Author Topic: Object detection  (Read 1107 times)

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Offline robotcyTopic starter

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Object detection
« on: February 19, 2010, 08:10:58 AM »
If i use 3 ultrasonic sensors (e.g. a maxsonar EZ-51 or a ping))) on perpendicular of each other to detect object and determine its heights would i face any problems? Wave interference maybe? 


two kinds of objects cans and tetrapacks. Heights 3.5 cm and 8cm. If the lowest sensor gets a smaller reading than the two above then its a can if the two lower sensors have the same reading and the one above has a greater reading then its a tetrapack if the 3 sensors have the same reading the its  wall

Offline Soeren

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Re: Object detection
« Reply #1 on: February 19, 2010, 08:49:58 AM »
Hi,

If i use 3 ultrasonic sensors (e.g. a maxsonar EZ-51 or a ping))) on perpendicular of each other to detect object and determine its heights would i face any problems? Wave interference maybe? 
You could allways synchronize their clocks. Or, you could use one transmitter and 3 receivers.


two kinds of objects cans and tetrapacks. Heights 3.5 cm and 8cm. If the lowest sensor gets a smaller reading than the two above then its a can if the two lower sensors have the same reading and the one above has a greater reading then its a tetrapack if the 3 sensors have the same reading the its  wall
They'll see each others pings if you use 3 non-synch'ed sensors I'm sure. IR is probably better for this, but you could try making some US absorbing baffles to give each a vertical window.
Regards,
S°ren

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

Offline robotcyTopic starter

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Re: Object detection
« Reply #2 on: February 19, 2010, 10:37:13 AM »
http://www.maxbotix.com/MaxSonar-EZ1__FAQ.html

a friend of mine suggested the 6f technique what do you think about that? Could it work?

Offline Soeren

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Re: Object detection
« Reply #3 on: February 19, 2010, 01:49:51 PM »
Hi,

"6f" describes 3 modes of operation, which of them are you referring to?
Regards,
S°ren

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

Offline robotcyTopic starter

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Re: Object detection
« Reply #4 on: February 20, 2010, 12:44:23 AM »
mainly the third

Offline Soeren

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Re: Object detection
« Reply #5 on: February 20, 2010, 09:17:21 AM »
Hi,

That should do, if you follow their description - initialize with a 100ms pulse and make the pings 20Ás to 400Ás (90Ás being the mathematical mean).
They're not synchronized(!) so stay with 90Ás pulses.
Regards,
S°ren

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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