Power management between a propulsor and a coaxial rotor of a helicopter

A method of providing engine anticipation for propulsor loads on a rotary wing aircraft comprising a main rotor system, a translational thrust system, and an engine control system, the method comprising:

• producing flight control commands, by a flight control computer of the rotary wing aircraft, for the main rotor system and the translational thrust system;
• producing an anticipated rotor power demand associated with applying the flight control commands to the main rotor system;
• producing an anticipated auxiliary propulsor power demand associated with applying the flight control commands to the translational thrust system based on sensor-based data and command input, wherein the sensor-based data includes aircraft state data, the aircraft state data including at least one selected from a group consisting of an airspeed of the rotary wing aircraft and a density of air;
• and
• providing the engine control system with a total power demand anticipation signal based on a combination of the anticipated rotor power demand and the anticipated auxiliary propulsor power demand.

A method of providing engine anticipation for propulsor loads on a rotary wing aircraft comprising a main rotor system, a translational thrust system, and an engine control system, the method comprising:

• producing flight control commands, by a flight control computer of the rotary wing aircraft, for the main rotor system and the translational thrust system;
• producing a rotor power demand associated with applying the flight control commands to the main rotor system;
• producing a propulsor power demand value based on aircraft state;
• filtering the propulsor power demand value to produce a filtered power demand value;
• applying a drivetrain loss adjustment gain to the filtered power demand value to produce an auxiliary propulsor power demand;
• and
• providing the engine control system with a total power demand anticipation signal based on a combination of the rotor power demand and the auxiliary propulsor power demand.

A flight control system for a rotary wing aircraft comprising a main rotor system, a translational thrust system, and an engine control system, the flight control system comprising:

• a flight control computer configured to interface with the main rotor system, the translational thrust system, and the engine control system, the flight control computer configured to:
• produce flight control commands for the main rotor system and the translational thrust system,
• produce an anticipated rotor power demand associated with the main rotor system,
• produce an anticipated auxiliary propulsor power demand associated with the translational thrust system based on sensor-based data and command input, and
• provide the engine control system with a total power demand anticipation signal based on a combination of the anticipated rotor power demand and the anticipated auxiliary propulsor power demand,
• wherein the flight control computer is further configured to produce a propulsor power demand value based on aircraft state data, and wherein the anticipated auxiliary propulsor power demand is based on the propulsor power demand value, wherein the translational thrust system comprises an auxiliary propulsor including a plurality of propeller blades, wherein the aircraft state data comprises a propeller pitch command for the propeller blades and a reference rotational rate of the auxiliary propulsor, wherein the propeller pitch command and the reference rotational rate of the auxiliary propulsor are modeled parameters, and the aircraft state data further comprises an airspeed of the rotary wing aircraft and a density of air.

A flight control system for a rotary wing aircraft comprising a main rotor system, a translational thrust system, and an engine control system, the flight control system comprising:

• a flight control computer configured to interface with the main rotor system, the translational thrust system, and the engine control system, the flight control computer configured to:
• produce flight control commands for the main rotor system and the translational thrust system,
• produce an anticipated rotor power demand associated with the main rotor system,
• produce an anticipated auxiliary propulsor power demand associated with the translational thrust system based on sensor-based data and command input, and
• provide the engine control system with a total power demand anticipation signal based on a combination of the anticipated rotor power demand and the anticipated auxiliary propulsor power demand,
• wherein the flight control computer is further configured to produce a propulsor power demand value based on aircraft state data, and wherein the anticipated auxiliary propulsor power demand is based on the propulsor power demand value, wherein the translational thrust system comprises an auxiliary propulsor including a plurality of propeller blades, wherein the aircraft state data comprises a propeller pitch command for the propeller blades and a reference rotational rate of the auxiliary propulsor, and wherein the aircraft state data further comprises a propeller clutch engagement state of a propeller clutch and a propeller speed.