I am using the new anymocap model (from GitHub) with AnyBody v.7.0.1. My experimental setup is a leg press performed using a flywheel exercise device. I have motion and force data in a C3D-file as input and the model works fine when I run it. However, when looking at the output data in the chart window there are spikes on certain intervals and I can’t figure out what they originate from or how I can get rid of them. They can be seen in the output of Pmech and MaxMuscleActivity for example and I think they originate from the trunk somehow. I have a traction force attached to the trunk, but if I am plotting that force there are no matching spikes explaining the strange behavior in the aforementioned outputs. I would be very grateful if somebody could help me figure out what the problem is!
i have tested the model and found the following:
1 : The RASIS marker seem to drop out and move strangely, it should be fixed in data or excluded.
2: By looking at Thorax.rDDot you can see that the spikes comes from kinematics…
So inspect markers for dropouts and ensure segment acc has no spikes.
Thanks for your answer! Actually, I was pretty sure I had already excluded the RASI marker but obviously (and embarrassingly) not… As you said, that was the problem and the results look all fine.
However, I have more trials that I will add to my model later on and some of them have 2-3 markers dropping out in different parts of the trial. I thought adding the following code to my C3DSettings.any file would solve the problem (or at least smoothen the transition) with marker drop outs:
GapFillUsingResidualsOnOff = On;
Have I misinterpreted the function of that bit of code?
This setting will fill the gap using an interpolation function, but if the gap is too big it will nok make a good result, it is only intended to fill small gaps.
Ah, ok. Then I understand.
Thanks for your answer!
One more thing … it is ok to use GapFillUsingResidualsOnOff for large gaps if the markers weight is set low in these periods, please see https://github.com/AnyBody/anymocap/blob/master/Examples/SpecialFeatures/MarkerWeightsExample.main.any#L41
The GapFillUsingResidualsOnOff can be used to ensure there are no “edge artifacts” when the markers comes and goes…