Show HN: DIY Position Tracking Using HTC Vive's Lighthouse

Post by RossBencina » Mon, Nov 28, 2016, 11:33 AM UTC

RobertLong wrote: post #12

RossBencina wrote: post #10

Earlier quoted context omitted.

I'm not familiar with the SteamVR tracking modules that you linked, however from the link: > The CM1 contains all the circuitry necessary to convert SteamVR Tracking base station infrared light into a digital output that encodes the angle of the sensor from the base station. That implies that it's not a full location tracking solution by itself (angle only). The data sheet[0] doesn't seem to shed any further (ahem) l…

Correct, it's only going to give you a signal "upon incident light from an IR source once the threshold level for light intensity has been exceeded"[0]. What you are getting in this chip is all of the work Valve and Triad have done in improving the accuracy of that envelope signal. Essentially, the accuracy in the timing of that signal == the accuracy of the position. There's a really good talk from Steam Dev Days[1]…

Post by 70jS8h5L » Mon, Nov 28, 2016, 12:19 PM UTC

rebuilder wrote: post #19

ashtuchkin wrote: post #2

Hey, author here. I used the system described in the link for indoor stabilization of a drone, plus precise landing, to support an automatic battery swap station project (have a video there). Worked pretty well, so I decided to open-source it in hopes this would help fellow hackers. Let me know if you have any questions!

Very nice work! Do I understand correctly that a single sensor board as described here will get position, but can't get orientation? If so, how does the drone handle orienting itself correctly to land on the battery swapping station?

Post by ashtuchkin » Mon, Nov 28, 2016, 2:37 PM UTC

CraigJPerry wrote: post #22

ashtuchkin wrote: post #6

Earlier quoted context omitted.

Thanks, that's nice to hear! Seamless switching is definitely doable and shouldn't be hard, just need some time to implement. I'm using PX4 autopilot and it's very friendly for adding new functionality. Orchestration is also close - in current demo both station and drone use Wifi to coordinate, so it's a matter of adding new logic. Currently the most limiting resource for that project is my time :) I'd be happy if ot…

Dude that video is an amazing demo. I left a comment on YT but you should take this further! P.s. I think the I-term in your pid control loop is too high on your quadcopter, that oscillation isn't really affecting your flight control too badly but it heats the motors more than a stable tune would which reduces the service life of the permanent magnets in them. Could be the P-term but the oscillation looks too slow fo…

Post by ashtuchkin » Mon, Nov 28, 2016, 2:49 PM UTC

RossBencina wrote: post #20

ashtuchkin wrote: post #2

Hey, author here. I used the system described in the link for indoor stabilization of a drone, plus precise landing, to support an automatic battery swap station project (have a video there). Worked pretty well, so I decided to open-source it in hopes this would help fellow hackers. Let me know if you have any questions!

Hi, I have some questions: > 3d position accuracy: currently ~10mm; less than 2mm possible with additional work. Could you outline what is required to take your solution from 10mm to 2mm accuracy? what factors limit maximum accuracy? Presumably the lighthouse-derived position could be fused with IMU data for better temporal accuracy. Does your drone software do that? Thanks!

Post by ashtuchkin » Mon, Nov 28, 2016, 2:54 PM UTC

thenomad wrote: post #24

Fantastic! Having been developing with the Vive for most of the last year for Left-Hand Path ( http://store.steampowered.com/app/488760 ), and given I've got a lot of mocap experience before that, I can confirm that Lighthouse's tracking is ridiculously good. It's not just as good as something like an Optitrack system: it's significantly better. If this provides comparable tracking to what the Vive offers, it's an ab…