Society of Robots - Robot Forum

General Misc => Misc => Topic started by: Kohanbash on November 15, 2007, 09:28:44 PM

Title: Laser Scanner
Post by: Kohanbash on November 15, 2007, 09:28:44 PM
Hi
While pricey for home brew robots, this laser scanner is definitely a good price. The main issue is that they don't really work in direct sunlight(ie outdoors).
FOV=240
Range =4m
$$$=2695

http://www.acroname.com/robotics/parts/R283-HOKUYO-LASER1.html
Title: Re: Laser Scanner
Post by: Admin on November 16, 2007, 11:15:13 AM
Its been posted many times (http://www.societyofrobots.com/robotforum/index.php?action=search2;params=YWR2YW5jZWR8J3wwfCJ8YnJkfCd8MiwzLDQsNSw2fCJ8c2hvd19jb21wbGV0ZXwnfHwifHN1YmplY3Rfb25seXwnfHwifHNvcnR8J3xyZWxldmFuY2V8Inxzb3J0X2RpcnwnfGRlc2N8InxzZWFyY2h8J3xIT0tVWU8=) already :P

a bit out of my price and size range tho :-\
Title: Re: Laser Scanner
Post by: Kohanbash on November 16, 2007, 01:20:16 PM
My bad  :'(

I just started using them and wanted to share the wealth (knowledge=power=wealth)
Title: Re: Laser Scanner
Post by: Admin on November 16, 2007, 01:35:49 PM
dont forget to report your findings :P

(have you used a SICK? I'm curious how they compare . . .)
Title: Re: Laser Scanner
Post by: Kohanbash on November 17, 2007, 06:14:33 PM
I have used SICKS.

SICKS are more expensive, have a smaller FOV, and a much greater range
The Hokuyo has a 4m range (optimally) but can only be used indoors or outside at night (Since it can not handle sunlight or direct reflections), the SICKS can be used outdoors with relatively little problem.
The SICKS have a faster refresh rate than the Hokuyo's.
The Hokuyo's use less power and are easier to wire up/communicate with (I'm working with Linux).
The Hokuyo is very light and small, while the SICKS are large, heavy, and virtually indestructible.
The resolution is about the same for both scanners.
Title: Re: Laser Scanner
Post by: Kohanbash on December 11, 2007, 06:27:20 AM
On wet dark ground the effective range for the Hokuyo drop's significantly.
In testing I have been limited to ~1m range.
If I cover the ground with a dry light color fabric than I can get the 4m range returns.

Also if your going to use multiple Hokuyo's you need to be careful about which firmware version you use.
Some firmwares seem to be less stable than others when used outdoors (surprisingly older firmwares performed better than the newest firmware).
However the nice thing with the newest firmware is the power to reset the laser using software commands.

Title: Re: Laser Scanner
Post by: Admin on December 11, 2007, 07:35:21 AM
Quote
In testing I have been limited to ~1m range.
If I cover the ground with a dry light color fabric than I can get the 4m range returns.
interesting . . . sounds like its very susceptible to IR absorbence to the surroundings . . . 1m isn't much better than a Sharp IR!!!
Title: Re: Laser Scanner
Post by: Kohanbash on December 11, 2007, 08:58:00 AM
Black cardboard has a 10% reflectivity. The dark ground is probably only slightly better.