Hi Ayman Thanks for your help. I have another strange problem. I changed my code to this: const Set<Actuator>& actuatorSet = osimModel.getActuators(); ActivationFiberLengthMuscle* muscle1 = dynamic_cast<ActivationFiberLengthMuscle*>( &actuatorSet.get(0) ); ActivationFiberLengthMuscle* muscle2 = dyna...

Hi all; I am trying to load an existing osim file to perform a forward dynamic. But I cannot initiate the muscle states (activation and fiber length). The model has 2 Thelen muscles. Here is my code: ///////////////////////// // Load the Osim model // ///////////////////////// Model osimModel ("twoM...

Hi Ajay and Romain, sorry for my late reply. Thanks, it works now. The problem was the missed line as Ajay mentioned. I just understood that the same line is missing in the API example file in opensim directory. (c:\OpenSim2.4.0\sdk\APIExamples\ExampleMain\TugOfWar_Complete.cpp) It would be great if...

Hi Ayman, I do still have problem with the tugOfWar example. In the "developers guide - section 2.16" we define two linear functions for each of the muscles. I compiled and ran the code and loaded the results in the GUI. I expected linear activation in the muscles, but as you can see in the attached...

Hi Ayman,
according to the code, I expect piece-wise linear excitation/activation for muscles. I have attached the activation plots which is not linear. The activatoin initiates at its initial value and decreases by time.
Cheers,
Sina.

Hi, I am trying to compile the tugOfWar example in the "OpenSim Developers Guide" step by step. I want to modify step 15 (which uses some functions to make the muscle control history at page 34) and replace the LinearFunction with PiecewiseLinearFunction. So I replaced this piece of code: Prescribed...

Hi all,
I was wondering how does static optimization account for force-velocity and force-length properties of muscle? As I have to type some equations to explain my question, please take a look at the attached file

Hi Craig According to your post: "The solve for equilibrium actuator states solves for the muscle fiber length state values so that that they are in equilibrium with their tendon." Does it mean (Muscle active force + muscle passive force)*cos(pennation angle) = (tendon elastic force) I still cannot ...

Hi Sherm Thanks for your reply, it was really helpful. I have one other question about the mentioned paper. The paper indicates that a variety of numerical integrators are available for forward dynamics. But I do not know how should I implement these integrators in "ForwardTool" <ForwardTool> <model...

Hi All, According to this paper, in order to define a contact between two bodies I need elastic modulus and dissipation coefficients of each of the bodies(4 parameters): http://www.stanford.edu/group/nmbl/publications/pdf/Sherm2011.pdf but in the *.osim file, I can only define 2 parameters including...