AP_MotorsHeli: Create parameter_check method.

libraries/AP_Motors/AP_MotorsHeli.cpp

@@ -354,6 +354,18 @@ bool AP_MotorsHeli::allow_arming() const
     return true;
 }
 
+// parameter_check - check if helicopter specific parameters are sensible
+bool AP_MotorsHeli::parameter_check() const
+{
+    // returns false if _rsc_setpoint is not higher than _rsc_critical as this would not allow rotor_runup_complete to ever return true
+    if (_rsc_critical >= _rsc_setpoint) {
+        return false;
+    }
+
+    // all other cases parameters are OK
+    return true;
+}
+
 // return true if the main rotor is up to speed
 bool AP_MotorsHeli::rotor_runup_complete() const
 {

libraries/AP_Motors/AP_MotorsHeli.h

@@ -151,6 +151,9 @@ public:
     // allow_arming - returns true if main rotor is spinning and it is ok to arm
     bool allow_arming() const;
 
+    // parameter_check - returns true if helicopter specific parameters are sensible, used for pre-arm check
+    bool parameter_check() const;
+
     // _tail_type - returns the tail type (servo, servo with ext gyro, direct drive var pitch, direct drive fixed pitch)
     int16_t tail_type() const { return _tail_type; }