Search found 14 matches

by Russell Johnson
Sat Sep 09, 2023 10:13 am
Forum: OpenSim Moco
Topic: Distance Constraint Pairs with OMOCO files
Replies: 2
Views: 596

Re: Distance Constraint Pairs with OMOCO files

Thanks for the help Nick! I'll find a workaround for now.
Russell
by Russell Johnson
Wed Sep 06, 2023 2:38 pm
Forum: OpenSim Moco
Topic: Distance Constraint Pairs with OMOCO files
Replies: 2
Views: 596

Distance Constraint Pairs with OMOCO files

Hi All, I'm trying to run Moco optimizations that are loaded in from an .OMOCO file for 3-D gait simulations. When I do this in MATLAB, I get a warning message that looks like the image below: ignoring moco frame pairs 2.PNG It seems like when I run an optimization without loading the .OMOCO file - ...
by Russell Johnson
Mon Feb 21, 2022 3:52 pm
Forum: OpenSim Moco
Topic: Slow iterations on predictive simulations
Replies: 8
Views: 1341

Re: Slow iterations on predictive simulations

Hi Ross, I have run into that exact timing issue with "purely" predictive optimizations when compared with optimizations with kinematic tracking terms. I was confused by this discrepancy, but dismissed it (maybe naively) as due to some sort of underlying computational process in the gradient that wa...
by Russell Johnson
Sun Jan 16, 2022 3:29 pm
Forum: OpenSim Moco
Topic: Synergies and Spasticity in OpenSim Moco
Replies: 6
Views: 856

Re: Synergies and Spasticity in OpenSim Moco

Hi Carlos, I was wondering if you, or broadly any other Moco user, has made any progress on implementing either the muscle synergies or muscle spasticity within a Moco optimization. I'm assuming given the nature of Moco's setup, that the muscle synergies are still prohibitively complicated to implem...
by Russell Johnson
Thu May 06, 2021 10:30 am
Forum: OpenSim Moco
Topic: Predicted GRF and Inverse Dynamics
Replies: 8
Views: 1849

Re: Predicted GRF and Inverse Dynamics

Hi Ross, Thanks for linking to that thread for the reaction moments - I was able to calculate those as described, but agree that the joint moments there are a bit unexpected and I'm not sure why - wondering if anyone might have some insight as to which part I am missing. I also used your suggestion ...
by Russell Johnson
Thu May 06, 2021 10:10 am
Forum: OpenSim Moco
Topic: (close to) minimizing metabolic cost
Replies: 51
Views: 9057

Re: (close to) minimizing metabolic cost

Does anyone have experience something similar? What are the scaling procedures for muscles that are commonly used? Best regards. Carlos Hi Carlos, I had encountered this issue as well when I was testing out 4.2 (I tried to record the issue, but probably put it in the wrong place so that's my fault)...
by Russell Johnson
Wed May 05, 2021 2:13 pm
Forum: OpenSim Moco
Topic: Predicted GRF and Inverse Dynamics
Replies: 8
Views: 1849

Re: Predicted GRF and Inverse Dynamics

Hi All, I am wondering if anyone had been able to get the study.analyze() method to work to calculate joint moments, as Ross suggested was maybe possible in the above post. I have been trying to calculate the joint moments with Moco solutions. I have a pipeline to calculate moments after calculating...
by Russell Johnson
Tue Nov 17, 2020 7:39 pm
Forum: OpenSim Moco
Topic: Fiber Velocity Outputs
Replies: 12
Views: 2117

Re: Fiber Velocity Outputs

Hi Ross- Thanks for the explanation, makes a lot of sense. I had a figure in one of my earlier posts with the CC length, and it doesn't seem to be happening at minimums for the CC length, but it could be some combination of CC length, its rate of change, and the low activation. I'm still curious to ...
by Russell Johnson
Mon Nov 16, 2020 9:52 pm
Forum: OpenSim Moco
Topic: Fiber Velocity Outputs
Replies: 12
Views: 2117

Re: Fiber Velocity Outputs

Hi Nick and Ross, I've run a series of other optimizations with a few different settings and I think I've gotten some better results for my model. After getting better velocity outputs with the minimum activation bound set to 0.01, I then tried changing the fiber damping coefficient. First I increas...
by Russell Johnson
Fri Nov 13, 2020 10:38 am
Forum: OpenSim Moco
Topic: Fiber Velocity Outputs
Replies: 12
Views: 2117

Re: Fiber Velocity Outputs

Hi Nick and Ross, My above results were with a minimum activation bound set at 0.001, which seems to line up with what Ross has done. When looking through the activations, it looks like the solution is staying within the minimum bounds and not producing muscle activations less than 0.001 or negative...