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Author Topic: IR Sensors Underwater To Detect Glass or Black Line  (Read 4354 times)

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Offline farterxTopic starter

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IR Sensors Underwater To Detect Glass or Black Line
« on: October 16, 2008, 11:40:33 AM »
 ??? ??? ??? ??? ??? ??? ??? I hope someone can help me? I need
IR sensors which can detect a black line over a transparent glass tank mounted on a  Styrofoam white surface. IR sensors to be mounted inside a translucent container. sensing environment - (underwater) I really need IR sensors which can do this.

OR

IR sensors to detect transparent glass while underwater. It is a glass tank, dimensions are 50x50x1.1cm, glass is transparent.

Can the SHARP sensor do the task? distance range required 10cm to 100cm. Must not detect items outside the tank I've tried using W303 PIC controlled IR reflex which i bought from Sim Lim tower for 30 bucks! but it detect things outside of the tank, and it is irradic! sometimes it detects the glass and sometimes things which are outside. The W303 detects objects based on reflection and gives a digital signal. It works well on land, at around 0 to 2 meters. However when used in water, the performance reduces drastically to about 0 - 20cm, or it may be detecting things outside i don't know:(.

 The housing i am using is a waterproof water container. I was just thinking if the light can pass through the container, it could pass through glass as well:( I've been working on this since 2 months ago, and my project is due in 1 more month. I am stuck!!!

I will try anything as long as it is below $400 and it is easy to use. any recommendations? I've tried ultrasonic sensors also, the waterproofed types, works well on land able to detect distance, but when used in water it is a totally different result. :'( :'( :'( :'( Unknown signals get picked up through the receiver even though the transmitter has been taken out. The signal can be received only when TX and RX are placed very close together underwater.

Offline Admin

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Re: IR Sensors Underwater To Detect Glass or Black Line
« Reply #1 on: October 19, 2008, 04:31:40 AM »
Quote
IR sensors which can detect a black line over a transparent glass tank mounted on a  Styrofoam white surface. . . . IR sensors to detect transparent glass while underwater. It is a glass tank, dimensions are 50x50x1.1cm, glass is transparent.

Can the SHARP sensor do the task? distance range required 10cm to 100cm.
I'm not aware of any sensor capable of doing either task at the range you require other than a camera.


Probably not useful info for you, but glass is transparent to IR. I've used the Sharp IR through glass underwater and got a range of several feet.

Offline kobilica

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Re: IR Sensors Underwater To Detect Glass or Black Line
« Reply #2 on: October 19, 2008, 08:57:32 AM »
I think camera would be only way, not sure, but you could use normal laser and then sensor ( LDR etc ) to see if light reflects from surface. As you know black adsorbs more light, that would be possible.
More lasers and receivers, there you have line follower.

But If am sure, doesn't water bend light?

Offline Soeren

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Re: IR Sensors Underwater To Detect Glass or Black Line
« Reply #3 on: October 19, 2008, 01:29:50 PM »
But If am sure, doesn't water bend light?

You are probably thinking on the effect of crossing through materials with different refractive indexes. as long as the beam(s) keeps in the same medium it won't appear as a broken "line"
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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