first build

src/main/flight/failsafe.c

@@ -346,6 +346,11 @@ static failsafeProcedure_e failsafeChooseFailsafeProcedure(void)
         }
     }
 
+    // Inhibit Failsafe if emergency landing triggered manually
+    if (posControl.flags.manualEmergLandActive) {
+        return FAILSAFE_PROCEDURE_NONE;
+    }
+
     // Craft is closer than minimum failsafe procedure distance (if set to non-zero)
     // GPS must also be working, and home position set
     if (failsafeConfig()->failsafe_min_distance > 0 &&

src/main/navigation/navigation.c

@@ -1788,9 +1788,13 @@ static navigationFSMEvent_t navOnEnteringState_NAV_STATE_WAYPOINT_FINISHED(navig
 
 static navigationFSMEvent_t navOnEnteringState_NAV_STATE_EMERGENCY_LANDING_INITIALIZE(navigationFSMState_t previousState)
 {
-    // TODO:
     UNUSED(previousState);
 
+    if ((posControl.flags.estPosStatus >= EST_USABLE)) {
+        resetPositionController();
+        setDesiredPosition(&navGetCurrentActualPositionAndVelocity()->pos, 0, NAV_POS_UPDATE_XY);
+    }
+
     // Emergency landing MAY use common altitude controller if vertical position is valid - initialize it
     // Make sure terrain following is not enabled
     resetAltitudeController(false);
@@ -3437,7 +3441,10 @@ bool isNavHoldPositionActive(void)
         return isLastMissionWaypoint() || NAV_Status.state == MW_NAV_STATE_HOLD_TIMED;
     }
     // RTH mode (spiral climb and Home positions but excluding RTH Trackback point positions) and POSHOLD mode
-    return (FLIGHT_MODE(NAV_RTH_MODE) && !posControl.flags.rthTrackbackActive) || FLIGHT_MODE(NAV_POSHOLD_MODE);
+    // Also hold position during emergency landing if position valid
+    return (FLIGHT_MODE(NAV_RTH_MODE) && !posControl.flags.rthTrackbackActive) ||
+            FLIGHT_MODE(NAV_POSHOLD_MODE) ||
+            navigationIsExecutingAnEmergencyLanding();
 }
 
 float getActiveWaypointSpeed(void)
@@ -3612,6 +3619,35 @@ static bool isWaypointMissionValid(void)
     return posControl.waypointListValid && (posControl.waypointCount > 0);
 }
 
+static bool isManualEmergencyLandingActivated(void)
+{
+    // Emergency landing initiated manually by toggling Poshold 4 times within 2 seconds
+    static timeMs_t timeout = 0;
+    static int8_t counter = 0;
+    static bool toggle;
+    timeMs_t currentTimeMs = millis();
+
+    if (timeout && currentTimeMs > timeout) {
+        timeout += 500;
+        counter--;
+        if (counter <= 0) {
+            timeout = 0;
+        }
+    }
+    if (IS_RC_MODE_ACTIVE(BOXNAVPOSHOLD)) {
+        if (!timeout) {
+            timeout = currentTimeMs + 2000;
+        }
+        counter += toggle;
+        toggle = false;
+    } else {
+        toggle = true;
+    }
+    constrain(counter, 0, 4);
+
+    return counter >= 4;
+}
+
 static navigationFSMEvent_t selectNavEventFromBoxModeInput(void)
 {
     static bool canActivateWaypoint = false;
@@ -3636,8 +3672,16 @@ static navigationFSMEvent_t selectNavEventFromBoxModeInput(void)
             posControl.flags.rthTrackbackActive = isExecutingRTH;
         }
 
-        /* Emergency landing triggered by failsafe when Failsafe procedure set to Landing */
-        if (posControl.flags.forcedEmergLandingActivated) {
+        // Emergency landing initiated manually. Cancelled when throttle high.
+        if (isManualEmergencyLandingActivated()) {
+            posControl.flags.manualEmergLandActive = true;
+        } else if (posControl.flags.manualEmergLandActive && checkStickPosition(THR_HI)) {
+            posControl.flags.manualEmergLandActive = false;
+            return NAV_FSM_EVENT_SWITCH_TO_IDLE;
+        }
+
+        /* Emergency landing triggered by failsafe Landing or manually initiated */
+        if (posControl.flags.forcedEmergLandingActivated || posControl.flags.manualEmergLandActive) {
             return NAV_FSM_EVENT_SWITCH_TO_EMERGENCY_LANDING;
         }
 

src/main/navigation/navigation_fixedwing.c

@@ -743,8 +743,6 @@ bool isFixedWingLandingDetected(void)
  *-----------------------------------------------------------*/
 void applyFixedWingEmergencyLandingController(timeUs_t currentTimeUs)
 {
-    rcCommand[ROLL] = pidAngleToRcCommand(failsafeConfig()->failsafe_fw_roll_angle, pidProfile()->max_angle_inclination[FD_ROLL]);
-    rcCommand[YAW] = -pidRateToRcCommand(failsafeConfig()->failsafe_fw_yaw_rate, currentControlRateProfile->stabilized.rates[FD_YAW]);
     rcCommand[THROTTLE] = currentBatteryProfile->failsafe_throttle;
 
     if (posControl.flags.estAltStatus >= EST_USABLE) {
@@ -756,6 +754,19 @@ void applyFixedWingEmergencyLandingController(timeUs_t currentTimeUs)
     } else {
         rcCommand[PITCH] = pidAngleToRcCommand(failsafeConfig()->failsafe_fw_pitch_angle, pidProfile()->max_angle_inclination[FD_PITCH]);
     }
+
+    // Hold position of possible
+    if (posControl.flags.estPosStatus >= EST_USABLE) {
+        applyFixedWingPositionController(currentTimeUs);
+        if (isRollAdjustmentValid) {
+            // ROLL >0 right, <0 left
+            int16_t rollCorrection = constrain(posControl.rcAdjustment[ROLL], -DEGREES_TO_DECIDEGREES(navConfig()->fw.max_bank_angle), DEGREES_TO_DECIDEGREES(navConfig()->fw.max_bank_angle));
+            rcCommand[ROLL] = pidAngleToRcCommand(rollCorrection, pidProfile()->max_angle_inclination[FD_ROLL]);
+        }
+    } else {
+        rcCommand[ROLL] = pidAngleToRcCommand(failsafeConfig()->failsafe_fw_roll_angle, pidProfile()->max_angle_inclination[FD_ROLL]);
+        rcCommand[YAW] = -pidRateToRcCommand(failsafeConfig()->failsafe_fw_yaw_rate, currentControlRateProfile->stabilized.rates[FD_YAW]);
+    }
 }
 
 /*-----------------------------------------------------------

src/main/navigation/navigation_multicopter.c

@@ -852,6 +852,14 @@ static void applyMulticopterEmergencyLandingController(timeUs_t currentTimeUs)
 
     // Update throttle controller
     rcCommand[THROTTLE] = posControl.rcAdjustment[THROTTLE];
+
+    // Hold position if possible
+    if ((posControl.flags.estPosStatus >= EST_USABLE)) {
+        applyMulticopterPositionController(currentTimeUs);
+    } else {
+        rcCommand[ROLL] = 0;
+        rcCommand[PITCH] = 0;
+    }
 }
 
 /*-----------------------------------------------------------

src/main/navigation/navigation_private.h

@@ -104,14 +104,13 @@ typedef struct navigationFlags_s {
     bool forcedRTHActivated;
     bool forcedEmergLandingActivated;
 
-    bool wpMissionPlannerActive;            // Activation status of WP mission planner
-
     /* Landing detector */
     bool resetLandingDetector;
 
+    bool wpMissionPlannerActive;            // Activation status of WP mission planner
     bool rthTrackbackActive;                // Activation status of RTH trackback
-
     bool wpTurnSmoothingActive;             // Activation status WP turn smoothing
+    bool manualEmergLandActive;             // Activation status of manual emergency landing
 } navigationFlags_t;
 
 typedef struct {