Do you know how to measure angle?

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trail_hehe

Joined: 19 Jun 2009
Posts: 2
Location: malaysia

19 Jun 2009 7:59 how to measure an angle

Please help me, i looking someone to guide how to measure an angle.

My project is to calculate an angle of pendulum but i cannot found the suitable sensor for my project.

sau_sol

Joined: 27 Feb 2008
Posts: 249
Helped: 27
Location: India

19 Jun 2009 10:05 how to measure angle

you can try with magnet sensors
like reed relays or hall effect transistors

Kripton2035

Joined: 19 Jul 2001
Posts: 587
Helped: 20
Location: Earth

19 Jun 2009 10:21 measure angle

you can try an optical encoder, they are expensive
or a mems (accelerator) it can tell you the direction of g.
so you get 2 mems sensors, one on the rigid part, one on the pendulum, and you get two directions from which you can get an angle with a very good precision.

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trail_hehe

Joined: 19 Jun 2009
Posts: 2
Location: malaysia

19 Jun 2009 13:48 mems inclinometer accelerator difference

magnet sensors? sound interesting... could you describe more... advance thank...

sau_sol

Joined: 27 Feb 2008
Posts: 249
Helped: 27
Location: India

19 Jun 2009 14:14 measuring angle pendulum

On the pendulum/Thread you can use magnet and for detecting them use a reed switch
Check the reed switch and based on that get the angle

jorgito

Joined: 26 Mar 2003
Posts: 198
Helped: 13
Location: Argentina

19 Jun 2009 19:51 how to measure the angle

Hello trail_hehe,

Could you please elaborate a bit more on your application?

The encoder could work if the mass of the pendulum and accelerations are enough as to overcome encoder friction, and you have a rigid link between pendulum bob and fulcrum.
With reed type magnetic sensors you could only detect the presence of the pendulum's bob in a certain position, but hardly measure an angle.
Optical sensors share the same characteristics, but they will not damp the movement as could be the case with mag sensors.
There are magnetic sensors with an analog output mesuring distance from sensor to object, but I don't know if the precision is enough for you application.

Hope this helps.

wh00per

Joined: 14 Jul 2009
Posts: 12
Location: Canada

14 Jul 2009 18:20 how to measure angle?

http://www.axiomatic.com/sensors.html

:) You'll find something interesting there .. ( Inclinometers, Tilt sensors .. etc)

bhas_pp

Joined: 11 Jun 2009
Posts: 4

14 Jul 2009 18:36 how to measure the angle with an encoder

you can use Accelerometers

Try

http://www.analog.com/en/mems/low-g-accelerometers/products/index.html

Also you can check for freescale Accelerometers...they are little less expensive i guess

elrayes

Joined: 03 Jun 2008
Posts: 164
Helped: 8
Location: Egypt

25 Sep 2009 1:19 Do you know how to measure angle?

if the motion isn't continuous then use simple potentiometer, cheap and easy to interface.
if continuous motion then you can build your own optical encoder using a LED on the motor shat and plenty of photo transistors connect in a circle around the shaft.
these are cheap and easy ideas.

kender

Joined: 19 Jun 2005
Posts: 1231
Helped: 88
Location: Stanford, SF Bay Peninsula, California, Earth, Solar System, Milky Way

26 Sep 2009 21:53 Re: how to measure the angle with an encoder

bhas_pp wrote:

you can use Accelerometers

Pendulum always moves with acceleration. Solving for pendulum angle given 2 accelerometers mounted on a pendulum would be a good mathematical exercise.

haker_fox

Joined: 24 Jun 2009
Posts: 51
Helped: 4
Location: Russia, Irkutsk

28 Sep 2009 1:01 Do you know how to measure angle?

I think you can take any optical encoder. You should to pay attention to it's accuracy. Considering that the pendulum hasn't high velocity the encoder needn't ball bearing. But if it does you can find some suitable cheap encoder like ENS1J-B28-L00128L.