Plane: Logs NaN on ATT.DesPitch when not used

ArduPlane/Log.cpp

@@ -10,6 +10,9 @@ void Plane::Log_Write_Attitude(void)
         demanded_pitch_cd * 0.01f,
         0 //Plane does not have the concept of navyaw. This is a placeholder.
     };
+    if (!flag_demanded_pitch_used) {
+        targets.y = NAN;
+    }
 
 #if HAL_QUADPLANE_ENABLED
     if (quadplane.show_vtol_view()) {

ArduPlane/Plane.h

@@ -671,8 +671,8 @@ class Plane : public AP_Vehicle {
     // The instantaneous navigator-commanded pitch angle. Hundredths of a degree
     int32_t nav_pitch_cd;
 
-    // The instantaneous desired pitch angle. Hundredths of a degree.
-    int32_t demanded_pitch_cd;
+    int32_t demanded_pitch_cd; // The instantaneous desired pitch angle. Hundredths of a degree.
+    bool flag_demanded_pitch_used; // For logging purposes, declares if active pitch control is happening.
 
     // the aerodynamic load factor. This is calculated from the demanded
     // roll before the roll is clipped, using 1/sqrt(cos(nav_roll))

ArduPlane/mode.cpp

@@ -71,6 +71,9 @@ bool Mode::enter()
     plane.auto_state.highest_airspeed = 0;
     plane.auto_state.initial_pitch_cd = ahrs.pitch_sensor;
 
+    // Declare that pitch is actively controlled, unless children ovewrite.
+    plane.flag_demanded_pitch_used = true;
+
     // disable taildrag takeoff on mode change
     plane.auto_state.fbwa_tdrag_takeoff_mode = false;
 

ArduPlane/mode.h

@@ -439,6 +439,8 @@ class ModeManual : public Mode
     const char *name4() const override { return "MANU"; }
 
     // methods that affect movement of the vehicle in this mode
+    bool _enter() override;
+
     void update() override;
 
     void run() override;

ArduPlane/mode_acro.cpp

@@ -5,6 +5,7 @@ bool ModeAcro::_enter()
 {
     acro_state.locked_roll = false;
     acro_state.locked_pitch = false;
+    plane.flag_demanded_pitch_used = false; // ACRO does not control pitch through demanded_pitch_cd.
     IGNORE_RETURN(ahrs.get_quaternion(acro_state.q));
     return true;
 }

ArduPlane/mode_manual.cpp

@@ -1,6 +1,12 @@
 #include "mode.h"
 #include "Plane.h"
 
+bool ModeManual::_enter()
+{
+    plane.flag_demanded_pitch_used = false;
+    return true;
+}
+
 void ModeManual::update()
 {
     SRV_Channels::set_output_scaled(SRV_Channel::k_aileron, plane.roll_in_expo(false));

ArduPlane/mode_training.cpp

@@ -54,8 +54,10 @@ void ModeTraining::run()
 
     if (plane.training_manual_pitch) {
         SRV_Channels::set_output_scaled(SRV_Channel::k_elevator, pexpo);
+        plane.flag_demanded_pitch_used = false;
     } else {
         plane.stabilize_pitch();
+        plane.flag_demanded_pitch_used = true;
         if ((plane.nav_pitch_cd > 0 && pexpo < SRV_Channels::get_output_scaled(SRV_Channel::k_elevator)) ||
             (plane.nav_pitch_cd < 0 && pexpo > SRV_Channels::get_output_scaled(SRV_Channel::k_elevator))) {
             // allow user to get back to level