Hi, I am interested in studying the effect of a time-varying assistive force (F) applied on the pelvis when walking. This force F could be a controller since I can define F as a function of state. Can I implement a controller and attach it to a model en then use this model directly in Moco? I found ...

Hi Sepehr, I have completely abandoned trying to generate new GRF's by myself and using RRA and/or CMC. Instead, I have started using OpenSim Moco which does just what you suggest : minimize a cost function based on kinematics as well as GRF. This is achieved by using direct collocation optimization...

To Aaron, the sprinting simulation is a 2D predictive simulation, but with the initial guess coming from a walking tracking problem. More specifically, I achieved this predictive simulation by only slightly modifiying the code in the 2D walking example : loosening the bounds on the model's coordinat...

Thank you for your reply. I will definitely refine the mesh. I was also wondering whether it will be possible in Moco to manage contacts in a ''discontinuous'' fashion through the use multiple phases? Either by scheduling the modes in advance or even without scheduling (like as ''trough-contact meth...

Hi, First of all, I just discovered Moco and I strongly believe in its potential ! I have tried optimal running at 4 m/s with Moco and wish to bring it to 10 m/s (sprint). I started from the 2D walking example. Upon foot landing, the model's feet slip (see video of my simulation here: https://imgur....

Hi,

Thank you very much for pointing out this Moco project, which is extremely relevant for my problem. I easily got started with it and the results are highly promising ! I will continue with Moco for my project.

Hi, Yes, I intend to apply a vertial force on the pelvis (see my other post on the forum, for which your insight would also be very valuable : https://simtk.org/plugins/phpBB/viewtopicPhpbb.php?f=91&t=11773&p=0&start=0&view=&sid=daffcdbda8b0c4f87d71195aabeca824 ) I tried with 6, 10 12 Hz, but this d...

Edit to the previous post : There was a mistake in my external loads file. I solved the pelvic drift and the FY residual is now small. However the MZ residuals is still large (average of 15 Nm, range +-50 Nm). One hypothesis for the somewhat large MZ residual is that I should also modify the ground ...

Hi, does anybody has some insight about the resampling issue ?

Thanks,

Charles

HI, I am trying to run an inverse dynamics (ID) analysis from CMC kinematic data and ground reaction forces for a data set of about 1 s. When I run an ID without filtering the kinematics, the ID runs in a reasonable time without resampling, but a lot of noise apears in the computed torques due to di...