Hello Forum,
Does anybody have a plugin for ligaments?
Thanks,
Anne
Ligament Models
- Andrea Morelli
- Posts: 89
- Joined: Thu Jan 24, 2008 1:10 pm
RE: Ligament Models
Did you received any answer ?
I think you can model a ligament using muscle editor and having specific parameters to simulate a ligament.
Anybody have added ligament to a model ?
Would be very helpful.
Thank you
Andrea
I think you can model a ligament using muscle editor and having specific parameters to simulate a ligament.
Anybody have added ligament to a model ?
Would be very helpful.
Thank you
Andrea
- Anne Schmitz
- Posts: 76
- Joined: Thu May 31, 2007 7:44 am
RE: Ligament Models
Ajay Seth, a member of the OpenSim team, has a plugin for this. I think it is a modified muscle that doesn't have activation dynamics.
- Ayman Habib
- Posts: 2240
- Joined: Fri Apr 01, 2005 12:24 pm
RE: Ligament Models
Anne,
I went ahead and posted some version of the source of our ligament plugin on the Wiki page at:
http://wiki.simtk.org/opensim/SamplePlugins
You can give it a try.
Note that you need to make/change your model to use <Ligament> in-addition-to/in-place-of some of your regular muscle (e.g. <Thelen2003Muscle>) for this to have any effect.
Best,
-Ayman
I went ahead and posted some version of the source of our ligament plugin on the Wiki page at:
http://wiki.simtk.org/opensim/SamplePlugins
You can give it a try.
Note that you need to make/change your model to use <Ligament> in-addition-to/in-place-of some of your regular muscle (e.g. <Thelen2003Muscle>) for this to have any effect.
Best,
-Ayman
RE: Ligament Models
Hi all,
I went ahead and inserted a ligament into my model using the Ligament plugin. However everytime I try and use CMC, it always fails when trying to find initial conditions. When removing the ligament, CMC works fine. I am not sure if this could be a bug or if anyone has tried this before and has a way around it...
The error is below:
=============================================
rdCMC.computeInitialStates: ti=0.15
=============================================
rdCMC.computeControls: t = 0.15
WARN- small force range for my_lig_r (-0.145283 to -0.145283)
WARN- small force range for my_lig_l (-0.000873351 to -0.000873351)
SimTK Exception thrown at CFSQPOptimizer.cpp:225:
Optimizer failed: CFSQP failed with status = 1
OPTIMIZATION FAILED...
rdCMC.computeControls: WARN- The optimizer could not find a solution at time = 0.150000.
If using the fast target, try using the slow target.
Starting at a slightly different initial time may also help.
I went ahead and inserted a ligament into my model using the Ligament plugin. However everytime I try and use CMC, it always fails when trying to find initial conditions. When removing the ligament, CMC works fine. I am not sure if this could be a bug or if anyone has tried this before and has a way around it...
The error is below:
=============================================
rdCMC.computeInitialStates: ti=0.15
=============================================
rdCMC.computeControls: t = 0.15
WARN- small force range for my_lig_r (-0.145283 to -0.145283)
WARN- small force range for my_lig_l (-0.000873351 to -0.000873351)
SimTK Exception thrown at CFSQPOptimizer.cpp:225:
Optimizer failed: CFSQP failed with status = 1
OPTIMIZATION FAILED...
rdCMC.computeControls: WARN- The optimizer could not find a solution at time = 0.150000.
If using the fast target, try using the slow target.
Starting at a slightly different initial time may also help.
RE: Ligament Models
Tim,
Did you get the problem associated with CMC and ligament solved.
Thanks,
Kang
Did you get the problem associated with CMC and ligament solved.
Thanks,
Kang