From simbody documentation, it seems getMobilityForces() and getRigidBodyForces() functions could be used for this. Can someone tell what is the difference between these two functions? And which one is appropriate for getting joint moments/torques due to muscles, gravity, centrifugal and coriolis? A...

Hi,

I would like to know how to get access to joint torques during forward simulation using python API? Is there any API command for it?

Thanks,
Saurabh

Hi All, I am using upper extremity dynamic model which uses CoordinateCoupler constraint to calculate the dependent coordinates. When I set the values of independent coordinates, the dependent coordinates also change due to constraints as expected. But when I set the velocities of independent coordi...

Hi All,

Is there any way to calculate the jacobian of the joint angles w.r.t. the marker points?

Thanks,
Saurabh

Hi All, I was looking through the source code of following muscle models in OpenSim: 1) Delp1990Muscle_Deprecated 2) Schutte1993Muscle_Deprecated In both the models, the activation dynamics is described as follows: If u(t) >= a(t), da/dt = [u(t) - a(t)] * [k1*u(t) + k2] else da/dt = k2 * [u(t) - a(t...

Hi All,

I am still unable to fix this problem. Is there any solution to this?

Thanks,
Saurabh

Hi All, I am trying to run the forward dynamics simulation with attached model and controls. The simulation runs smoothly for about 0.6 sec after which it stopped working. I inspected the resulting states file and found nan values in the last two rows where last second row has all joint velocities a...

Dear Thomas, I have changed the model to have identical properties for the left and right muscles. The problem still persists. I have also tried changing force-velocity curve parameters in other models which uses Millard_equilibrium muscles and got the same error there too. Interestingly, I have fou...

Hi All, When loading the attached model file, I am getting the following error: SimTK Exception thrown at SmoothSegmentedFunctionFactory.cpp:303: Error detected by Simbody method SmoothSegmentedFunctionFactory::createFiberForceVelocityCurve: ForceVelocityInverseCurve: dydxNearE must be greater than ...

Hi All, I am using windows 10 64 bit system and trying to install OpenSim 4.0 python package in conda environment having 64 bit python 3.5. I have followed this steps: https://simtk-confluence.stanford.edu:8443/display/OpenSim/Scripting+in+Python#ScriptinginPython-InstallingAnacondaandthe%22opensim%...