Visual size sensor?

My niece has a koi pond that was raided by a heron.
I thought a motion detector scarecrow would be a nice project but she doesn't want small birds to be scared off.

So is there a way to detect size?

What do you mean by scarecrow? There are motion detector+impulse sprinkler combinations called scarecrows and they work well to discourage large birds. They may not even be sensitive to small birds. http://www.amazon.com/Contech-CRO101-Scarecrow-Activated-Sprinkler/dp/B000071NUS

jremington:
What do you mean by scarecrow? There are motion detector+impulse sprinkler combinations called scarecrows and they work well to discourage large birds. They may not even be sensitive to small birds. http://www.amazon.com/Contech-CRO101-Scarecrow-Activated-Sprinkler/dp/B000071NUS

Yes I know about this product. It has a simple motion sensor. It doesn't care about size.

Maybe this IR array sensor?
The larger the IR signature, the bigger the animal.

http://pewa.panasonic.com/components/built-in-sensors/infrared-array-sensors/grid-eye/

I would not bet on visual sensor. Personally, i would use sound sensor and I would use sound pattern recognition.

and I would use sound pattern recognition.

On an Arduino!

Well not only Arduino, you need a sound analising module, an humming bird does not emmit the same frequency set the an eagle. You only need small sample. Worst case scenario, you send the sample by RF to a computer that will do the job.

I did not try it yet but tel me Mike, how does voice recognition module work? Must you presample command and then it wait for the same wave patern to show up?

I was thinking some thing like this:

how does voice recognition module work

Not very well.

It uses parameter extraction and then correlation from a template to give you a percentage probility of a match. A voice recognition module would not be much good for bird sound as it is taylored for voice frequencies.

Yes basically get something else to do it an arduino is not up to the job.

Anyway a Heron makes little noise when fishing.

Yeah, i agree, arduino would be ok to gatter and send data to a processing unit like a computer, then the computer tel Arduino to start a sirene or sprinkler if need it.

But Arduino will not analyse audio or video properly. Well not the first generation of Arduino at least.

You could get a serial cam and a movement detection unit. When there is mouvement, arduino take a pictureand send it to computer for analysis.

Or you could put well placed sonars mounted on servos, but the 5m limitation of unit like SR04, tend to make me think it is not ideal depending on the pond size.

Althouth with sonar, size become proportional to the angle mesured by the servo and sonar, and is invertly proportional to distance measured by the sonar.

hmm, I can only see sonar/ultrasonic sensors that outputs distance. It doesn't distinguish object size.

Frédéric_Plante:
I would not bet on visual sensor. Personally, i would use sound sensor and I would use sound pattern recognition.

This assumes every animal that comes by to make an announcement by making a call. They don’t.

Thanks for the creative suggestions though!

No, I was more thinking about the noise of flying. The wings tend to flap harder then they land, to land smootly. I would use that noise. I would not count on the fact that the bird screem or any thing.

Since the bird kinda try to land the same way evety time
Question of habit, i would use that sound.

But still, i would still choose the sonar, if the pond is not to big. If it is big, then an OV-528 camera + 1 mega + 1 uartwifi kit might be cheaper then a bunch of servo and sonar.

It all depend on the size of the pond.

hmm, I can only see sonar/ultrasonic sensors that outputs distance. It doesn't distinguish object size.

If you mount the sonar on a servo, then you can sweep the pound with the sonar. The size would then be calculable using the angle that the object represent.

Wait, i will go on my computer to do a picture

here I know it’s ugly, I’m no artist, but with the servo, you can gather data from the returning ping that will represent an angle, and you will know by the returning ping the distance, it’s simple trigo, you can calculate the size no problem.

654.bmp (2.01 MB)

Any way's do it as you please, that is how I find gap where my smartcar can pass, well instead of looking for where there is something it look for where there is a nothing wide enough. I know that principle work.

Ah thanks. That sonar solution definitely should work.

Well it depend of the strengt of the sonar, SR04 ill only detect a position within 5 meters, so depending on the size of the pond, you might need more then one of those. Or you can get bether then SR04.

Any ways, that is how they do it in submarine movies. :wink: