Plane: Fix FBWB/CRUISE missing zero crossing of elevator input

ArduPilot · Apr 15, 2024 · 41474f8 · 41474f8
1 parent b95bd8f
commit 41474f8
Showing 1 changed file with 7 additions and 6 deletions.
diff --git a/ArduPlane/navigation.cpp b/ArduPlane/navigation.cpp
@@ -394,15 +394,16 @@ void Plane::update_fbwb_speed_height(void)
             elevator_input = -elevator_input;
         }
 
-        int32_t alt_change_cm = g.flybywire_climb_rate * elevator_input * dt * 100;
-        change_target_altitude(alt_change_cm);
-
-        if (is_zero(elevator_input) && !is_zero(target_altitude.last_elevator_input)) {
-            // the user has just released the elevator, lock in
-            // the current altitude
+        bool input_stop_climb = !is_positive(elevator_input) && is_positive(target_altitude.last_elevator_input);
+        bool input_stop_descent = !is_negative(elevator_input) && is_negative(target_altitude.last_elevator_input);
+        if (input_stop_climb || input_stop_descent) {
+            // user elevator input reached or passed zero, lock in the current altitude
             set_target_altitude_current();
         }
 
+        int32_t alt_change_cm = g.flybywire_climb_rate * elevator_input * dt * 100;
+        change_target_altitude(alt_change_cm);
+
 #if HAL_SOARING_ENABLED
         if (g2.soaring_controller.is_active()) {
             if (g2.soaring_controller.get_throttle_suppressed()) {