Plane: added Q_TILT_RATE_UP and Q_TILT_RATE_DN as separate parameters

allow control of tilt rate separately for UP and DOWN

always allow at least 90 degrees/second for switching to MANUAL

ArduPlane/quadplane.cpp

@@ -270,14 +270,14 @@ const AP_Param::GroupInfo QuadPlane::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("TILT_MASK", 37, QuadPlane, tilt.tilt_mask, 0),
 
-    // @Param: TILT_RATE
+    // @Param: TILT_RATE_UP
-    // @DisplayName: Tiltrotor tilt rate
+    // @DisplayName: Tiltrotor upwards tilt rate
-    // @Description: This is the maximum speed at which the motor angle will change for a tiltrotor
+    // @Description: This is the maximum speed at which the motor angle will change for a tiltrotor when moving from forward flight to hover
     // @Units: degrees/second
     // @Increment: 1
     // @Range: 10 300
     // @User: Standard
-    AP_GROUPINFO("TILT_RATE", 38, QuadPlane, tilt.max_rate_dps, 40),
+    AP_GROUPINFO("TILT_RATE_UP", 38, QuadPlane, tilt.max_rate_up_dps, 40),
 
     // @Param: TILT_MAX
     // @DisplayName: Tiltrotor maximum VTOL angle
@@ -339,7 +339,16 @@ const AP_Param::GroupInfo QuadPlane::var_info[] = {
     // @Description: This is the angle at which tailsitter aircraft will change from VTOL control to fixed wing control.
     // @Range: 5 80
     AP_GROUPINFO("TAILSIT_ANGLE", 48, QuadPlane, tailsitter.transition_angle, 30),
-    
+
+    // @Param: TILT_RATE_DN
+    // @DisplayName: Tiltrotor downwards tilt rate
+    // @Description: This is the maximum speed at which the motor angle will change for a tiltrotor when moving from hover to forward flight. When this is zero the Q_TILT_RATE_UP value is used.
+    // @Units: degrees/second
+    // @Increment: 1
+    // @Range: 10 300
+    // @User: Standard
+    AP_GROUPINFO("TILT_RATE_DN", 49, QuadPlane, tilt.max_rate_down_dps, 0),
+        
     AP_GROUPEND
 };
 

ArduPlane/quadplane.h

@@ -319,7 +319,8 @@ private:
     // tiltrotor control variables
     struct {
         AP_Int16 tilt_mask;
-        AP_Int16 max_rate_dps;
+        AP_Int16 max_rate_up_dps;
+        AP_Int16 max_rate_down_dps;
         AP_Int8  max_angle_deg;
         AP_Int8  tilt_type;
         float current_tilt;
@@ -345,6 +346,7 @@ private:
     void tiltrotor_binary_update(void);
     void tilt_compensate(float *thrust, uint8_t num_motors);
     bool tiltrotor_fully_fwd(void);
+    float tilt_max_change(bool up);
 
     void afs_terminate(void);
     bool guided_mode_enabled(void);

ArduPlane/tiltrotor.cpp

@@ -6,12 +6,30 @@
  */
 
 
+/*
+  calculate maximum tilt change as a proportion from 0 to 1 of tilt
+ */
+float QuadPlane::tilt_max_change(bool up)
+{
+    float rate;
+    if (up || tilt.max_rate_down_dps <= 0) {
+        rate = tilt.max_rate_up_dps;
+    } else {
+        rate = tilt.max_rate_down_dps;
+    }
+    if (plane.control_mode == MANUAL && tilt.tilt_type != TILT_TYPE_BINARY) {
+        // allow a minimum of 90 DPS in manual, to give fast control
+        rate = MAX(rate, 90);
+    }
+    return rate * plane.G_Dt / 90.0f;
+}
+
 /*
   output a slew limited tiltrotor angle. tilt is from 0 to 1
  */
 void QuadPlane::tiltrotor_slew(float newtilt)
 {
-    float max_change = (tilt.max_rate_dps.get() * plane.G_Dt) / 90.0f;
+    float max_change = tilt_max_change(newtilt<tilt.current_tilt);
     tilt.current_tilt = constrain_float(newtilt, tilt.current_tilt-max_change, tilt.current_tilt+max_change);
 
     // translate to 0..1000 range and output
@@ -30,13 +48,15 @@ void QuadPlane::tiltrotor_continuous_update(void)
     tilt.motors_active = false;
 
     // the maximum rate of throttle change
-    float max_change = (tilt.max_rate_dps.get() * plane.G_Dt) / 90.0f;
+    float max_change;
     
     if (!in_vtol_mode() && !assisted_flight) {
         // we are in pure fixed wing mode. Move the tiltable motors all the way forward and run them as
         // a forward motor
         tiltrotor_slew(1);
 
+        max_change = tilt_max_change(false);
+        
         float new_throttle = constrain_float(SRV_Channels::get_output_scaled(SRV_Channel::k_throttle)*0.01, 0, 1);
         if (tilt.current_tilt < 1) {
             tilt.current_throttle = constrain_float(new_throttle,
@@ -58,7 +78,9 @@ void QuadPlane::tiltrotor_continuous_update(void)
     }
 
     // remember the throttle level we're using for VTOL flight
-    tilt.current_throttle = constrain_float(motors->get_throttle(),
+    float motors_throttle = motors->get_throttle();
+    max_change = tilt_max_change(motors_throttle<tilt.current_throttle);
+    tilt.current_throttle = constrain_float(motors_throttle,
                                             tilt.current_throttle-max_change,
                                             tilt.current_throttle+max_change);
     
@@ -106,7 +128,7 @@ void QuadPlane::tiltrotor_binary_slew(bool forward)
 {
     SRV_Channels::set_output_scaled(SRV_Channel::k_motor_tilt, forward?1000:0);
 
-    float max_change = (tilt.max_rate_dps.get() * plane.G_Dt) / 90.0f;
+    float max_change = tilt_max_change(!forward);
     if (forward) {
         tilt.current_tilt = constrain_float(tilt.current_tilt+max_change, 0, 1);
     } else {