Let's Make Robots!

Navigational aid (programming)

Guys I need my tank bot to navigate around my house like bedroom to kitchen but without a camera or a GPS like system.

I plan to do it using simple pre programmed paths, like go front for 10 secs, turn right about 45 degrees go forward again.

But I think this idea will lack precision.

Kindly give me some suggestions people!


Thanks in advance!

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The basic idea (shown in all the videos above) is a 38khz sensor, inside of a tube. That's it. The "beacons" simply spit-out a IR TV signal --I am actually using "volume up", I think. The tube around the sensor allows the sensor to only see what is directly in front of it,making it directional. I have tried different sized tubes, different lengths, I have painted some black on the inside. I have also allowed the sensor to be uncovered and shielded the beacon (to make the beacon directional --shooting only one way). All of these configurations have led to varying results. The overall idea is that when the tube gets smaller, the sensor is far more pin-point accurate, but will have a much harder time finding the beam. --This is true both vert. and horz.

You will have to play with it a bit.


Took me a while but I found some of what I was looking for.

IR beacon and docking


Triangulation via IR beacon


WOO HOO I FOUND THE GOOD ONE!! Here's how it's done --watch the video below


Wow Thanks a lot! Can't say anything more :)

Seems like you could set up a few IR beacons, each with its own unique serialized identity, that way you could tell where it was based on the ID of the beacon.

Found something...

http://letsmakerobots.com/node/6737, http://letsmakerobots.com/node/10590, http://letsmakerobots.com/node/6499, http://letsmakerobots.com/node/10003

I am sure the beacon version will be the best solution for your task. Another benefit...you just can re-organize the beacons to let your bot go another path...

Firstly thanks a lot! I saw those 4 pages understood a bit about beacons but what is the typical range of a beacon? Suppose I want the robot to navigate my entire house I will need a LOT of beacons!

You could place RFID tags in all doorways and have a map for each room. I believe another point I would make is that a few of the more navigationally intense robots that I have seen use 2 way communication for navigation.

EDIT: WOW! Talk about a partial thought. I intended to say that some of the more traveled robots I have seen use 2 way communication between the robot and a PC. Offloading some of the work that the robot would be required to do onboard otherwise.

RFID is really something new and interesting but have you used it? Or has some one used it ? My floor does have some black lines at the edge of each tile so I guess I can make a line follower... But I was also thinking whether it will be possible to use a capacitor so that voltage would not drop abruptly and change the speed of the motors
Thanks lot! But I prefer the IR line follower but the lines are very thin but it can be distinguished easily. Hope the sharp will do a good job , nevertheless I do have a line reader but apparently I bought only one of those, stupid me!