Center of mass of shoulder segment seems wrong for small values

[harmooni]

Hello,

First, thank you for your work on Hatze's model!

I'm trying to use your matlab script to create a model of the upper body.

When I run your script using my measurements, then the center of mass of the shoulder segments are far off.
The problem seems to be within the calculation of theta7
If the values for the length and the depth of the shoulder are small, the center of mass moves further aside.

I attached a picture of the model and my file with the measurements (the values of the lower part (pelvis and legs) are taken from "hatze_meas.txt").

subject_2907_2.txt

subject.pdf

[wspr]

Thanks for writing! Indeed, I have noticed a number of problems with the shoulder geometry — it’s not clear to me whether my code is wrong or whether his model has limitations. Unfortunately I don’t have time right now to dive into the maths to confirm further, but I’ll try and let you know if I discover anything...

[harmooni]

Thanks for the fast reply!

I try to understand and reproduce the calculations, but it is a little bit difficult with the information I have. Do you have access to the technical report by Hatze and if yes, could you share it with me, please?

Thanks again!
I'll write if I make progress.

[wspr]

I do, yes — send me an email at my university account and I should be able to send them through shortly. Contact details at: http://www.adelaide.edu.au/directory/will.robertson

[harmooni]

Hi,

did you get my last email? Or are you still on vacation?

I am currently working on a paper and want to thank you for your work in it. Is that fine with you?

I also did a few changes on your code that we can discuss about...

[wspr]

I just tried to send you an email so we can continue the discussion there… let me know if you don't receive it!