My first project, lawnmower...
July 31, 2009
Im new to this forum, and new to robotics in general. The same could be said abou my knowledge about microprocessors and programming language (other than .html notepad stuff).
I have some basic knowledge about electronics, but nothing worth braging about.
But, i have been thinking about starting on a new project soon (I'm currently in the finishing stages of a little cnc project i have for cutting out rc airplane foamies...) which i would like to start this fall, and hopefully be done with before next summer.
I have for a long time been interested in microprocessors and what they can do, but I have not seen any projects that i really cared enough for to try out for myself as a first project (nothing that has had any real practical value for me), until I started getting bored with mowing the lawn this summer.. (lazy, huh?).
Therefore i have been reading up on different automated lawnmower projects out there on the internets, and i havent found alot, i found some commercial ones, and i think one on this page.
But i have figuered some things out for my self about what i want and a coupple things i can see i need.
I havent thought much about how much this project will cost, but im thinking something in the range of 4-6k NOK; that would be about 450-700 EUR
I need a frame for the thing, thats something i can handle by welding together some steel squared pipes and some sheet metal.
I need something to make it go forwards, backwards and such, so im thinking about a coupple wheelchair motors with wheels ive seen on ebay, since they usualy come in pairs for left and right. And having two motors makes steering possible without using servos to turn the wheels in front. I would probably also need some kind of speed control for these, it might depend on what kind of controller you think i should use.
I also need another electrical motor and a blade for the cutting, this is something i think i will figure out when i actually have started the project
Since im probably going to use wheelchair motors, the voltage would be 24 volt, aka two 12v batteries.
What i absolutely dont know is which sensors i "need" and what kind of microcontroller i should use etc.
I figured i need some kind of bumper switch or radar or something, which makes it go around obstacles that can happen to be on my lawn, also some kind of sensor which makes it stop entirely when it senses movable objects as cats, dogs and kids.
I need a tilt switch or a gyro or something to make it stop if it gets tilted so that blades are accessible or it gets turned over or something like that.
But some of the things im most curious about is navigation of the thing, i've figuered i would need some kind of remote control of it, preferably wireless. But what im really curious about is the automatic navigation system. I have been looking at gps, which i have found out to be either to inaccurate or too expencive; i might be wrong though. I figuered i would need some kind of electrical dog fence as a safety guard so that it would not exit the lawn. I have also looked at the commercially made one called Robomow, which cuts the grass in zig zag order, and thats something i find somewhat impractical. What i really would like is to teach it a specific path and order to follow, and have it learn something about the surroundings while i teach it, so it wont get "lost". But how? And maybe, can i use gps?
I'm also curious about what kind of microcontroller or what kind of processing unit i would need for this, and that be preferably something not too expencive and relatively newbie friendly..
So, if you can help me with any of these sollutions, have links to other projects like this, have any questions for me, or can give me somekind of helpfull knowledge about the subject at all.
In short, i would be really gratefull for any feedback i can get.
ps. I know this project might be kinda advanced for a newbie, but i've figuered the more advanced a project i start, the more i learn. lol xD