A Robotic Lawn Mower

I don't intend to make a career of robotics reporting, but my investigation of the Roomba vacuum raised an obvious question: if the state of consumer robotics has produced a practical vacuum cleaner, why not a robotic lawn mower?  Well, as it turns out, a little research into robotic lawn mowers turns up a few failures, some of them spectacular, and one possible success.  As you can imagine, unleashing a robot that prowls around the neighborhood swinging sharp blades at several thousand revolutions per minute takes a certain amount of chutzpah. Although the same basic ideas are employed with both a vacuum and a lawn mower, the stakes are a bit higher when you are chopping rather than sucking.  

Which brings us to Robomower 

Friendly Robotics1, the makers of Robomower, hosts a website that is very friendly indeed.  I was greeted with a cute but clunky little daisy motif. A dozen or so yellow "petals," form a circle, apparently waiting to be mowed down by the little "Sony-yellow" Robomower at the center.  The catchy hook for the page is as follows: 

"You need Robomower, a fully automatic lawnmower, because..."

Each of the petals illuminates a fascinating insight into this pressing question:

  • Hate Mowing? ---Yes, hell yes!!!
  • Tired of hassling with the kids about mowing? ---Also Yes!!!
  • Tired of your lawn service? ---Groan, those bastards...
  • Love Gadgets? ---Always have, always will.
  • Need a Friend?  ---Nah, I've got E2 to absorb my extra time, but mowing the lawn would be useful...

Okay, already, I'm totally sold.  Where do I sign up?  The Friendly Robotics website also provides a "Buy Now," link, but unfortunately when I went there, I was disappointed to find the following message:

"We are sold out of the 2002 RL500 Robomower
2003 Product will not be available until next year 
when we will have two brand new models..."

The good news is that Robomower 2002 is still available from several distributors including Amazon & the Sharper Image.  Better move fast though4, it looks as like we may have a Robomower shortage looming in the near future!

The gritty details

Unlike the Roomba vacuum, Robomower utilizes an onboard compass and a fly-by-wire navigation system to keep track of where it has been and where it still needs to go.  In practice, this means that prior to using Robomower, you need to prepare your yard by installing a sensor wire, at ground level, along the perimeter of your lawn areas.   The ends of the perimeter wire connect to a battery-powered transmitter that emits a low level magnetic field. This signal is recognized by Robomower and used to stay inside the bounds of the lawn area Robomower is working on. 

It's just like those electronic doggy fences where the collar gives O'l Blue a jolt when he approaches the edge of the yard.. According to Friendly Robotics, one twelve hour charge on the battery will allow Robomower to cut a quarter of an acre (about 0.1 hectare).  For lot sizes, over a quarter acre, extra battery packs are recommended, and for anything over two thirds of an acre, two Robomowers are suggested.  Slopes up to fifteen degrees, which is steeper than you would think, can be mowed.

It looks like Robomower is pretty simple to set up and use. You charge the battery for 12 hours, then manually guide it to the lawn of the day using the very cool remote control joystick widget.  To start mowing, you point Robomower at the lawn and push the "Big Green Button" to set em free.  Robomower first works the perimeter of the lawn a few times to get a good edge, then it uses a clever "V" pattern to cover the large expanses of grass.  Finally, it comes back and picks up the areas it missed along the way.  From a human perspective, this may not seem optimal, but, like Roomba, it's more effective than you'd think, and, who really cares if it takes a bit longer as long as you aren't the one pushing the beast?  

If you think a picture is worth a thousand words, The whole process is nicely documented in a geeky-kitsch video starring technology pundit Dave Matthews2 who has trained his Robomower to deliver his ice tea as he lounges like a smirking knobby kneed pasha in his lawn chair

Oh yeah, did I mention that Robomower talks?  It also comes with that totally bitchin little gameboy controller, a battery charger, perimeter wire kit, transmitter, docs and an instructional video complete the package.  All this uber-tech treasure for a measly $499 U.S. 

What about safety?

Friendly Robotics has clearly considered the lessons learned in this area, and Robomower features several levels of safety features designed to prevent injury.  Like on Roomba, Robomower has touch sensitive bumpers that detect any collision with an upright object and redirect the mower's path away from the obstacle.  In addition, if for any reason, Robomower is lifted off the ground, the blades will stop immediately.  If Robomower strays outside the wired perimeter that you've established, it shuts down.

It strikes me though that, for all of these efforts, Robomower doesn't actually have enough brains to unequivocally follow the very first rule of robotics, "A robot may not injure a human being, or, through inaction, allow a human being to come to harm." It looks like Robomower is as safe as they could make it, but it's just not smart enough to ensure that no damage is possible.  

I suppose it's only fair to let Friendly Robotics have the last word on this topic, since they are the ones who will ultimately be held responsible for Robomower's actions:

Q: How safe is it?
A: Since it is a fully automatic mower the Robomower is by far safer than any traditional mower due to the fact that you are not with it or even near it while it is mowing.

What's the cost again?

Robomower is battery powered, and that may be the system's Achilles heel.  The battery and charger are both pretty sophisticated, but I'm betting that two seasons is probably all you'll get before replacement is required.  Extra batteries cost $150 U.S. including shipping. You'll also need to replace Robomower's three high tech mulching blades once a year and they cost $50 a set. 

If Robomower's life span is five years or so, you'll have a hundred bucks a year in the amoritized cost of the mower.  And  if you need to replace the battery every other year, and the blades every year, Robomower will cost you a little over $100 a year to operate. So you're looking at $200 U.S. per year total.  That's cheaper than a lawn service, but not by much, and a little more expensive than the cost of a surly teenager.  If you factor in the aggravation of dealing with either lawn services, or surly teenagers, the Robomower sounds like a pretty good deal . 


Personally, I'm going to wait a year or so.  Unlike the Roomba, that is clearly priced to sell, Robomower seems a little pricey.  More importantly, I bet the technology is going to really improve in the near future.  I'd also like to see if there are any safety issues raised as these little sling blade monsters migrate from the lab into our imperfect world.  

There appears to be some significant competition brewing in the home robotics industry.  Those clever and resourceful Swedes at Husqvarna are branching out from motorcycles, sewing machines and chainsaws, to introduce AutoMower, a direct competitor to Robomower.  Interestingly, iRobot, the Roomba folks are hinting that they are working on a lawn mower, while Friendly Robotics has a press release announcing their partnership with Hoover in a robot vacuum.

It's going to be fun to watch this develop! 

1 Friendly Robotics USA website:   http://www.friendlyrobotics.com/

2 Dave Matthews video: http://www.davemathews.com/reviews/txcn-robomow.wmv

3 Popular Mechanics Review: http://www.friendlyrobotics.com/docs/popular.htm 

4 Sharper Image Robomower page: http://www.robomower.info/etailer_countresponse.asp?which=3

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