Measuring speed of moving object ?

[bianchi77]

Guys,

How can I measure the speed of moving object, for example measuring speed of the car passing ?
What sensor do I need ?
Please see my illustration to understand my question, thank you

Any experiments / links will be appreciated,
Thanks

 

[W_Heisenberg]

you need acceleration meter, so that if you get a sensor say, accelerometer, you will find out the speed. Because v= at.

Or if you get the distance, you will get avg speed, v = s/t

actually, this could be solved by simply cell phones today.


try the above, the idea is simple since you got GPS chip in your cell phone, it will finally give the distance you travelled.

 

[BradtheRad]

If you are stationary, and the car is passing close to you...

Then you might set up two bright led's. Each is aimed at a photo-sensor. The spacing is a foot or two apart, so that the car will block led #1, then led #2.

Measure elapsed time between sensor 1 and sensor 2 being blocked, and calculate the speed.

 

[ravi1488]

Well the first thing is that, what is that moving object and whether is a controlled situation? If the situation, object and place is already known we can put sensors. For example, we can to 2 proximity sensors at known distances. As the car pass through them, we will get the difference of time from those 2 sensors. So, Distance = speed x time, we will get speed. Simple.

 

[jayanth.devarayanadurga]

Yes. As mentioned earlier accelerometer is the right sensor but it can be used if you are measuring the speed of a car and the device to calculate the speed is inside the car. That is you cannot use accelerometer sensor to calculate speed of moving device by remote method.

 

[bianchi77]

you need acceleration meter, so that if you get a sensor say, accelerometer, you will find out the speed. Because v= at.

Or if you get the distance, you will get avg speed, v = s/t

actually, this could be solved by simply cell phones today.


try the above, the idea is simple since you got GPS chip in your cell phone, it will finally give the distance you travelled.

that's not what I mean, because I'm gonna use microcontroller not cell phone, if I'm using cellphone, I can use Eclipse and android but the application I want, is different, but thanks anyway

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If you are stationary, and the car is passing close to you...

Then you might set up two bright led's. Each is aimed at a photo-sensor. The spacing is a foot or two apart, so that the car will block led #1, then led #2.

Measure elapsed time between sensor 1 and sensor 2 being blocked, and calculate the speed.

I see, how about the car is about 10 to 20 metres from me ?

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Well the first thing is that, what is that moving object and whether is a controlled situation? If the situation, object and place is already known we can put sensors. For example, we can to 2 proximity sensors at known distances. As the car pass through them, we will get the difference of time from those 2 sensors. So, Distance = speed x time, we will get speed. Simple.

Can you give me one example of proximity sensor ? what type and link if you have ? thanks

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Can I use PIR sensor, sonar / doppler ? any idea on doppler sensor ?

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The illustration with radar, this is what I want, is there any modules for this one ? thanks

This could be the answer, anyone knows how to use it ?
Microwave Doppler X-Band Radar Sensor Wireless Module Move Motion Speed Sensor

 

[Jestin_cubetech]

Speed measuring using Microwave Doppler Radar Sensor
https://www.edaboard.com/threads/265749/

 

[bianchi77]

Speed measuring using Microwave Doppler Radar Sensor
https://www.edaboard.com/threads/265749/

What's the bandwidth for that amplifier ? can it accept from 0km/h until 150km/h ?
what do you use for signal conditioner before sending to ADC or directly connect pre amp to ADC ?
thanks