Slashdot Mirror
Building A Homebrew Robotic Lawnmower?
mmonkey writes "With the seemingly small amount of summer we get here in the UK, the last thing I want to be doing on a sunny day is mow the lawn. So I started thinking "surely a light-ish lawnmower could 'gain' a couple of motors, and suddenly be computer-controlled?". Then I started thinking about stuff like obstacle avoidance, optimum path planning, guidance system, how to get pretty-looking stripes, and I realised that it's actually a potentially complex (read: fun) thing to do. So, have any Slashdotters done this before? Did you modify an existing lawnmower or build a whole new one from scratch? What motors work best? For that matter, what type of mower works best? I know you can already get these, but that detracts from both my geek-drive and my wallet, both of which I'd prefer to keep as full as possible."
The safe way to do it is to have the thing run with very low power, and just nibble at the lawn, but do it all day. The big gas engine on the top of your push mower is really for the convenience of the operator, so that he can mow tall grass without stalling the thing or slowing down.
But if you mowed the grass yourself, one time, and then let loose your robot to simply maintain the height with a low power electric motor and some relatively safe blades, etc.... After all, it can stay out there all damn day!
eikimartinson.com
Yes, I would implement the following:
1. A _safe_ mowing method as you describe
2. The position measurement could be done with (ultra)sonic sensors and a transmitter on the mower. Doesn't work if you have to change garden often.
3. A power and communication cable. Can be cheap because of low power requirements because of 1.
4. A tower from where the cable goes to the mower and a mechanism to ensure that the cable doesn't get in the way.
Of course there is no obstacle avoidance etc., but I would start such a project in a modest size, not with all the 1000 features which _could_ be implemented!
As I'm doing such things also (Homemade microcontroller applications are everywhere in my home), I would say that it is far better to have a little thing working than big plans for a big thing but get nothing implemented.