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oeven-zohar40
12-12-2007, 04:53 AM
Hi Ravi.
The CAREN software from MOTEK MEDICAL (www.motekmedical.com) has Custom Vicon drivers that get raw data from Vicon and do not suffer from the delay you mentiond. have a look
Good luck
Oshri Even Zohar

________________________________

From: * Biomechanics and Movement Science listserver on behalf of Philippe Archambault, Dr.
Sent: Wed 12/12/2007 15:45
To: BIOMCH-L@NIC.SURFNET.NL
Subject: Re: [BIOMCH-L] Using Real-Time VICON with MATLAB



Ravi,

I am also looking at possible solutions on how to use a motion capture
system in real time. I see two potential pitfalls with a real time
system combining Vicon and Matlab xPC. The first is that Vicon
communicates its data through TCP/IP, however, xPC can only use UDP;
TCP/IP is not possible and this has been confirmed by a Mathworks
software engineer.

The other problem is that Vicon introduces a delay of 10-50 ms
(depending on your setup) between actual, physical movement and the time
that this data is communicated to the target computer. For my needs,
this delay is much too high. Personally, I believe that an active marker
system is more appropriate for real time.

Hope this helps,

Philippe

Philippe Archambault, OT, PhD
Assistant professor
School of Physical & Occupational Therapy, McGill University
3654 Promenade Sir-William-Osler
Montreal QC H3G 1Y5
T: (+1) 514 398-7323
F: (+1) 514 398-6360
W: www.mcgill.ca/spot


On Dec 10, 2007 7:42 AM, Raviraj Nataraj
wrote:

> Hello, Biomech-L,
>
> Our lab has recently upgraded its VICON motion capture system, which
> now includes real-time data capture. We are looking to use real-time
> marker data for controller feedback. The controller will be under
> real-time operation using the xPC-Target software toolkit within
> MATLAB. Thus, we ultimately need to link the real-time data stream
> from VICON to a "target" computer. If anyone has had experience with
> this or something similar, any advice on how best to proceed would be
greatly appreciated.
>
> Sincerely,
> Ravi Nataraj
> PhD Student, BME Department, Case Western Reserve University Motion
> Study Lab, Cleveland Stokes VAMC
>

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