Capture people sitting on a bench

Hi,
I want to check how often people sit on one selected bench in park. I need to gather data time: start of sitting - end of sitting.

What is the best way to catch it?
Should i use PIR sensor (how to track only sitting people, not that just are passing by?). Maybe use some piezo sensor to track vibrations that people are making while sitting and getting up from the bench. What do you recommend?

Any particular reason why you want to do this?

Pressure pads, millis() function, SD card shield or some kind of data logger.

Can you add sensors to the seat?

What about something sensitive to temperature?

...R

What about something sensitive to temperature?

If he lives in a warm climate that will probably not work.

@ motivo is this bench at a city park or is it just a park bench on privet property.

Pressure pads are the way to go, however, I personally will not be sitting on a city bench with a pressure plate attached to it. If this is for some type of survey the results could be skewed as less people will sit on that bench. You could also find your self in some trouble.

If it is not your property you could go with a water proof ultrasonic sensor…

With a good program you could probably get reliable results with just two sensor (one per side).

Best of luck!

I would have thought that a camera with some image processing software is your best bet.

Nothing to do with an arduino however.

Pay a college or high school kid to walk by at one hour intervals and record if someone is sitting there.

Why not?
I think temperature sensors could be almost invisible and thus wouldn't deter the guests.

PS - if this is for a survey aimed at justifying the removal of park benches I hereby withdraw all my suggestions!

...R

That’s exactly what we used to do when I started out in traffic engineering: walk a set route taking about 10 mins to note the reg of cars in on-street parking bays. That way we measured the stay time and noted vacancy.

In the film Columbiana the bomb under the seat uses a pressure pad and a timer plus obligatory flashing LED.

I think there is plenty of scope for getting into serious trouble attaching electronic devices (however innocent they may be) to public benches.

radman:
I think there is plenty of scope for getting into serious trouble attaching electronic devices (however innocent they may be) to public benches.

Unless of course this is a survey sanctioned or even contracted for by the council.

You didn't mention how the bench is constructed. If it has boards on it, you could loosen one and slip a pressure sensor under it. Wiring could be well hidden and a small box for the electronics out of sight underneath.

Sounds like a challenging project.

Unless of course this is a survey sanctioned or even contracted for by the council.

If this is a public bench then anybody seen attaching an electronic device to it will be viewed as "suspicious" even if they are wearing a council uniform.

I'm interested in designing public spaces. I want to do it, to show how many benches are poorly placed in public parks.
Here is a great movie about it:
http://vimeo.com/6821934

@James C4S
I know i can count people, or pay someone but it's a lot of benches and it will take a lot of time/money to do it right :~

@Robin2
I could place pressure pad on the bench, put i think no one would sit on it. I live in Poland so in summers we have quite hot, checking temparature may be unreliable.
I want to suggest moving benches in better places, not just removing :wink:

@Grumpy_Mike
Video processing sound like it will be complicated an not scalable (many benches)

@radman
In Poland we are not so strict about placing things in public spaces :wink:

What is sensitivity of a piezo sensor, will it detect vibraton if i will stick it to a bench like this -> http://ks366875.kimsufi.com/p3/201006/11/67186335.jpg ?

motivo:
I'm interested in designing public spaces. I want to do it, to show how many benches are poorly placed in public parks.

The easy options for detecting a person sitting down all seem easy to spot and therefor unlikely to survive long on a public bench. I can't think of any hidden options which would be practical to get working and also sufficiently subtle to avoid being noticed, while also being obviously benign to anyone who does spot them.

Do you have any authority for the benches? For example, are you authorised to paint them, or repair them etc? If they aren't your benches and you have no authority to modify them then attaching any equipment to them will be problematic. Added to that, in this day and age people noticing unknown electronic equipment hidden in a public place are likely to be alarmed and once that equipment is traced to you you might find yourself facing some rather unpleasant questions. Similarly, installing hidden video surveillance equipment which records people sitting on a public bench seems like the sort of thing that people would object to in many cultures and I suppose it might even be illegal in some places.

will it detect vibraton if i will stick it to a bench like this

No.

What about a few photoresistors or a strip of photoresistors? If the bench has gaps between the wood or plastic beams, you could tuck the photoresistor between them. If some one sits down, the photoresistor value will change indicating a person is there. And photoresistors are very small, so it should fit easily between the gaps.
I wouldn't put the photoresistors where the person actually sits down, but on the part where the persons back leans against the bench, this way if someone puts a bag down, the photoresistor wont get covered and no incorrect readings.

What about a handful of capacitive sensors under the bench? They can have a range into the tens of centimeters and should work through non conductive materials (e.g. wooden bench).

Capture people sitting on a bench?

Have a large metal clamp come out of either side of the back rest an grab them. Then have an ether spray to knock them out.

Grumpy_Mike:
Capture people sitting on a bench?

Have a large metal clamp come out of either side of the back rest an grab them. Then have an ether spray to knock them out.

I was going to suggest dropping a large net.

I would go for the loosened plank + microswitch, hooked up to an Ardulog (www.hobbtronics.co.uk). Very small (easily hidden under the plank), very cheap, very effective, not going to be triggered by birds or squirrels.