Hi! I’m planning on using VL53L1X sensors to control an aircraft maintenance platform. I would like to know how dust (for example when the aircraft is being painted), luminosity and vibrations affect measurements. Thank you in advance!

MCost · ‎2019-09-04

John E KVAM · ‎2019-09-04

Dust is an issue will all optical sensors. But if you buy (or build) a proper coverglass you won't have any issues.

There is a video on the topic.

https://www.youtube.com/watch?v=BHM2CZVXZGc&t=5s

There is a better coverglass than the one in the video, all ready to go. Company is http://www.hornix.com.tw/en/home/

The reflectivity is important. Our sensor emits a 940nm laser light in a 25 degree cone, which lights up the target. If the target is very mirror-like and the angle is steep, al the photons will bounce away. But if you are roughly perpendicular to the surface you won't have an issue.

Small vibrations (or even relatively large ones) won't matter. You will get the average distance over the ranging period - maybe 30ms.

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MCost · ‎2019-09-05

Thank you very much for your reply and suggestion!

Where can I find more information about the influence of dust on measurements? I understand that I can protect the sensor by using glass covers, but does the dust affect the measuring range or the resolution, for example?

John E KVAM · ‎2019-09-05

In our system we average ALL the photons we get back. So if some hit off a spec of dust and bounce back we will average that in and start to under-range. More and more dust would reflect more photons until eventually you wouldn't see any of the actual object.

By building (or buying) a separated coverglass the dust would not reflect any photons. At some point the dust would get so think that you could not range very far due to the blocked light, but if you did get a range, it would be right.

Best thing do to is buy the P-Nucleo-51A1 evaluation kit ($56 at Mouser or Digikey) and get the brand new Hornix coverglass.

Use salt or coffee creamer as 'dust' and see what happens.

(I tried actual dust, but couldn't make a repeatable experiment.)

It's that barrier between the two separate bits of 'glass' that does the work. Light simply cannot bypass going out and reflecting off your target.

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