speed sensor

[Woolie Willie]

I need to be able to sense the speed of automobiles kind of like the radar guns that police use to check the speed of cars. I want to bring this into CVI. What sensor can I use, and what card wouild I need? The sensor needs to be placed about 30 feet from the PC.

[Sastry V.]

Hi,

You need to decide about the speed sensor. Once you decide on the sensor, lets say it generates a signal based on the speed it detects. Then you can aquire that signal performing Analog or Digital Input in which programming language you want, for example, CVI in this case. To do the Analog Input you will need a multifunction data acquisition card from National Instruments.

You can take a look at the following link for the data acquisition cards from National Instruments.

Link 1

Please do let me know if I could answer your question.

Sincerely,
Sastry
Applications Engineer
National Instruments

[Woolie Willie]

At this point I don't know here to get the speed sensor!

[PdB]

The easiest solution is to just buy a laser gun speed-sensor with an interface/output.
Then you have the old radar-type sensors, relatively cheap but easy to detect.
Another non-mobile solution is using induction-based wire-loops that are placed in the road.
There is also a german company selling an optical-based (they claim it holds 3 camera's) speed-sensor.
The cheapest solution will be placing a few light-cells with reflectors across the road and tie that to a counter-board.
Or a camera with board based solution.
Or you can do experimenting yourself using a microphone with the advanced processing help of labView to use the doppler-effect as a means of detection.
Or design your own optical speed sensor using the low-cost chip used in optical mice.


Lots of options and I bet this list is not complete,

Patrick de Boevere

[Woolie Willie]

>>old radar-type sensors, relatively cheap but easy to detect

Where can I get one of these? I have a limited amount of time so I don't want to re-invent the wheel (no pun).

[Woolie Willie]

OK. I have not been able to find one of these cheap, old type of sensors. I am interested in generating a signal that radar detectors will signal. How can I generate this type of signal? Is it directional? Do I need to run it from my CVI?