Method of driving rotation of a rotorcraft rotor by anticipating torque needs between two rotary speed setpoints of the rotor

Patent metadata

Field	Value
Publication number	US-10005560-B2
Application number	US-201514887682-A
Country	US
Kind code	B2
Filing date	Oct 20, 2015
Priority date	Dec 27, 2012
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A method of driving a rotorcraft rotor ( 1, 2 ) at variable controlled speeds. Starting from a required speed (Nr), a setpoint for total power (Pt) is calculated while taking account of an anticipated power (Pf) to be delivered by the power plant ( 3 ) for driving the main rotor ( 1 ) at the required speed (Nr), and while taking account of a power surplus (S) relating to progressive power needs to be delivered from a current power (Pc) for driving the main rotor ( 1 ) at a current speed (V) of rotation to an anticipated power (Pf) for driving the main rotor ( 1 ) at the required speed (Nr). By way of example, account may be taken at least of the acceleration or conversely of the deceleration of the main rotor ( 1 ) between the current speed (V) and the required speed (Nr), or indeed account may be taken of the flight circumstance of the rotorcraft 30 determining the calculated required speed (Nr).

First claim

What is claimed is:

1. A method of driving rotation of at least one rotorcraft rotor by a power plant of the rotorcraft, the method comprising the following steps:
a control unit identifying a required speed (Nr) for driving rotation of at least one vertical-axis main rotor of the rotorcraft, the required speed (Nr) being calculated by applying a first calculation rule incorporating at least a first calculation parameter giving rise to controlled variation, within a predefined range of values, in the value of the required speed (Nr) depending on variation in the value of the first calculation parameter;
the control unit applying a method of calculating a power setpoint identifying a total power (Pt) to be delivered by the power plant, the calculation of the power setpoint being based at least on applying a second calculation rule incorporating at least one second calculation parameter for calculating an anticipated power (Pf) that the power plant must deliver as a function at least of loads supported by the main rotor driven at the previously-identified required speed (Nr); and
transmitting at least one control order (C) relating at least to the power setpoint to regulator means for regulating the operation of the power plant, the regulator means causing the power plant to be operated to drive the at least one rotor in rotation in compliance with driving the main rotor in rotation at the required speed (Nr) according to the power setpoint, the regulator means including at least one regulator unit for regulating injection of fuel to at least one fuel-burning engine of the power plant;
wherein the second calculation rule for calculating the power setpoint incorporates at least one third calculation parameter concerning a power surplus (S), the power surplus (S) relating to progressive power needs to be delivered from a current power (Pc) for driving the main rotor at a current speed (V) of rotation to the anticipated power (Pf) for driving the main rotor at the required speed (Nr);
wherein the third calculation parameter incorporates a first calculation criterion relating to the acceleration or conversely to the deceleration of the main rotor between the current speed (V) and the required speed (Nr);
wherein the third calculation parameter further incorporates a second calculation parameter relating to modes of using auxiliary members on board the rotorcraft that consume mechanical power over a time period (T 1 , T 2 ) between driving the main rotor at the current speed (V) and at the required speed (Nr); and
the method further comprising the following steps,
evaluating the current power (Pc) delivered by the power plant;
collecting the required speed (Nr) as generated by main calculation means incorporating the first calculation rule;
deducing the anticipated power (Pf) corresponding to the power needed for driving the main rotor at the required speed (Nr) by executing the second calculation rule in application of the second calculation parameter;
deducing the total power (Pt) to be delivered depending on the previously deduced anticipated power (Pf) and depending on the power surplus (S) calculated by executing the second calculation rule in application of the third calculation parameter; and
transmitting to the regulator unit a control order (C) relating at least to the previously-deduced total power (Pt) to be delivered;
wherein the step of evaluating the current power (Pc) delivered by the power plant includes at least one of:
an operation of collecting known information relating to the current power (Pc) as previously calculated by implementing the method; and
an operation of measuring in real time the number of revolutions performed by the main rotor at a given instant.

2. The method according to claim 1 , wherein the first calculation criterion is a calculation criterion relating to a progressive variation in the speed of rotation of the main rotor, the first calculation criterion including any of at least the following calculation criteria:
a time period (T 1 , T 2 ) between driving the main rotor at the current speed (V) and at the required speed (Nr);
a progressive variation in the number of revolutions of the main rotor between the number of revolutions of the main rotor driven at the current speed (V) and the number of revolutions of the main rotor driven at the required speed (Nr);
the instantaneous time derivative of the anticipated power (Pf); and
any of at least first calculation parameters from which the required speed (Nr) is defined.

3. The method according to claim 1 , wherein the second calculation criterion is a calculation criterion comprising any of at least the following calculation criteria:
varying forces developed by an anti-torque device of the rotorcraft;
varying the cyclic pitch of the blades of the main rotor;
controlling the operation of at least one movable control of the rotorcraft suitable for modifying its flight behavior;
controlling the operation of at least one piece of ancillary equipment of the rotorcraft; and
controlling the operation of an electrical machine.

4. The method according to claim 1 , wherein the third calculation parameter incorporates a third calculation criterion relating to a flight situation of the rotorcraft and including any of at least the following calculation criteria:
progressive variation in the distance along the gravity axis between the rotorcraft and a terrestrial frame of reference;
variation in the aerodynamic characteristics of the rotorcraft; and
progressive variation in any of at least physicochemical parameters of the ambient air outside the rotorcraft.

5. The method according to claim 1 , wherein the method further comprises the following steps:
calculating the power surplus (S) by executing the second calculation rule in application of the third calculation parameter; and
transmitting a first control order (C) relating at least to the anticipated power (Pf) to the regulator unit, and transmitting a second control order (C) relating at least to the power surplus (S) to control means for operating an electrical machine of the power plant, which machine is engaged in a drivetrain for driving the main rotor.

6. The method according to claim 1 , wherein the step of deducing the anticipated power (Pf) includes an operation of calculating the load to which the main rotor driven at the required speed (Nr) will be subjected, and an operation of calculating the anticipated power (Pf) on the basis of the calculated load.

7. The method according to claim 1 , wherein the step of calculating the power surplus (S) includes an operation of calculating the derivative of the difference between the revolutions of the main rotor driven respectively at the current speed (V) and at the required speed (Nr) over a given time period.

8. The method according to claim 1 , wherein the second calculation rule may be executed by sequences at a given frequency or continuously depending on continuous variation in the value of the third calculation parameter.

9. The method according to claim 1 , wherein the required speed (Nr) is determined by the first calculation rule by detecting a value threshold reached by at least one the first calculation parameter for the required speed (Nr), or by detecting a continuous progressive variation in the value of at least one the first calculation parameter.

10. The method according to claim 1 , wherein the control unit generates a required speed (Nr) setpoint that is transmitted at least to servo-control means for servo-controlling the drive of the main rotor to the required speed (Nr).

11. A method of driving rotation of at least one rotorcraft rotor by a power plant of the rotorcraft,

Assignees

• Airbus Helicopters

Inventors

• Vallart Jean-Baptiste
• Vieira Hilario

Classifications

• B64C27/57 Primary

  automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust · CPC title

• B64D31/00

  Power plant control systems; Arrangement of power plant control systems in aircraft · CPC title

• F05D2220/329

  in helicopters · CPC title

• F02C9/00

  Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants (controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05) · CPC title

• B64C27/12

  Rotor drives · CPC title