CoM AnyKinCoM

Main Forum
1

Hi,

i have difficulties in using AnyKinCoM. When i use it in the Study folder i get as result: Pos, Vel, and Acc. Furthermore there is “folder” containing the segments. But there is no mass summed up.

How can i get the sum of the masses?

Thanks and kind regards,

Thomaz

Here my code:

AnyFolder UpperExtremitiesSegs = {
AnySeg &seg1 = Main.HumanModel.BodyModel.Right.ShoulderArm.Seg.Humerus;
AnySeg &seg2 = Main.HumanModel.BodyModel.Right.ShoulderArm.Seg.Ulna;
AnySeg &seg3 = Main.HumanModel.BodyModel.Right.ShoulderArm.Seg.Radius;
AnySeg &seg4 = Main.HumanModel.BodyModel.Right.ShoulderArm.Seg.Hand;
AnySeg &seg6 = Main.HumanModel.BodyModel.Left.ShoulderArm.Seg.Humerus;
AnySeg &seg7 = Main.HumanModel.BodyModel.Left.ShoulderArm.Seg.Ulna;
AnySeg &seg8 = Main.HumanModel.BodyModel.Left.ShoulderArm.Seg.Radius;
AnySeg &seg9 = Main.HumanModel.BodyModel.Left.ShoulderArm.Seg.Hand;
};

AnyBodyStudy Study = {
AnyFolder &Model = .Model;

tEnd = 1.0;
Gravity = {0.0, -9.81, 0.0};
nStep = 1;

AnyKinCoM CoMObereExt = {
  AnyFolder &folder = Main.UpperExtremitiesSegs;
};

}; // End of study

2

Hi,

I have not checked the old versions of AMS yet.
But when I see the reference manual of AMS V5.3 regarding this AnyKinCoM object, there is an output value called ‘MassTotal’ which shows the total sum of masses in the AnyKinCoM object.

Of course you can use this feature in our latest AMS V6.0.1.

Best regards,
Moonki

3

Dear Moonki,

that is exactly why i asked the question. Unfortunately i cannot see MassTotal in the tree, only Pos, Vel, and Acc.

The question is why is this the case?

Thanks,

Thomaz

4

Some additional info:

When i place the AnyKinCoM driver outside of the Study folder, then i have MassTotal, but then all values (Pos, Vel, Acc, … MassTotal) are zero even after analysis.
What is the mistake?

Thanks in advance,

Thomaz

5

Hi Thomaz,

As I told already, you can find the MassTotal property in the AnyKinCoM object.

And I usually use this AnyKinCoM object inside my model folder.
Of course usually AnyBodyStudy object should have a reference of your model folder.

But even if your AnyKinCoM object is not inside your model folder, then you should create a separate reference of your AnyKinCoM object (or the reference of AnyFolder which contains your AnyKinCoM object) in your AnyBodyStudy object.

AnyBodyStudy object will only consider the objects which AnyBodyStudy object has their references.

Best regards,
Moonki

6

Hi Moonki,

thanks for your helpfulness.
I found the problem: The AnyKinCoM folder was accidentally placed in between Model and Study. It was neither in Model nor in Study. Now i placed it in the Model section and i now have non-zero values and a mass. :slight_smile:

But is still don’t understand why there is no MassTotal in Study/Output/Model/CoMUpperExt neither now nor in the first version (see code in my first question). Is this what you mean with “AnyBodyStudy object will only consider the objects which AnyBodyStudy object has their references.”? What do you mean with this?

Thanks again,

Thomaz

7

Perhaps it is not clear what i mean with “there is not MassTotal”. I don’t mean that it is zero but that it does not exist (see attachment).

8

Hi,

I’ve already told that we can see this ‘MassTotal’ property from the AnyKinCoM object in the AMS V5.3 and later versions.

Can you check which version of AMS you are using currently?

Best regards,
Moonki

9

Hi Moonki,

yes, you said this already. And i read it already. I use version 5.3.

Kind regards,

Thomaz

10

Hi Thomaz,

First, I would say I’m sorry for wrong information.

My working version is AnyBody version : 5. 3. 1. 3556.

You can download it in the customer download section:
http://www.anybodytech.com/index.php?id=877

I hope you can try with this version.

Best regards,
Moonki

11

Moonki,

could you please have a look at my posting from Yesterday 09:20 AM, there i wrote that i have a MassTotal, i. e. i have a version which provides MassTotal. In fact i have exactly the version you recommended me, 5. 3. 1. 3556
I am afraid, another download wouldn’t help :wink:

The question was however, why the MassTotal is not always present.

Best regards,

Thomaz

12

Hi Thomaz,

Sorry again for not understanding your question very well.

  1. In your picture you are looking the output folder of AnyBodyStudy object.
    This output folder will show all time-varying values.
    But this MassTotal will not be changed according to time.
    That’s the reason why you could not find this value in the output folder of AnyBodyStudy object.

  2. Instead, you should see where this object is actually defined in your model tree. Then you can find this MassTotal value.

Best regards,
Moonki

13

Thanks, Moonki,

now i understand that there were two sources of my problem.
Just to summarize:

1.) In the study folder there are only time dependent variables. Variables which do not depend on time can’t be found in the Study part.

2.) The AnyKinCoM should not be placed in the same level as the model folder but inside the model folder (i don’t know why.)

Thanks and kind regards,

Thomaz

14

Hi Thomaz,

AnyKinCoM can be defined outside of your model folder.
The only thing is that AnyBodyStudy should have the reference of that folder.

I created a simple example to explain how this can be done.

I hope this may help you.

Best regards,
Moonki

15

Thanks a lot, Moonki

for your help!

Best regards,

Thomaz