Cool news for those interested in SLAM (Simultaneous Localization and Mapping) for indoors robotics. From Hizook
"A commercially-available ultra low-cost laser rangefinder is finally set to hit department store shelves in February! I'm speaking of the laser rangefinder presented at ICRA 2008 that costs $30 to build that sits atop the recently announced Neato Robotics XV-11 vacuum cleaner. Others have thoroughly discussed the XV-11's competitiveness with iRobot products
, the possible patent infringement of iRobots square-front design, and its ability to perform SLAM
. But everyone has glossed over the coolest part: Forget the $400 robot, $60 batteries, $30 wheels (etc.) available for pre-order on Neato's website
... if made available, sub-$100 laser rangefinders would revolutionize hobby robotics! Read on for a description of this compelling (future?) component.
Neato sponsored an ICRA 2008 research paper entitled, "A Low-Cost Laser Distance Sensor
," that detailed the design of laser rangefinder that costs only $30 to build. Called the "Revo LDS", it is pictured above. Diagram of operation below:
Unlike the more expensive (many thousands of dollars) laser rangefinders that use time of flight measurements, such as those discussed here
, the Revo LDS triangulates the distance to an object using a fixed-angle laser pointer and a CMOS imager, with a known baseline between the two. To quote:
`A compact, rigid point-beam triangulation module incorporating laser, imager, and electronics. With a low-cost CMOS imager and a DSP for subpixel interpolation, we get good range resolution out to 6 m with a 5 cm baseline, at a 4 KHz rate. The key insight to the Revo is that high precision is possible with a small baseline, because of the digital image sensor.`
A motor spins the unit at 10Hz to give a full 360-degree field of view. An optical encoder gives 1-degree angular accuracy. Not exactly Earth-shattering, but simple and low-cost. An enclosed, robust USB version of this sensor would have broad appeal, and open up the world of hobby robotics to a sensor that is ubiquitous on research robots. Oh, and I suppose the XV-11 isn't half-bad either:
I seriously hope that Neato makes the laser rangefinder component available separately, but it is currently not listed on their website for purchase. At the moment, I am a bit worried about the possibility of litigation due to similarities between the XV-11 and an iRobot patent (see below). Hopefully they see the light and avoid destructive lawsuits."
Read the whole thing here