Society of Robots - Robot Forum
General Misc => Misc => Topic started by: kutalinelucas on January 19, 2012, 06:00:48 PM
-
Hey Guys. Just have a quick question, if a robot hand was actuated by 9 motors, one for each base knuckle and then one motor to actuate the medial and distal knuckles on each finger, this makes the device underactuated right? so it would have 9 degrees of actuation, 13 joints, but how many degrees of freedom?
I've found some conflicting stuff...some sources refer to a degree of freedom as the number of independant displacements which provide the kinematic characteristics, but as the medial/distal knuckles engage linearly, the motion of both coupled joints define the hand's characteristics...
So basically...could I present my hand as having 13 degrees of freedom?...sounds much cooler than 9!
Any input would be brilliant
Martyn
-
I would say that because you can only control 9 different positions then it is only 9 DOF but then again if you can't see how many motors there are than you could easily say that its 13DOF. Its your choice.
Cheers
Elijah
-
Well its for my Msc robotics thesis which I'm presenting to a bunch of people who really know about this stuff next week...so I should really be sticking to nine then
Thanks for the input
-
Hi,
[...] if a robot hand was actuated by 9 motors, one for each base knuckle and then one motor to actuate the medial and distal knuckles on each finger, this makes the device underactuated right? so it would have 9 degrees of actuation, 13 joints, but how many degrees of freedom?
Assuming a humanoid (i.e. 5 fingers) hand...
"one for each base knuckle" = 5
"one motor to actuate the medial and distal knuckles on each finger" = 5 more
Don't see how you get to 9?
If each finger is more or less parallel, it could be debated whether they actually was only one DoF per joint-"type", i.e. 3 in all.