Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: arctic101 on April 12, 2012, 08:00:50 PM

Title: Color Sensors Outdoors
Post by: arctic101 on April 12, 2012, 08:00:50 PM
I'm currently working with the engineering club at my school to design a robot that can navigate to a GPS location and locate an orange cone. The robot has to be able to bump into the cone and come to a stop. Our problem is, GPS coordinates are not always accurate and its possible that the robot may end up several meters away from the actual cone. We were thinking about using color sensors to detect if an object was orange and then driving towards that once the robot was near its GPS determined destination. I've been looking at the color sensor guide on this site, but would something like that work outdoors with interference from sunlight affecting the photo resistor? If that doesn't work, is there something else we could do to detect an orange cone?
Title: Re: Color Sensors Outdoors
Post by: Soeren on April 12, 2012, 10:57:31 PM
Hi,

My experience with GPS is that placement may "jump" as much as 50m or more when stationary, so while it's good for things like the Darpa, I wouldn't use it for close quarter navigation, but that's just me... At what initial distance do you expect to color detect the cone?

If it's a regular traffic cone, it will likely be fluorescent, so just turn off the sun and use an ultraviolet beam to detect it, it will glow like on fire ;D
Seriously, the fluorescent effect should help you with the sun as well, and a color filtered receiver, matched to the cone, shouldn't be hard to make (eg. using yellow and red filters as used in front of stage light, to make up the right color).
A pulsed (color filtered, UV/Blue LEDs or what experiments reveal as useful) emitter will help filter out ambient light.
Assuming it stands on plain ground, you know at which height to scan for it.
Title: Re: Color Sensors Outdoors
Post by: robotcoder on April 13, 2012, 08:54:58 AM
If you have a way to integrate a laptop, I would suggest using opencv