OpenSim crash in IK analysis

[Erik Dijkstra]

Hi all,

I am trying to run Inverse Kinematics Tool in OpenSim 3.1.0 but I encounter some problems.

First of all it does not auto fill the weighting section when loading the setup file.
IK doesn't run without because then I get the following in the message window:

Code: Select all

Loaded model subject01 from file C:\Users\Erik Dijkstra\Documents\OpenSim\ModelFiles_2013\subject01_gait2354_scaled.osim
reading object from file [subject01_IK_Tasks.xml] cwd =C:\OpenSim 3.1.0
failure reading object from file [subject01_IK_Tasks.xml] cwd =C:\OpenSim 3.1.0Error:SimTK Exception thrown at Xml.cpp:72:
  Error detected by Simbody method Xml::readFromFile(): Failed to load the Xml file 'subject01_IK_Tasks.xml' with error 'Failed to open file (line=0, col=0)'.
  (Required condition 'loadOK' was not met.)

Loaded marker file C:\Users\Erik Dijkstra\Documents\OpenSim\ModelFiles_2013\Viktor_gait.trc (155 markers, 121 frames)
               MODEL: subject01
         coordinates: 23
              forces: 54
           actuators: 54
             muscles: 54
            analyses: 2
              probes: 0
              bodies: 13
              joints: 12
         constraints: 0
             markers: 27
         controllers: 0
  contact geometries: 0
misc modelcomponents: 0
Running tool subject01.
Loaded marker file C:\Users\Erik Dijkstra\Documents\OpenSim\ModelFiles_2013\Viktor_gait.trc (155 markers, 121 frames)
InverseKinematicsTool Failed: AssemblySolver::assemble() Failed: SimTK Exception thrown at Assembler.cpp:842:
  Method Assembler::assemble() failed because:
Optimizer failed with message: SimTK Exception thrown at Assembler.cpp:225:
  Error detected by Simbody method AssemblerSystem::objectiveFunc(): calcGoal() method of assembly condition Markers returned a negative or non-finite value -1.#IND.
  (Required condition 'goalValue >= 0' was not met.)

Assembly error tolerance achieved: 0 required: 1e-006.

Closing the IK tool and opening a new IK tool and loading the setup file for a second time goes fine. At first it would run the IK analysis but now, after a few iterations with scaling, OpenSim closes and writes the error report attached.

I hope someone can help

Best regards,
Erik

[jimmy d]

Hi Erik,

OpenSIm 3.1 has a known issue handling ikTask files that are separate to the ikSetup file. Write the ikTask Set into the ikSetup.xml and use the inverse kinematic tool on this. You should see improved behavior.

let us know how it goes,
-james

[Erik Dijkstra]

Hi James,

Thank you for the suggestion.
I tested a few times and so far it seems to solve the problem with the IK tool. Thanks!

Best regards,
Erik

[Pagnon David]

Hello,

I have exactly the same problem so I suppose I don't need to post another topic. (?)

Yet I get the problem whereas my ikTask set is written into the ikSetup.xml.
I'm working on Opensim 3.2 x86 (and not on Opensim 3.1)

Any help would be much appreciated !