Small, man-carry data recorder

[R. Pare]

Anyone have knowledge of an small data recorders ( battery- powered) that would be suitable for a skier to wear?

I am working on a project with a couple ex-Olympians, and we need to record readings from a couple strain gauges and displacement scales - no more than 4-6 channels, most likely. Can't say more than that at the moment, unfortunately.

Any opinions?

[DanW]

Anyone have knowledge of an small data recorders ( battery- powered) that would be suitable for a skier to wear?

I am working on a project with a couple ex-Olympians, and we need to record readings from a couple strain gauges and displacement scales - no more than 4-6 channels, most likely. Can't say more than that at the moment, unfortunately.

Any opinions?

http://www.dataq.com/resources/pdfs/...cquisition.pdf

I have used something similar to this.

[R. Pare]

Figured somebody here would have ideas - this forum is such a great repository of expertise in all sorts of areas!

Will look at that recorder for sure - just about the size I was thinking of.

Any more, anyone?

[suzrm121]

I worked with vbox (racelogic) years and years ago, they were working on a small box then for our needs. They might have something or be willing to work with you-

[romoman]

People have added battery packs to an AiM Evo4 to use on bicycles, sleds, and more.

[Spengo]

Wouldn't the AIM SOLO or MyChron 5 be more ideal than an EVO? With those everything you need is contained in one device, EVO needs an external display. Even those seem a bit overkill for this purpose though. Surely there is something simpler that can get the job done.

[romoman]

Wouldn't the AIM SOLO or MyChron 5 be more ideal than an EVO? With those everything you need is contained in one device, EVO needs an external display.

You can't put external inputs into a Solo or Solo DL, so those won't work with a strain gauge. The MyChron 5 could probably work but would need the expansion pack.

[Spengo]

You can't put external inputs into a Solo or Solo DL, so those won't work with a strain gauge. The MyChron 5 could probably work but would need the expansion pack.

I see, nevermind then. I guess a skiier probably doesn't care to look at his lap times either so a display isn't important provided the evo can be set up somehow without a display.

[BLS]

What sample rate do you need?

How will your strain gauges be powered? And what voltage?

Are the strain gauge outputs amplified? If not you will need a millivolt input range.

What is the "displacement scale" signal and power.

How much data needs to be stored before offloading?

The answers will go a long way toward determining what equipment you will need.


Something like this might work:

http://www.dataq.com/products/di-710...l#nested-tab-1

[David Ferguson]

The DataQ system linked in post #2 only works attached to a PC, so it's not as portable as you might think. I think that a Race Technology DL-1 might work well for this application. They don't need much power, can sample lots of data on removable memory cars. Software has sufficient math channel capability to deal with the processing you might want.

I have built several self-contained systems (using Aim Evo4, MXL2 and RT DL-1) for instrumenting vehicles that don't have power (from downhill sleds to sprint cars). So this is very doable.

[LJennings]

if you knew someone that could code, I would look at either a Raspberry Pi or an Arduino with an Adafruit daq shield based soultion.

Both boards are about the size of a credit card or smaller.

Power either unit with a couple of laptop batteries and you are set to go.

We built a couple Arduino units for impact testing. They survived a 12g test. Not a great deal of force but substantial for the application.

[Steve Demeter]

So are the skiers knees going to be instrumented or the equipment?

[DanW]

The DataQ system linked in post #2 only works attached to a PC, so it's not as portable as you might think. I think that a Race Technology DL-1 might work well for this application. They don't need much power, can sample lots of data on removable memory cars. Software has sufficient math channel capability to deal with the processing you might want.

I have built several self-contained systems (using Aim Evo4, MXL2 and RT DL-1) for instrumenting vehicles that don't have power (from downhill sleds to sprint cars). So this is very doable.

David,

I agree completely. My thought was ultimate flexibility using a small tablet pc with the USB I/O. I guess one would have to fool the AIM unit with RPM signal so it would begin collecting data.

Dan

[R. Pare]

No real good idea on all of the questions asked so far, but I'm guessing a sample rate of at least 1000/sec. Strain gauge, displacment sensor(s), g-load sensor, and possibly GPS all need to be able to run off of a battery pack that will not screw up the skier.

Got a long ways to go on this, obviously! Winter will come too fast!

But not fast enough for me personally!

[R. Pare]

So are the skiers knees going to be instrumented or the equipment?

Both.

[CDS]

Richard, I sent you a PM.

-Peter Kelly

[TimW]

if you knew someone that could code, I would look at either a Raspberry Pi or an Arduino with an Adafruit daq shield based soultion.

Both boards are about the size of a credit card or smaller.

Power either unit with a couple of laptop batteries and you are set to go.

We built a couple Arduino units for impact testing. They survived a 12g test. Not a great deal of force but substantial for the application.

This was also announced yesterday for the BeagleBone:
https://research.googleblog.com/2016...board-for.html

[captain_pants]

I own a Race Technology DL1 and have used it for many years. Random data points that may be helpful:

The DL1 logs to 100 Hz only, unless you get the recent Pro model. It can log GPS position, but the antenna cable is surprisingly fragile and I fear wouldn't last long on a skier.

If you don't plug in the antenna, it'll still work but you lose all time stamps and positional data. It's then a little tricky to distinguish which 'run' is which.

It is not tolerant of water. Must be kept dry!

It will run on an array of 8 AA batteries for a long time. I haven't quantified how long exactly, but it lasted the 2 hours I needed without issue.

[Pi_guy]

A few years ago there was a product called

ripxx a personal measurement device

great device worked well internal company politics blew it apart as much of the phone app helped to take away market share.

I would be very happy to have a personal measurement device, as most of the circuit board style kits are too fragile for ski racing and picking electronic splinters out of the body is no fun.

But on a side note USSA masters do not allow any electronic device outside of the speed suit. Cameras included.

[Shanerc]

I have noticed that the Supercross Guys are using some type of data device. I don't know what or how it works, I seen them talking about it in a post race interview with one of the top teams. It appeared to velcro to the top area of the riders helmet.

[R. Pare]

Looks like there are plenty of options available. Thanks everyone.

The more difficult part I still have to sort out is mounting the strain gauges. Got a few months to mull that over, thankfully!

[aims20]

I apologize in advance for not giving the best information, but Senior year at Virginia Tech we were doing a heap of testing on our 2012 FSAE Car with an AiM Data logger, a LabVIEW CompactDAQ/cRIOS and everything we could get our hands on. In one instance, We used a team member's phone to independently verify some downhill coastdown testing we were doing for our aero package.

So I pose the question: Is there a smartphone app that you could get that can record using the phone's internal accelerometers/and other sensors that might fit the bill? I know you said strain gauges, so the hardware might not be up to the task in "stock"/oem form, but more and more electronics companies are building add-in/plug-in devices like FLIR's infrared camera add-on for iphones.

Just a thought really.