Plane: suppress rate D terms in ground mode

this prevents a common oscillation issue on the ground

ArduPlane/Attitude.cpp

@@ -128,7 +128,8 @@ void Plane::stabilize_roll(float speed_scaler)
         */
         rollController.decay_I();
     } else {
-        roll_out = rollController.get_servo_out(nav_roll_cd - ahrs.roll_sensor, speed_scaler, disable_integrator);
+        roll_out = rollController.get_servo_out(nav_roll_cd - ahrs.roll_sensor, speed_scaler, disable_integrator,
+                                                ground_mode && !(plane.g2.flight_options & FlightOptions::DISABLE_GROUND_PID_SUPPRESSION));
     }
     SRV_Channels::set_output_scaled(SRV_Channel::k_aileron, roll_out);
 }
@@ -172,7 +173,8 @@ void Plane::stabilize_pitch(float speed_scaler)
             demanded_pitch = landing.get_pitch_cd();
         }
 
-        pitch_out = pitchController.get_servo_out(demanded_pitch - ahrs.pitch_sensor, speed_scaler, disable_integrator);
+        pitch_out = pitchController.get_servo_out(demanded_pitch - ahrs.pitch_sensor, speed_scaler, disable_integrator,
+                                                  ground_mode && !(plane.g2.flight_options & FlightOptions::DISABLE_GROUND_PID_SUPPRESSION));
     }
     SRV_Channels::set_output_scaled(SRV_Channel::k_elevator, pitch_out);
 }
@@ -372,7 +374,7 @@ void Plane::stabilize_acro(float speed_scaler)
         // 'stabilze' to true, which disables the roll integrator
         SRV_Channels::set_output_scaled(SRV_Channel::k_aileron, rollController.get_servo_out(roll_error_cd,
                                                                                              speed_scaler,
-                                                                                             true));
+                                                                                             true, false));
     } else {
         /*
           aileron stick is non-zero, use pure rate control until the
@@ -396,7 +398,7 @@ void Plane::stabilize_acro(float speed_scaler)
         nav_pitch_cd = acro_state.locked_pitch_cd;
         SRV_Channels::set_output_scaled(SRV_Channel::k_elevator, pitchController.get_servo_out(nav_pitch_cd - ahrs.pitch_sensor,
                                                                                                speed_scaler,
-                                                                                               false));
+                                                                                               false, false));
     } else {
         /*
           user has non-zero pitch input, use a pure rate controller

ArduPlane/Parameters.cpp

@@ -1105,7 +1105,7 @@ const AP_Param::GroupInfo ParametersG2::var_info[] = {
     // @Param: FLIGHT_OPTIONS
     // @DisplayName: Flight mode options
     // @Description: Flight mode specific options
-    // @Bitmask: 0:Rudder mixing in direct flight modes only (Manual / Stabilize / Acro),1:Use centered throttle in Cruise or FBWB to indicate trim airspeed, 2:Disable attitude check for takeoff arming, 3:Force target airspeed to trim airspeed in Cruise or FBWB, 4: Climb to ALT_HOLD_RTL before turning for RTL, 5: Enable yaw damper in acro mode, 6: Surpress speed scaling during auto takeoffs to be 1 or less to prevent oscillations without airpseed sensor, 7:EnableDefaultAirspeed for takeoff
+    // @Bitmask: 0:Rudder mixing in direct flight modes only (Manual / Stabilize / Acro),1:Use centered throttle in Cruise or FBWB to indicate trim airspeed, 2:Disable attitude check for takeoff arming, 3:Force target airspeed to trim airspeed in Cruise or FBWB, 4: Climb to ALT_HOLD_RTL before turning for RTL, 5: Enable yaw damper in acro mode, 6: Surpress speed scaling during auto takeoffs to be 1 or less to prevent oscillations without airpseed sensor, 7:EnableDefaultAirspeed for takeoff, 11:Disable suppression of fixed wing rate gains in ground mode
     // @User: Advanced
     AP_GROUPINFO("FLIGHT_OPTIONS", 13, ParametersG2, flight_options, 0),
 

ArduPlane/Plane.h

@@ -597,6 +597,9 @@ private:
     // time since started flying in any mode in milliseconds
     uint32_t started_flying_ms;
 
+    // ground mode is true when disarmed and not flying
+    bool ground_mode;
+
     // Navigation control variables
     // The instantaneous desired bank angle.  Hundredths of a degree
     int32_t nav_roll_cd;
@@ -680,7 +683,6 @@ private:
         uint32_t time_max_ms;
     } loiter;
 
-
     // Conditional command
     // A value used in condition commands (eg delay, change alt, etc.)
     // For example in a change altitude command, it is the altitude to change to.

ArduPlane/defines.h

@@ -161,6 +161,7 @@ enum FlightOptions {
     ACRO_YAW_DAMPER = (1 << 5),
     SURPRESS_TKOFF_SCALING = (1<<6),
     ENABLE_DEFAULT_AIRSPEED = (1<<7),
+    DISABLE_GROUND_PID_SUPPRESSION = (1<<11),
 };
 
 enum CrowFlapOptions {

ArduPlane/is_flying.cpp

@@ -172,6 +172,9 @@ void Plane::update_is_flying_5Hz(void)
 
     // tell AHRS flying state
     set_likely_flying(new_is_flying);
+
+    // conservative ground mode value for rate D suppression
+    ground_mode = !is_flying() && !hal.util->get_soft_armed();
 }
 
 /*