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Help me design a Kitesurfing Wind-gage.

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abo
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Help me design a Kitesurfing Wind-gage.

Postby abo » Sat Jun 04, 2011 8:36 pm

Hi all :bye:


As a part of my final bachelor project. I need your help to make some user driven design of a wind-meter (anemometer) for kitesurfers. I'm creating a wind-meter, which utilize the capabilities of smartphones.

Please fill out the online survey if you want to help me design the final product and improve my bachelor report:

http://www.surveymonkey.com/s/PRD37SP

I have already created a prototype, which you can see below
Image


I'm hoping that i will be able to design a wind-meter, which can be constructed of simple widely accessable materials, so "everyone" can make their own :) I would provide the software needed and a online tutorial on how to make it.

What do you think of that idea??

Thanks for your time

Good Wind
/Andreas

blueforest
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Re: Help me design a Kitesurfing Wind-gage.

Postby blueforest » Sun Jun 05, 2011 2:42 pm

Cool looking app, and not so cool looking gizmo

tomatkins
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Re: Help me design a Kitesurfing Wind-gage.

Postby tomatkins » Sun Jun 05, 2011 3:09 pm

If you really want to "wow" your professors...and make a truly useful wind meter, then, you should design the app to judge the "quality"of the wind. The wind could be rated on a scale of one-to-ten for "quality".

This would not be too hard to do, using 3 sets of statistics to rate the wind on these 3 parameters:

(1) Gustiness
(2) Holeyness
(3) Shiftiness

For each of these factors, you would use the "Variance" from the time-weighted "mean". For instance for the characteristic of "Shiftiness", you would average the degrees to determine the wind direction, and then determine the variance from this average to judge "shiftiness" (changes in direction over a predetermined time period)... the higher the variance, the shiftier the wind.

Good luck with your project.

abo
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Re: Help me design a Kitesurfing Wind-gage.

Postby abo » Sun Jun 05, 2011 3:51 pm

tomatkins wrote:
The wind could be rated on a scale of one-to-ten for "quality".

This would not be too hard to do, using 3 sets of statistics to rate the wind on these 3 parameters:

(1) Gustiness
(2) Holeyness
(3) Shiftiness


Thanks for taking your time to comment on my project.

Sounds like a great idea. It should not be too hard to implement. I'm not sure what Holeyness mean?

And thank you all who has completed my survey. :thumb:

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El Rudo
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Re: Help me design a Kitesurfing Wind-gage.

Postby El Rudo » Sun Jun 05, 2011 4:39 pm

something more useful for kite surfers would be a device that also tells you the energy level of the wind. Wind speed is cool but the energy differs with humidity and temperature.

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Re: Help me design a Kitesurfing Wind-gage.

Postby DrLightWind » Sun Jun 05, 2011 6:15 pm

If you really want to "wow" your professors...and make a truly useful wind meter, then,
you should design the app to judge the "quality"of the wind.
The wind could be rated on a scale of one-to-ten for "quality".
and if you want to really impress us kiteboarders,
than you should be able add a Jumping Hight to 20m or 60 feet hight with a combined Hang Time Meter. :lol:
The calibration maybe could be zero-ed before the session
and should be rated within a foot of accuracy.
It should be able to record all the hight and Hang-time of a session
and compare with others who had the highest boost and Hang Time as a competition.

Don't forget there are some apps already available like the iPhone Wind Meter
which is not that bad, I have on my iPad.
But myself I'm using the Windscribe which I think is the most accurate,
since it measures the velocity of the molecules without any moving parts.

Good luck for the project and don't forget you need to use some
new feature what nobody thought of yet.
For example a remote wind speed indicator which could take a pic every 5 minute
and load it to the web so people wouldn't get skunk and drive when there is no wind :idea:

DrLW
Attachments
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tomatkins
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Re: Help me design a Kitesurfing Wind-gage.

Postby tomatkins » Sun Jun 05, 2011 6:30 pm

abo wrote:
tomatkins wrote:
The wind could be rated on a scale of one-to-ten for "quality".

This would not be too hard to do, using 3 sets of statistics to rate the wind on these 3 parameters:

(1) Gustiness
(2) Holeyness
(3) Shiftiness


Thanks for taking your time to comment on my project.

Sounds like a great idea. It should not be too hard to implement. I'm not sure what Holeyness mean?

And thank you all who has completed my survey. :thumb:



Holeyness:

This describes the character of wind where there are long periods (best measured in 10s of seconds) of various wind velocities. We call them "holes", where the average wind speed drops 5 to 10 miles an hour, and stays there for 10 to 20 seconds. This character of wind differs from what we call "gusty" conditions, in that "gusts" describe very short periods of wind speed fluctuation, measures in periods of a few seconds, each.

Both "holes" and "gusts" decrease the quality of wind used for kiting...where "steady" wind is the golden standard. The other characteristic "shifty" wind describes both a "backing" and/or a "veering" wind, and again this characteristic decreases the quality of the wind.

I have a question for you: At what time intervals will the incoming data be recorded?

abo
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Re: Help me design a Kitesurfing Wind-gage.

Postby abo » Mon Jun 06, 2011 7:15 pm

@El Rudo
Energy in the wind... Do you know how much of a impact it really does? is it a couple percent or more?

Often you will kite at roughly the same temperature and humidity, so i would guess that most kites would not be too interested in the exact value of these. The wind speed will vary too much anyway (at least at the beaches in Denmark where I kite). If you are a wind nerd it would properly be nice information.

@DrLW
I totally agree that the product should add some value over existing offers. I have thought about making the jump height app - as that's really interesting for a lot of surfers. It's just technically unfeasible with most android phones - and properly all. WIth out a gyroscope you have know way to know what's up or down. And mistaking the gravitational acceleration for the actual acceleration relative to the surface will produce some very bad results.

Some on my local danish forum has also suggested that you places a stationary vind-meter at each spot. You would then connect your phone to get the wind measurement. At the same time the phone would upload the data, so others could benefit from the data. I'm not sure how that wind-meter would look like, but i love the idea :)

iPhone wind meter is fun. But not really precise enough.

@tomatkins
Thanks for the Holeyness :)
The way my prototype works atm: It basically logs all accelerometer outputs as fast as it can. This happens at roughly 70 Hz. There is some variation. (I can not improve this). To get a steady stream of data i then interpolate between these datapoints to get a set of acceleration values at a constant frequency. Atm. 50 Hz.

On this set of data I do a Fast Fourier Transformation, which gives me the frequency of the oscillations. I do that FFT at a frequency of 5 Hz as thats an appropriate for the display. So basically i get a speed reading every 200 milliseconds. My phone could properly do the FFT calculations at 20 Hz or more I have not tested this.

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Re: Help me design a Kitesurfing Wind-gage.

Postby southflorida » Tue Jun 07, 2011 12:11 am

Interesting, something I've thought about as well when I have time...

Comments on the size of your anemometer (the moving parts). Too big to pick up any quick fluctuations in wind speed. The moving mass of those big cups and large diameter will average and smooth the wind speed for you and whack your finger if you are not careful. I'd rather average in software post-collection of good instantaneous data, because then it's my choice, not a limitation of the hardware.

Your other biggest problem I see is calibration. You'll need a good rpm to wind-speed translation for your moving parts, which also means you'll need precise mechanical reproduction of that piece so that your calibration curve is accurate for all devices made. You don't want a calibration curve for each one you make, if you can avoid it.

I have no idea if a smartphone has a digital input that allows you to count edges in a precise manner. You really do need that. A cheap microcontroller can do that extremely well - a bloatware smartphone, not so sure. Will you lose edges due to latency on the part of the phone? Lost edges will equate to lower than true readings. My BB has senior moments all the time where no inputs are registered - software is out to lunch waiting for something more critical than a user input.

Nice things for kiters...historical graphs for last 5, 20, 40 minutes, 1 hour, 2 hours. That is, if it can be mounted and left to collect data while beer is being consumed waiting for the wind to blow :) Problem is, since its a phone, no one will leave their phone sitting somewhere...so - ta-da: bluetooth! lol feature creep

Good luck

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Re: Help me design a Kitesurfing Wind-gage.

Postby plummet » Tue Jun 07, 2011 12:22 am

Ok i'm going abit left feild here.

But i think that any device you have to plug into the phone is pointless. you might as well have an separate wind meter.

So.... you need to use the phones exsisting sensors to make the reading. Therefore you need to design the app around photo/video evidence and then have the app cross reference it against the Beaufort scale to give an indication.

As a cross reference to this you give local all known current weather stations in the world. The app would locate the closest weather station and give you that reading, historical data and current forecast for you location so you can have all data at your fingure tips.


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