trrafic signal:- help

[aht]

Hello,
I am a 2nd year electronics student. I am trying to do a simple project
of counting the time for which a signal should be open. I have thought
of placing a laser at one side of the road and a sensor at exactly the
opposite, when a vechile crosses this laser it is blocked from reaching
the sensor and at exactly the same time a device starts counting the
duration of obstruction.

Can any one please help me out as for which devices to be used. Any
other sugestion concerning this idea will be greatly appreaciated.

please : - I am just a new comer in the field of electronics.

 

[Rune Christensen]

"aht" <ahtesham_rulz@yahoo.com> skrev i en meddelelse
news:1124623336.582622.64170@g43g2000cwa.googlegroups.com...

Hello,
I am a 2nd year electronics student. I am trying to do a simple project
of counting the time for which a signal should be open. I have thought
of placing a laser at one side of the road and a sensor at exactly the
opposite, when a vechile crosses this laser it is blocked from reaching
the sensor and at exactly the same time a device starts counting the
duration of obstruction.

Can any one please help me out as for which devices to be used. Any
other sugestion concerning this idea will be greatly appreaciated.

please : - I am just a new comer in the field of electronics.

Hello

In Denmark some of the traffic signals is controlled by coils in the ground
(Metal detectors).

Rune

 

[Richard Crowley]

"Rune Christensen" <christ@os.dk> wrote in message
news:43097883$0$68359$edfadb0f@dread14.news.tele.dk...

"aht" <ahtesham_rulz@yahoo.com> skrev i en meddelelse
news:1124623336.582622.64170@g43g2000cwa.googlegroups.com...
Hello,
I am a 2nd year electronics student. I am trying to do a simple
project
of counting the time for which a signal should be open. I have
thought
of placing a laser at one side of the road and a sensor at exactly
the
opposite, when a vechile crosses this laser it is blocked from
reaching
the sensor and at exactly the same time a device starts counting the
duration of obstruction.

Can any one please help me out as for which devices to be used. Any
other sugestion concerning this idea will be greatly appreaciated.

please : - I am just a new comer in the field of electronics.


Hello

In Denmark some of the traffic signals is controlled by coils in the
ground (Metal detectors).

Those were popular for decades here in the US (at least in
my part), but are being replaced by video cameras.

 

[JeffM]

aht wrote:

Hello,
I am trying to do a simple project
of counting the time for which a signal should be open.
I have thought of placing a laser at one side of the road
and a sensor at exactly the opposite

Your optical model does not account for staggered traffic.
View with monospaced font (Courier).

.--. | ^
| | |
| | | |
~~| |~~~.--.~~~~~~~ optical path
`--' | | |
| |
.--. | | |
| | `--'
| | |
| | .--.
`--' | | |
| |
| | |
`--'

The coils-embedded-in-the-pavement approach (think: metal detector)
avoids this problem.

 

[Al]

In article <1124745016.721585.293070@z14g2000cwz.googlegroups.com>,
"JeffM" <jeffm_@email.com> wrote:

aht wrote:
Hello,
I am trying to do a simple project
of counting the time for which a signal should be open.
I have thought of placing a laser at one side of the road
and a sensor at exactly the opposite

Your optical model does not account for staggered traffic.
View with monospaced font (Courier).

.--. | ^
| | |
| | | |
~~| |~~~.--.~~~~~~~ optical path
`--' | | |
| |
.--. | | |
| | `--'
| | |
| | .--.
`--' | | |
| |
| | |
`--'

The coils-embedded-in-the-pavement approach (think: metal detector)
avoids this problem.

He said "simple." Your software then rejects the anomalous readings.

Al