EK3 failsafe when optical flow is present in GPS jamming enviroments

ArduCopter Copter 4.3
1

I am testing gps jamming with cheap usb dongle jammers
When EK3_vel_xy is setup as optical flow then the position accuracy should be better. When I turn on the usb dongle then I start getting a lot of EK3 failsafe messages that is to be expected and when the GPS count reaches 0, then I get either althold (that happens pretty quickly) or land that takes about 1 minute to reach.
My question is that when optical flow is present and it is setup correctly, would using the RC command to “disable gps” help in this kind of a situation? My initial thought was that if the optical flow is present and the GPS is being jammed, EK3 would discard the messages coming from the gps and would hold the drone stable in place, but it somehow still forces it to land even if it is in flow hold mode.

I would somehow need to filter gps messages out and rely on the flow sensor more.

2

I found the answer myself - GPS to no gps transition needs ek3_src_options needs to be not fused. EK3_SRC_OPTIONS should default to 1 meaning both GPS and optical flow velocities will be fused. But i do not need that.

3

Take a look at EKF3: improve support multiple navigation sources fusion · Issue #25189 · ArduPilot/ardupilot · GitHub
Can you help us develop it?

1 Like
4

We can try to help. I dont write code, but I am testing the code changes.