Triangulation For IR Background Suppression Sensor

[josephraja_2006]

Hi,

I am doing a project background suppression photoelectric sensor. I am using two receivers for near far detection.Now i got signal from one receiver only that is the near receiver.i felt i have problem with my triangulation .will any one help me for the IR triangulation?

And also suggest me any software for the triangulation?

Thanks In Advance

Regards
Joseph.D

 

[HTA]

Hi,

you might take a look at the iC-LO from iC-Haus which has an ambient light supression and 129 photo transistor for near, middle and far field. Here is a short overview:
www.techonlineindia.com/article/12-...ion_up_to_13_9_kHz_switching_frequencies.aspx and the data sheet: https://www.ichaus.biz/LO .

Enjoy your design work!

 

[josephraja_2006]

Hi,

you might take a look at the iC-LO from iC-Haus which has an ambient light supression and 129 photo transistor for near, middle and far field. Here is a short overview:
www.techonlineindia.com/article/12-...ion_up_to_13_9_kHz_switching_frequencies.aspx and the data sheet: https://www.ichaus.biz/LO .

Enjoy your design work!

Hi,

Thank you for your response. I checked the the ic but my problem is the triangulation.How to form a triangle?that is the seperation distance between the emitter and receiver and the optics. I want to sense 2m distance.Before 2m much of the reflected signal fall on the near receiver after 2 m it is in the Far receiver.....

Regards,
Joseph.D

 

[milind.a.kulkarni]

Can it is possible to put the sensor transmitter positions using picture or image on the forum so one can very easily make out what did you mean by far and near distance in the triangulation ( optical triangulation ) that you are taking about?

with regards

 

[josephraja_2006]

Can it is possible to put the sensor transmitter positions using picture or image on the forum so one can very easily make out what did you mean by far and near distance in the triangulation ( optical triangulation ) that you are taking about?

with regards

Hi,

Thank you for your response.Here I attached the image.In this Image E1 is near receiver and E2 is far receiver .if the target is in the sensing range most of the reflected signal from the target fall on E1 receiver .if the target away form the sensing range then most of the signal is on E2 receiver. form the image how i calculate the distance between the Transmitter and Receiver?the sensing range is 2m.

Regards
Joseph.D

 

[milind.a.kulkarni]

Frist of all ,

Nice idea to work with , but I have some concerns

1) You are planning to use IR radiation....but As per as my knowledge IR radiation most of the time is spherical wave it is not propagate like a coherent beam as you are shown in the picture...when you try to use the transmitter available in the market....
2) One can focus the spherical waves into the plane wave using lens but in that case you need to design the lens for the frequency of your radiation other wise it will generate either diverging of converging beam based on the distance
3) The traditional method of optical triangulation uses the laser beam most of the time with focused diameter, one of the key aspect in your approach is how you are making the beam fall every time on the lens bcz the angle of incidence of the beam will change based on the target position and as it will results in the change in angle of reflection....
4) The present IR system uses two different method for such linear position estimation using single IR detection method ( in which the magnitude of the IR radiation is key signal, however this is most of the time empirical calculation [Experimental ]) , the second one is use of multiple IR detector ( in which the magnitude at every position of IR sensor acts as a signal , the method that is similar to your idea)

Now coming back to the detection of object position using optical triangulation is based on the magnitude of the Radiation receiver ....but in case you are planning to use laser of optical radiation I will suggest you to go for position sensitive detector or array of the detectors....

One need to do some mathematical model for the idea ...In my view you should start writing the optical triangulation formalism with out lens initially ...

Good Luck

 

[josephraja_2006]

Frist of all ,

Nice idea to work with , but I have some concerns

1) You are planning to use IR radiation....but As per as my knowledge IR radiation most of the time is spherical wave it is not propagate like a coherent beam as you are shown in the picture...when you try to use the transmitter available in the market....
2) One can focus the spherical waves into the plane wave using lens but in that case you need to design the lens for the frequency of your radiation other wise it will generate either diverging of converging beam based on the distance
3) The traditional method of optical triangulation uses the laser beam most of the time with focused diameter, one of the key aspect in your approach is how you are making the beam fall every time on the lens bcz the angle of incidence of the beam will change based on the target position and as it will results in the change in angle of reflection....
4) The present IR system uses two different method for such linear position estimation using single IR detection method ( in which the magnitude of the IR radiation is key signal, however this is most of the time empirical calculation [Experimental ]) , the second one is use of multiple IR detector ( in which the magnitude at every position of IR sensor acts as a signal , the method that is similar to your idea)

Now coming back to the detection of object position using optical triangulation is based on the magnitude of the Radiation receiver ....but in case you are planning to use laser of optical radiation I will suggest you to go for position sensitive detector or array of the detectors....

One need to do some mathematical model for the idea ...In my view you should start writing the optical triangulation formalism with out lens initially ...

Good Luck

Hi,

Thank you for your response.

The Image i posted just a reference image .

Here in my design i am using lens for to converge the beam of IR Emitter.

And Also i am using Dual Diode receiver in a single package. For the Costing purpose i am using this dual diode Receiver .

Now only my hurdle is the triangulation....

Once again thank you.....

Regards
Joseph.D

 

[milind.a.kulkarni]

I am not able to catch your problem still...with this new post...what are you looking for in the optical triangulation ?

with regards,

milind

 

[FvM]

You should be able to check your receive optic by putting a light source in place of the object and watch the image at the dual sensor.

It's a simple geometrical optics problem.

Your exact triangulation problem hasn't been said, however. If you want e.g. something like a continuous position measurement, you either need a multiple element sensors array (precise measurement) or you need to restrict it to a rough intensity ratio measurement with two sensors and a defocussed beam.