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jortega46
05-23-2009, 11:02 AM
Colleagues,

Below I have included the various responses regarding timing systems that can be used with a motion capture system (either to trigger capture or simply as a measure of speed) or independently such as outside a lab.
There appears to be two strategies:

1)Buy an existing system such as Brower (start at $1185), Microgait (more expensive than Brower), Lafayette Instruments (~$ 1400), Farm Tech, Equine systems (could not find online), kinematic measurement system (Fittech), etc
2)Build your own system:
a.Omron E3G- or KEYENCE. Keyonce FS-V30 series photoelectric sensor + Omron time interval meter (can read time immediately)…system can be wired into motion capture system for use as trigger or to record time for each trial
b.Garage door sensors wired to motion capture system

For more info read below:

Justus Ortega, Ph.D.
Biomechanics Lab
Department of Kinesiology
Humboldt State University
Arcata, CA 95521
Telephone: (707) 826-4274
Fax: (707) 826- 5451

RESPONSES:

I have come across to this equipment online: http://www.espnshop.com/catalog/productdetail.cfm?model_nbr=70004&sku=7-0635&SID=9436&inceptor=1&cm_mmc=SEO-_-Feeds-_-Froogle-_-null .
I called the company manufacturing these and they told me that they are not producing SPARQ timing systems anymore. You may be able to purchase this at the site above though.

Although some academic departments use the Brower system, as a responsible sports technologist I would be trying to guide you towards the Microgate system (or something resembling that quality). Radio frequency communication can be a problem at times and it’s the last thing you want as a professional organization. When I was the biomechanics lab manager at the VA at Palo Alto, CA I sourced a photogate timing system by Equine Electronics. It was a completely portable RF system that I wired to run off of AC (w/ a DC transformer). The system was very inexpensive and easy to use. It automatically resets, and can output either to a stopwatch or led display.


We have ours set up so that the Omron sensors trigger our motion capture system, which also has all of our analog signals fed into it through a junction circuit board. So basically, we have motion and 64 analog channels synchronized and can be set to record by using external triggers (the Omron system). We have used our motion capture system to record walking speed before through our motion capture system. We have had two motion capture systems (Motion Analysis and currently Qualisys) and the Omron system has worked for both. With the Motion Analysis system we basically had them going directly into the computer via the serial port. With the Qualisys system, we have a simple circuit that uses the voltage from the triggers to trigger the master camera. I think they can work for multiple systems.

I have used garage door sensors in the past for this. You can get an infrared switch like that at Radio Shack I believe. I would find the output signal and use that to initialize the collection system.

Try using 2 undergrads yelling GO!

Try: http://www.omron247.com/doc/pdfcatal.nsf/82288A6B4E0E96FD86256AFD0074A578/$FILE/D04E3G1101.pdf This photo eye works very well with the Qualisys Motion Capture Systems. Having two at either end of the runway can both start and stop our data collection (Real-time) 3D system.

Maybe try looking at www.omron.com. Are you looking for the photocells to trigger your system? What type of motion capture system are you using? If this is your purpose, I can give you more information on our set-up. Just to follow-up with more specific information. We use the Omron E3G-MR19-US sensors to trigger our system. I can let you know how we have it set up if you want to inquire further.

You might be interested to buy one of our systems. We supply the following:
http://www.redbackbiotek.com/timing_gates_11.html
http://www.microgate.it/eng/timing%5Fsport/training_kit_light.asp

I have had success with fiber-optic sensors from KEYENCE. FS-V30 series. I run them into a NI-cDAQ 9172 Chassis with a NI-9421 module to aquire the data (hardware timed). One word of caution, this setup (12 sensors and the National Instruments DAQ) costs about $5000, but only two sensors and the NI-DAQ would probably be ~ $1,500; my understanding is that this is much more pricey than using photocells (I did it because the FS-V30 offers a ~ 6 cm beam which ideal when running different sized lizards).
Have you looked at Fitness Technology? www.fittech.com.au (The Kinematic Measurement System)
I have been using them for years, they are used widely in research and sporting applications. They are an open system making them easy to interact with, for example, taking a line out to use as a trigger, I do this to trigger Vicon data collection. When the light beam is broken there is a 5 volt drop. I take this signal into the back of the Vicon unit. Then the options in the Vicon collection allow you to tell it start on the trigger. Hope that makes sense.

I simply bought 2 pairs of photoelectric sensors of Keyence, and connected them to an Omron time interval meter. I takes a little bit of extra work to connect and install these things, but it was cheap
compared to ready-to-use commercially available devices. If you want, I can send the exact data of the sensors etc. If you want more sophisticated (and expensive) equipment, I can recommend the systems produced by Timetronics (Olen, Belgium).

You can try the FarmTek ones. I have used them and they are great. I have used the ones designed for track and field. http://farmtek-fti.com/

The Brower are ok, but we have some issues with them going off when our camera system is triggered.

If you are not looking to physically integrate the system with your motion analysis/EMG system, Equine Systems sells an inexpensive unit that we have used in our lab.

We have and use the brower timing system and works perfecrly for us.