LidarLite v3 finetuning

ArduCopter Copter 3.5
1

Hello,

I’ve connected LidarLitev3 to Pixhawk, and in general, it works great - out of the box.
But distance measurement is a little bit off. It shows 2.4 meters when actual distance is 2 meters.
Is there any possible way to fine tune this measurement ?
According to documentation, RNGFND_OFFSET should do that trick, but change that parameters have no effect on lidar reading.

–
BR,
Kristjan

2

Hi kpihus.

I noticed exactly the same issue - changing the RNGFND settings have virtually no effect on the lidar/sonar readings.
Did you find a way to “scale” or “offset” the lidar’s reading, so it reads correctly?

Thanks

3

I opened an issue on this a few time ago

Not merged yet

4

Hello:

I’ve been using the LIDAR Lites for a few years now and initially had the problem you’re describing. All my devices are older models.

I ended up taking voltage readings from 1ft out to over 100ft, every foot until the 10 foot mark, then every 5ft. The data suggested the voltage output wasn’t linear, so I don’t think a normal offset or scaling will give you respectable accuracy.

Unfortunately, I do not use the LIDAR with inputs to a Pix Hawk. The input goes into a Pitlabs OSD board and I provided the PItlabs firmware developer the voltage data. He then wrote a special scaling algorithm to make it work correctly.

With his algorithm, the ranging is accurate to the foot out past 20ft. That’s as far as I checked it.

Regards