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Hi, suddenly all analyses in OpenSim give me an error:

RRA Exception:
Storage: ERROR- failed to open file C:\Users\L\Desktop\BiG
Projects\Walk&RunMechanics\V3DtoOS_2017_10_23\Visual3d_SIMM_grf.mot
file= C:\OpenSim33\src\opensim32\OpenSim\Common\Storage.cpp
line= 127

Static optimization Loading coordinates from file C:\Users\L\Desktop\BiG Projects\Walk&RunMechanics\OpenSIm_Workshop\V3StoOS_2017_10_24_single stance only\Results_RRA\Visual3d_Kinematics_q.sto.
Storage: file=C:\Users\L\Desktop\BiG Projects\Walk&RunMechanics\OpenSIm_Workshop\V3StoOS_2017_10_24_single stance only\Results_RRA\Visual3d_Kinematics_q.sto (nr=410 nc=24)
Coordinate.setValue: WARN- coordinate subtalar_angle_r is locked. Unable to change its value.
Coordinate.setValue: WARN- coordinate mtp_angle_r is locked. Unable to change its value.
Coordinate.setValue: WARN- coordinate subtalar_angle_l is locked. Unable to change its value.
Coordinate.setValue: WARN- coordinate mtp_angle_l is locked. Unable to change its value.
Found 409 state vectors with time stamps ranging from 1.785 to 2.193.

Forward dynamics
Integrating from 0.001 to 0.2
ForwardTool::run() caught exception
SimTK Exception thrown at AbstractIntegratorRep.cpp:428:
Integrator step failed at time 0.001 apparently because:
SimTK Exception thrown at AbstractIntegratorRep.cpp:547:
Error detected by Simbody method AbstractIntegrator::takeOneStep(): Unable to advance time past 0.001.
(Required condition 't1 > t0' was not met.)



It all started with Forward dynamics, then I could not run also any other analysis. I had tried restarting OpenSim, restarting PC, even reinstalling the OpenSim but nothing helped.

I have Windows 7, OpenSim 3.3

I would be grateful for any help.
Martin

I managed to solve the errors with RRA and SO by recreating the SIMM_input_grf.xml.

Forward dynamics is still giving the same error...

The integrator is unable to proceed beyond the initial time step. If a variable-time-step integrator detects high error, it will reduce the step size until the required tolerance is met. In this case, the integrator has decreased the time step down to (essentially) zero (hence, "Required condition 't1 > t0' was not met."). There are a few possible explanations for such behavior (e.g., bodies with very small inertia), but they depend on your model. I suggest searching the general OpenSim Forum for "required condition was not met" for a list of possible explanations. Also, you mentioned that "suddenly all analyses in OpenSim give me an error", so presumably a change was made to the model that is responsible for this integration failure.

Hi,

Looking at the error dialogs I see long path names with spaces in them, these are land mines, especially when a file name needs to be included within another file. You probably recreated the files with new names/paths that worked around the problem by coincidence. Is that possible?

-Ayman

Thank you for your suggestions.
I ascribe the troubles with simulations to moving the files to a new folder, thus changing the paths.

I have been using the forward dynamics just to evaluate the effect of an action of one or two muscles (tib_post_r and its parts) on ankle motion and forces using my modification of Gait2392 model with all the joints locked except for the right ankle. I used simple controls .sto file like this:

Static Optimization
version=1
nRows=200
nColumns=2
inDegrees=no
This file contains static optimization results.

endheader
time tib_post_r
0.001 0
0.002 0
0.003 0
0.004 0
0.005 0
0.006 0
0.007 0
0.008 0
0.009 0
0.01 0
0.011 0
0.012 0
0.013 0
0.014 0
0.015 0
0.016 0
0.017 0
0.018 0
0.019 0
0.02 0.2
0.021 0.4
0.022 0.6
0.023 0.8
0.024 1
0.025 1
0.026 1
0.027 1
0.028 1
0.029 1
0.03 1
0.031 1
0.032 1
0.033 1
0.034 1
.....

It was working nicely but now it does not work even with the original Gait2392 model.

Martin

Martin,

It's possible that some file paths are still referring to another folder with special characters or that is too long. This is particularly hard to find for external forces files that refer to .sto/.mot files. I'd suggest you use the GUI to browse for and open all the files needed/used for setup to make sure file paths are correct.

Hope this helps,
-Ayman

Thank you, Ayman. I will check the file paths thoroughly.
Martin