Hi, I just understood that the HuntCrossleyForce contact model applies both forces and torques to the contact sphere, While according to this paper, it should only be a spring and damper force actuator (not a torque actuator). http://www.stanford.edu/group/nmbl/publications/pdf/Sherm2011.pdf When I ...

Hi Ayman,
the Osim files are attached
Tnx

Hi Ayman and Thank you, Here is the simple version. If DefaultModel (line 8) contains wapping cylinders, this code will generate an error, but it will work if the loaded model on line 8 does not have wraping objects. thanks Sina P.S: How can I send you the osim files that I am using? I cannot upload...

Hi all. I am using a model which uses wrapping cylinders for some of the muscles. I am using this model to solve a dynamic optimization problem and I have two problems. First, let's have a look at my algorithem: - Load the Osim File - for i=1:1000 --- create a random muscle excitation pattern for ea...

Thank you Sherm

Hi everyone. I am using CoordinateLimitForce to represent ligaments in my model. I know that this force has a constant stiffness except through the transition region which uses a non-linear function to change the stiffness smoothly from zero to the specified stiffness. I was wondering if I can know ...

Thankyou Ajay.

Hi again, I reckon it shouldn't be that tricky, because the forward dynamic tool needs the same ydot vector in order to integrate the state equations forward in time. Something like y(t+h) = y(t) + h*ydot( t, y(t), u(t) ) which is a first order Euler method. Of course the FD tool uses more accurate ...

Hi Sherm. In General, an optimal control problem is to find the optimum control u* which causes the system: ydot(t) = f (y(t), u(t), t) (eq.1) To follow the optimum trajectory y* that minimizes/maximizes a cost function. In (eq. 1) y is the state vector, u is the control vector and t is the independ...

Hi Sherm and thank you for the reply. I am using the OpenSim API to solve an optimal control problem and I am using an open source optimizer which is written in C++. (Everything is happening in C++). I will try my best to avoid a super technical question! I am trying to solve a constraint problem wh...