Effort Measure (Wang2012)

[Chun Kwang Tan]

Dear Thomas,

I am trying to reproduce the Effort Measure in Python, but I have a query about Wang2012 effort calculations in EffortMeasure.

Assuming I am using the correct paper (at the end of the post), Wang2012 has a lambda parameter, which denotes the ratio between the Type I and Type II muscles fibers for each muscle, however, this parameter is not provided for the adductors and abductors. How do you calculate the muscle activation heat rate and muscle maintenance heat rate terms for the adductors and abductors in H1922 Hyfydy model?

(J. M. Wang, S. R. Hamner, S. L. Delp and V. Koltun, "Optimizing locomotion controllers using biologically-based actuators and objectives", ACM Trans. Graph., vol. 31, no. 4, pp. 1-11, 2012.)

Thanks in advance.

Best,
Chun Kwang

[Thomas Geijtenbeek]

If not specified, the ratios are indeed set to the default_muscle_slow_twitch_ratio, which is 0.5 by default. For more implementation details, it is also possible to look at the source code:

https://github.com/tgeijten/scone-core/ ... e.cpp#L135

[Mustafa Kamal]

Dear Thomas,

I have a quick question regarding the unit of the values returned by measure.final_result() and measure.current_result() when using the following EffortMeasure configurations with SconePy:

EffortMeasure {
name = Effort
weight = 0.1
measure_type = Wang2012
use_cost_of_transport = 1
}
EffortMeasure {
name = MuscleActivation
weight = 2000
measure_type = CubedMuscleActivation
use_average_per_muscle = 1
use_cost_of_transport = 1
}

Could you please let me know the units for these values?

Thank you in advance for your help!

Best regards,
Mustafa

[Thomas Geijtenbeek]

The Effort is in Joules, while the MuscleActivation is a value between 0 and 1.