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 and 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.