82 Commits

Author SHA1 Message Date
kamilritz
1bf09fd370 Remove EKF prefix from logged messages 2019-12-12 08:48:10 +01:00
kamilritz
07e804676c Rename IMU biases 2019-12-05 20:09:34 +11:00
Mathieu Bresciani
c7bdf25663
[ekf] controlMagFusion refactor and mag field strength check (#662)
* ekf_control: Inhibit mag fusion when field magnitude is large
Move mag inhibition check in separate function

* ekf_control: pull out of functionalities out of controlMagFusion
- yaw abd mag bias observability checks
- mag 3D conditions
- load mag covariances
- set and clear mag control modes

* ekf_control: refactor mag heading/3D start/stop.
Move mag declination, mag 3d and mag heading fusion out of the main function

* ekf_control: extract mag yaw reset and mag declination fusion requirements

* ekf_control: use WMM in isStronMagneticField for mag fusion inhibition
- Correct units of WMM strength table

* ekf_control: extract mag_state_only functionality of AUTOFW (VTOL custom)
Also split inAirYawReset from onGroundYawReset

* ekf_control: extract mag automatic selection
- transform if-else into switch-case for parameter fusion type selection

* ekf_control: extract run3DMagAndDeclFusion, reorganize functions, fix
flag naming in Test script

* ekf_control: do not run mag fusion if tilt is not aligned.
Reset some variables on ground even if mag fusion is not running yet. It
could be that it runs later so we need to make sure that those variables
are properly set.

* ekf_control: move controlMagFusion and related functions to mag_control.cpp

* ekf control: check for validity of mag strength from WMM and falls back
to average earth mag field with larger gate if not valid

* ekf control: remove evyaw check for mag inhibition

* ekf control: change nested ternary operator into if-else if

* Ekf: create AlphaFilter template class for simple low-pass filtering
0.1/0.9 type low-pass filters are commonly used to smooth data, this
class is meant to abstract the computation of this filter

* ekf control: reset heading using mag_lpf data to avoid resetting on an outlier
fixes ecl issue #525

* ekf control: replace mag_states_only flag with mag_field_disturbed and
add parameter to enable or disable mag field strength check

* ekf control: remove AUTOFW mag fusion type as not needed This was implemented for VTOL but did not solve the problem and should not be used anymore

* ekf control: use start/stop mag functions everywhere instead of setting the flag

* ekf control: Run mag fusion depending on yaw_align instead of tilt_align
as there is no reason to fuse mag when the ekf isn't aligned

* AlphaFilter: add test for float and Vector3f
2019-11-08 16:02:59 +01:00
kritz
4a38f5a2f6 Add timestamp to ECL print statements, (#644)
which is helpful for EKF replay debugging.
2019-09-25 11:24:42 +02:00
Roman
cef2ba5ab9 implemented Kahan summation algorithm for adding process noise to delta
angle- and delta velocity bias variance

- the contribution of process noise per iteration for these states can be so
small that it gets lost if using standard floating point summation

Signed-off-by: Roman <bapstroman@gmail.com>
2019-06-11 19:28:06 +10:00
CarlOlsson
32ca6f7030 ekf: scale wind process noise with low pass filtered height rate 2019-03-19 13:10:12 +11:00
Carl Olsson
f0889c1760 EKF: fixed some comment typos
Signed-off-by: CarlOlsson <carlolsson.co@gmail.com>
2019-03-18 10:20:33 -04:00
Paul Riseborough
fe378fd761 EKF: Prevent unwanted declination fusion when re-starting 3-axis fusion 2019-01-31 09:53:57 -05:00
Paul Riseborough
bd1647a7fb EKF: Rework use of fuseDeclination()
Simplify calling so that it is only called in two ways:
1) Immediately before 3-axis mag fusion if not called since the last earth field covariance reset so that the earth field declination information can be formed.
2) Immediately after 3-axis mag fusion otherwise.
2019-01-31 09:53:57 -05:00
Paul Riseborough
82ce7a83a5 EKF: Save mag field covariance information on startup 2019-01-31 09:53:57 -05:00
Paul Riseborough
708c79eb8f EKF: Ensure mag field state covariance data is always available for re-use
Prevents use of  _saved_mag_ef_covmat and _saved_mag_bf_variance before being initialised or when stale.
2019-01-31 09:53:57 -05:00
Paul Riseborough
25148e1b45 EKF: Prevent rapid changes in declination estimate after a reset
Ensures that each time the earth field covariance and variance data is reset, that the off-diagonal elements containing earth field declination angle certainty is restored.
2019-01-31 09:53:57 -05:00
Daniel Agar
41953ab582 EKF angle constants in degrees for readability (#465)
* EKF angle constants in degrees for readability

* EKF make FILTER_UPDATE_PERIOD_MS static constexpr and add FILTER_UPDATE_PERIOD_S

* EKF controlOpticalFlowFusion() use constants and update comments

* EKF controlMagFusion() use angle in degrees

* EKF move earth spin rate to geo and update usage

* EKF: Fix numerical constant error and clean up comments

Comments do not need to contain numerical values when the code makes these clear.
2018-07-05 08:55:22 +10:00
Paul Riseborough
93c456f2b8 EKF: Improve protection against badly conditioned dVel bias covariances
Reduces likelihood of Z delta velocity bias learning to wrong value.
2018-06-09 22:23:55 +02:00
Paul Riseborough
bf902e5eca EKF: Prevent flow motion check false positives
The previous implementation could false trigger if there was significant vibration below 200Hz during startup.
2018-05-09 07:47:17 +10:00
Daniel Agar
c5b2f59f57 PX4 style fixes (excluding EKF generated code) 2018-05-03 22:25:36 -04:00
Paul Riseborough
31142c0322
EKF: tighten wind variance growth check 2018-04-21 13:04:04 -04:00
Paul Riseborough
02055acee2
EKF: Fix non GPS aiding data reset logic (#418)
* EKF: Move optical flow specific state reset to helper functions

* EKF: Ensure loss of optical flow aiding is handled correctly

If data is only source of aiding and has been rejected for too long - reset using flow data as a velocity reference.
If flow data is unavailable for too long - declare optical flow use stopped.
Use consistent time periods for all resets

* EKF: Ensure loss of external vision aiding is handled correctly

If data is only source of aiding and has been rejected for too long - reset using data as a position.
Don't reset velocity if there is another source of aiding constraining it.
If data is unavailable for too long, declare external vision use stopped.
Use consistent time periods for all resets.

* EKF: Update parameter documentation

Make the distinction between the no_gps_timeout_max and no_aid_timeout_max parameters clearer

* EKF: make class variable units consistent with documentation

* EKF: Don't reset states when optical flow use commences if using external vision

* EKF: Stop optical flow fusion when on ground if excessive movement is detected.

* EKF: fix terrain estimator vulnerabilities

Reset estimate to sensor value if rejected for 10 seconds
Protect against user motion when on ground.
Fix unnecessary duplication of terrain validity check and separate validity update and reporting.

* EKF: remove unnecessary Info console prints

Optical flow use information can be obtained from the estimator_status.control_mode_flags message

* EKF: fix inaccurate comment

* EKF: remove duplicate calculation from terrain validity accessor function
2018-04-09 18:35:15 +10:00
Daniel Agar
cd12f049fe move geo and geo_lookup from PX4 Firmware to ECL 2018-03-26 21:52:11 -04:00
ChristophTobler
e388e59f32 EKF: use uint64_t cast for XeY to avoid float casting of variables
The default type for XeY is float
2017-11-08 11:40:26 +01:00
Paul Riseborough
063533afae EKF: Add method to enable the IMU bias states to be reset externally 2017-10-26 10:41:39 +11:00
Daniel Agar
99ba1c3745
EKF trivial code style cleanup 2017-08-25 10:09:11 -04:00
Paul Riseborough
929f205a00 EKF: Changes arising from code review 2017-07-04 08:12:15 +10:00
Paul Riseborough
7b5f55303a EKF: Prevent covariance instability in delta velocity bias state estimation 2017-07-03 21:04:07 +10:00
Paul Riseborough
8e0cd1bc39 EKF: Add parameter to set initial and max allowed wind uncertainty
This enables the initial uncertainty to be set based on application and also ensures that the max allowed growth in wind state variance is consistent with the initial uncertainty specified.
2017-06-30 10:31:16 +10:00
Paul Riseborough
394dd95cba EKF: Don't do magnetic field estimation without earth frame measurements
Use horizontal acceleration to check if yaw is observable independent of the magnetometer.
Use rotation about the vertical to check if mag raises are observable.
If neither yaw of mag biases are observable, save the magnetic field variances and switch to magnetic yaw fusion.
Use the last learned declination when using magnetic yaw fusion so that the yaw reference remains consistent.
When yaw or biases become observable, reinstate the saved variances and switch back to 3D mag fusion.
2017-05-17 08:59:01 +02:00
Paul Riseborough
20db74eca8 Revert "EKF: Add parameter control of individual IMU axis delta velocity bias estimation"
This reverts commit 9c31632e2bd8c53843dfc9dc419256607578350e.
2017-05-15 16:38:17 +10:00
Paul Riseborough
9c31632e2b EKF: Add parameter control of individual IMU axis delta velocity bias estimation
Add a bitmask parameter to control bias learning for individual axes. This is achieved by setting the disabled states to zero together with their corresponding covariances.
Minor cleanup of the covariance prediction comments.
Removal of unnecessary variable copy operations.
Replace index operations to initialise covariance to zero with the more efficient memset.
2017-05-11 07:51:37 +02:00
Paul Riseborough
1e393530ed EKF: Fix travis clang build error 2017-04-18 17:06:31 +10:00
Paul Riseborough
9f48c0505b EKF: improve covariance stability when estimating wind 2017-04-16 13:07:12 +02:00
Paul Riseborough
465b145929 EKF: Add multi-rotor drag model for wind estimation 2017-04-16 13:07:12 +02:00
Paul Riseborough
7b996c5972 EKF: Increase measurement error allowance for accelerometer clipping 2017-04-07 16:37:27 +10:00
Paul Riseborough
2f2ac5be43 EKF: Improve protection against severe IMU accel errors
Use vertical velocity and position innovation failure to detect bad accelerometer data caused by clipping or aliasing which can cause large vertical acceleration errors and loss of height estimation. When bad accel data is detected:

1) Inhibit accelerometer bias learning
2) Force fusion of vertical velocity and height data
3) Increase accelerometer process noise
2017-04-07 08:47:13 +10:00
Paul Riseborough
bef7325884 EKF: protect covariance prediction from delta time errors
Allow time step to vary by a factor of 2 to allow for jitter.
2017-04-06 13:34:37 +10:00
Paul Riseborough
fa07536314 EKF: Prevent rounding errors causing bad conditioned covariance matrix
The previous practice of relying on the off-diagonals being zero caused problems with conditioning of the magnetometer fusion on one flight. By storing the variances when the learning inhibit becomes active and ensuring that the rows and columns in the covariance matrix for the inhibited states are always zero, the observed numerical conditioning error has been eliminated for replay of the problem flight log .
2017-04-06 13:34:37 +10:00
Paul Riseborough
ed2938c8a4 EKF: fix bug causing bad accel bias status to latch 2017-03-21 07:57:23 +11:00
Paul Riseborough
9ddfd66d01 EKF: Fix bug in accelerometer bias learning inhibit
This bug caused X and Y delta velocity bias state variance to be reset to the same value as the Z axis when learning was inhibited.
Documentation has also been updated.
2017-03-16 09:34:05 +01:00
Paul Riseborough
588b27bde7 EKF: inhibit accelerometer bias learning if manoeuvre levels are excessive
This prevents bad scale factors and other errors associated with rapid manoeuvres corrupting the accelerometer bias estimates.
2017-03-10 10:14:06 +01:00
Paul Riseborough
324fe3b0c7 EKF: Add accel bias estimation fault to reporting 2017-03-10 10:14:06 +01:00
Paul Riseborough
b51abf4aff EKF: Add console notification for accel bias covariance reset 2017-03-10 10:14:06 +01:00
Paul Riseborough
8511754094 EKF - detect and fix badly conditioned accel bias covariance values. 2017-03-10 10:14:06 +01:00
Paul Riseborough
951c8b77af EKF: Improve wind state reset logic
Enables wind estimation without an airspeed sensor and enables synthetic sideslip to be used with an airspeed sensor for improved wind state estimation.
Wind states and covariances are reset differently depending on whether airspeed is available.
2016-11-05 12:19:01 +01:00
CarlOlsson
8d60da1442 removed old wind initialization 2016-08-11 15:26:21 +02:00
Paul Riseborough
6dff2df28e EKF: Add method to reset wind state covariances
Set variances in polar coordinates and rotate into cartesian frame
2016-08-11 15:26:21 +02:00
Paul Riseborough
99b34f0df4 EKF: Only reset necessary terms when mag fusion covariance reset required
Only the quaternion and mag fusion state covariances are used in the mag fusion calculations.
2016-06-08 11:58:33 +10:00
Paul Riseborough
79228352e9 EKF: Reset mag and wind state variances to 'reasonable' values
If an in-flight reset is required, we do not want these variances going to zero as that will significantly delay recovery
2016-06-08 11:58:33 +10:00
Carl Olsson
0fafc49a49 fixed typos (#147) 2016-05-22 17:40:43 +02:00
Carl Olsson
dbe2513d48 updated logic of calculation of body field variance (#146) 2016-05-22 17:39:25 +02:00
Paul Riseborough
57b2a256f7 EKF: Improve initialisation of quaternion covariances
Convert uncertainty in initial rotate vector into quaternion covariances using symbolic toolbox derived expressions.
Enable setting of initial angle uncertainty via a parameter
2016-05-17 12:47:20 +10:00
Paul Riseborough
88860d0307 EKF: Enable tuning for IMU switch on bias errors 2016-05-17 11:17:24 +10:00