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sensors

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ritviknk

New Member
hello friends.
i am doing a project on collision avoidence system. and i lack information as to what all types of sensors are available regarding the above topic.
i have heard something called proximity sensors and i dont know a thing abt that.
please help me out friends. i really am in a terrible fix.
thank u.
 

epilot

Member
ritviknk said:
hello friends.
i am doing a project on collision avoidence system. and i lack information as to what all types of sensors are available regarding the above topic.
i have heard something called proximity sensors and i dont know a thing abt that.
please help me out friends. i really am in a terrible fix.
thank u.

there are a kind of sensors called "pressure sensors" in commercial
but these sensors will act after a HIT

it was so better if you mentioned what you want the system to do for you?

proximity sensors work based on reflection,
**broken link removed**



does anyone know if a coin piezo sounder can work as a pressure sensor?
 

akg

New Member
epilot said:
ritviknk said:
hello friends.
i am doing a project on collision avoidence system. and i lack information as to what all types of sensors are available regarding the above topic.
i have heard something called proximity sensors and i dont know a thing abt that.
please help me out friends. i really am in a terrible fix.
thank u.

there are a kind of sensors called "pressure sensors" in commercial
but these sensors will act after a HIT

it was so better if you mentioned what you want the system to do for you?

proximity sensors work based on reflection,
**broken link removed**



does anyone know if a coin piezo sounder can work as a pressure sensor?

epilot , "ritviknk" want to avoid the HIT :)
ok , the proximity detector should do the work , ultrasound/rf being the best.
 

epilot

Member
akg said:
epilot said:
ritviknk said:
hello friends.
i am doing a project on collision avoidence system. and i lack information as to what all types of sensors are available regarding the above topic.
i have heard something called proximity sensors and i dont know a thing abt that.
please help me out friends. i really am in a terrible fix.
thank u.

there are a kind of sensors called "pressure sensors" in commercial
but these sensors will act after a HIT

it was so better if you mentioned what you want the system to do for you?

proximity sensors work based on reflection,
**broken link removed**



does anyone know if a coin piezo sounder can work as a pressure sensor?

epilot , "ritviknk" want to avoid the HIT :)
ok , the proximity detector should do the work , ultrasound/rf being the best.

oh yes you are right :lol:
i should read the words completely
 

Roff

Well-Known Member
Here is one I designed, but it only has a range of 10 feet. The OP on that thread claimed (in a PM) that he built it, and it worked perfectly. I did not build it, and I certainly won't guarantee that it will work. I think a micro-controller based unit would be simpler and more versatile. I don't know if ultrasonic has the range you need. You might need to use radar.
 
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audioguru

Well-Known Member
Most Helpful Member
How can you avoid a collision if you are driving a big, tall and heavy SUV?
Turn the steering and the darn thing just rolls over and over sideways on top of the obstacle.
I saw a lady drive one too fast on an icy road. It slid into the curb and the tires on that side burst into a dust-cloud, then over and over it rolled. Of course it ended-up upside-down and she hung there without any injuries.
She is lucky that she is short because a taller driver would have been decapitated.
I also agree that a 10ft range is too short, unless it is for a slow little robot.
 

akg

New Member
audioguru said:
How can you avoid a collision if you are driving a big, tall and heavy SUV?
u should be driving not sleeping :lol:
audioguru said:
I saw a lady drive one too fast on an icy road. It slid into the curb and the tires on that side burst into a dust-cloud, then over and over it rolled. Of course it ended-up upside-down and she hung there without any injuries.
She is lucky that she is short because a taller driver would have been decapitated.
was it a collision ??
 

audioguru

Well-Known Member
Most Helpful Member
akg said:
was it a collision ??
The guy she nearly hit got away because his light little car was nimble on the ice. Her SUV was so heavy that it kept sliding until the curb jumped up and collided with her. :lol:
 

Oznog

Active Member
The systems I heard of used radar, though laser has certainly been experimented with by now. Actually machine vision is the hot item and all the autonomous vehicles are trying to use it as the most critical sensor. There was recently a challenge to design an autonomous vehicle to do a significant cross-country drive by itself. I don't think any vehicles finished.

Distance is not very useful. Distance and velocity are. For a system to be useful, really distance, velocity, and direction and needed.

For example, if you're going forward and somebody changes lanes to get 20 ft in front of you, you don't want to hit the brakes like you would if a building was 20 ft in front of you. So you need to know how fast it's closing.

And you may be travelling down a nondivided road, someone on a side road pulls in front of you to get on the lanes going the other direction in a smooth motion. This is alarming because a system may detect that there is suddenly an obstacle in front of you, and you're approaching it at the speedometer speed. But in fact it is not standing still, it has horizontal motion and will be out of the way by the time you cross paths.

The geometry is also important. Going through a turn, you may register telephone poles on the side approaching rapidly. Since you're turning this shouldn't be a situation that requires braking. In fact you may be approaching a turn and the steering wheel is straight while the system registers the pole/tree approaching at a speed that would require braking if you don't turn. It doesn't understand your intent to turn.
 

akg

New Member
Oznog said:
The systems I heard of used radar, though laser has certainly been experimented with by now. Actually machine vision is the hot item and all the autonomous vehicles are trying to use it as the most critical sensor. There was recently a challenge to design an autonomous vehicle to do a significant cross-country drive by itself. I don't think any vehicles finished.

Distance is not very useful. Distance and velocity are. For a system to be useful, really distance, velocity, and direction and needed.

For example, if you're going forward and somebody changes lanes to get 20 ft in front of you, you don't want to hit the brakes like you would if a building was 20 ft in front of you. So you need to know how fast it's closing.

And you may be travelling down a nondivided road, someone on a side road pulls in front of you to get on the lanes going the other direction in a smooth motion. This is alarming because a system may detect that there is suddenly an obstacle in front of you, and you're approaching it at the speedometer speed. But in fact it is not standing still, it has horizontal motion and will be out of the way by the time you cross paths.

The geometry is also important. Going through a turn, you may register telephone poles on the side approaching rapidly. Since you're turning this shouldn't be a situation that requires braking. In fact you may be approaching a turn and the steering wheel is straight while the system registers the pole/tree approaching at a speed that would require braking if you don't turn. It doesn't understand your intent to turn.
i agree with oznog that a machine vision is a hot topic . but isn't it too hot for a collision avoidance system?.
the cross country race conducted by DARPA met its objective .
the 'stanley' by stanford univ and 5 others completed the mission (that's great!!! )
see this
https://www.defenselink.mil/news/Oct2005/20051012_3025.html
 
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