Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: airman00 on July 14, 2009, 02:47:56 PM

Title: Getting too close alarm on robot
Post by: airman00 on July 14, 2009, 02:47:56 PM

I've been building this big robot(4 feet tall) for a display and one feature I have to add is a "do not touch me warning." Basically whenever a person gets too close to the robot with his hand or body or whatever, the robot must say "Please back up and do not touch me"

Any idea how to do that?

I was thinking of putting IR heat sensors in several places and detect people that way. I dont think I can do sonar because sonar does not have a wide enough beam angle, and I don't want to put 50 ultrasonic sensors

Title: Re: Getting too close alarm on robot
Post by: Trumpkin on July 14, 2009, 03:12:45 PM

I can't remember what It's called but this one guy at a robotics club I go to had a metal frame and when you got really close to it it sensed it. I'll try to find out more about it.  
*EDIT*
I think the metal frame must have been acting as a capacitive sensor.

Title: Re: Getting too close alarm on robot
Post by: SmAsH on July 14, 2009, 04:05:42 PM

Quote from: Trumpkin on July 14, 2009, 03:12:45 PM

I can't remember what It's called but this one guy at a robotics club I go to had a metal frame and when you got really close to it it sensed it. I'll try to find out more about it. 

would that use EMR?
I think ir would be one of the best approaches for this, how far are we talking?

Title: Re: Getting too close alarm on robot
Post by: Razor Concepts on July 14, 2009, 08:36:13 PM

Capacitive touch would be a good idea... a QT100A costs like a buck, turn up the gain really high and then it should work (as long as there is metal where you want the detection)

Title: Re: Getting too close alarm on robot
Post by: spizzak on July 17, 2009, 12:57:43 PM

I'm not sure how they work but I know a lot of motorcycle alarms have proximity sensors of some sort and they usually aren't too too expensive. Maybe if you find out how they work you can replicate that.

Title: Re: Getting too close alarm on robot
Post by: HyperNerd on July 19, 2009, 02:46:12 PM

I agree that capacitive sensing is a good idea. I saw somewhere on YouTube (can't find it now >:() someone who added vibrating motors and a capacitive sensor to an old computer mouse, so when your hand got near it, it jiggled away.

Can't remember many details though ???

 -HyperNerd