Basic Doubts from a Beginner

[Mainak Chakraborty]

Hi,
I have some doubts, I can not seem to find answers on my own,
1. I want to change specific parameters like the duration of the walk (not simulation). What parameter will increase the duration of GAIT (suppose for 2 minutes )? Will this make the optimisation take more time? In this case, Hyfydy will help?
2. The units of the data obtained in the .sto file, are normalised to body weight? (for GRF data, the unit is Force/N )
3. What is the meaning of Significance of Score value in Optimisation results?
4. Last doubt, Some times when the optimisation is going on for too long, I abort the optimisation. In this case, the .sto file is not saved. What am I doing wrong?
I am new to SCONE. I may be missing something, please guide me.
Thanks,
Mainak C

[Thomas Geijtenbeek]

1. The duration of the gait is set through the simulation_duration. This determines the virtual amount of time to simulate, not the real-world amount of time it takes for the simulation to complete. There is a strong correlation between the simulation_duration and the time it takes to complete, though, and Hyfydy indeed will generally make similar simulations complete much faster.

2. The GRF data is indeed normalized to mass * gravity, so a value of 1 corresponds to the gravitational force applied to the model.

3. The 'Score' is the fitness value of the optimization -- a measure of 'how well' the controller performed during this iteration. The goal of the optimization is to minimize (or maximize, depending on the objective) this value.

4. You can generate .sto files by double clicking on a .par file in the Optimization Results. This works while the optimization is running, but also after the optimization is aborted. The latter is safe to do and will not affect the existing results.

[Mainak Chakraborty]

Thanks a lot. One more doubt though.
What parameter should I change to obtain data of any model walking/jumping for 60 sec in the real world? Also, What does the x-axis of the data represent in GRFs(others too)?

[Thomas Geijtenbeek]

To generate 60s walking data in SCONE you should set simulation_duration = 60 and then optimize until it is able to walk for 60s. In the analysis window in SCONE, the x-axis is time. The grf_x channel represents the ground reaction force in the x direction (i.e. friction force).

[Mainak Chakraborty]

Thanks a lot. One doubt, How many contact points are in the scone model(feet) when it is touching the ground throughout the simulation? Also, Is there any parameter where I can change the type of platform type?

[Thomas Geijtenbeek]

The default model in the Examples has two contact points, but you can basically use any OpenSim model you like. The model can be changed in OpenSim, so I would advise to look there for more details on how to change it.