The idea was that the RC vehicle in question would be an off road RC buggy capable of navigating through typical English field and countryside terrain. If the operator was standing in the center of a field with a laptop, potentially would need a range of somewhere between 50-100m? Following roads isn't important, purely point to point navigation data that can be fed to the Arduino unit on the fly. Wouldn't even need to be able to store waypoints, just constantly heading to a specified set of GPS coordinates and speed controlling the motors. i.e. it either stops at the final destination, or if the final destination changes mid route, corrects its course while moving etc.
Imagine being able to point and click on a Google Maps/Earth overlay and then the RC vehicle in question moving to the specified last destination marker. Also being in a field - obstacle avoidance is less of an issue.
I've seen various examples of similar things being built from blogs & YouTube videos, however typically I've found them to be US based. Was just wondering if someone in the UK had built anything similar....?
Well that sounds easy enough. Many people have made reverse-geocahe boxes which basically do half of what you're after - they have waypoints and work out how far and sometimes what direction it is to that waypoint, then the person with the box has to work out where the waypoint actually is.
I don't know of anyone personally why has built one but I'm sure there will be people who have.
That wireless range sounds easy enough, many people use XBee modules for wireless communication - they are easy to use and come in a range of module types with varying powers (the lowest power Series 1 modules will do 100m LOS - well I can't say I've tested that theory :P)
You I'd suggest you possibly want a magnetic compass on the car as although you can work out the heading of the car (while it's moving), as soon as it stops, you have a bit of an issue as to what direction it's pointing in.
Simple trig to work with the GPS position of the car and the GPS position that you want to move to will tell the car the heading it wants to follow and then the compass can be used to point the car in that direction. An update of 1Hz on the GPS should be enough to get up a reasonable speed on the car and still maintain the correct heading.
Regarding the car to use, I might suggest that you use something with four wheel drive and skid steer, this would mean it could move on the spot to get its heading more easily.
I look forward to what happens!