Commit Graph

528 Commits

Author SHA1 Message Date
Arthur Benemann 1d9beed42f AP_SmallEKF: add function to report if the EKF is stable 2015-04-21 21:45:29 +09:00
Arthur Benemann 7b28bf7d44 AP_NavEKF: Remove small EKF dependency on navigation EKF 2015-04-21 21:45:28 +09:00
Andrew Tridgell 4586de6637 AP_NavEKF: enable optimisation in Linux build
only really need debugging for SITL
2015-04-16 08:36:16 +10:00
Paul Riseborough dffa2e19bf AP_NavEKF: Make copter glitch accel consistent with timeout and radius 2015-04-15 17:32:48 +09:00
Paul Riseborough 5d70854c08 AP_NavEKF: Fix minor bug in calculation of innovation variance
the innovation variance for GPS should be the sum of squares of the state and measurement uncertainty.
2015-04-15 17:32:46 +09:00
Paul Riseborough 1008c6390c AP_NavEKF: Fail absolute position status if GPS repeatedly rejected 2015-04-15 17:32:44 +09:00
Paul Riseborough 77d3798278 AP_NavEKF: Reduce recovery time after a GPS fusion timeout 2015-04-15 17:32:41 +09:00
Paul Riseborough 0852aeab6e AP_NavEKF: Allow raw innovations to be monitored during timeouts 2015-04-15 17:32:39 +09:00
Paul Riseborough d3f4b4a02b AP_NavEKF: Fix name consistency for data check time stamps 2015-04-15 17:32:36 +09:00
Paul Riseborough e79ccf1fcc AP_NavEKF: Fix bug allowing terrain to be above vehicle position
The terrain state and vehicle state need to be compared at the same time horizon.
2015-04-11 15:51:08 +09:00
Paul Riseborough 6d58c63c4c AP_NavEKF: Prevent potential divide by zeros in OF fusion 2015-04-11 15:51:03 +09:00
Paul Riseborough 89142f1c5f AP_NavEKF: Prevent inadvertent use of DCM roll and pitch estimates.
the use of roll and pitch from the AHRS object is bad because that object could be returning estimates from the backup DCM algorithm.
2015-04-11 15:19:05 +09:00
Paul Riseborough 9268024094 AP_NavEKF: Update default parameters for copter optical flow fusion 2015-04-10 11:08:11 +09:00
Paul Riseborough 4fbdab27ff AP_NavEKF: Use range finder for primary hgt ref in opt flow mode
Falls back to baro if range finder is unavailable
Adds parameter enabling user to select which height source (baro or range finder) will be used during optical flow nav.
2015-04-10 11:08:07 +09:00
Paul Riseborough d618c55e2f AP_NavEKF: Improved handling of noisy GPS speed accuracy data 2015-04-10 11:07:34 +09:00
Paul Riseborough e98edaa6cb AP_NavEKF: Return more accurate validity status for height above ground 2015-04-10 11:07:24 +09:00
Paul Riseborough 586e4a7d2b AP_NavEKF: Add Matlab derivations and simulations behind small EKF 2015-04-10 11:07:21 +09:00
Paul Riseborough c57e25142c AP_NavEKF: Update optical flow fusion maths to reduce height errors 2015-04-07 20:51:18 -07:00
myly10 55befdc345 AP_NavEKF: Typo correction for EAS_NOISE description 2015-04-06 15:52:29 -07:00
Paul Riseborough 9b3656e77c AP_NavEKF: Fix bug introduced in Y axis flow fusion 2015-04-05 21:17:20 -07:00
Andrew Tridgell baf292def1 AP_NavEKF: prevent float exception on startup 2015-04-05 09:16:14 -07:00
Paul Riseborough 7fc0f026d2 AP_NavEKF: Fix bug in optical flow innovation variance integrity check
The check allowed negative innovation variances to pass. If this did occur, the filter would diverge.
2015-04-04 17:03:06 -07:00
Andrew Tridgell c1a0375562 AP_NavEKF: prevent divide by zero in EKF logging 2015-04-04 07:09:02 -07:00
Paul Riseborough 10f050c53b AP_NavEKF: Prevent baro drift causing toilet bowling
The magnetic field states are reset once at 1.5 metres and again at 5 metres. This height check was using the height at the first arm event as the reference. In the situation where there is baro drift and extgended time between the first arm event and flight, this can cause the magnetic field state to be reset when on the ground. If this happens when flying off a metallic surface, the resultant heading errors can cause sever toilet bowling.
2015-04-03 15:18:42 -07:00
Paul Riseborough d4c60ca956 AP_NavEKF: Fix bug preventing reset of velocity after OF fusion timeout 2015-04-03 15:18:39 -07:00
Jonathan Challinger 95cd3480ec AP_NavEKF: review all uses of dtIMU and use dtIMUactual where necessary
pair-programmed-with: Paul Riseborough <p_riseborough@live.com.au>
2015-04-03 15:18:09 -07:00
Andrew Tridgell 79b44d3988 AP_NavEKF: initialise gndEffectMode 2015-04-03 15:15:11 -07:00
Andrew Tridgell 3165c43dfe AP_NavEKF: initialise gpsSpdAccuracy 2015-04-03 15:15:11 -07:00
Paul Riseborough 98c32012fa AP_NavEKF: remove accel bias rate limit when disarmed 2015-04-03 15:15:11 -07:00
Paul Riseborough fe76cb4c0b AP_NavEKF : Make initial height variance consistent with baro noise
This makes sense to do because we initialise the state to the instantaneous baro reading
2015-04-03 15:15:11 -07:00
Paul Riseborough a976e9dad2 AP_NavEKF : Fix bug in scaling of initial Z accel bias state variance 2015-04-03 15:15:11 -07:00
Paul Riseborough 92df3adb5e AP_NavEKF : Fix bug in Z accel bias update for IMU1 2015-04-03 15:15:10 -07:00
Paul Riseborough 5d0952ba23 AP_NavEKF: eliminate onGndBaroNoise 2015-04-03 15:15:10 -07:00
Paul Riseborough fafb898341 AP_NavEKF: tuning change to accel bias learning 2015-04-03 15:15:10 -07:00
Paul Riseborough 398accd151 AP_NavEKF: Improve pre-flight ready checking 2015-04-03 15:15:10 -07:00
Paul Riseborough 5c1a226bef AP_NavEKF : Improvements to pre-arm IMU bias estimation 2015-04-03 15:15:10 -07:00
Jonathan Challinger a5924acb3d AP_NavEKF: set dtIMU from ins expected sample rate 2015-04-03 15:15:10 -07:00
Paul Riseborough a1351e73ab AP_NavEKF : Compensate mag bias states for external copass offset changes 2015-04-03 15:15:09 -07:00
Paul Riseborough 14795719f6 AP_NavEKF: Add public function for estimated magnetometer offsets 2015-04-03 15:15:09 -07:00
Paul Riseborough 1c244af3d8 AP_NavEKF: Fix bug affecting in-flight GPS acquisition
This bug caused velocities to be reset to zero
2015-04-03 15:15:09 -07:00
Paul Riseborough b9b6938b1d AP_NavEKF: Add ability to start using GPS in-flight
Improve the quality of the GPS required to set an EKF  origin
Eliminate repeated update of origin height - origin height updates once when EKF origin is set.
Operation in GPS mode is linked to setting of origin
2015-04-03 15:15:09 -07:00
Paul Riseborough 98fa918b84 AP_NavEKF: Add new compass learning option
Enables compass learning to be on continuously for non-position hold operation
2015-04-03 15:15:09 -07:00
Paul Riseborough 961faa59d9 AP_NavEKF: Don't let reported GPS accuracy modify horiz vel data checks 2015-04-03 15:15:08 -07:00
Paul Riseborough a607eb8469 AP_NavEKF: Reduce the GPS glitch tether length from 100 to 50m 2015-04-03 15:15:08 -07:00
Paul Riseborough 496d31ab83 AP_NavEKF: Reduce max time Copters can reject GPS
The maximum time copters can reject GPS has been reduced from 10 to 7 seconds as flight logs have show that inertial dead reckoning with vibration and calibration errors is not good enough to support 10 seconds without aiding.
2015-04-03 15:15:08 -07:00
Paul Riseborough 8c2029d896 AP_NavEKF: Accel bias learning improvements
Speed up pre-flight learning
Smoothen in-flight learning
2015-04-03 15:15:08 -07:00
Paul Riseborough 19d1b3b813 AP_NavEKF: Update EKF origin height whilst disarmed
This patch causes the EKF to update the height of its origin each time it receives a valid GPs message whislt disarmed.
The resultant EKF origin height represents the height of the zero baro alt datum relative to the GPS height datum.
2015-04-03 15:15:08 -07:00
Paul Riseborough 70afcd7e70 AP_NavEKF: Add second stage alignment of yaw and earth field states
Flight tests have shown that the magnetic field distortion associated with flight from steel structures can extend 3m or higher. To counteract this, a second and final yaw and magnetic field alignment has been added which is activated when the height exceeds 5m for the first time.
2015-04-03 15:15:08 -07:00
Paul Riseborough ed9c05cf2a AP_NavEKF: Remove logic used to delay fusion for load levelling
Logic used to delay optical flow and airspeed fusion to prevent it occurring on the same time step as magnetometer fusion has been removed. This is no longer required to efficiency improvements made at the firmware level.
2015-04-03 15:15:07 -07:00
Paul Riseborough c0d23ffc30 AP_NavEKF: Filter accuracy and stability improvements
Improvements in PX4 firmware have reduced the computational load  and mkae the previous practicwe of splitting magnetometer and optical flow fusion across multiple time steps unnecessary and make it possible to perform a covariance prediction prior to fusing data on the same time step. This patch:

1) Ensures that a covariance prediction is always performed prior to fusion of any observation
2) Removes the splitting of magnetometer fusion so that fusion of the X,Y and Z components occurs on the same time time step
3) Removes the splitting of optical flow fusion so that fusion of X and Y components occurs on the same time step
2015-04-03 15:15:07 -07:00
Jonathan Challinger de1f7f5e63 AP_NavEKF: use published delta velocities and delta angles if available 2015-04-03 15:15:07 -07:00
priseborough 3421a320b5 AP_NavEKF: Compensate for ground effect when takeoff or landing expected 2015-04-03 15:15:07 -07:00
Jonathan Challinger 20d92f5f9d AP_NavEKF: floor GPS velocity noise at parameter value for conservatism 2015-04-03 15:15:07 -07:00
priseborough 9a797a5d49 AP_NavEKF: Use GPS reported speed accuracy if available
UBlox receivers report an estimate of the speed accuracy that tests show correlates well to speed glitches. Using this to scale the GPS velocity observation noise will reduce the effect of bad GPS velocity data.
2015-04-03 15:15:06 -07:00
Andrew Tridgell 3289d38339 AP_NavEKF: make the init functions return bool
we need to know if it has initialised successfully
2015-03-28 10:51:38 -07:00
Andrew Tridgell de3f461a55 AP_NavEKF: use compass->last_update_usec() 2015-03-14 12:31:39 +11:00
Randy Mackay 230ca583d1 NavEKF: support sending EKF_STATUS_REPORT 2015-03-12 12:20:00 +09:00
Paul Riseborough 9f552eaa4b AP_NavEKF: Fix bug that resets position to origin when vehicle arms 2015-02-12 12:40:55 +11:00
Paul Riseborough b8d3da3846 AP_NavEKF: Report last known position when vehicle is disarmed 2015-02-12 12:40:55 +11:00
Andrew Tridgell 55041c7a7a AP_NavEKF: prevent division by zero in SmallEKF 2015-02-12 09:02:59 +11:00
Jonathan Challinger 50466848f7 AP_NavEKF: use hal.util soft_armed state 2015-02-11 20:25:11 +11:00
Grant Morphett 4860c84dff AP_NavEKF: Changes to fix the warnings in rover sitl build.
We are starting the process of resolving all the warnings in the
ardupilot builds of all vehicles and platforms.
2015-02-11 18:16:46 +11:00
Paul Riseborough aa94ff629d AP_NavEKF: Prevent bad GPS pre-arming casuing initial position errors
If the vehicle moves significantly or the GPS changes position significantly pre-armed, then the GPS glitch logic was being invoked when the first GPs measurements were fused. This patch resets the position to the GPS when the vehicle arms.
2015-02-03 15:57:10 +09:00
priseborough bc5581d634 AP_NavEKF: Prevent arming delays from failing GPS
Due to the way that gyro calibration is done, the EKF could be effectively not run for up to 30 seconds in extreme cases, making it possible that the GPS would be failed on arming and the copter put into a non-GPS mode.

the longer term solution is to update the gyro calibration so that it does not hold up other processing. the short tyermfix in thsi patch is to look for evidence of a 3D lock in the last received GPS message.
2015-02-03 15:57:09 +09:00
priseborough 2c012c2763 AP_NavEKF: Always check for new GPS data
This fixes a bug that meant that once the EKF had started up in a non-GPS mode, it would no longer read the GPS and therefore would never be able to use GPS again until reset.
2015-02-03 15:57:08 +09:00
Paul Riseborough 925d625ed1 AP_NavEKF: fix bug in small EKF velocity fusion 2015-02-03 09:49:17 +11:00
Paul Riseborough 5f24603ceb AP_NavEKF: Publish small EKF quaternion and gyro bias outputs 2015-02-03 09:49:16 +11:00
Andrew Tridgell 4c8b663200 AP_NavEKF: added initial version of SmallEKF
This will be used for gimbal bias estimations. 

Pair-Programmed-With: Paul Riseborough <p_riseborough@live.com.au>
2015-02-03 09:49:16 +11:00
Andrew Tridgell 850af14949 AP_NavEKF: raise EKF_POS_GATE and EKF_GLITCH_RAD for planes
This weights GPS position more heavily for planes

Pair-Programmed-With: Paul Riseborough <p_riseborough@live.com.au>
2015-01-31 21:49:20 +11:00
priseborough 5df733a883 AP_NavEKF: Allow flight transition to optical flow mode if GPS is lost 2015-01-22 14:41:04 +09:00
priseborough 04810c012d AP_NavEKF: Increase flow data valid timeout to handle arming delays
When Copter arms, the AHRS/EKF may not be run for a few hundred msec depending on conditions. This can cause the arming check to fail the optical flow sensor and place the EKF in a constant position mode.
2015-01-22 14:41:01 +09:00
priseborough 073b8e7c43 AP_NavEKF: Always explicitly set required const pos or vel mode when arming
This additional explicit setting of the constPosMode and constVelMode reduces the likelihood of logic errors being introduced in the future as it places the intended setting of these parameters at arming in the one place. the constVelmode and constPosMode only have one set of conditions each that can trigger these modes in flight, so if these modes are true after arming it will be clear that it was the in-flight condition that triggered.
2015-01-22 14:40:59 +09:00
priseborough 9c6dabe1cc AP_NavEKF: Add separate flow default parameters for platform types
Also reduces flow measurement noise default for copter only and increases gate to compensate.
2015-01-22 14:40:57 +09:00
priseborough d2da16e652 AP_NavEKF: Consistently set timeout flags whenever aiding is inhibited
This ensures the position and velocity measurement status will be set as timed out immediately after use of those measurements is inhibited. This will improve the timeliness of filter status reporting.
2015-01-22 14:40:55 +09:00
priseborough 824425625c AP_NavEKF: Update public method used to inhibit GPS use
This method is not currently used by any of our vehicle types, but will be required to enable a user selectable 'indoor mode'.
2015-01-22 14:40:52 +09:00
priseborough 1033f5fc1e AP_NavEKF: Apply flow nav vehicle limits regardless of sensor health
It does not make sense to relax the limits on vehicle speed and nav gains just because we have received some invalid flow data. This could make the situation worse if the invalid data was being caused by too much speed.
If we are relying on flow data the vehicle limits should always be applied.
2015-01-22 14:40:50 +09:00
priseborough 14b51f6d74 AP_NavEKF: Unconditionally fuse velocity in constant velocity mode
The zero velocity measurements in this mode are by definition always correct and should never be rejected
2015-01-22 14:40:48 +09:00
priseborough 6663d80176 AP_NavEKF: Simplify nested logic - functionally equivalent
Additional if else statement was unnecessary
2015-01-22 14:40:45 +09:00
priseborough 12c3368c4d AP_NavEKF: Bypass GPS glitch logic when not aiding
When we are not using GPS measurements, we should not be allowing the GPS glitch logic to reset position states as this can interfere with operation of non GPS modes.
2015-01-22 14:40:43 +09:00
priseborough 5c8e71a8d1 AP_NavEKF: Don't reset the position measurement timeout if not aiding
When PV aiding is disabled, then the timeout time reference should not be reset becasue we want the position measurement timeout status to remain true the whole time the measurement is not being used.
2015-01-22 14:40:41 +09:00
priseborough c505a458de AP_NavEKF: Always declare a position measurement timeout if aiding not used
If position and velocity aiding is turned off, then the position measurement should always be reported as timed out.
2015-01-22 14:40:39 +09:00
priseborough 3b166372cc AP_NavEKF: Always declare a velocity measurement timeout if velocity not used
If position and velocity aiding is turned off, then the velocity measurement should always be reported as timed out.
2015-01-22 14:40:36 +09:00
priseborough 95c3197170 AP_NavEKF: Ensure velocity will not be reset unless needed for aiding 2015-01-22 14:40:34 +09:00
priseborough 8aeec82846 AP_NavEKF: Continually turn off aiding whilst the vehicle is disarmed
This prevents the possibility of any logic errors turning aiding back on.

AP_NavEKF: Fix bug in logic
2015-01-22 14:40:31 +09:00
priseborough 81ee339e25 AP_NavEKF: Synchronise non-aiding mode state corrections
Synchronise with covariance prediction to improve numerical stability and accuracy of angle corrections. The 'noise' this produces in the position and velocity estimate is irrelevantbecause these are not used by the control loops during this mode of operation (they are nominally zero anyway).
2015-01-22 14:40:29 +09:00
priseborough ae6b85e63d AP_NavEKF: Explicitly set aiding to off when disarmed
This fixes a bug that could cause the AHRS to drift whilst the vehicle was disarmed depending sensor combinations at startup.
2015-01-22 14:40:27 +09:00
priseborough fb1962b111 AP_NavEKF: Let reported position whilst disarmed show inertial errors
Showing the positon states (which are nominally zero) in addition to the last known offset can provide useful log information.
2015-01-22 14:40:25 +09:00
Andrew Tridgell e8017a5079 AP_NavEKF: cope with the changed semantics of airspeed.use() 2015-01-20 11:28:14 +11:00
priseborough c40c3632bb AP_NavEKF: Critical Bug Fix
Prevents possible loss of attitude reference for flights without optical flow and GPS.

The optical flow measurement timeout can reset the velocity states which decouples the position states from IMU errors and therefore significantly reduces the amount of attitude error correction.
2015-01-13 16:05:31 +13:00
Andrew Tridgell ef5cdb0d6c AP_NavEKF: use more array bounds checked variables 2015-01-09 11:05:07 +11:00
priseborough 3d46680348 AP_NavEKF: Make NED origin independent of home position
This enables the filter to report the last known position after disarm.
The LLH location of the filters NED origin is published and should be logged every time the vehicle is armed to assist with post-flight trajectory reconstruction.
The LLH location of the filters NED origin can be set externally whilst the vehicle is disarmed.
2015-01-09 10:51:24 +11:00
priseborough f0ea858e4c AP_NavEKF: Make LLH output report last known position in const pos mode 2015-01-09 10:51:24 +11:00
priseborough a0957a83f8 AP_NavEKF: Fix bug in reported position and velocity
The last known position was being output on the velocities when in constant position mode.
2015-01-09 10:51:24 +11:00
priseborough 7d1cd604a8 AP_NavEKF: Report last known position when GPS is lost 2015-01-09 10:51:24 +11:00
priseborough 1789dc08a3 AP_NavEKF: Correctly report position timeout when GPS is lost 2015-01-09 10:51:24 +11:00
Randy Mackay e6e6a781c1 AP_NavEKF: init filter status bits to zero 2015-01-09 10:51:23 +11:00
priseborough ffd9f7a4ed AP_NavEKF: Predict filter solution status 2015-01-09 10:51:23 +11:00
Randy Mackay 657afcfe7a AP_NavEKF: add pred_horiz_pos flags to filter status 2015-01-09 10:51:23 +11:00
Randy Mackay f4d8bc586c Nav_EKF: getFilterStatus returns nav_filter_status struct 2015-01-09 10:51:23 +11:00
Randy Mackay 8a914af4a8 AP_NavEKF: add nav_filter_status definition 2015-01-09 10:51:23 +11:00