Error 'estimating joint loads in OpenSim' tutorial/example

[Joe Prinold]

I am having a problem running the example data included with the webinar in July on "Estimating Joint Loads in OpenSim"

When I load the analysis settings for static optimisation and press Run I get the following message: "Tool execution failed..." and then the following in the messages window:

Adding force object set from C:\OpenSim 3.0\Models\WebinarDemo - SO and JR - 2.4.0\gait2392_SO_weak_Residual_Actuators.xml

Loading coordinates from file C:\OpenSim 3.0\Models\WebinarDemo - SO and JR - 2.4.0\subject01_walk1_Kinematics.sto.
Storage: file=C:\OpenSim 3.0\Models\WebinarDemo - SO and JR - 2.4.0\subject01_walk1_Kinematics.sto (nr=1500 nc=24)
Found 1500 state vectors with time stamps ranging from 0.5 to 1.999.

Please let me know if you have any ideas about where this error is coming from.

Thanks,

Joe

[jimmy d]

Hi Joe,

Are you using 3.1? I replicated the error but it may be because the example was built for version 2.4. Some significant changes have been made since then.

Please let me know,
-james

[Joe Prinold]

Hi James,

I have tried both with 3.0 and 3.1.

Joe

[Joe Prinold]

sorry... and it worked with neither. Perhaps I can try getting 2.4 and testing with that.

[Maria Isabel Orselli]

Hi Joe,

goes at your foot_floor_load.xml file and edit

<datafile> C:\Users\matt\Desktop\webinarDemo\subject01_walk1_grf.mot </datafile>

<external_loads_model_kinematics_file> C:\Users\matt\Desktop\webinarDemo\subject01_walk1_Kinematics.sto </external_loads_model_kinematics_file>

with the correct directory they are in your computer.

It worked for me.

hope it helps
Bel

[Joe Prinold]

Fantastic - thank you that has fixed the problem.

Something else that is happening is that I am getting px, py and pz components in my JointReaction outputs (in addition to the expected fx, fy, fz, mx, my and mz).

Do you know what these refer to?

Joe

[Maria Isabel Orselli]

Hi Joe,

I think it is the instantaneous joint location location.

Bel

[Joe Prinold]

Hi Bel,

Thank you, yes that looks correct. The hip joint centre in ground moves up and down with the gait cycle, whilst the other joints (e.g. hip in femur) remain constant.

Joe

[jimmy d]

Joe and Bel,

thanks for spotting that Bel! The xml tags can either give an absolute path (C:\Users\...\subject01_walk1_Kinematics.sto) or a relative path (subject01_walk1_Kinematics.sto). The relative path assumes the file is in the same directory as the setup.xml.

We will change the package to represent relative paths and republish shortly.

thanks again,

-james