Commit Graph

63 Commits

Author SHA1 Message Date
Paul Riseborough
ddb7d92fc8 AP_NavEKF2: Fix timing jitter in airspeed fusion
The airspeed observation buffer was only being checked when new data arrived instead of every frame which introduced some timing jitter. The buffer is now checked every filer update step.
The duplication and inconsistent naming of booleans used to indicate availability f data has been fixed.
2015-11-26 09:22:03 +11:00
Siddharth Purohit and Paul Riseborough
3014eb4001 AP_NavEKF2: Rework measurement buffer refactor
These changes were pair coded an tested by Siddharth Purohit and Paul Riseborough

Fix indexing errors
Move buffer code into a separate file
Split observer and IMU/output buffers and remove duplicate sample time
Optimise observation buffer search
Reduce maximum allowed fusion age to 100 msec
2015-11-23 19:42:06 +11:00
Siddharth Bharat Purohit
b3c8dcee34 AP_NavEKF2: measurement buffer refactor 2015-11-23 19:34:50 +11:00
Paul Riseborough
d820a538d5 AP_NavEKF2: Make magnetometer data available status global
This assists with debugging and makes it consistent with other measurements that are buffered
2015-11-18 11:18:46 +11:00
Paul Riseborough
04228e0b3b AP_NavEKF2: Rework selection of height measurements for fusion
GPS height has been added as a measurement option along with range finder and baro
Selection of the height measurement source has been moved into a separate function
Each height source is assigned its own measurement noise
If GPS or baro alt is not able to be used, it reverts to baro
When baro is not being used, an offset is continually calculated which enables a switch to baro without a height step.
2015-11-18 11:18:42 +11:00
Paul Riseborough
4c72a14e22 AP_NavEKF2: Add function to LPF and spike filter baro data 2015-11-18 11:18:17 +11:00
Paul Riseborough
34311bedfa AP_NavEKF2: Add data buffers for range finder data 2015-11-18 11:18:17 +11:00
Andrew Tridgell
99da195e37 AP_NavEKF2: make IMU buffer length depend on main loop rate
this fixes a problem with Replay and baro data
2015-11-18 10:20:39 +11:00
Paul Riseborough
9b82b2200c AP_NavEKF2: Fix plane in-flight yaw reset
The copter method was being used for plane and the plane method was not being run due to the change in flight status not being detected.
The plane reset method did not trigger if the EKF had already dragged the velocity states along with the GPS or could align to an incorrect heading.
The method has been reworked so that it resets to the GPS course, but only if there are inconsistent angles and large innovations.
To stop a failed magnetometer causing a loss of yaw reference later in flight, if all available sensors have been tried in flight and timed out, then no further magnetoemter data will be used
2015-11-16 09:05:42 +11:00
Paul Riseborough
577670ccee AP_NavEKF2: Reduce memory required by 6KB when running at 400Hz
Down-sample the IMU and output observer state data to 100Hz for storage in the buffer.
This reduces storage requirements for Copter by 75% or 6KB
It does not affect memory required by plane which already uses short buffers due to its 50Hz execution rate.
This means that the EKF filter operations operate at a maximum rate of 100Hz.
The output observer continues to operate at 400Hz and coning and sculling corrections are applied during the down-sampling so there is no loss of accuracy.
2015-11-10 15:51:18 +11:00
Paul Riseborough
5d2f78996a AP_NavEKF2: Remove un-used data in IMU buffer
Recovers 416 Bytes of memory per EKF2 instance for Copter
2015-11-09 22:07:10 +11:00
Paul Riseborough
f00b1ff22d AP_NavEKF2: Publish the magnetometer selection index 2015-11-09 22:07:10 +11:00
Paul Riseborough
7294c8004b AP_NavEKF2: Enable use of backup magnetometers after a timeout
If the magnetometer fails innovation consistency checks for too long (currently 10 sec), then the next available sensor approved for yaw measurement will be used.
2015-11-09 22:07:09 +11:00
Paul Riseborough
afeadfca51 AP_NavEKF2: Don't attempt to compensate for external mag calibration
This was problematic to implement with magnetometer switching. It is likely that slow magnetometer learning can still be performed externally (eg plane) but this will need to be monitored to see if it causes issues.
2015-11-09 22:07:09 +11:00
Paul Riseborough
5f6d1d8d25 AP_NavEKF2: Add fault score calculation 2015-11-08 15:37:27 +11:00
Paul Riseborough
04165a60a7 AP_NavEKF2: Reduce false positive on EKF health check
Apply filtering to baro innovation check and and don't apply innovation checks once aiding has commenced because GPS and baro disturbances on the ground and during launch could generate a false positive
2015-11-08 15:37:27 +11:00
Paul Riseborough
2340e18fdc AP_NavEKF2: Offset the fusion time horizon between multiple instances
Prevents frame over-runs due to simultaneous fusion of measurements on each instance.
The offset is only applied if less than 5msec available between frames
2015-11-08 15:37:26 +11:00
Paul Riseborough
3eeff8dbc6 AP_NavEKF2: Remove unused code
This method of correcting for the fusion time horizon delay was too computationally expensive for our application and did not smooth fusion noise.
2015-11-08 15:37:26 +11:00
Paul Riseborough
d48454ee2d AP_NavEKF2: Use nominated IMU unless unavailable
We now run a separate instance of the EKF for each IMU, so input data fusion of IMU's is no longer required.
2015-11-08 15:37:26 +11:00
Andrew Tridgell
2ab2afc86a AP_NavEKF2: added EK2_IMU_MASK for multiple IMUs
no voting between multiple IMUs yet
2015-11-06 10:42:58 +11:00
Paul Riseborough
aa14de9d39 AP_NavEKF2: Fix failure to start mag cal due to gyro noise
Vibration in the 400Hz delta angles could cause the angular rate condition check for in-flight magnetic field alignment to fail.
The symptons were failure to start magnetic field learning as expected when EK2_MAG_CAL=3 was set.
2015-11-02 14:12:17 +11:00
Paul Riseborough
b6d63d4b4e AP_NavEKF2: Fix reporting of pre-flight GPS checks
Re-order checks so that that less important messages are not hidden when the 40 character buffer overflows
Add required output methods
2015-11-02 14:12:16 +11:00
Paul Riseborough
5533a9a149 AP_NavEKF2: Add improved health monitoring when using simple compass yaw fusion 2015-10-30 15:34:23 +09:00
Paul Riseborough
844ed95718 AP_NavEKF2: Add method to rotate output quaternion history 2015-10-30 15:34:17 +09:00
Randy Mackay
94adaba305 AP_NavEKF2: constify getLastPosNorthEastReset
Also constify getLastVelNorthEastReset
2015-10-30 12:24:16 +09:00
Randy Mackay
52ed075405 AP_NavEKF2: constify getLastYawResetAngle 2015-10-30 12:24:12 +09:00
Paul Riseborough
74da4d8e57 AP_NavEKF2: Remove GPS glitch offset logic
Correction for steps in position and velocity caused by resets following GPS glitches and other events are now handled by the control loops.
2015-10-30 12:24:04 +09:00
Paul Riseborough
4fdec67546 AP_NavEKF2: Publish the position and velocity state reset deltas
Used by the control loops to compensate for step changes in position and velocity when the EKF needs to do a reset of these states.
2015-10-30 12:24:02 +09:00
Paul Riseborough
4c5ba60578 AP_NavEKF2: Remove dead code 2015-10-26 08:05:15 +11:00
Paul Riseborough
5eb7cf1fbf AP_NavEKF: Reduce roll/pitch disturbance when magnetic field is reset
Because we have changed the yaw angle and have taken a point sample on the magnetic field, covariances associated with the magnetic field states will be invalid and subsequent innovations could cause an unwanted disturbance in roll and pitch.
The reset of the Euler angles to a new yaw orientation was being done using roll and pitch from the output observer states, not the EKF state vector which meant that when roll and pitch were changing, the reset to a new yaw angle would also cause a roll and pitch disturbance.
2015-10-23 19:04:30 +11:00
Paul Riseborough
aabb9b4e02 AP_NavEKF2: handle uncertain build type 2015-10-21 17:27:00 +11:00
Paul Riseborough
e6312d91ce AP_NavEKF2: Correct variable name 2015-10-21 17:27:00 +11:00
Paul Riseborough
cd8b9c7d26 AP_NavEKF: prevent high rate mag data locking out other data fusion 2015-10-20 20:16:04 +11:00
Paul Riseborough
ab8c28a7cc AP_NavEKF: Fix bug allowing takeoff in GPS modes without aiding
The legacy EKF switches GPs aiding on on arming, whereas the new EKF switches it on based on GPS data quality.
This means the decision to arm and therefore the predicted solution flags must now reflect the actual status of the navigation solution as it will no longer change when motor arming occurs.
2015-10-20 20:16:00 +11:00
Andrew Tridgell
cb0f7cb370 NavEKF2: use new perf counter API 2015-10-20 18:16:15 +11:00
Andrew Tridgell
d1dfd5fd01 AP_NavEKF2: use common header for optimisation level and irq disable 2015-10-20 15:21:40 +11:00
Andrew Tridgell
b6c1352e4c AP_NavEKF2: added 10 test perf counters
used for fine grained performance tuning
2015-10-20 15:21:40 +11:00
Paul Riseborough
2fbd050418 AP_NavEKF2: Use blended accelerometer data
If high vibration levels cause offsets between the two, it switches to the accelerometer with lower vibration levels. The default behaviour is to use the average of both accelerometers.
2015-10-20 15:21:40 +11:00
Paul Riseborough
225b81baf4 AP_NavEKF2: Prevent users breaking filter by setting excessive time delays
If time deelays greater than the IMU buffer length are used, then it is possible for measurements to be dropped.
2015-10-20 15:21:39 +11:00
Paul Riseborough
e0ed2dab63 AP_NavEKF2: Adjust IMU FIFO buffer for different IMU data rates
The values chosen ensure that up to consistent 250 msec of sensor delay compensation is available for different platform types
The revised values also ensure that fusion occurs at different time to when the 10Hz magnetometer measurements are read
2015-10-20 15:21:39 +11:00
Paul Riseborough
baa8692960 AP_NavEKF2: Allow use of magnetometer learning during optical flow nav
Adds fusion of the declination when there are no earth relative measurements so that the declination angle and therefore the copters yaw angle have an absolute reference.
This enables the length (but not the declination) of the earth field North/East states to change along with the magnetometer offsets.
2015-10-20 15:21:38 +11:00
Paul Riseborough
35b08849f7 AP_NavEKF2: Reduce effect of rounding errors on covariance prediction 2015-10-20 15:21:37 +11:00
Paul Riseborough
47ae0f35f6 AP_NavEKF2: Make EKF2 PosDownDerivative interface follow coding conventions
Updates arising from peer review.
2015-10-20 15:21:37 +11:00
Paul Riseborough
52fd369b2f AP_NavEKF2: Add methods to output and calculate vertical position derivative
This patch calculates a derivative of the vertical position (positive down).
The derivative is exposed via a public function.
2015-10-20 15:21:35 +11:00
Paul Riseborough
e3013b493b AP_NavEKF2: Critical bug fix - perf counter not initialised 2015-10-15 09:48:13 +11:00
Paul Riseborough
20a3f9782e AP_NavEKF2: Add full set of selectable pre-flight GPS checks 2015-10-10 21:22:53 +09:00
Paul Riseborough
db4dfce7b1 AP_NavEKF2: Add fix status to GPS check report message 2015-10-10 14:49:07 +09:00
Paul Riseborough
22920aafad AP_NavEKF2: Improve GPS status reporting 2015-10-10 14:48:59 +09:00
Paul Riseborough
f467a89fa3 AP_NavEKF2: Update comments for filter status output function 2015-10-10 14:48:52 +09:00
Paul Riseborough
cde140354a AP_NavEKF2: Clean up control logic 2015-10-05 13:35:32 +09:00