This code cuts D by a specified percentage durning normal flight.
It lets D smoothly rise up to normal during rapid gyro moves like flips and rolls, and increase during prop wash events.
D should now be tuned to values the 'normal' 30-45 range.
If D is 40, a dterm_cut_percentage of 65 will cut D to 14 in normal flight, but the quad will still get full 40 of D to control bounce-back after flips and about 25 of D during strong prop wash.
The dterm_cut_percentage can be adjusted via the OSD, from the D filtering page.
Adding d_cut results in cooler motors, lower amounts of noise in motor traces and faster reactions to quick stick inputs.
Too high a dterm_cut_percentage may bring out P oscillation from lack of D. Values of 70% are generally OK.
Input is gyro differential (delta). Frequencies above 40hz (above propwash) are attenuated with a configurable (dterm_cut_range_hz) biquad filter. Lower values for range can be used if the quad is very noisy or gets low frequency D resonant oscillation. Up to 50 or 60hz may suit clean quads where prop wash control is the main priority. Too high a range value results in D being boosted from noise in normal flight.
The boost signal is 'integrated, smoothed and delayed' with a 7hz PT1 'dterm_cut_lowpass_hz' filter. The default of 7Hz gives about the right amount of smoothing and delay. Higher numbers cause the boost to come on faster, with less delay. Lower values delay the boost effect and cause it to last longer.
The dterm_cut_gain amount controls the strength of the boost effect by amplifying the input to the boosting effect. If the quad is flow gently, a higher gain value may be needed to gain full boost.
Logging with set debug_mode = D_CUT allows recording of realtime D values on roll and pitch into debug 2 and 3. The reatime D value should reach its set maximum during rapid turns, ideally at about the time D itself peaks. If it fails to reach the maximum, gain should be increased.
The D_Cut feature is not enabled on LUXV2RACE, OMNIBUS, SPRACINGF3NEO because there isn't enough flash space.
Adds a new `tpa_mode` parameter that accepts `PD` (default) and `D`. Allows the user to configer to affect P/D as it always has, or switch to D-only mode.
Note: the `tpa_mode` parameter was added to the PID Profile instead of rate profiles with the other TPA parameters. This can be discussed, but I didn't think it made sense to have this be part of rate profiles as it affects PID tuning (the same argument could be made for the other TPA parameters).
Code is wrapped in `USE_TPA_MODE` so it can be disabled if needed.
If the quad is in an extreme orientation (like upside down) the transition to self-level modes can cause enough motion to trigger crash recovery. Added a 1 second delay during which crash recovery detection is blocked immediately after entering a self-level mode.
This also addresses an issue with GPS Rescue as when it activates it enables self-level. If in the above scenario this triggered a crash recovery detection then GPS Rescue would interpret this as a crash and immediately disarm.
Adds a race start assistance system that allows the pilot to pitch forward and then release the sticks with the quad holding position for the race start.
Refactor iterm_relax to iterm_relax_axis
Isolate pidLevel test
Isolate pidHorizon tests
remove if UNIT_TEST
revert to iterm_relax from iterm_relax_axis
Refactor PID code Iterm Relax and Absolute control
Move defines for unittest to Makefile
Fix unittest isAirmodeActivated()
Absolute control unittests + optimizations
Fix dead code absolute control // unittests
Further optimizations to absolute control switch logic
The dterm notch is disabled and dterm_notch_hz is already 0 by default. When the Configurator saves changes from the PID Tuning tab and the notch is disabled it sets both dterm_notch_hz and dterm_notch_cutoff to 0. Since the default was left at 160, this makes dterm_notch_cutoff appear in diff outputs. Ultimately it's just cosmetic since the dterm notch is disabled if either value is zero. But there's no reason for the dterm_notch_cutoff to remain set to the legacy 160 value.
Iterm Relax was inserted before crash recovery and this was causing the recovery to be ineffective or fail completely. The problem was that the subsequent iterm calculation was not using the calculated recovery error and instead was using the setpoint error. As such I ended up accumulating and opposing P based on recovery error. This prevented the efforts of crash recovery to level the quad and since it couldn't reach the level state crash recovery wouldn't shut off. This resulted in the pilot only having control over yaw and throttle while crash recovery was still ineffectually trying to control roll/pitch.
The fix is to move crash recovery handling ahead of the iterm relax calculations and make sure that iterm relax uses the error calculated from crash recovery if active. This also allows crash recovery to reset the iterm accumulation as originally designed.
