--------------------------------------------------------------------------------
01/01/10 T.Kreitler test implementation
01/10/11 T.Kreitler changed to single rotor model
+03/06/11 T.Kreitler added brake, clutch, and experimental free-wheeling-unit
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
SENTRY
DEFINITIONS
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-#define ID_ROTOR "$Id: FGRotor.h,v 1.8 2011/01/17 22:09:59 jberndt Exp $"
+#define ID_ROTOR "$Id: FGRotor.h,v 1.9 2011/03/10 01:35:25 dpculp Exp $"
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FORWARD DECLARATIONS
<polarmoment unit="{MOMENT}"> {number} </polarmoment>
<inflowlag> {number} </inflowlag>
<tiplossfactor> {number} </tiplossfactor>
+ <maxbrakepower unit="{POWER}"> {number} </maxbrakepower>
<controlmap> {MAIN|TAIL|TANDEM} </controlmap>
<ExternalRPM> {number} </ExternalRPM>
<groundeffectexp> {number} </groundeffectexp>
<groundeffectshift unit="{LENGTH}"> {number} </groundeffectshift>
+
+ <freewheelthresh> {number} </freewheelthresh>
</rotor>
// LENGTH means any of the supported units, same for ANGLE and MOMENT.
\<massmoment> - Blade mass moment. Mass of a single blade times the blade's
cg-distance from the hub, optional.
\<polarmoment> - Moment of inertia for the whole rotor disk, optional.
- \<inflowlag> - Rotor inflow time constant, sec. Smaller values yield to
- quicker responses to control input (defaults to 0.2).
+ \<inflowlag> - Rotor inflow time constant, sec. Smaller values yield to quicker
+ responses (typical values for main rotor: 0.1 - 0.2 s).
\<tiplossfactor> - Tip-loss factor. The Blade fraction that produces lift.
Value usually ranges between 0.95 - 1.0, optional (B).
+ \<maxbrakepower> - Rotor brake, 20-30 hp should work for a mid size helicopter.
\<controlmap> - Defines the control inputs used (see notes).
\<ExternalRPM> - Links the rotor to another rotor, or an user controllable property.
Omitting or setting to 0.0 disables the effect calculation.
\<groundeffectshift> - Further adjustment of ground effect, approx. hub height or slightly above.
+ \<freewheelthresh> - Ratio of thruster power to engine power. The FWU will release when above
+ the threshold. The value shouldn't be too close to 1.0, 1.5 seems ok.
+ 0 disables this feature, which is also the default.
+
</pre>
<h3>Notes:</h3>
<h4>- Engine issues -</h4>
- Currently the rotor can only be driven with piston and electrical engines. An adaption
- for the turboprop engine might become available in the future.
In order to keep the rotor speed constant, use of a RPM-Governor system is
encouraged (see examples).
<dt>/AM50/</dt><dd>Amer, Kenneth B.,"Theory of Helicopter Damping in Pitch or Roll and a
Comparison With Flight Measurements", NACA TN-2136, 1950.</dd>
<dt>/TA77/</dt><dd>Talbot, Peter D., Corliss, Lloyd D., "A Mathematical Force and Moment
- Model of a UH-1H Helicopter for Flight Dynamics Simulations", NASA TM-73,254, 1977.</dd>
+ Model of a UH-1H Helicopter for Flight Dynamics Simulations", NASA TM-73,254, 1977.</dd>
+ <dt>/GE49/</dt><dd>Gessow, Alfred, Amer, Kenneth B. "An Introduction to the Physical
+ Aspects of Helicopter Stability", NACA TN-1982, 1949.</dd>
</dl>
@author Thomas Kreitler
- @version $Id: FGRotor.h,v 1.8 2011/01/17 22:09:59 jberndt Exp $
+ @version $Id: FGRotor.h,v 1.9 2011/03/10 01:35:25 dpculp Exp $
*/
/// Destructor for FGRotor
~FGRotor();
- /** Returns the power required by the rotor. Well, to achieve this the rotor
- is cycled through the whole machinery, yielding to a new state.
- (hmm, sort of a huge side effect)
- */
- double GetPowerRequired(void);
+ /** Returns the power required by the rotor. */
+ double GetPowerRequired(void)const { return PowerRequired; }
/** Returns the scalar thrust of the rotor, and adjusts the RPM value. */
- double Calculate(double PowerAvailable);
+ double Calculate(double EnginePower);
/// Retrieves the RPMs of the rotor.
double GetCT(void) const { return C_T; }
/// Retrieves the torque
double GetTorque(void) const { return Torque; }
+ /// Retrieves the state of the free-wheeling-unit (FWU).
+ double GetFreeWheelTransmission(void) const { return FreeWheelTransmission; }
/// Downwash angle - currently only valid for a rotor that spins horizontally
double GetThetaDW(void) const { return theta_downwash; }
double GetLateralCtrl(void) const { return LateralCtrl; }
/// Retrieves the longitudinal control input in radians.
double GetLongitudinalCtrl(void) const { return LongitudinalCtrl; }
+ /// Retrieves the normalized brake control input.
+ double GetBrakeCtrl(void) const { return BrakeCtrlNorm; }
/// Sets the collective control input in radians.
void SetCollectiveCtrl(double c) { CollectiveCtrl = c; }
void SetLateralCtrl(double c) { LateralCtrl = c; }
/// Sets the longitudinal control input in radians.
void SetLongitudinalCtrl(double c) { LongitudinalCtrl = c; }
+ /// Sets the normalized brake control input.
+ void SetBrakeCtrl(double c) { BrakeCtrlNorm = c; }
// Stubs. Only main rotor RPM is returned
string GetThrusterLabels(int id, string delimeter);
void calc_drag_and_side_forces(double theta_0);
void calc_torque(double theta_0);
+ void calc_freewheel_state(double pwr_in, double pwr_out);
+
// transformations
FGColumnVector3 hub_vel_body2ca( const FGColumnVector3 &uvw, const FGColumnVector3 &pqr,
double a_ic = 0.0 , double b_ic = 0.0 );
double LateralCtrl;
double LongitudinalCtrl;
+ double BrakeCtrlNorm, MaxBrakePower;
+
+ // free-wheeling-unit (FWU)
+ int FreeWheelPresent; // 'installed' or not
+ double FreeWheelThresh; // when to release
+ Filter FreeWheelLag;
+ double FreeWheelTransmission; // state, 0: free, 1:locked
+
+
};
}
projects / flightgear.git / blobdiff