Question: are there hobbyist time-of-flight (ToF) cameras, and if not are they likely to start appearing in the near-ish future?
The big promise held out by ToF is that one can build a 3D picture of a scene without the need for moving parts. To do this one needs a ToF camera, i.e. a ToF device with an array of pixels that in addition to the wavelength information, captured by the individual pixels of a traditional digital camera, also captures depth information.
At the moment all the hobbyist priced ToF devices seem to be simple rangefinders, i.e. you could attach one to the front of your drone and use it for simple forward facing crash avoidance but you couldn’t use it for simultaneous localization and mapping (SLAM) without adding something mechanical to spin it (as seen in the video for this hexapod using the TeraRanger One) or by using an array of them (like the TeraRanger Tower).
The TeraRanger One (at around $130 from the RobotShop) seems to be one of the lowest priced ready-to-go ToF sensors. There are cheaper units like the TFMini (around $40 from Sparkfun) or the VL53L0X hobbyist module for $15 from Adafruit but my impression is that these are not really ready to go in the same way as the TeraRanger One.
The fact that even at the $1K mark it still makes more sense to combine individual sensors (as in TeraBee’s tower) than to use a sensor consisting of a grid of pixels seems to suggest to me hobbyist priced cameras, capable of measuring the distances within a complete scene in a single shot, are still way off.
Does anyone see any signs that this is likely to change in the near-ish future, are there devices in the pipeline or are ToF cameras really just a thing for well-funded autonomous car researchers and the like for the time being?
At the moment LIDAR still looks like the best option for hobbyist SLAM. Obviously, you can buy something like the LIDAR-Lite (around $150 for the v3HP at Sparkfun) and build your own solution for rotating it. But for ready-to-go, the best solution currently, for hobbyists, seems to be the RPLIDAR A2 from Slamtec (warning: their site is super slow to load, for its ArduCopter documentation see here instead). Note: the more advanced A3 is either already shipping or almost ready to ship.
As I’m always inclined towards open-source hardware and software I did love the Scanse Sweep but it’s been retired and its producers have closed up shop (the Scanse website is now essentially closed). But it does look anyway as if the RPLIDAR is a better product (see this DIY Drones comparison) and cheaper (the Sweep sold for around $350 while the A2 is now available for around $320).
I’d be curious to hear what other products people think are interesting for SLAM in the hobbyist space (I’m defining hobbyist very broadly to mean anything in the sub-$1K range) beyond TeraBee and Slamtec products? Preferably devices where the device isn’t a separate project in itself, i.e. where you spend 6 months building and calibrating something to spin the sensor (however much fun that may be if that’s what you’re interested in, rather than a bigger overall project).