US 7,900,869 B2Granted

Helicopter rotor control system with individual blade control

AssigneeZF Friedrichshafen AG

InventorsChristoph Keβler, Daniel Fürst

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Abstract

Controlling the pitch of individual rotor blades of a helicopter to reduce control loads, vibration and noise in or from the rotating rotor control elements. The system generates blade dynamics signals representing dynamic forces acting on either or both of the rotating and non-rotating elements of the helicopter, including rotor blades of a rotating assembly. The system extracts information representing at least one dynamic force, generates a dynamic force compensation output that represents a compensation for the dynamic force, and generates, from flight control signals and the dynamic force compensation output, a compensated pitch actuator control signal for each rotor blade wherein the compensation factor of the pitch control signal compensates for the dynamic force.

Claims15

Dependent claims

An individual blade control system for controlling rotor pitch in a helicopter control system, the helicopter control system including pilot controls for generating pilot control inputs directing operation of a rotor assembly including a plurality of blades mounted to a rotor hub supported by a rotating shaft and a blade actuator responsive to the pilot control signals and coupled to the rotor assembly for controlling pitch of the blades, the individual blade control system comprising:

at least one blade dynamics sensor for generating at least one blade dynamics signal representing a corresponding blade dynamics factor,
a plurality of individual blade actuators, each blade actuator corresponding to a blade and controlling pitch of the corresponding blade, and
a blade pitch controller, including
an inner control loop for each blade for blade pitch position control by matching an actual pitch position of the blade actuator to a commanded actuator pitch position by comparing an actuator pitch position output representing the actual stroke position of the blade actuator with the corresponding commanded actuator pitch position and generating a corresponding corrected actuator position output to the blade actuator, and
an outer control loop for reducing control loads on the blade actuators, including
a system identification mechanism receiving the at least one blade dynamics signal and generating modeled outputs representing a linear T-matrix model of the helicopter control system, and
a controller mechanism generating a commanded actuator stroke position output for each blade actuator, including
an outer loop processor receiving flight control commands and the modeled outputs of the system identification mechanism and generating a commanded stroke output for each individual blade actuator, each commanded stroke output including a flight control command component and a control load reduction component.

5 more elements

A method for controlling individual rotor blade pitch in a helicopter control system, the helicopter control system including pilot controls for generating pilot control inputs directing operation of a rotor assembly including a plurality of blades mounted to a rotor hub supported by a rotating shaft and a blade actuator responsive to the pilot control signals and coupled to the rotor assembly for controlling pitch of the blades, the individual blade control system comprising the steps of:

generating at least one blade dynamics signal representing a corresponding blade dynamics factor, and
in an inner control loop and for each blade,
matching an actual pitch position of a corresponding blade actuator to a commanded actuator pitch position by comparing an actuator pitch position output representing an actual stroke position of the blade actuator with the corresponding commanded actuator pitch position and generating a corresponding corrected actuator position output to the blade actuator, and
in an outer control loop,
generating from the at least one blade dynamics signal system modeled outputs representing a linear T-matrix model of the helicopter control system wherein the system modeled outputs represent a control load compensation for the blade dynamics factor, and
modifying flight control commands with the system modeled outputs to generate a commanded actuator stroke position output to each blade actuator wherein each commanded actuator stroke position output includes a flight control command component and a control load reduction component compensating for the blade dynamics factor.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/579,281Filed 6 May 2005 · us provisional application
Priority: 6 May 2004
Published: US 2008/0279685 A113 Nov 2008
Granted: 8 Mar 2011
Term ends: Not estimatedThe source records don’t support an estimate.