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Author Topic: software and vision  (Read 2620 times)

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Offline sillydipstixs21Topic starter

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software and vision
« on: September 08, 2007, 04:22:31 AM »
Ive been planning a "dream bot" in my spare time and i got carried away with some ideas.  I want to make an explorer that could go a great distance (more than a couple hundred feet or so).  included was a p4 mini itx board, RF modem for control, and a long range video transmitter.  the question i have is since the video transmitter is only one input, would it be possible to use its on-board computer to create on large resolution streaming video composed of 3 different cameras, and have the control computer (ig laptop) break it down into 3 different views on the screen?

Offline Nyx

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Re: software and vision
« Reply #1 on: September 08, 2007, 08:32:56 AM »
You could just use a wifi card and an onboard laptop, that way you can have all communications through one link. You may be able to boost the signal to get a better range.

Offline JesseWelling

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Re: software and vision
« Reply #2 on: September 08, 2007, 03:16:41 PM »
Cheap laptops throwaway laptops can be found here if you go that route...
http://www.usanotebook.com/

Offline sillydipstixs21Topic starter

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Re: software and vision
« Reply #3 on: September 08, 2007, 06:20:18 PM »
Sorry, Im not very clear with my post in the wee hours of the morning.  what question was, is it possible to take 3 cameras and input the feed into the robots computer, use the computer to combine the video streams into one, output it to the transmitter and from the recieving end, break it back down into three video feeds?

Offline dunk

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Re: software and vision
« Reply #4 on: September 08, 2007, 06:40:52 PM »
i think what Nyx was suggesting was if you are going to have an on-board computer, why bother with an AV transmitter?
just plug 3 USB web cams into the on-board computer and transmit the images to the control computer over wireless ethernet.

if you really want to use AV transmitters and receivers then why have an on-board computer do anything with the images?
just pick transmitters that have selectable channels and use 3 separate devices.

it would be possible to digitize the output from 3 cameras using an on-board computer, combine them into one display and output the image on a VGA card with TV out and then transmit the picture but it seems like an overly complicated way to do things to me.
you also don't get any of the other benefits of the wireless ethernet solution. ie. being able to control the robot over the network, etc.


dunk.

Offline sillydipstixs21Topic starter

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Re: software and vision
« Reply #5 on: September 08, 2007, 06:56:44 PM »
I saw a couple robots online that used an rf modem to send and receive data and a video transmitter to transmit the picture from just one camera.  i was just curious.  plus with long range ethernet, the band rant is not the reliable for video transmittion, let alone three.  and at $500 a pop for a video transmitter and reciever multiple just isnt cost effective.

Offline Nyx

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Re: software and vision
« Reply #6 on: September 08, 2007, 10:40:19 PM »
I saw a couple robots online that used an rf modem to send and receive data and a video transmitter to transmit the picture from just one camera.  i was just curious.  plus with long range ethernet, the band rant is not the reliable for video transmittion, let alone three.  and at $500 a pop for a video transmitter and reciever multiple just isnt cost effective.

Depends.... An rf modem is going to give you a bandwidth of something like 54kbps at best, which isn't fantastic. With wireless ethernet, you can get up to 300 feet of range in outdoor conditions, and ideally 54 mbps. If you use some good antennas, you can augment that range... And you can get even more by amplifying the signal, if you are willing to do that. Of course you won't get the full 54 mbps, but even if you only get an eight of that, it should be enough for compressed video streams.

Wireless video transmitters could possibly get you more range, but they are analog devices, and the more the distance, the more noise you will get at the receiving end, which isn't always practical with robotics applications.

Offline dunk

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Re: software and vision
« Reply #7 on: September 09, 2007, 03:43:50 AM »
Quote
and at $500 a pop for a video transmitter and receiver multiple just isnt cost effective.

i don't know what the range of these units is like but ebay is awash with wireless cameras at the moment for very cheap prices:
http://search.ebay.ie/wireless-security-cam_W0QQfbfmtZ1QQsabfmtsZ2QQsascsZ2QQsbrbinZt

if you are interested in increasing the range on some of these try looking in Radio Control forums.
a lot of those guys like putting wireless cameras on RC aircraft.

with wireless cameras you are never going to get a crystal clear image (although spending $500 per transmitter and receiver will increase your chances...) so i would argue the reduced frame rate you might get with wireless ethernet is preferable to fuzzy images.
that's something only you can make the decision on though.


dunk.

Offline airman00

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Re: software and vision
« Reply #8 on: September 09, 2007, 06:31:38 AM »
Those mini spy cameras have a range of around 40 ft indoors and ~ 80 ft outdoors. They also do not give such good quality video but the refresh rate is pretty good.
Check out the Roboduino, Arduino-compatible board!


Link: http://curiousinventor.com/kits/roboduino

www.Narobo.com

Offline sillydipstixs21Topic starter

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Re: software and vision
« Reply #9 on: September 09, 2007, 04:59:55 PM »
thanx for the input guys. this project is merely a drawing at this point.  the range i was looking to achieve was atleast a mile.  my parents own acres of property and i wanted to be able to explore all of it using this robot.  The other conclusion that i came to on the multiple cameras and to design a circuit that switches from one camera source to another and feed it to the transmitter. 

 


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