Object avoidance robot with GPS

[wany]

Hey
I am new to this forum. I need to build a final year project for College. I am thinking of building an object avoidance robot with GPS. I want to use the GPS to create a check point and let the robot go to it.
My method of navigation would be using the GPS and the Ultrasound device on the robot would just avoid any object it's way.

If i have to either draw a 2d map for the robot and then let it find it way to the checkpoint using the GPS.

Has anyone done anything like this could you let me know. I don't really want to draw a map using GPS i was hoping that it could work more like a GPS system in a car ( yes i know it's complicated)
Basically the gps system in the car already draw out the line and you know the longitude and latitude of the entire line so what happens you set check point along the LINE using longitude and latitude positions and let the robot go to each check point until it reaches it's finaly goal.
I am not sure if this possible since it's only in the idea phase.. But can someone please give me there input on this and if anyone has done this before on this forum i would love to hear how it was done.

[waltr]

There have been a few projects in these forums doing this.

Do searches and read the many forum threads. Answers are there.
Also read through all the info in the SoR 'Robot Tutorials' found in the above title bar.

[nickc]

Another search term is robo-magellan which is a hobby robot contest that does just that. The contest involves navigating and touching a series of traffic cones with known gps locations while avoiding obstacles and navigating terrain.The contest is a little more complicated than your project as it requires vision to find the cone.

http://www.robothon.org/robothon/robo-magellan.php

 Many robot builders have personal websites or blogs describing their creations. 
Also look up path planning algorithms which is a major research area.  Lots of papers for you to read.

[wany]

Hi thanks for the info...
In terms of path planning what i was gonna do. Is use google map and map out a route. Then you can get the checkpoint along that route. I then upload these check point to the MICRO and every few seconds the Micro check the GPS location and compares it to the check point to see if it close. When it close enough it goes onto the next check point.

That basically how i was planning to do path mapping. I know GPS arn't very accurate espically the small ones.. I saw one which had 5Meter accuracy which is ALOT of error.

I'll read through the post and see what i can find if anything i'll post what problem i have here.

[AtomHex]

Check out this article in Robot Mag

http://www.botmag.com/issue25/  

 scroll down where it says "38  Build a Robot"

 I'm building this now with an electric wheelchair as my drive platform.

[wany]

hey i read your project...
But your basically using your laptop to do all of this. I need to use a Mirco... to do all my processing ... thanks though some the code could help me out.. to write my own...

[nickc]

http://www.geology.smu.edu/~dpa-www/robo/jbot/index.html
Here's a nice six wheel drive with gps

[mstacho]

This might be a bit too complex for a uC, but there are ways to make the little GPS units work better, with a considerably better accuracy.  One of them is called "Differential GPS", which (vaguely) works like this:

Take two GPS units.  Put one at a known location -- you'll either have to survey the location yourself, which isn't practical, or just ask and try to find an old survey marker, which has lat/long.  Put the other GPS on your robot.  Since they are "close enough together", they should both have the same error, but since you know where the fixed one is, you can determine exactly what the error is in both lat and long.

Of course, wikipedia has an article: http://en.wikipedia.org/wiki/Differential_GPS, but I took a GPS/surveying course in university and we did something similar with two GPS units that didn't require getting the national Differential GPS service to help out...Whether it can be done in real-time is also an open question...