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Second dterm pt1 (#5458)

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* 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
This commit is contained in:
ctzsnooze 2018-03-20 23:40:23 +11:00 • committed by Michael Keller
parent d2bc4e5af5
commit ab231b7c84
6 changed files with 70 additions and 62 deletions
Download patch file Download diff file Expand all files Collapse all files

8
src/main/interface/msp.c
View file

@ -1186,8 +1186,8 @@ static bool mspProcessOutCommand(uint8_t cmdMSP, sbuf_t *dst)
case MSP_FILTER_CONFIG :
sbufWriteU8(dst, gyroConfig()->gyro_soft_lpf_hz);
sbufWriteU16(dst, currentPidProfile->dterm_lpf_hz);
sbufWriteU16(dst, currentPidProfile->yaw_lpf_hz);
sbufWriteU16(dst, currentPidProfile->dterm_lowpass_hz);
sbufWriteU16(dst, currentPidProfile->yaw_lowpass_hz);
sbufWriteU16(dst, gyroConfig()->gyro_soft_notch_hz_1);
sbufWriteU16(dst, gyroConfig()->gyro_soft_notch_cutoff_1);
sbufWriteU16(dst, currentPidProfile->dterm_notch_hz);
@ -1658,8 +1658,8 @@ static mspResult_e mspProcessInCommand(uint8_t cmdMSP, sbuf_t *src)
case MSP_SET_FILTER_CONFIG:
gyroConfigMutable()->gyro_soft_lpf_hz = sbufReadU8(src);
currentPidProfile->dterm_lpf_hz = sbufReadU16(src);
currentPidProfile->yaw_lpf_hz = sbufReadU16(src);
currentPidProfile->dterm_lowpass_hz = sbufReadU16(src);
currentPidProfile->yaw_lowpass_hz = sbufReadU16(src);
if (sbufBytesRemaining(src) >= 8) {
gyroConfigMutable()->gyro_soft_notch_hz_1 = sbufReadU16(src);
gyroConfigMutable()->gyro_soft_notch_cutoff_1 = sbufReadU16(src);