Hi Dafne,

I've attached the three files you'll need to run RRA with the LaiArnold2017 model. Note that the task file is generic so you'll need to tinker with the weights and coefficients in order to balance the reduction of residuals and maintaining kinematic consistent.

Hope that helps!

Adrian

Another thing you could try is if some of the constraints are simple enough that you can derive them by hand, you could leave them out of OpenSim and instead implement them in IPOPT. So the loop in OpenSim is (deliberately) open then you close it in IPOPT. That's what I was thinking because it's a ...

Hi Josh,

To do it in MATLAB, you need to safeDownCast the Millard2012EquilibriumMuscle down to the TendonForceLengthCurve of each muscle, set/update the strain and then print the model.

Adrian

With that setup, I think the equations of motion are implemented as constraints in the optimization routine, just like any task constraints e.g. periodicity (it's all the same to IPOPT, big vector of equality constraints). If it's converging, IPOPT is essentially telling you "All the constraints I ...

Hi Ross, Thanks for the reply. Could you describe some more details on how you're solving the optimal control problem? - are you doing forward integration, direct collocation, something else? - what optimization routine? - how big are the constraint violations? I'm doing direct collocation using IPO...

I guess it’s forward dynamics? I’m solving an optimal control problem outside of OpenSim. I use the OpenSim’s dynamic engine to compute state derivative but I was hoping that the constraints were included in the equations of motion.

Adrian

Hi everyone, I've been trying to solve a basic optimal control problem of a single leg pedal using some custom MATLAB code that calls OpenSim's dynamics engine. The model is currently closed loop with the hip/pelvis and the crank pinned to the ground and then I applied a weld constraint between two ...

Does stateSimulate.size() return 0? Yes, it returns 0. Am I creating the StateTrajectory incorrectly? stateStorage = Storage('tugOfWar_states.sto'); stateSimulate = StatesTrajectory(); stateSimulate.createFromStatesStorage(osimModel,stateStorage); Alternatively, I tried stateSimulate.createFromStat...

Hi Chris, Thanks for the reply. I was able to create the StateTrajectory using createFromStatesStorage() but when I tried to visualise the individual states, I get the following error. I tried different values but I get the same error. Any ideas? osimModel.getVisualizer().show(stateSimulate.get(0)) ...

Hi all, I was wondering if anyone has tried visualising results obtained using OpenSim 4.0? I have control and state files computed using my own optimal control approach in conjunction with OpenSim 4.0. I have tried to use StatesTrajectory to load the states storage file but I'm unsure how to conver...