Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: YoungGenius on February 09, 2010, 03:55:13 PM

Title: Robot that Follows You?
Post by: YoungGenius on February 09, 2010, 03:55:13 PM
I working on a project of making something like a backpack follow you. I thinking of creating the 50 dollar robot but big enough to support a load. But how would I get it to follow me?

Btw, this is my first post here so if I'm doing something wrong I would like to know. Thanks.
Title: Re: Robot that Follows You?
Post by: waltr on February 09, 2010, 04:26:28 PM
Well it would need sensors. One type is a PIR like is used to turn on outdoor lights. http://www.sparkfun.com/commerce/product_info.php?products_id=9587 (http://www.sparkfun.com/commerce/product_info.php?products_id=9587)

Another way is to use distance sensor, IR or SONAR, and the robot detect you moving then keeps a 'lock' on you to follow. Not really hard to program but challenging.
Title: Re: Robot that Follows You?
Post by: madsci1016 on February 09, 2010, 04:58:16 PM
probably too expensive, but

http://www.instructables.com/id/How-to-make-a-Robo-Bellhop/ (http://www.instructables.com/id/How-to-make-a-Robo-Bellhop/)
Title: Re: Robot that Follows You?
Post by: Cybran on February 09, 2010, 05:52:46 PM
Well, there are several ways to go, but my original design with the T1ER was 3 IR sensors used to triangulate the position and distance of a flashing beacon (or remote control). Something you could do is buy a Lego Spybot and modify it, since it has this ability already built in as a GUI program, though it is also open to more advanced modding via NQC.
Some issues do come up with this kind of follower, I.E. it will always be behind you (or the beacon) and therefore cannot pass through doors without additional programming, sensors, and other fiddly bits.
Hope I helped.
Title: Re: Robot that Follows You?
Post by: YoungGenius on February 10, 2010, 03:47:35 PM
Can I use the Sharp IR Rangefinder? Doesn't that follow an object? There is already a tuorial for that.
Title: Re: Robot that Follows You?
Post by: Cybran on February 10, 2010, 04:06:35 PM

Well, nevermind.
Title: Re: Robot that Follows You?
Post by: madsci1016 on February 10, 2010, 04:21:23 PM
Can I use the Sharp IR Rangefinder? Doesn't that follow an object? There is already a tuorial for that.

Yes, you can. but you need a few other things.


Watch these:

iRobot Create with Stampy Edge-Detection (http://www.youtube.com/watch?v=f_VOQNXpt3g#)

Florida State University IEEE SouthEastCon 2009 Robot Design Test Runs (http://www.youtube.com/watch?v=QpEDXo-Rw_c#)

Both are robots with a single Sharp IR used to hone in on objects. The first one is Admin's, the second, mine.

There can be some problems with environmental, like objects and other people. But there are ways to deal with that. Admin keeps his IR concentrated on an edge, I have some filtering to only have reactions based the closest object detected.

Title: Re: Robot that Follows You?
Post by: Spoil9 on February 10, 2010, 05:09:44 PM
ROBOT magazine had an article about someone who did this a couple years ago. He used a pair of Sharp IR sensors to keep the bot from running into the person it was following or running into a wall. And used some kind of thermal sensor array to detect his body heat.

Just found the Mag...
ROBOT Mag from Summer 2007
Article Name: Follow Me Rover
Decantech TPA81 Thermal Sensor Array
Programmed via 'Object-oriented' approach for future upgrades
Basic Stamp on a BOE

Here is his website:
http://www.norrislabs.com/Projects/FollowMeRov/index.html (http://www.norrislabs.com/Projects/FollowMeRov/index.html)
Title: Re: Robot that Follows You?
Post by: YoungGenius on February 10, 2010, 06:09:27 PM
Can I have IR LED's on me and I have a sensor on the robot. Can this work?
Title: Re: Robot that Follows You?
Post by: waltr on February 10, 2010, 06:27:31 PM
Can I have IR LED's on me and I have a sensor on the robot. Can this work?
Yes, that what some above was referring to when they to have a 'beacon' on you.
Title: Re: Robot that Follows You?
Post by: YoungGenius on February 10, 2010, 09:05:29 PM
Tell me if this is going to work. I have a IR Emitter on me and on the robot I have 2 IR Detectors. One of them controls the left servo and the other controls the other. Any suggestions?
Title: Re: Robot that Follows You?
Post by: Spoil9 on February 10, 2010, 11:27:17 PM
Yeah, you need to add to the programming instructions for what happens when you walk around a corner, or someone walks between you and the bot. And how does the IR sensors tell the difference between you and the sun or other IR light in the room?
I'm assuming you'll clip this beacon on your belt which means the bot will have to look up at a pretty decent angle to see it. Not sure how sensitive those IR detectors can be so your bot may have to be pretty close to you to get any decent signal.
Title: Re: Robot that Follows You?
Post by: Admin on February 11, 2010, 12:06:00 AM
http://www.societyofrobots.com/robot_faq.shtml#robot_track_person (http://www.societyofrobots.com/robot_faq.shtml#robot_track_person)
Title: Re: Robot that Follows You?
Post by: YoungGenius on February 11, 2010, 05:10:11 PM
I would use middle mass detection but it's quite expensive and this is my first time building a robot. How would I use my IR detector idea but avoids the sun or other IR light in the room? I don't know much programming so I'm really an idiot to these things.
Title: Re: Robot that Follows You?
Post by: richardkalaf on February 17, 2010, 01:19:59 PM
Modulation dude... That might be the answer.
Use lenses to amplify the angle and range of the beacon and sensors, and modulate the beacon and receptor, so it will know that it is you , and not another IR light source like a remote, the sun, or whatever.

Title: Re: Robot that Follows You?
Post by: YoungGenius on March 11, 2010, 05:11:00 PM
So now I actually have to build it for real. I got two motors, and two wheels and that's all. btw, the motors aren't servos but is there a way to change them? Do I need to buy an IR Emitter and 2 IR sensors, and how will the sensors change the speed of each motor so that it can turn (differential drive)? Can someone help me by explaining in detail? Please it's really urgent!
Title: Re: Robot that Follows You?
Post by: Cybran on March 18, 2010, 09:21:44 PM
Yes, I've always had a similar question. How can you make as servo circuit out of discrete components? Whenever I Google this, it turns up with nothing.
Title: Re: Robot that Follows You?
Post by: waltr on March 19, 2010, 08:40:36 AM
Yes, I've always had a similar question. How can you make as servo circuit out of discrete components? Whenever I Google this, it turns up with nothing.

Try googling servo motor and get this:
http://www.electricmotors.machinedesign.com/guiEdits/Content/bdeee4a/bdeee4a_1.aspx (http://www.electricmotors.machinedesign.com/guiEdits/Content/bdeee4a/bdeee4a_1.aspx)

Any motor can be turned into a "servo" with position feedback and control. Just don't confuse the generic definition to the specific device that is called an "RC servo".
Title: Re: Robot that Follows You?
Post by: Soeren on March 19, 2010, 11:39:20 PM
Hi,

How can you make as servo circuit out of discrete components? Whenever I Google this, it turns up with nothing.
You must be using bad search terms.

A discrete build would be much to large for the intended use. Go with a chip like the NE544 - and some power MOSFETs if you want it to drive a large motor.