How does a VL53L0X react with multiple targets in FOV

[DOelk.1]

I understand that there are models with multiple zones, but what I am trying to figure out is how a single zone TOF sensor will react when inside the FOV there are multiple targets.

For example - if there is a wall at 100cm covering the full FOV, but also an object covering say 10% of the FOV at only 50cm. What kind of measurement can be expected? What if that object covers 25% or 50% of the FOV?

Any resources that you can point me to, or a good explanation of how the measurement is made I would appreciate.

I work with FIRST Tech Challenge teams. This is for Jr. High & High School students who build robots and compete. There is a VL53L0X based sensor that is common, but there appears to be misunderstandings about how it works. I want to put together a tutorial for them, but the data sheet doesn't seem to address this situation. And this kind of situation is pretty common with how the sensor is being used.

[John E KVAM]

With the VL53L0X, all the photons will be averaged and you get a distance somewhere in the middle.

Generally the average is waited toward the closest object as the light disperses as a square of the distance. But if the near object were barely in the FoV and the far object was reflective, you would get a number very near the far object.

If you want better, you can switch to the VL53L3CX or the VL53L4CX. These sensors use histograms. (But have identical footprints and shapes as the L0X. - The VL53L4CX does have a more narrow FoV.)

By using histograms you can resolve any targets that are more that 80cm seperated in distance.

(The histogram bins contain the number of photons received during that clock cycle.)

So someone sholder at 50cm and a wall at 150cm would appear as 2 separate objects.

The reason for the 80cm has to do with the clock speed and the 2ns pulse width.

If I were doing a student-based robot, I'd consider the VL53L4CD. It works the same way as your VL53L0X, but has a max distance of 1.3 meters and a more narrow (18 degree) FoV.

(And it really is good to that 1.3 meters.) And it's our least expensive sensor as well.