Robot Surgery 101
By user13366078 on Sep 20, 2007
Today, Roomba was ill. Roomba is our vacuuming robot.
How come we have one? Well, during CeBIT 2006 I met Roger Meike. He works at SunLabs and was presenting one of my favourite projects: Sun SPOT. Anyway, we talked a bit about robots and if they really can be useful or just expensive toys. He recommended Roomba to me and said it would really work.
So I checked out the iRobot home page. Gosh! Their main business is building robots for military purposes! You know, just like in the movies with robot arms and belt-drive, searching for bombs, that kind of thing. So if there is a company capable of building a real working vacuum bot, then it must be these guys. Millions of dollars of robot research hovering around my home for just a few hundred bucks.
It actually works well and Roomba has been vacuuming our home for quite a while now. The deal is this: You save time because you don't have to vacuum your home, Roomba does it while you're away working or at the supermarket. It may be slower, but it doesn't steal you time, so it really acts as a time-saver. If you save, say 15 minutes of time per week by not vacuuming and value your free time at, say 10-20 dollars per hour, then you have more than paid off the cost of a Roomba after a year or two. And you can have a lot of geek fun too!
Anyway, today Roomba decided to not work correctly anymore, it would spin around in circles and never go straight. After checking iRobot's support area and some forums, it seemed to be the bumper sensor. But thorough cleaning of the robot and more or less gentle banging on its bumper wouldn't improve Roomba's behaviour much. More drastic measures were needed.
Thanks to some diagnostic instructions I found on the web, it became clear that the right bumper sensor was really kinda stuck. Fortunately, I found some well-documented disassembly instructions and was able to remove the bumper assembly to check out the sensors. Roomba uses a lot of optical sensors, even for the mechanical stuff (based on rods interrupting light flow etc.) which make them very robust, but sometimes sensitive to dust cluttering. Now that the sensors have all been cleared, our Roomba is back and can continue to happily vacuum our home again!