While a yaw test ration > 1 rejects the mag data in air, the fusion is
forced with a limited innovation on ground to fix gyro bias and local
magnetic effects problems pre-takeoff. However, the same logic is
applied after landing and immediately after the land detector detects
landing. In some cases, this can disturb the other EKF states which can
lead to a state change of the land detector.
To avoid such a loop, the start of this forced yaw fusion is delayed by
5 seconds after landing.
These changes fix a bug that allowed IMU gyro errors that cause large tilt errors prior to start of aiding not resulting in large innovation test ratios.
The failsafe from rng height to baro height should occur after a reset
to baro triggered by the controlHeightSensorTimeouts function and not in
the fusion selector.
Until now, the EKF was fusing baro measurements between rng updates if
the range finder ODR was slower than the EKF update rate. This is not
the case anymore as the height reset occurs after 5 seconds.
The unit test has been extended to show this behavior.
The comment said that the horizontal accuracy needs to be scaled up
using the typical epv/eph ratio but the epv (vacc) is already available,
so no scaling is required.
- extract motion checks performed on ground
- move all non-timing check to controlOpticalFlowFusion. This simplifies and standardirzes the setOpticalFlowData function. Furthermore, in some cases (SITL, PX4Flow), the dt is forced to 0 when the quality is 0 (which is usual on ground) so the ekf needs to ignore those values on ground to initialize properly the flow fusion.
- add filter convergence test
- move check for dt time max in setOpticalFlowData
- in the simulator, do not update dt as this is the sensor integration
period.
- allocate IMU and output buffers on construction according to defaults
- determine buffer max time delay based on configuration parameters
- reorder flowSample and extVisionSample to minimize padding
- adjust parameter defaults to match PX4-Autopilot
bresch