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Parameter meanings

Posted: Thu Aug 04, 2022 3:43 am
by stalay
Hi! When we run a simulation, the messages window gives us some results.

Code: Select all

Result            = 0.523427
  Gait            = 0 <- 100 * (0.00551275 > 0.05)
    step_velocity = 0.94465
    step_count    = 19
  Effort          = 0.523068 <- 0.1 * 5.23068
    effort        = 3761.37
    distance      = 9.64824
  DofLimits       = 0
    ankle_angle_l = 0 <- 0.1 * 0
    ankle_angle_r = 0 <- 0.1 * 0
    knee_angle_l  = 0 <- 0.01 * (1.25153 > 5)
    knee_angle_r  = 0 <- 0.01 * (1.48045 > 5)
  GRF             = 0.000358707 <- 10 * 3.58707e-05
Evaluation took 8.21212s for 10s (1.21771x real-time)
What does the step_velocity signify in this? Also, please explain the GRF values.

Also, in the analysis window, are the pelvic tilt, and other angles in degrees?

In the sto. files, there's a variable called [Muscle name] Tendon length normalized. How are these normalized?
And the variable that defines muscle activation, is it in Newtons?

Re: Parameter meanings

Posted: Mon Aug 08, 2022 3:25 am
by tgeijten
step_velocity is an internal variable used by the GaitMeasure, it is shown there for information purposes only. The value next to Gait is the actual measure.

GRF is the result of a ReactionForceMeasure, see:

https://scone.software/doku.php?id=ref: ... ce_measure

The normalized muscle outputs in the .sto are normalized to tendon slack length, optimal fiber length, or max isometric force. Muscle activation is always between 0 and 1.