Jaw motion capture analysis

system · June 19, 2008, 1:33am

Hi all
i am trying to drive the lower jaw using motion capture data. i used
c3d2any to convert into .any files. I have modified my
JawModel_mocap_c3d.any file to create a link between lower jaw and
marker segments. However i am unable to solve kinematic and inverse
dynamic analysis due to kinematic indeterminacy. i hope somebody can
help me with this. Also how do we make sure the reference frame of
motion capture matches with that of AnyBody so that we have same x,y,z
co-ordinates to drive the model in AnyBody?

Please find a folder “HumanJawMotionCapture.rar” attached under files
section in yahoo groups. Any help from you is deeply appreciated.

thanks
madu

system · June 20, 2008, 10:06am

Hi Madu,

The problem comes from the drivers of the lower jaw. For one same point
of the lower jaw you have two AnyKinLinear with two different markers:
more exactly you set the point Saber2 to have zero distance with the
marker 100002 and then the same point Saber2 to also have zero distance
with the marker 100093. This is unsolvable because the same point
cannot be at two different locations in space at the same time.
Moreover you are not driving the rotations of the lower jaw so the
position of the lower jaw cannot be fully determined by the system.
In conclusion you have to remove one of the redundant constraints for
the point Saber2 and replace it by a constraint driving the rotation of
the lower jaw.

When converting the c3d file, the markers are displayed in the
GlobalRef of AnyBody. So it is like the reference frame of the motion
capture matches exactly the GlobalRef. Then you can orient you model in
the GlobalRef so that if fits with the markers.

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogroups.com, “hi_maddy_1984” <hellomadu@…> wrote:
>
> Hi all
> i am trying to drive the lower jaw using motion capture data. i used
> c3d2any to convert into .any files. I have modified my
> JawModel_mocap_c3d.any file to create a link between lower jaw and
> marker segments. However i am unable to solve kinematic and inverse
> dynamic analysis due to kinematic indeterminacy. i hope somebody can
> help me with this. Also how do we make sure the reference frame of
> motion capture matches with that of AnyBody so that we have same x,y,z
> co-ordinates to drive the model in AnyBody?
>
> Please find a folder “HumanJawMotionCapture.rar” attached under files
> section in yahoo groups. Any help from you is deeply appreciated.
>
> thanks
> madu
>

system · June 20, 2008, 10:25am

Hi again Madu,

Just one thing I wanted to add, there is a human jaw model available
in the repository 7, you’ll find it at
Rep7/Application/Validation/MandibleChewingAndClenching. If you want
to have a look at it I think it can help you to set up your model.

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogroups.com, “AnyBody Support” <support@…>
wrote:
>
>
> Hi Madu,
>
> The problem comes from the drivers of the lower jaw. For one same
point
> of the lower jaw you have two AnyKinLinear with two different
markers:
> more exactly you set the point Saber2 to have zero distance with
the
> marker 100002 and then the same point Saber2 to also have zero
distance
> with the marker 100093. This is unsolvable because the same point
> cannot be at two different locations in space at the same time.
> Moreover you are not driving the rotations of the lower jaw so the
> position of the lower jaw cannot be fully determined by the system.
> In conclusion you have to remove one of the redundant constraints
for
> the point Saber2 and replace it by a constraint driving the
rotation of
> the lower jaw.
>
> When converting the c3d file, the markers are displayed in the
> GlobalRef of AnyBody. So it is like the reference frame of the
motion
> capture matches exactly the GlobalRef. Then you can orient you
model in
> the GlobalRef so that if fits with the markers.
>
> Best regards,
> Sylvain, AnyBody Support.
>
>
>
>
> — In anyscript@yahoogroups.com, “hi_maddy_1984” <hellomadu@>
wrote:
> >
> > Hi all
> > i am trying to drive the lower jaw using motion capture data. i
used
> > c3d2any to convert into .any files. I have modified my
> > JawModel_mocap_c3d.any file to create a link between lower jaw and
> > marker segments. However i am unable to solve kinematic and
inverse
> > dynamic analysis due to kinematic indeterminacy. i hope somebody
can
> > help me with this. Also how do we make sure the reference frame of
> > motion capture matches with that of AnyBody so that we have same
x,y,z
> > co-ordinates to drive the model in AnyBody?
> >
> > Please find a folder “HumanJawMotionCapture.rar” attached under
files
> > section in yahoo groups. Any help from you is deeply appreciated.
> >
> > thanks
> > madu
> >
>

system · June 20, 2008, 5:27pm

Hi Sylvain
i am working with madu to solve this problem. i tried replacing the redundant
constraint on Saber2 by a driver to drive rotation of lower jaw. Here is what i
did

AnyKinRotational Rot_LJRev_ToothTip =
{
AnyRefNode &Saber11 = …Segment.LowerJaw.Saber3;
AnyRefNode &GNode= …GlobalRef.GBase1;
Type = EulerParam;
};
}; Rotational Measure for driving rotation of lower jaw

AnyKinEqInterPolDriver P2Driver =
{
Type = Bspline;
BsplineOrder = 4;
FileName = “madu_mandible_Rot.txt”;//roll pitch yaw movement
AnyKinMeasure &Rot1 = .Joint.Rot_LJRev_ToothTip;
MeasureOrganizer = {0,0,0};
Reaction.Type = {Off,Off,Off};
};//driver driving rotation of lower jaw

AnyKinEq MarkerBodyConstraint = {
AnyKinLinear lin = {
AnyRefFrame &Marker = …ProcessedData._100093.Seg;
AnyRefFrame &Body = …Segment.LowerJaw.Saber2;
};
MeasureOrganizer = {0,0,0};
}; same translation constraint on saber2
i also commented other two markers. Now i have only one marker(segment) in my
model which has translation and rotational constraint same as before (files that
you have).
i still get same problem of kinematic indeterminacy. Please let me know if this
is wrong.

thanks
Srikanth Kannan
Teaching & Research Assistant
Automation Robotics & Mechatronics Lab
State University of New York at Buffalo
Buffalo,NY,USA-14221

----- Original Message ----
From: AnyBody Support <support@anybodytech.com>
To: anyscript@yahoogroups.com
Sent: Friday, 20 June, 2008 4:06:56 AM
Subject: [AnyScript] Re: Jaw motion capture analysis

Hi Madu,

The problem comes from the drivers of the lower jaw. For one same point
of the lower jaw you have two AnyKinLinear with two different markers:
more exactly you set the point Saber2 to have zero distance with the
marker 100002 and then the same point Saber2 to also have zero distance
with the marker 100093. This is unsolvable because the same point
cannot be at two different locations in space at the same time.
Moreover you are not driving the rotations of the lower jaw so the
position of the lower jaw cannot be fully determined by the system.
In conclusion you have to remove one of the redundant constraints for
the point Saber2 and replace it by a constraint driving the rotation of
the lower jaw.

When converting the c3d file, the markers are displayed in the
GlobalRef of AnyBody. So it is like the reference frame of the motion
capture matches exactly the GlobalRef. Then you can orient you model in
the GlobalRef so that if fits with the markers.

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogrou ps.com, “hi_maddy_1984” <hellomadu@. …> wrote:
>
> Hi all
> i am trying to drive the lower jaw using motion capture data. i used
> c3d2any to convert into .any files. I have modified my
> JawModel_mocap_ c3d.any file to create a link between lower jaw and
> marker segments. However i am unable to solve kinematic and inverse
> dynamic analysis due to kinematic indeterminacy. i hope somebody can
> help me with this. Also how do we make sure the reference frame of
> motion capture matches with that of AnyBody so that we have same x,y,z
> co-ordinates to drive the model in AnyBody?
>
> Please find a folder “HumanJawMotionCapt ure.rar” attached under files
> section in yahoo groups. Any help from you is deeply appreciated.
>
> thanks
> madu
>

   Bollywood, fun, friendship, sports and more. You name it, we have it on

http://in.promos.yahoo.com/groups/bestofyahoo/

[Non-text portions of this message have been removed]

system · June 22, 2008, 9:11pm

Hej,

How did you model the TMJ?

In my model of the human jaw I force the condyles of the TMJ to be in
contact with the fossa. In this way I end up with a mandible with 4 DoF.

For driving the model I used one marker at the frontal incisors.
Moreover I drive the sideways movement of the condyle to be zero. In
this way I end up with kinematic determinant system.

Greetings, Mark

–
Mark de Zee, Ph.D., Post doc.
Aalborg University, Department of Health Science and Technology
Center for Sensory-Motor Interaction (SMI)

Srikanth Kannan wrote:
>
> Hi Sylvain
> i am working with madu to solve this problem. i tried replacing the
> redundant constraint on Saber2 by a driver to drive rotation of lower
> jaw. Here is what i did
>
> AnyKinRotational Rot_LJRev_ToothTip =
> {
> AnyRefNode &Saber11 = …Segment.LowerJaw.Saber3;
> AnyRefNode &GNode= …GlobalRef.GBase1;
> Type = EulerParam;
> };
> }; Rotational Measure for driving rotation of lower jaw
>
> AnyKinEqInterPolDriver P2Driver =
> {
> Type = Bspline;
> BsplineOrder = 4;
> FileName = “madu_mandible_Rot.txt”;//roll pitch yaw movement
> AnyKinMeasure &Rot1 = .Joint.Rot_LJRev_ToothTip;
> MeasureOrganizer = {0,0,0};
> Reaction.Type = {Off,Off,Off};
> };//driver driving rotation of lower jaw
>
> AnyKinEq MarkerBodyConstraint = {
> AnyKinLinear lin = {
> AnyRefFrame &Marker = …ProcessedData.100093.Seg;
> AnyRefFrame &Body = …Segment.LowerJaw.Saber2;
> };
> MeasureOrganizer = {0,0,0};
> }; same translation constraint on saber2
> i also commented other two markers. Now i have only one
> marker(segment) in my model which has translation and rotational
> constraint same as before (files that you have).
> i still get same problem of kinematic indeterminacy. Please let me
> know if this is wrong.
>
> thanks
> Srikanth Kannan
> Teaching & Research Assistant
> Automation Robotics & Mechatronics Lab
> State University of New York at Buffalo
> Buffalo,NY,USA-14221
>
> ----- Original Message ----
> From: AnyBody Support <support@anybodytech.com
> <mailto:support%40anybodytech.com>>
> To: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
> Sent: Friday, 20 June, 2008 4:06:56 AM
> Subject: [AnyScript] Re: Jaw motion capture analysis
>
> Hi Madu,
>
> The problem comes from the drivers of the lower jaw. For one same point
> of the lower jaw you have two AnyKinLinear with two different markers:
> more exactly you set the point Saber2 to have zero distance with the
> marker 100002 and then the same point Saber2 to also have zero distance
> with the marker 100093. This is unsolvable because the same point
> cannot be at two different locations in space at the same time.
> Moreover you are not driving the rotations of the lower jaw so the
> position of the lower jaw cannot be fully determined by the system.
> In conclusion you have to remove one of the redundant constraints for
> the point Saber2 and replace it by a constraint driving the rotation of
> the lower jaw.
>
> When converting the c3d file, the markers are displayed in the
> GlobalRef of AnyBody. So it is like the reference frame of the motion
> capture matches exactly the GlobalRef. Then you can orient you model in
> the GlobalRef so that if fits with the markers.
>
> Best regards,
> Sylvain, AnyBody Support.
>
> — In anyscript@yahoogrou ps.com, “hi_maddy_1984” <hellomadu@. …> wrote:
> >
> > Hi all
> > i am trying to drive the lower jaw using motion capture data. i used
> > c3d2any to convert into .any files. I have modified my
> > JawModel_mocap c3d.any file to create a link between lower jaw and
> > marker segments. However i am unable to solve kinematic and inverse
> > dynamic analysis due to kinematic indeterminacy. i hope somebody can
> > help me with this. Also how do we make sure the reference frame of
> > motion capture matches with that of AnyBody so that we have same x,y,z
> > co-ordinates to drive the model in AnyBody?
> >
> > Please find a folder “HumanJawMotionCapt ure.rar” attached under files
> > section in yahoo groups. Any help from you is deeply appreciated.
> >
> > thanks
> > madu
> >
>
> Bollywood, fun, friendship, sports and more. You name it, we have it
> on http://in.promos.yahoo.com/groups/bestofyahoo/
> <http://in.promos.yahoo.com/groups/bestofyahoo/>
>
> [Non-text portions of this message have been removed]
>
>

system · June 23, 2008, 9:42am

Hi Srikanth and Madu,

I think Mark’s way to drive the jaw is a good one.

I just wanted to tell you that I noticed a mistake in the code that
will for sure give you kinematics errors. It is about the
MeasureOrganizer: this command allows you to choose which components
of the kinematics measure you want to drive. The numbers inside the
braces refer to the different directions: 0 for X, 1 for Y, 2 for Z
(notice that for the rotational measure the order can be different
because you can modify the sequence of rotation).
Now in both drivers you specified MeasureOrganizer = {0, 0, 0};
This mean you are driving three times the same direction, but you are
not driving at all the two other ones (1 and 2). So you end up with
kinematics indeterminacy. Make sure to drive the good directions, I
suppose in your case you want to drive the three directions of both
translation and rotation, so you should write MeasureOrganizer = {0,
1, 2};

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogroups.com, Mark de Zee <mdz@…> wrote:
>
> Hej,
>
> How did you model the TMJ?
>
> In my model of the human jaw I force the condyles of the TMJ to be
in
> contact with the fossa. In this way I end up with a mandible with 4
DoF.
>
> For driving the model I used one marker at the frontal incisors.
> Moreover I drive the sideways movement of the condyle to be zero.
In
> this way I end up with kinematic determinant system.
>
> Greetings, Mark
>
> –
> Mark de Zee, Ph.D., Post doc.
> Aalborg University, Department of Health Science and Technology
> Center for Sensory-Motor Interaction (SMI)
>
> Srikanth Kannan wrote:
> >
> > Hi Sylvain
> > i am working with madu to solve this problem. i tried replacing
the
> > redundant constraint on Saber2 by a driver to drive rotation of
lower
> > jaw. Here is what i did
> >
> > AnyKinRotational Rot_LJRev_ToothTip =
> > {
> > AnyRefNode &Saber11 = …Segment.LowerJaw.Saber3;
> > AnyRefNode &GNode= …GlobalRef.GBase1;
> > Type = EulerParam;
> > };
> > }; Rotational Measure for driving rotation of lower jaw
> >
> > AnyKinEqInterPolDriver P2Driver =
> > {
> > Type = Bspline;
> > BsplineOrder = 4;
> > FileName = “madu_mandible_Rot.txt”;//roll pitch yaw movement
> > AnyKinMeasure &Rot1 = .Joint.Rot_LJRev_ToothTip;
> > MeasureOrganizer = {0,0,0};
> > Reaction.Type = {Off,Off,Off};
> > };//driver driving rotation of lower jaw
> >
> > AnyKinEq MarkerBodyConstraint = {
> > AnyKinLinear lin = {
> > AnyRefFrame &Marker = …ProcessedData.100093.Seg;
> > AnyRefFrame &Body = …Segment.LowerJaw.Saber2;
> > };
> > MeasureOrganizer = {0,0,0};
> > }; same translation constraint on saber2
> > i also commented other two markers. Now i have only one
> > marker(segment) in my model which has translation and rotational
> > constraint same as before (files that you have).
> > i still get same problem of kinematic indeterminacy. Please let
me
> > know if this is wrong.
> >
> > thanks
> > Srikanth Kannan
> > Teaching & Research Assistant
> > Automation Robotics & Mechatronics Lab
> > State University of New York at Buffalo
> > Buffalo,NY,USA-14221
> >
> > ----- Original Message ----
> > From: AnyBody Support <support@…
> > <mailto:support%40anybodytech.com>>
> > To: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
> > Sent: Friday, 20 June, 2008 4:06:56 AM
> > Subject: [AnyScript] Re: Jaw motion capture analysis
> >
> > Hi Madu,
> >
> > The problem comes from the drivers of the lower jaw. For one same
point
> > of the lower jaw you have two AnyKinLinear with two different
markers:
> > more exactly you set the point Saber2 to have zero distance with
the
> > marker 100002 and then the same point Saber2 to also have zero
distance
> > with the marker 100093. This is unsolvable because the same point
> > cannot be at two different locations in space at the same time.
> > Moreover you are not driving the rotations of the lower jaw so the
> > position of the lower jaw cannot be fully determined by the
system.
> > In conclusion you have to remove one of the redundant constraints
for
> > the point Saber2 and replace it by a constraint driving the
rotation of
> > the lower jaw.
> >
> > When converting the c3d file, the markers are displayed in the
> > GlobalRef of AnyBody. So it is like the reference frame of the
motion
> > capture matches exactly the GlobalRef. Then you can orient you
model in
> > the GlobalRef so that if fits with the markers.
> >
> > Best regards,
> > Sylvain, AnyBody Support.
> >
> > — In anyscript@yahoogrou ps.com, “hi_maddy_1984”
<hellomadu@ …> wrote:
> > >
> > > Hi all
> > > i am trying to drive the lower jaw using motion capture data. i
used
> > > c3d2any to convert into .any files. I have modified my
> > > JawModel_mocap c3d.any file to create a link between lower jaw
and
> > > marker segments. However i am unable to solve kinematic and
inverse
> > > dynamic analysis due to kinematic indeterminacy. i hope
somebody can
> > > help me with this. Also how do we make sure the reference frame
of
> > > motion capture matches with that of AnyBody so that we have
same x,y,z
> > > co-ordinates to drive the model in AnyBody?
> > >
> > > Please find a folder “HumanJawMotionCapt ure.rar” attached
under files
> > > section in yahoo groups. Any help from you is deeply
appreciated.
> > >
> > > thanks
> > > madu
> > >
> >
> > Bollywood, fun, friendship, sports and more. You name it, we have
it
> > on http://in.promos.yahoo.com/groups/bestofyahoo/
> > <http://in.promos.yahoo.com/groups/bestofyahoo/>
> >
> > [Non-text portions of this message have been removed]
> >
> >
>

system · June 25, 2008, 1:02am

Hi Mark
i express my sincere thanks for your response. From your model, it seems you are
ensuring

the condyles to be in contact with fossa by constraining TMJ in Z direction.
sideways movement of the condyle to be zero by constraining only Left TMJ in
Y direction.
Is there any other way of constraining mandible (apart from 3 movements from
motion capture of front incisor)? Is there any reason why you constrained the
Left TMJ (and not right)?

thanks
Srikanth Kannan
Teaching & Research Assistant
Automation Robotics & Mechatronics Lab
State University of New York at Buffalo
Buffalo,NY,USA-14221

----- Original Message ----
From: Mark de Zee <mdz@hst.aau.dk>
To: anyscript@yahoogroups.com
Sent: Sunday, 22 June, 2008 3:11:25 PM
Subject: Re: [AnyScript] Re: Jaw motion capture analysis

Hej,

How did you model the TMJ?

In my model of the human jaw I force the condyles of the TMJ to be in
contact with the fossa. In this way I end up with a mandible with 4 DoF.

For driving the model I used one marker at the frontal incisors.
Moreover I drive the sideways movement of the condyle to be zero. In
this way I end up with kinematic determinant system.

Greetings, Mark

–
Mark de Zee, Ph.D., Post doc.
Aalborg University, Department of Health Science and Technology
Center for Sensory-Motor Interaction (SMI)

Srikanth Kannan wrote:
>
> Hi Sylvain
> i am working with madu to solve this problem. i tried replacing the
> redundant constraint on Saber2 by a driver to drive rotation of lower
> jaw. Here is what i did
>
> AnyKinRotational Rot_LJRev_ToothTip =
> {
> AnyRefNode &Saber11 = …Segment.LowerJaw. Saber3;
> AnyRefNode &GNode= …GlobalRef. GBase1;
> Type = EulerParam;
> };
> }; Rotational Measure for driving rotation of lower jaw
>
> AnyKinEqInterPolDri ver P2Driver =
> {
> Type = Bspline;
> BsplineOrder = 4;
> FileName = “madu_mandible_ Rot.txt”; //roll pitch yaw movement
> AnyKinMeasure &Rot1 = .Joint.Rot_LJRev_ ToothTip;
> MeasureOrganizer = {0,0,0};
> Reaction.Type = {Off,Off,Off} ;
> };//driver driving rotation of lower jaw
>
> AnyKinEq MarkerBodyConstrain t = {
> AnyKinLinear lin = {
> AnyRefFrame &Marker = …ProcessedData. 100093.Seg;
> AnyRefFrame &Body = …Segment.LowerJaw. Saber2;
> };
> MeasureOrganizer = {0,0,0};
> }; same translation constraint on saber2
> i also commented other two markers. Now i have only one
> marker(segment) in my model which has translation and rotational
> constraint same as before (files that you have).
> i still get same problem of kinematic indeterminacy. Please let me
> know if this is wrong.
>
> thanks
> Srikanth Kannan
> Teaching & Research Assistant
> Automation Robotics & Mechatronics Lab
> State University of New York at Buffalo
> Buffalo,NY,USA- 14221
>
> ----- Original Message ----
> From: AnyBody Support <support@anybodytech .com
> <mailto:support% 40anybodytech. com>>
> To: anyscript@yahoogrou ps.com <mailto:anyscript% 40yahoogroups. com>
> Sent: Friday, 20 June, 2008 4:06:56 AM
> Subject: [AnyScript] Re: Jaw motion capture analysis
>
> Hi Madu,
>
> The problem comes from the drivers of the lower jaw. For one same point
> of the lower jaw you have two AnyKinLinear with two different markers:
> more exactly you set the point Saber2 to have zero distance with the
> marker 100002 and then the same point Saber2 to also have zero distance
> with the marker 100093. This is unsolvable because the same point
> cannot be at two different locations in space at the same time.
> Moreover you are not driving the rotations of the lower jaw so the
> position of the lower jaw cannot be fully determined by the system.
> In conclusion you have to remove one of the redundant constraints for
> the point Saber2 and replace it by a constraint driving the rotation of
> the lower jaw.
>
> When converting the c3d file, the markers are displayed in the
> GlobalRef of AnyBody. So it is like the reference frame of the motion
> capture matches exactly the GlobalRef. Then you can orient you model in
> the GlobalRef so that if fits with the markers.
>
> Best regards,
> Sylvain, AnyBody Support.
>
> — In anyscript@yahoogrou ps.com, “hi_maddy_1984” <hellomadu@. …> wrote:
> >
> > Hi all
> > i am trying to drive the lower jaw using motion capture data. i used
> > c3d2any to convert into .any files. I have modified my
> > JawModel_mocap c3d.any file to create a link between lower jaw and
> > marker segments. However i am unable to solve kinematic and inverse
> > dynamic analysis due to kinematic indeterminacy. i hope somebody can
> > help me with this. Also how do we make sure the reference frame of
> > motion capture matches with that of AnyBody so that we have same x,y,z
> > co-ordinates to drive the model in AnyBody?
> >
> > Please find a folder “HumanJawMotionCapt ure.rar” attached under files
> > section in yahoo groups. Any help from you is deeply appreciated.
> >
> > thanks
> > madu
> >
>
> Bollywood, fun, friendship, sports and more. You name it, we have it
> on http://in.promos. yahoo.com/ groups/bestofyah oo/
> <http://in.promos. yahoo.com/ groups/bestofyah oo/>
>
> [Non-text portions of this message have been removed]
>
>

   Did you know? You can CHAT without downloading messenger. Go to

http://in.messenger.yahoo.com/webmessengerpromo.php/

[Non-text portions of this message have been removed]

system · June 25, 2008, 12:04pm

Hi Srikanth,

> From your model, it seems you are ensuring
> 1. the condyles to be in contact with fossa by constraining TMJ in Z
> direction.

Yes, that is correct. Note though, that from a kinetic viewpoint my
model only allows reaction forces in one direction.

> 2. sideways movement of the condyle to be zero by constraining only
> Left TMJ in Y direction.

Also correct.

> Is there any other way of constraining mandible (apart from 3
> movements from motion capture of front incisor)? Is there any reason
> why you constrained the Left TMJ (and not right)?
No, not really. I had to choose on of them. When doing this, you will
introduce a little error. In reality the sideway movement of the condyle
is most probably not zero. However, I think that in most cases this
error is small and acceptable. The other way of constraining the
mandible, maybe the best way, is to drive the real sideway movement of
the condyle provided that you have these measurements. This was though
not possible with the tracking system I had available.

Greetings, Mark

–
Mark de Zee, Ph.D., Post doc.
Aalborg University, Department of Health Science and Technology
Center for Sensory-Motor Interaction (SMI)

Srikanth Kannan wrote:
>
> Hi Mark
> i express my sincere thanks for your response. From your model, it
> seems you are ensuring
> 1. the condyles to be in contact with fossa by constraining TMJ in Z
> direction.
> 2. sideways movement of the condyle to be zero by constraining only
> Left TMJ in Y direction.
> Is there any other way of constraining mandible (apart from 3
> movements from motion capture of front incisor)? Is there any reason
> why you constrained the Left TMJ (and not right)?
>
> thanks
> Srikanth Kannan
> Teaching & Research Assistant
> Automation Robotics & Mechatronics Lab
> State University of New York at Buffalo
> Buffalo,NY,USA-14221
>
> ----- Original Message ----
> From: Mark de Zee <mdz@hst.aau.dk <mailto:mdz%40hst.aau.dk>>
> To: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
> Sent: Sunday, 22 June, 2008 3:11:25 PM
> Subject: Re: [AnyScript] Re: Jaw motion capture analysis
>
> Hej,
>
> How did you model the TMJ?
>
> In my model of the human jaw I force the condyles of the TMJ to be in
> contact with the fossa. In this way I end up with a mandible with 4 DoF.
>
> For driving the model I used one marker at the frontal incisors.
> Moreover I drive the sideways movement of the condyle to be zero. In
> this way I end up with kinematic determinant system.
>
> Greetings, Mark
>
> –
> Mark de Zee, Ph.D., Post doc.
> Aalborg University, Department of Health Science and Technology
> Center for Sensory-Motor Interaction (SMI)
>
> Srikanth Kannan wrote:
> >
> > Hi Sylvain
> > i am working with madu to solve this problem. i tried replacing the
> > redundant constraint on Saber2 by a driver to drive rotation of lower
> > jaw. Here is what i did
> >
> > AnyKinRotational Rot_LJRev_ToothTip =
> > {
> > AnyRefNode &Saber11 = …Segment.LowerJaw. Saber3;
> > AnyRefNode &GNode= …GlobalRef. GBase1;
> > Type = EulerParam;
> > };
> > }; Rotational Measure for driving rotation of lower jaw
> >
> > AnyKinEqInterPolDri ver P2Driver =
> > {
> > Type = Bspline;
> > BsplineOrder = 4;
> > FileName = “madu_mandible_ Rot.txt”; //roll pitch yaw movement
> > AnyKinMeasure &Rot1 = .Joint.Rot_LJRev_ ToothTip;
> > MeasureOrganizer = {0,0,0};
> > Reaction.Type = {Off,Off,Off} ;
> > };//driver driving rotation of lower jaw
> >
> > AnyKinEq MarkerBodyConstrain t = {
> > AnyKinLinear lin = {
> > AnyRefFrame &Marker = …ProcessedData. 100093.Seg;
> > AnyRefFrame &Body = …Segment.LowerJaw. Saber2;
> > };
> > MeasureOrganizer = {0,0,0};
> > }; same translation constraint on saber2
> > i also commented other two markers. Now i have only one
> > marker(segment) in my model which has translation and rotational
> > constraint same as before (files that you have).
> > i still get same problem of kinematic indeterminacy. Please let me
> > know if this is wrong.
> >
> > thanks
> > Srikanth Kannan
> > Teaching & Research Assistant
> > Automation Robotics & Mechatronics Lab
> > State University of New York at Buffalo
> > Buffalo,NY,USA- 14221
> >
> > ----- Original Message ----
> > From: AnyBody Support <support@anybodytech .com
> > <mailto:support% 40anybodytech. com>>
> > To: anyscript@yahoogrou ps.com <mailto:anyscript% 40yahoogroups. com>
> > Sent: Friday, 20 June, 2008 4:06:56 AM
> > Subject: [AnyScript] Re: Jaw motion capture analysis
> >
> > Hi Madu,
> >
> > The problem comes from the drivers of the lower jaw. For one same point
> > of the lower jaw you have two AnyKinLinear with two different markers:
> > more exactly you set the point Saber2 to have zero distance with the
> > marker 100002 and then the same point Saber2 to also have zero distance
> > with the marker 100093. This is unsolvable because the same point
> > cannot be at two different locations in space at the same time.
> > Moreover you are not driving the rotations of the lower jaw so the
> > position of the lower jaw cannot be fully determined by the system.
> > In conclusion you have to remove one of the redundant constraints for
> > the point Saber2 and replace it by a constraint driving the rotation of
> > the lower jaw.
> >
> > When converting the c3d file, the markers are displayed in the
> > GlobalRef of AnyBody. So it is like the reference frame of the motion
> > capture matches exactly the GlobalRef. Then you can orient you model in
> > the GlobalRef so that if fits with the markers.
> >
> > Best regards,
> > Sylvain, AnyBody Support.
> >
> > — In anyscript@yahoogrou ps.com, “hi_maddy_1984” <hellomadu@. …>
> wrote:
> > >
> > > Hi all
> > > i am trying to drive the lower jaw using motion capture data. i used
> > > c3d2any to convert into .any files. I have modified my
> > > JawModel_mocap c3d.any file to create a link between lower jaw and
> > > marker segments. However i am unable to solve kinematic and inverse
> > > dynamic analysis due to kinematic indeterminacy. i hope somebody can
> > > help me with this. Also how do we make sure the reference frame of
> > > motion capture matches with that of AnyBody so that we have same x,y,z
> > > co-ordinates to drive the model in AnyBody?
> > >
> > > Please find a folder “HumanJawMotionCapt ure.rar” attached under files
> > > section in yahoo groups. Any help from you is deeply appreciated.
> > >
> > > thanks
> > > madu
> > >
> >
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> >
> > [Non-text portions of this message have been removed]
> >
> >
>
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