of singularity that has no counterpart in serial mechanisms. When the mechanism is at or near this type of singularity, it loses the ability to counteract external forces in certain directions. The determination of unstable singular configurations in parallel robots is challenging, and in the past has been tackled by exhaustive numerical searches of the mechanism workspace using an accurate analytical model of the mechanism kinematics. This paper considers the singularity determination problem from a geometric perspective for n-legged spatial parallel mechanisms. By using the constraints on the passive joint velocities, a necessary condition for unstable singularity is derived that identifies the reason for such singularities.
AB - Parallel mechanisms frequently possess an unstable type of singularity that has no counterpart in serial mechanisms. When the mechanism is at or near this type of singularity, it loses the ability to counteract external forces in certain directions. The determination of unstable singular configurations in parallel robots is challenging, and in the past has been tackled by exhaustive numerical searches of the mechanism workspace using an accurate analytical model of the mechanism kinematics. This paper considers the singularity determination problem from a geometric perspective for n-legged spatial parallel mechanisms. By using the constraints on the passive joint velocities, a necessary condition for unstable singularity is derived that identifies the reason for such singularities.
UR - http://www.scopus.com/inward/record.url?scp=33846156244&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33846156244&partnerID=8YFLogxK
U2 - 10.1109/ROBOT.2005.1570240
DO - 10.1109/ROBOT.2005.1570240
M3 - Conference contribution
AN - SCOPUS:33846156244
SN - 078038914X
SN - 9780780389144
T3 - Proceedings - IEEE International Conference on Robotics and Automation
SP - 954
EP - 959
BT - Proceedings of the 2005 IEEE International Conference on Robotics and Automation
T2 - 2005 IEEE International Conference on Robotics and Automation
Y2 - 18 April 2005 through 22 April 2005
ER -