Hi Maren
I am not sure whether I understand your problem correctly
There is a Revolute joint called:
Main.Model.HumanModel.Right.ShoulderArm.Jnt.FE
that uses the two nodes
Main.Model.HumanModel.Right.ShoulderArm.Seg.Humerus.fe (the one I
mentioned)
and
Main.Model.HumanModel.Right.ShoulderArm.Seg.Ulna.fe
The (global) position of these node, ‘r’, are indentical as far as I
can see, but only after you solve the kinematic analysis.
I have dumbed the following values from a model by double-clicking
the ‘r’-objects:
-------------------------------Objects dump--------------------------
Main.Model.HumanModel.Right.ShoulderArm.Seg.Ulna.fe.r = {0.1215727,
1.315634, 0.2169811};
-------------------------------Objects dump--------------------------
Main.Model.HumanModel.Right.ShoulderArm.Seg.Humerus.fe.r =
{0.1215727, 1.315634, 0.2169811};
Before the kinematical analysis has done at least one step (either
by the SetInitialPosition or the real kinematic analysis), the
values look like this:
-------------------------------Objects dump--------------------------
Main.Model.HumanModel.Right.ShoulderArm.Seg.Ulna.fe.r = {-
0.007244633, 1.249246, 0.2856014};
-------------------------------Objects dump--------------------------
Main.Model.HumanModel.Right.ShoulderArm.Seg.Humerus.fe.r = {-
0.009015867, 1.25663, 0.2830825};
Here the points do not coincide, but this is because the kinematic
constaints are violated. The violation is small because the guy that
made the model did a good job on making the initial positions, but
he didn’t do it perfectly (he has no reason to). Good initial
conditions are just needed
On the other joints he might have done a perfect job of matching the
joint translations (if ‘r’ match), but he didn’t have to. Also, it
is not all joint type that actually do match the translations in all
directions.
‘sRel’ is the local (segment-fixed) coordinates of the node,
whereas ‘r’ is the global position - just to make that clear. The
global position is given by
r_node = r_owner + A_owner*s_rel
where A_owner is the segment frame rotational transformation matrix
(i.e. ‘Axes’ in AnyScript terms).
Just a hint for locating stuff in the files:
If you want to find ulna.fe or something else in the code and you
have the objects in the Model Tree. Then right-click the object in
question and select “Dumb locations”. In the Operations/Report View
it will dumb some text with some file-links. Here you get
Construction and sometimes also Initialization locations. You can
double-click the file location and you will jump to the place in the
file.
I know this is well hidden, but it is a nice feature for getting to
specific places in the files.
I hope some of this helps you,
Michael
AnyBody Support
— In anyscript@yahoogroups.com, Maren Lühring <anystarter@…>
wrote:
>
> Hi Michael,
> no problem as long as there will be an answer for me. I found the
humerus fe node and it´s location is ok, but the second joint
patrner, the ulna has an fe node too, but with other coordinates. In
all the other joints both joint partners have equal coordinates in
the nodes which are used to define the joint. They don´t differ
much, but they are not equal. And there are some sRel defined which
i can´t understand and which doesn´t make the nodes fit better. I
use the free posture standing model. Because of this joint i´m now a
little bit confused about “r”, “sRel” and other funny positioning
tools. If you can show me the part of the file which makes the
ulna.fe node and the humerus.fe node having the same position this
would be a great help.
> With best regards, Maren
>
> ----- Ursprüngliche Mail ----
> Von: AnyBody Support <support@…>
> An: anyscript@yahoogroups.com
> Gesendet: Freitag, den 7. Juli 2006, 11:28:36 Uhr
> Betreff: [anyscript] Re: Position of the elbow FE joint
>
> Hi Maren,
>
> It’s Michael. Soeren is on vacation, so I shall try to cover for
him.
> I am not completely sure either; I have only little experience
with
> the arm model myself.
>
> I found this node on the Humerus segment:
>
> Main.Model.HumanMod el.Right. ShoulderArm. Seg.Humerus. fe
>
> I believe ‘fe’ means Flexion-Extension. Inside it, there is a
another
> node, which is only rotate relative to the ‘fe’ node. It is called
>
> Main.Model.HumanMod el.Right. ShoulderArm. Seg.Humerus. fe.RotNode
>
> It is used to define the Flexion-Extension angular measure, as
far I
> can see.
>
> I made an AnyDrawRefFrame
> inside ‘Main.Model. HumanModel. Right.ShoulderAr m.Seg.Humerus.
fe’ and it
> looks like it is located in the elbow alright.
>
> Please have a look and see if this is what you need, or write me
again
> and complain;-)
>
> Best regards,
>
> Michael
> AnyBody Support
>
> — In anyscript@yahoogrou ps.com, Maren Lühring
<anystarter@ …> wrote:
> >
> > Hi Sören,
> > the training in Aalborg helps me a lot when i´m now working
with the
> model. In this moment i try to find aout where the joints are, to
> scale the model. Most of them are easy to find but with the elbow
it
> seems to be complicate: the RefNodes for the joint definition
from
> humerus and ulna are different while all the other joints have
the
> same RefNode coordinates for both joint partners. Which node
defines
> the position of the elbow fe joint?
> > With best regards, Maren
> >
> >
> > ------------ --------- --------- —
> > Sie denken an Ihre Sicherheit? Das tun wir auch.
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
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> [Non-text portions of this message have been removed]
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