SCONE Parameters

SCONE can optimize both Control parameters and Model parameters. During optimization, parameter values are stored in a .par file. In a SCONE Scenario, parameters are specified as follows:

parameter = mean~stdev<min,max>

where mean is the initial mean value, stdev is the initial standard deviation, and min and max represent the allowed range for the parameter. A higher version for stdev means the initial guesses are more spread out, which can lead to better results quickly, but also leads to higher variance between optimizations.

Alternatively, there is the following shorthand notation:

parameter = ~mean<min,max>

in which the standard deviation is set to 10% of the absolute value of mean.

The most common type of parameters to optimize are for SCONE Controllers. Examples of control parameters are:

Model parameters are specified in the Model { Parameters { … } } section of a scenario. Examples are:

  • Muscle maximum isometric force
  • Muscle optimal fiber length
  • Body mass or inertia
  • Coordinate limit forces of a model joint