Delay in time-of-flight data or uSD card

[Thomsson7]

Hello,
After reviewing some data that I cannot explain in detail, it shows that there is a shift of about 100ms which corresponds to the period between 2 new measurements of the time-of-flights. We are using a slightly modified version of the multiranger deck and the z-ranger 2. To summarize the image below, we compare the position from the EKF with the vive lighthouse system as the ground truth against the position calculated from the time-of-flight.

We do not know if this shift is caused by a delay in logging on the uSD card or by the time to get the data from the time-of-flight.

Is it possible to reproduce this using the Lighthouse Deck + multiranger and try to do a periodic movement with a wall (or curved wall to compensate for the roll/pitch, but maybe this is negligible) near the drone ?

[tobbeanton]

Interesting find. I don't think it is the logging but I'm not sure. You could try to setup a event based logging for the TOF to get the exact sample time.