Plane: added Q_TAILSIT_INPUT

this allows the user to control tailsitters either in body frame (like
a plane) or in earth frame (like a multicopter). This is useful for
people wanting to learn to fly prop-hang on 3D planes

ArduPlane/ArduPlane.cpp

@@ -763,7 +763,7 @@ void Plane::update_flight_mode(void)
     case QRTL: {
         // set nav_roll and nav_pitch using sticks
         int16_t roll_limit = MIN(roll_limit_cd, quadplane.aparm.angle_max);
-        nav_roll_cd  = channel_roll->norm_input() * roll_limit;
+        nav_roll_cd  = (channel_roll->get_control_in() / 4500.0) * roll_limit;
         nav_roll_cd = constrain_int32(nav_roll_cd, -roll_limit, roll_limit);
         float pitch_input = channel_pitch->norm_input();
         if (pitch_input > 0) {

ArduPlane/quadplane.cpp

@@ -334,7 +334,7 @@ const AP_Param::GroupInfo QuadPlane::var_info[] = {
     // @Values: 0:Continuous,1:Binary
     AP_GROUPINFO("TILT_TYPE", 47, QuadPlane, tilt.tilt_type, TILT_TYPE_CONTINUOUS),
 
-    // @Param: Q_TAILSIT_ANGLE
+    // @Param: TAILSIT_ANGLE
     // @DisplayName: Tailsitter transition angle
     // @Description: This is the angle at which tailsitter aircraft will change from VTOL control to fixed wing control.
     // @Range: 5 80
@@ -349,6 +349,12 @@ const AP_Param::GroupInfo QuadPlane::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("TILT_RATE_DN", 49, QuadPlane, tilt.max_rate_down_dps, 0),
         
+    // @Param: TAILSIT_INPUT
+    // @DisplayName: Tailsitter input type
+    // @Description: This controls whether stick input when hovering as a tailsitter follows the conventions for fixed wing hovering or multicopter hovering. When multicopter input is selected the roll stick will roll the aircraft in earth frame and yaw stick will yaw in earth frame. When using fixed wing input the roll and yaw sticks will control the aircraft in body frame.
+    // @Values: 0:MultiCopterInput,1:FixedWingInput
+    AP_GROUPINFO("TAILSIT_INPUT", 50, QuadPlane, tailsitter.input_type, TAILSITTER_INPUT_MULTICOPTER),
+
     AP_GROUPEND
 };
 
@@ -851,7 +857,7 @@ float QuadPlane::get_pilot_input_yaw_rate_cds(void)
     }
 
     // add in rudder input
-    return plane.channel_rudder->norm_input() * 100 * yaw_rate_max;
+    return plane.channel_rudder->get_control_in() * yaw_rate_max / 45;
 }
 
 /*
@@ -1191,6 +1197,7 @@ void QuadPlane::update(void)
             transition_state = TRANSITION_DONE;
         } else if (is_tailsitter()) {
             transition_state = TRANSITION_ANGLE_WAIT;
+            transition_start_ms = AP_HAL::millis();
         } else {
             transition_state = TRANSITION_AIRSPEED_WAIT;
         }

ArduPlane/quadplane.h

@@ -84,6 +84,9 @@ public:
     // create outputs for tailsitters
     void tailsitter_output(void);
 
+    // handle different tailsitter input types
+    void tailsitter_check_input(void);
+    
     // check if we have completed transition
     bool tailsitter_transition_complete(void);
     
@@ -328,9 +331,15 @@ private:
         bool motors_active:1;
     } tilt;
 
+    enum tailsitter_input {
+        TAILSITTER_INPUT_MULTICOPTER = 0,
+        TAILSITTER_INPUT_PLANE       = 1,
+    };
+    
     // tailsitter control variables
     struct {
         AP_Int8 transition_angle;
+        AP_Int8 input_type;
     } tailsitter;
 
     // the attitude view of the VTOL attitude controller

ArduPlane/radio.cpp

@@ -240,6 +240,9 @@ void Plane::read_radio()
         rudder_input = 0;
     }
 
+    // potentially swap inputs for tailsitters
+    quadplane.tailsitter_check_input();
+    
     // check for transmitter tuning changes
     tuning.check_input(control_mode);
 }

ArduPlane/tailsitter.cpp

@@ -56,10 +56,27 @@ bool QuadPlane::tailsitter_transition_complete(void)
         // transition immediately
         return true;
     }
-    if (ahrs_view->pitch_sensor < -tailsitter.transition_angle*100 ||
-        ahrs_view->roll_sensor < -tailsitter.transition_angle*100) {
+    if (labs(ahrs_view->pitch_sensor) > tailsitter.transition_angle*100 ||
+        labs(ahrs_view->roll_sensor) > tailsitter.transition_angle*100 ||
+        AP_HAL::millis() - transition_start_ms > 2000) {
         return true;
     }
     // still waiting
     return false;
 }
+
+// handle different tailsitter input types
+void QuadPlane::tailsitter_check_input(void)
+{
+    if (tailsitter_active() &&
+        tailsitter.input_type == TAILSITTER_INPUT_PLANE) {
+        // the user has asked for body frame controls when tailsitter
+        // is active. We switch around the control_in value for the
+        // channels to do this, as that ensures the value is
+        // consistent throughout the code
+        int16_t roll_in = plane.channel_roll->get_control_in();
+        int16_t yaw_in = plane.channel_rudder->get_control_in();
+        plane.channel_roll->set_control_in(yaw_in);
+        plane.channel_rudder->set_control_in(-roll_in);
+    }
+}