* Dual-stage Gyro Filtering: PT1, FKF, and Biquad RC+FIR2
* Builds on the previous work of apocolipse.
* Fixes 'stage2'/'stage1' mis-naming to reflect where it is applied in the loop.
That is, the older Biquad, PT1, Denoise (FIR) filters are 'stage2' - applied
after dynamic and static notches (if enabled), and the controversial PT1,
'fast Kalman' filter, and Biquad RC+FIR2 filters, are 'stage1'. e.g. before
dynamic notch.
* FKF bruteforce Kalman gain removed. Calculate from half of PT1 RC constant,
automatically taking loop-time into account.
* New union type definition for stage1 filtering.
* New gyro sensor members for stage1 filter application function and states for
all three supported filter types
* New enum types for stage1 v. stage2. dterm lowpass type references 'stage2'.
* updates to CMS/MSP/FC to allow compilation (untested, probably breaks
MSP, Lua, and ~comms with BFC~).
* Refactors FKF initialization, update and associated structures to be faster by
not continuously calculating 'k'. Filter gain is calculated once during
initialization from RC constant as per PT1 and Biquad RC+FIR2. It was
discovered this converges to static value within 100 samples at 32kHz, so can
be removed. Remove related interface (CLI) settings.
* update dterm_lowpass_type to use new 'TABLE_LOWPASS2_TYPE' (biquad/pt1/FIR)
* Stage 1 defaults to PT1, 763Hz (equivalent to Q400 / R88 from quasi-kalman
filter) - suitable for 32kHz sampling modes. Can be switched to Biquad
RC+FIR2, and FKF.
* Update `#if defined(USE_GYRO_SLEW_LIMITER) to `#ifdef`.
* Includes optional Lagged Moving Average 'smoothing' pipeline step, applied (in
code) after the output of stage1.
* (diehertz): Removed redundant pointers from gyro filtering
* blackbox: fix indentation
* cms IMU menu: fix indentation
* filters: remove USE_GYRO_FIR_FILTER_DENOISE in filter type enum
* gyro sensors: go back to `if defined()` form. for slew limiter
* gyro sensors: increment parameter group version
* due to non-appending changes, the version must be bumped.
* Second PT1 on DTerm
This PR replaces the default biquad filter with a second PT1 set to
200Hz.
Basically allows the user to enable a second, set point configurable,
PT1 type first order low-pass filter on DTerm.
This is useful because most noise in most logs arises from D, not P.
The default is set to on, at twice the normal Dterm setpoint. This
provides greater Dterm cut than a single PT1, and twice the steepness
of cut above the second setpoint. Modelling shows significant
reductions in higher frequency Dterm noise with only minor additional
delay.
The improvement in noise performance will be less than for biquad, but
the delay is considerably less.
If with the default settings the overall noise improves a lot, it may
be possible bring D both filtering set points to higher numbers (e.g.
140/280), or alternatively remove other filters such as the notch
filters, while maintaining an adequate level of control over noise.
* Update names, old defaults, fix whitespace
Defaults restored to biquad with second PT1 off. ‘lpf’ retained as
abbreviation for values, otherwise generally remove ‘Filter’ where
redundant, replace ‘FilterLpf’ with ‘Lowpass’, etc, thanks Fujin and
DieHertz
* Remove underscore in lowpass_2, add hz to setpoint for lowpass
Thanks DieHertz
* completed replacing lpf with lowpass, added _hz to all lowpass set points in profile
Thanks DieHertz
* fix whitespace
fixed whitespace in settings.c
* whitespace attempt #57
* change lpf to lowpass where appropriate elsewhere
Note did not change OSD abbreviations, they are still LPF, and did not
change gyro_lpf anywhere.
* second attempt at a simple PT1 implementation
Basically copied from the DtermNotch implementation
* Second PT1 on DTerm
This PR replaces the default biquad filter with a second PT1 set to
200Hz.
Basically allows the user to enable a second, set point configurable,
PT1 type first order low-pass filter on DTerm.
This is useful because most noise in most logs arises from D, not P.
The default is set to on, at twice the normal Dterm setpoint. This
provides greater Dterm cut than a single PT1, and twice the steepness
of cut above the second setpoint. Modelling shows significant
reductions in higher frequency Dterm noise with only minor additional
delay.
The improvement in noise performance will be less than for biquad, but
the delay is considerably less.
If with the default settings the overall noise improves a lot, it may
be possible bring D both filtering set points to higher numbers (e.g.
140/280), or alternatively remove other filters such as the notch
filters, while maintaining an adequate level of control over noise.
* Rebase
* Remove underscore in lowpass_2, add hz to setpoint for lowpass
Thanks DieHertz
* completed replacing lpf with lowpass, added _hz to all lowpass set points in profile
Thanks DieHertz
* fix whitespace
fixed whitespace in settings.c
* whitespace attempt #57
* change lpf to lowpass where appropriate elsewhere
Note did not change OSD abbreviations, they are still LPF, and did not
change gyro_lpf anywhere.
* second attempt at a simple PT1 implementation
Basically copied from the DtermNotch implementation
* Whitespace fix - thanks, Ledvinap
* Fix PG issue
by moving added dterm_lowpass2_hz to bottom of struct
* Got rid of redundant indirection
* Fixed indentantion shifts
the flight controller code.
Likely the dependencies can be further improved. This is a
minimal-impact solution while there are a lot of other Betaflight PR's
still pending.
- Created “OTHER PP” menu entry in PROFILE for “Other Per Profile”
items.
- Moved dterm set point weight and set point relax to OTHER PP.
- Added missing angle strength, horizon strength and transition.
This will make changed values to take effect immediately in the profile
related menus.
It’s only used for profile selection now; will be used more through out
the menu contents.
