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Reduce noise when targeting reflective curved surface

videojames
Associate III

Hi,

We are trying to measure distance from our sensor through an IR Translucent plastic to a curved metal surface, using a VL53L1X. We are getting reasonable results by they are rather noisy (~10% deviation at times)

What sort of changes should we be experimenting with to reduce noise in our signal?

1 ACCEPTED SOLUTION

Accepted Solutions
John E KVAM
ST Employee

First thing to try is extending the TimingBudget. A 4X increase in TB will double the accuracy.

You can also average several ranges together to eliminate noise, but it depends on your expected rate of change. I've had good luck with running averages.

The sensor is going to average all the photons it gets back. So if your object is near enough and the return signal is strong, you might consider reducing the Field of View. This will cut down on the photons coming from outside your target area.

I always create a measured drawing, but if you assume at some Target distance T, the circle of illumination will be 1/2 T in diameter. Does your beer keg fill the entire FoV? (Photons NOT hitting your target are averaged in with the one that do.)

Sometimes one can brighten up your target with a bit of reflective tape. But if it's a real beer keg, that aluminum is already pretty bright.

  • john

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question. It helps the next guy.

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2 REPLIES 2
John E KVAM
ST Employee

First thing to try is extending the TimingBudget. A 4X increase in TB will double the accuracy.

You can also average several ranges together to eliminate noise, but it depends on your expected rate of change. I've had good luck with running averages.

The sensor is going to average all the photons it gets back. So if your object is near enough and the return signal is strong, you might consider reducing the Field of View. This will cut down on the photons coming from outside your target area.

I always create a measured drawing, but if you assume at some Target distance T, the circle of illumination will be 1/2 T in diameter. Does your beer keg fill the entire FoV? (Photons NOT hitting your target are averaged in with the one that do.)

Sometimes one can brighten up your target with a bit of reflective tape. But if it's a real beer keg, that aluminum is already pretty bright.

  • john

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question. It helps the next guy.
videojames
Associate III

Thanks so much John, we will try both of those things in tandem.

I did not consider the implications of photo not returning. Makes sense.

The amount of reflectivity can vary depending on the condition/age/brand of the keg.