Sharp GP2D12 IR vs. Devantech SRF04

Archiver

Any insight as to who (Sharp or Devantech) would win the following
challenges?

1. Accuracy
2. Total amount of time to take a measurement (including if you have
to take several measurements and average the results)
3. Focus of "beam" - how wide is the "beam" of sound or IR light at
lets say 12"? at 24"?

I have found one science fair project that attempted to compare sound
vs. light but he didn't use these two products. Does anyone know of
a good article or research paper that addresses this topic (when the
sensors are used for robotic obstacle detection)

Thanks,

Steve

Archiver

hands down, the IR wins.

---- Original message ----
>Date: Wed, 04 Feb 2004 00:53:00 -0000
>From: "sjoblin001" <steven_joblin@h...>
>Subject: [noparse][[/noparse]basicstamps] Sharp GP2D12 IR vs. Devantech SRF04
>To: basicstamps@yahoogroups.com
>
>Any insight as to who (Sharp or Devantech) would win the
following
>challenges?
>
>1. Accuracy
>2. Total amount of time to take a measurement (including
if you have
>to take several measurements and average the results)
>3. Focus of "beam" - how wide is the "beam" of sound or IR
light at
>lets say 12"? at 24"?
>
>I have found one science fair project that attempted to
compare sound
>vs. light but he didn't use these two products. Does
anyone know of
>a good article or research paper that addresses this topic
(when the
>sensors are used for robotic obstacle detection)
>
>Thanks,
>
>Steve
>
>
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>
--
Regards

Dave Evartt

w:202 708-4932 x3250
h:410 439-2319

Archiver

I have used both sensors, and both will fail under certain circumstances. I
have found the Devantech sonar sensors to be more accurate. I would say
correct detections 90% of the time, where the Gp2d12 would fail 40% of the
time. I cannot report on the speed of detection however.
In real world use, I have a main loop that checks the srf04, if large space
ahead, I run my track motors, then I loop back to main and check the sensor
again. The robot can drive at a fairly fast speed indoors( a fast walk), and
the stamp and srf04 are fast enough to catch objects in real time.
I Have seen both the devantech and the gp2d12 miss detections on white
painted baseboard walls. Darned if I know why.
I did see a big improvement in the devantech in detecting chair legs and
narrow objects. The gp2d12 would have a 75% failure rate, whereas the
devantech would have a 25% failure rate.
The GP series sensors are of course much cheaper.
I use both sensors on my robot in real time, and also have the inexpensive
parallax IR sensors as well. I do not think you can have enough sensors
mounted forward on a robot to ensure 100% accuracy under all conditions.
I also have heard that IR sensors are more prone to failure in wierd
lightning conditions. Flourescent lights are bad for this.
Unfortunatly the only sensor that is going to be 100% accurate is a
mechanical bumper sensor.
I advise, and wish I could do it myself, to have as many forward sensors as
money will permit, of all differant types( sonar, ir, vision, etc). And than
they have to be mounted at differant heights as well. To catch detections
when a robot may drive under something. The other day, I had a robot bang
into a kitchen cabinet. The sensors were mounted so low that their detection
beam went under the kick plate of the cabinet. It thought it had an extra
few inches to drive, and the top of the robot hit the side of the cabinet.
Good luck to you.
-kerry



At 08:31 PM 2/3/04 -0500, you wrote:
>hands down, the IR wins.
>
>---- Original message ----
>>Date: Wed, 04 Feb 2004 00:53:00 -0000
>>From: "sjoblin001" <steven_joblin@h...>
>>Subject: [noparse][[/noparse]basicstamps] Sharp GP2D12 IR vs. Devantech SRF04
>>To: basicstamps@yahoogroups.com
>>
>>Any insight as to who (Sharp or Devantech) would win the
>following
>>challenges?
>>
>>1. Accuracy
>>2. Total amount of time to take a measurement (including
>if you have
>>to take several measurements and average the results)
>>3. Focus of "beam" - how wide is the "beam" of sound or IR
>light at
>>lets say 12"? at 24"?
>>
>>I have found one science fair project that attempted to
>compare sound
>>vs. light but he didn't use these two products. Does
>anyone know of
>>a good article or research paper that addresses this topic
>(when the
>>sensors are used for robotic obstacle detection)
>>
>>Thanks,
>>
>>Steve
>>
>>
>>To UNSUBSCRIBE, just send mail to:
>> basicstamps-unsubscribe@yahoogroups.com
>>from the same email address that you subscribed. Text in
>the Subject and Body of the message will be ignored.
>>
>>
>>Yahoo! Groups Links
>>
>>To visit your group on the web, go to:
>> http://groups.yahoo.com/group/basicstamps/
>>
>>To unsubscribe from this group, send an email to:
>> basicstamps-unsubscribe@yahoogroups.com
>>
>>Your use of Yahoo! Groups is subject to:
>> http://docs.yahoo.com/info/terms/
>>
>>
>--
>Regards
>
>Dave Evartt
>
>w:202 708-4932 x3250
>h:410 439-2319
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
>Yahoo! Groups Links
>
>To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
>To unsubscribe from this group, send an email to:
> basicstamps-unsubscribe@yahoogroups.com
>
>Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
Very respectfully, your obedient servant.
Brig. Gen. Johnston Pettigrew

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