EKF2: Spoofing GPS check #23366
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EKF2: Spoofing GPS check #23366
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dagar
reviewed
Jul 5, 2024
| @@ -703,6 +719,12 @@ void EstimatorChecks::checkGps(const Context &context, Report &reporter, const s | |||
| events::ID("check_estimator_gps_multiple_spoofing_indicated"), | |||
| events::Log::Critical, "GPS reports multiple spoofing indicated"); | |||
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| if (!_gps_spoofed) { | |||
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I think we should be getting this event any time it transitions to spoofed right?
dagar
reviewed
Jul 5, 2024
| @@ -450,6 +450,22 @@ void EstimatorChecks::checkEstimatorStatus(const Context &context, Report &repor | |||
| events::ID("check_estimator_gps_vert_speed_drift_too_high"), | |||
| log_level, "GPS Vertical Speed Drift too high"); | |||
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| } else if (estimator_status.gps_check_fail_flags & (1 << estimator_status_s::GPS_CHECK_FAIL_SPOOFED)) { | |||
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Now that we're getting this through the estimator I would delete all the checks directly on vehicle_gps_position spoofing.
The check through the estimator is better because we can decide to ignore it or need through the EKF2_GPS_CHECK bit.
dagar
reviewed
Jul 5, 2024
| @@ -136,6 +137,29 @@ void Ekf::collect_gps(const gnssSample &gps) | |||
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| bool Ekf::runGnssChecks(const gnssSample &gps) | |||
| { | |||
| // Check GPS spoofing | |||
| // hysterisis: spoofing needs to be consistent for 1 second before it is declared | |||
| constexpr uint64_t hysteresis_gps_spoofing_us = 1e6; // 1 second, hardcoded | |||
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- Does GNSS spoofing really require its own dedicated hysteresis (remember we have that on all these checks as a whole as well)
- If yes, then let's start using
src/lib/hysteresis/hysteresis.hfor these to keep it simple. https://github.com/PX4/PX4-Autopilot/blob/ac1effa32a4bc4541481778295d4a0d0c213f86f/src/lib/hysteresis/hysteresis.h
dagar
reviewed
Jul 5, 2024
| @@ -450,6 +450,22 @@ void EstimatorChecks::checkEstimatorStatus(const Context &context, Report &repor | |||
| events::ID("check_estimator_gps_vert_speed_drift_too_high"), | |||
| log_level, "GPS Vertical Speed Drift too high"); | |||
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| } else if (estimator_status.gps_check_fail_flags & (1 << estimator_status_s::GPS_CHECK_FAIL_SPOOFED)) { | |||
| message = "Preflight%s: GPS signal spoofed"; | |||
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This one is relevant beyond preflight.
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Here is a log with an example with false positive spoofing. We probably want spoofing state to be >=2 for a period of time before failing the check. https://review.px4.io/plot_app?log=8e03bae1-1551-4c93-bf6b-19c22e3c78a1
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Solved Problem
Currently the spoofing state, which gets set by the GPS driver, does not have any effect on the estimator.
Solution
One can now add the spoofing state to the EKF2_GPS_CHECK. For it to fail, the spoofing flag has to be consistently true over a second and vice-versa for it to pass again.
There is now also a event which gets sent once when the first spoofed message arrives. This will notify the user, independent of the settings chosen in EKF2_GPS_CHECK.