Static optimization failure

[Thomas Coulter]

Hello,

As new user to OpenSim 1.5.5, I've been reviewing the Tutorials and after completeing #3, I've been trying to run through all of the Tools available to try and understand what is occurring during each step.

I have run the Scale, Inverse Kinematics, and Inverse Dynamics following the default setting files for each (Gait2354_Simbody folder). Unfortunately, your tutorials stop here, and from reading the User's Guide, I believe the next logical step would be the Static Optimization.

I am trying to run this tool using the resultant subject01_walk1_ik.mot file as the Input Motion file on the Main Setting tab, and as the Kinematics for external loads file on the External Loads tab. For the External loads file I have selected the Inverse Dynamics result subject01_walk1_InverseDynamics_force.sto file. I set the time interval to 0.4 - 1.6 secs, which coincides with the above files.

The Tool enables the Run button, but when clicked I very quickly receive an information window stating "Tool execution canceled by user. Output files not written."

I have installed the latest Jave runtime, and started OpenSim using the *.bat file located in \bin.

Any help would be greatly appreciated. Thanks, Tom C.

[Kang Li]

Tom,
Did you solve this problem?
Kang

[Kang Li]

The external loads file should be the file, subject01_walk1_InverseDynamics_force.sto since it has no ground reaction force.

[Ayman Habib]

Kang,

Our Static Optimization performs Inverse Dynamics "internally", so the external loads file should be the ground reaction forces exactly as specified in the Inverse Dynamics Tool.

Hope this helps,

[Anders Sandholm]

Dear,

I have tried to run the Static optimization for some of our simulations and still I cant manage to get it working.

So instead i took the Gait2392_Simbody example and tried to setup a simulation:

Motion: from file, subject01_walk1_ik.mot
Filter: 6 Hz
Sum of muscle activation: 2
Time: 0.8 to 1
External loads: subject01_walk1_grf.mot
Body 1: calcn_r
Body 2: calcn_l
Kinematics for ex..: subject01_walk1_ik.mot
Filter kinematics: 6 Hz

Does anybody got this example to work, or have any clue what the problem could be.
Send me an email if anyone want the setup file.

regards
Anders

Static optimization output:

Loading coordinates from file C:\Program Files (x86)\OpenSimBin 2.0\examples\Gait2392_Simbody\subject01_walk1_ik.mot.
Storage: file=C:\Program Files (x86)\OpenSimBin 2.0\examples\Gait2392_Simbody\subject01_walk1_ik.mot (nr=211 nc=165)


Low-pass filtering coordinates data with a cutoff frequency of 6...

Found 438 state vectors with time stamps ranging from -1.25 to 5.742.


Loading external loads kinematics from file C:\Program Files (x86)\OpenSimBin 2.0\examples\Gait2392_Simbody\subject01_walk1_ik.mot ...
Storage: file=C:\Program Files (x86)\OpenSimBin 2.0\examples\Gait2392_Simbody\subject01_walk1_ik.mot (nr=211 nc=165)
Low-pass filtering external load kinematics with a cutoff frequency of 6...
Storage: file=C:\Program Files (x86)\OpenSimBin 2.0\examples\Gait2392_Simbody\subject01_walk1_grf.mot (nr=9009 nc=19)
Executing the analyses from 0.798 to 0.99...
SimTK Exception thrown at InteriorPointOptimizer.cpp:249:
Optimizer failed: Ipopt: Maximum iterations exceeded (status -1)
OPTIMIZATION FAILED...

StaticOptimization.record: WARN- The optimizer could not find a solution at time = 0.798

The model appears unsuitable for static optimization.
Try appending the model with additional force(s) or locking joint(s) to reduce the following acceleration constraint violation(s):
pelvis_tilt: constraint violation = -1.30341
pelvis_list: constraint violation = 0.161704
pelvis_rotation: constraint violation = 0.0219062
pelvis_tx: constraint violation = -0.00181739
pelvis_ty: constraint violation = 0.0725472
pelvis_tz: constraint violation = -0.0218905
hip_flexion_r: constraint violation = -0.0199286
hip_adduction_r: constraint violation = 0.253367
hip_rotation_r: constraint violation = -0.0399675
knee_angle_r: constraint violation = -0.168365
ankle_angle_r: constraint violation = 1.64064
subtalar_angle_r: constraint violation = 0.636214
mtp_angle_r: constraint violation = 0.812152
hip_flexion_l: constraint violation = -0.704876
hip_adduction_l: constraint violation = -0.141432
hip_rotation_l: constraint violation = 0.0183384
knee_angle_l: constraint violation = -0.375201
ankle_angle_l: constraint violation = -0.312476
subtalar_angle_l: constraint violation = -0.171635
mtp_angle_l: constraint violation = 0.0141696
lumbar_extension: constraint violation = 0.113357
lumbar_bending: constraint violation = -0.279458
lumbar_rotation: constraint violation = 0.0566428


time = 0.798 Performance =1.03884 Constraint violation = 2.5419

[Yi Wang]

I failed too, would any body afford an example and corresponding parameters which ever could run over the Static Optimization? Thanks

My email is tinyvane@gmail.com
Thanks in advance.
Yi.

[Ayman Habib]

Hi Yi,

The distribution has a setup file and data files to run StaticOptimization for the Arm26 model (under Examples/Arm26/OutputReference/StaticOptimization).

-Ayman

[Max Rusch]

Hey all,

Do you solve that problem just using the setup file from arm26?

I had the same problem using the upper limb model, but this file couldn't help me.

Regards, Max

[Ayman Habib]

Hi Max,

What are the symptoms?, and what version of OpenSim are you using?

-Ayman

[Max Rusch]

Hy Ayman,

Thank you very much for your attention!

I'm having problems with static optimization tool. I do not understand the meaning of these errors.

Example for one time(this problem occur in several time):

time = 0.233333 Performance =9.23433 Constraint violation = 635.744
SimTK Exception thrown at InteriorPointOptimizer.cpp:249:
Optimizer failed: Ipopt: Infeasible problem detected (status 2)
OPTIMIZATION FAILED...

StaticOptimization.record: WARN- The optimizer could not find a solution at time = 0.25

The model appears unsuitable for static optimization.
Try appending the model with additional force(s) or locking joint(s) to reduce the following acceleration constraint violation(s):
elv_angle: constraint violation = 0.0532864
shoulder_elv: constraint violation = -0.00109953
shoulder_rot: constraint violation = 0.0332366
elbow_flexion: constraint violation = 0.575879
pro_sup: constraint violation = -95.9118
deviation: constraint violation = -9.1774
flexion: constraint violation = 0.173407
cmc_flexion: constraint violation = 8.5887
cmc_abduction: constraint violation = -51.8523
mp_flexion: constraint violation = -0.168305
ip_flexion: constraint violation = 7.49353
2mcp_flexion: constraint violation = 55.9373
2mcp_abduction: constraint violation = 2.69856
2pm_flexion: constraint violation = -5.37656
2md_flexion: constraint violation = -1338.59



The suggestions for me, were:
- Add more muscles
- Make the muscles stronger

Add more muscles doesn't my intention.
And, when I tried to make the muscles stronger (modifying the max isometric force) the results that I found were erroneous, varying without a plausible behavior.

Any more suggestions or explanations for my analysis?

Regards, Max