TradHeli: Add yaw-only rate request function for flybar acro mode.

ArduCopter/heli_control_acro.pde

@@ -34,13 +34,15 @@ static void heli_acro_run()
     if(motors.armed() && heli_flags.init_targets_on_arming) {
         heli_flags.init_targets_on_arming=false;
         attitude_control.relax_bf_rate_controller();
-        
     }   
 
-    // To-Do: add support for flybarred helis
-
-    // convert the input to the desired body frame rate
-    get_pilot_desired_angle_rates(g.rc_1.control_in, g.rc_2.control_in, g.rc_4.control_in, target_roll, target_pitch, target_yaw);
+    if (!motors.has_flybar()){
+        // convert the input to the desired body frame rate
+        get_pilot_desired_angle_rates(g.rc_1.control_in, g.rc_2.control_in, g.rc_4.control_in, target_roll, target_pitch, target_yaw);
+    }else{
+        // flybar helis only need yaw rate control
+        get_pilot_desired_yaw_rate(g.rc_4.control_in, target_yaw);
+    }
 
     // run attitude controller
     attitude_control.rate_bf_roll_pitch_yaw(target_roll, target_pitch, target_yaw);
@@ -49,4 +51,15 @@ static void heli_acro_run()
     attitude_control.set_throttle_out(g.rc_3.control_in, false);
 }
 
+// get_pilot_desired_yaw_rate - transform pilot's yaw input into a desired yaw angle rate
+// returns desired yaw rate in centi-degrees-per-second
+static void get_pilot_desired_yaw_rate(int16_t yaw_in, float &yaw_out)
+{
+    // calculate rate request
+    float rate_bf_yaw_request = yaw_in * g.acro_yaw_p;
+
+    // hand back rate request
+    yaw_out = rate_bf_yaw_request;
+}
+
 #endif  //HELI_FRAME