Emergency Vehicle Siren Detector

ckrmustafa:
Hi again everyone :slight_smile:
I googled the strobe light's frequecy but there are many different information suc as 12Hz, 10-14Hz, <15Hz etc.
Isn't there any standart frequecy value for emergency vehicle that use strobe light ?

Thanks in advance to anyone who will advise.

Not all EV use the same signals. Within a 20 minute drive of my location, I can find a region that uses Infrared strobes to actuate the traffic signals, another that uses visible strobes, and a third that uses the audible siren sounds to trip the lights. And the sirens have to be of a specific tone/oscillation to trip the sensor. I spent many years as a paramedic (flight and ground), and the systems are specific to the city/county/region they are setup in. It depends on which manufacturer had the best sales pitch.

It is also very difficult to get exact info (I haven't looked in quite a few years though) on the specs for each system. 1) They are proprietary products of each manufacturer, and 2) It is illegal (in most places) to use such systems on non-authorized vehicles. Even authorized vehicles running just their opticon (the IR version I'm familiar with) without a good reason can get in trouble.

Another point: Any driver who is caring enough to want a detector, should be a good enough driver to have the situational awareness to notice an EV coming from a ways off. Installing a detector into a vehicle is just giving the driver an excuse to not pay attention. Any driver who normally wouldn't pay enough attention, doesn't care enough to think about this type of system. You should be checking every mirror and your gauges every 10-20 seconds or so. Reducing situational awareness is not a good idea. And those drivers who don't give a damn to start with won't even use the thing if it hits them in the face. I have followed drivers down the road for miles, (too) close to their bumpers blaring everything I had to get them to move.

Thirdly, at least in my local, yielding of right of way is NOT required. A motorist may continue on, at their pleasure, regardless of what an EV is trying to do, as long as that motorist would normally have right of way. That is why we are trained to stop at every red light and visually clear the intersection, I try to make eye contact with every first in line driver. Oddly enough, in my state an EV MUST yield to Mailmen and funeral processions (We're pretty sure that's why they died, the last ambulance had to yield to another funeral).

Side note on the use of Lights and sirens, On highways, EV's will only gain 3-5 seconds per mile running 'hot', and city driving they only gain about 10-15 seconds per mile, on average. The one report I read long ago, showed that running 'hot' only makes an actual difference in <.1% of calls. Of course, we never know if our next call will be that .1%, so we run hot.

/rant

Thirdly, at least in my local, yielding of right of way is NOT required. A motorist may continue on, at their pleasure, regardless of what an EV is trying to do, as long as that motorist would normally have right of way.

You should put a pair of Diesel Locomotive Horns on your cab and hit the horn when your right on their bumper.

You mean like some sort of a loud siren?

No. An EV already has a siren. Fire trucks have a special unique horn that is extremely loud, but a diesel locomotive has a special horn designed to be heard a mile away. If you were day dreaming behind the wheel with an EV on your bumper with the siren on, you might be able to ignore it, but a diesel locomotive
horn on your bumper is loud enough to make you jump out of your skin and every time it goes off your neves fire on full and you can't help but flinch. After several bursts, your nerves won't be able to take it much longer and you won't even be able to think straight. It's the closest thing to an electrical shock without actually being shocked. The response is almost the same. At 6 feet away it makes an EV siren look like a toy. There's no ignoring it. Your entire nervous system goes nuts at 6 feet away. Of course the effect at 200 to 300 ft is totally different. I'm talking about directly in the path of the horn at 6 ft away. Consider this. The horn, even when mounted 10 ft above the ground on the top of the locomotive is very loud. Now
imagine that being 6 ft (or less) off the ground. Now the sound pressure wave is not traveling over your head. It is coming right at you. That, by itself , makes a huge difference.

diesel locomotive horn

152 + db Train horn kit

Marmotjr:
Side note on the use of Lights and sirens, On highways, EV's will only gain 3-5 seconds per mile running 'hot', and city driving they only gain about 10-15 seconds per mile, on average. The one report I read long ago, showed that running 'hot' only makes an actual difference in <.1% of calls. Of course, we never know if our next call will be that .1%, so we run hot.

It's a particularly bad problem on some highways in Johannesburg. On some older stretches, where the geography prevents widening the road to make extra lanes, the municipality decided to make the emergency lanes into normal lanes.

Not that that matters actually: SA drivers are so ill-disciplined that vehicles often resort to the emergency lanes when the road blocks due to an incident. Then the EMTs can't get through anyway, and that's why my son's EV is one of these. Just about everything for ILS response in the panniers except road cones.

Hugh sanral bike.jpg

The Pediatric MICU I used to run on had an airhorn mounted on the roof of the cab, but some idiot decided to mount the air tank and compressor under the passenger seat. So if you hit the air horn, yes you would clear a path for miles, but then you had to listen to 10 minutes of the compressor running loudly inside the cab.

But it was worth it to wait for somebody with their windows open about to take a drink of coffee..........

But it was worth it to wait for somebody with their windows open about to take a drink of coffee..........

ROFLOL... :smiley:

I have followed drivers down the road for miles, (too) close to their bumpers blaring everything I had to get them to move.

To those that don't pull over to let an EV pass, I ask:
"What if it was their house on fire, their mother needing urgent medical treatment or their child being attacked?"

Well, they need to get home urgently to deal with that and pulling over for a truck to pass isn't going to help them accomplish that goal.

I had a misfortune of being on the deck of a large ship when some guy on the bridge decided it would be fun to honk.
I was perhaps 20 m from the actual horn. There's no ignoring THAT. You crumble down in pain and cover your head to protect yourself from the sky falling on it.
To make the things worse, it was the dead of the night.

Anyway, this IR strobe traffic light thing is interesting.
Now, everybody who installed it on their non-EVs, raise your hands. :smiley:

I would assume the IR opticon would be an encoded pattern for each vehicle, since I know of reports that showed when individual vehicles were at what intersection. Not all systems have this datalogging though. Either way, some sort of code/pattern is required.

But an arduino, IR detector, lawnchair, and a six pack near a hospital should eventually allow you to decrypt the signal. Then it would be pretty simple to build your own.

What happens when EVs approach these intersections on 90 degree legs?- can't have it go green all round...

Some systems are directional, where they can detect which way the strobe or siren is originating from. Those turn all the other directions Red, and leaves the one green. That usually clears the path so we can roll right through, but not always. Urban settings that use a siren signal rarely use this, as echos from buildings can confuse the sensor.

Most systems though turn everything red when they detect a signal. It's good because no one is moving, but because no one is moving, they tend to bunch up, and EV's get stopped at the light waiting for traffic to move out of the way.

Can i detect the ambulance siren using elechouse voice recognition module and arduino?

Probably not

you don't need arduino, google for, 567 Tone Decoder (narrow bandpass filter) , electret microphone and frequency of siren.

(narrow bandpass filter) = Notch Filter

raschemmel:
(narrow bandpass filter) = Notch Filter

almost, opposite way

almost, opposite way

Correct.

I meant Notch-PASS filter.

yes