Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: Rebelgium on September 04, 2007, 07:52:45 AM
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Ultrasonic is a bit more expensive, but is it worth it?
I want to use a 180? rotating servo with two Sharp IR sensors on top, and use this to navigate and later on even make maps.
What is best for this application? 2 ultrasonic sensors (= sonar?) or two IR sharps?
I know the range is better, but what about the speed? I want to ratate that servo asap, to have a higher map-refresh rate. Which is faster, IR or US?
Any other things I should know?
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Different sensors are made for different conditions. As you might imagine, IR sensors work faster than Ultrasonic sensors (light travels faster than sound).
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As you might imagine, IR sensors work faster than Ultrasonic sensors (light travels faster than sound).
Although true, there is another bigger reason why IR is faster. US must have a significant time delay between bursts so that there is no 'noise' (literally sound noise) echoing from previous bursts.
use this to navigate and later on even make maps
For accurate map making, IR is by far best. For basic object avoidance, US is best :P
If you really really need speed, consider using multiple sharp IR simultaneously. Ive used up to 3 with good success.
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I am going to use 2 IR Sharp sensors on top of my rotating servo, This should give me 180? front view.
I'll use these to avoid objects and to make a map. For the object avoidance I'll also use basic IR proximity sensors.
Does this sound like a solid plan to you?
I want to buy this so I can start simple (2 IR Sharp sensor that don't move), and advance later on when I'm more experienced, without having to buy new stuff.
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Sounds good to me. :)
For my 2 IR robot, the left sensor scanned 0 to -50 degrees, while the right sensor scanned 0 to +50 degrees. A full scan was about ~.8 seconds on an HS-311 servo.
In the future, if you want to get more complicated to increase speed and stay accurate . . . do slow high accuracy scan just in the direction of movement, then do a faster low accuracy scan on the sides . . .
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In the future, if you want to get more complicated to increase speed and stay accurate . . . do slow high accuracy scan just in the direction of movement, then do a faster low accuracy scan on the sides . . .
Tnx for the tip, I'll keep it in mind.