While waiting on my 3D printer to print a simple base for my laser distance scanner salvaged from a Neato robot vacuum, I went online to read more about this contraption. The more I read about it, the more I'm puzzled by its price. Shouldn't these simple geometry-based distance scanners be a lot cheaper by now?

The journey started with this Engadget review from 2010 when Neato's XV-11 was first introduced to fanfare that I apparently missed at the time. The laser scanner was a critical product differentiation for Neato, separating them from market leader iRobot's Roomba vacuums. It was an advantage that was easy to explain and easy for users to see in action on their product, both of which help to justify their price premium.

Of course the rest of its market responded and now high-end robot vacuums all have mapping capability of some sort or another, pushing Neato to introduce other features like internet connectivity and remote control via a phone app. In 2016 Ars Technica reviewed these new features and found them immature. But more interesting to my technical brain is that Ars linked to a paper on Neato's laser scanner design. Presented at May 19-23 2008 IEEE International Conference on Robotics and Automation titled A Low-Cost Laser Distance Sensor and listing multiple people from Neato Robotics as authors, it gave an insight into these spinning domes. Including this picture of internals.

Revo LDS

But even more interesting than the fascinating technology outlined in the paper, is the suggested economics advantage. The big claim is right in the abstract:

The build cost of this device, using COTS electronics and custom mechanical tooling, is under $30.

Considering that Neato robot vacuums have been in mass production for almost ten years, and that there's been ample time for clones and imitators to come on market, it's quite odd how these devices still cost significantly more than $30. If the claim in the paper is true, we should have these types of sensor for a few bucks by now, not $180 for an entry-level unit. If they were actually $20-$30, it would make ROS far more accessible. So what happened on the path to cheap laser scanner for everyone?

It's also interesting that some other robot vacuum makers - like iRobot themselves - have implemented mapping via other means. Or at least, there's no obvious dome of a laser scanner on top of some mapping-capable Neato competitors. What are they using, and are similar techniques available as ROS components? I hope to come across some answers in the near future.