Hi,
v6xrt with Px4 v1.16.2. I connected 2 CAN GPS,
How Px4 reacts if one GPS fail, any test method to verify it
A good way to verify this is with a controlled failure test rather than assuming that two detected CAN GPS units automatically guarantee seamless failover.
I would first confirm in the log that both receivers are actually present and being used/monitored as expected. Then establish a nominal baseline and inject failures one at a time:
1. Nominal: both GPS receivers healthy
2. GPS-A loss: disconnect or disable only GPS-A
3. GPS-B loss: repeat for GPS-B
4. Degraded GPS: if possible, test bad/stale data separately from complete loss
During each test, log the individual GPS instances and check:
GPS status/quality → selected estimator source → estimator innovations/status → position validity → failsafe/mode response
The interesting point is not only whether the vehicle continues to have a position estimate, but when PX4 detects the failure, whether/when the estimator changes source, and whether that transition introduces a position/velocity/heading discontinuity.
I would do the first tests disarmed/on the bench (or SITL if you can reproduce the configuration) before any flight test.
If you can share a ULog from a both-GPS-healthy test and one controlled single-GPS failure, I’d be happy to compare the transition timeline.