US 6,648,599 B2Granted

Method and control arrangement for adjusting a flap that is pivotally supported in a rotor blade of a helicopter

AssigneeEurocopter Deutschland GmbH

InventorDieter Preissler

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Abstract

A force transmitting linkage connects a piezoelectric actuator to a flap that is pivotably connected to a helicopter rotor blade. In a flap actuation control arrangement and method, a force transducer senses the force being transmitted through the linkage and generates a corresponding actual force signal, a flap position sensor senses the position of the flap and generates a corresponding actual flap position signal, a first controller receives a desired flap position signal and the actual flap position signal and responsively thereto generates a reference signal, and a second controller receives the reference signal and the actual force signal and responsively thereto generates a control signal that is provided to the piezoelectric actuator. This provides a real time flap actuation control with respect to highly dynamic forces as well as friction forces acting on the flap.

Claims22

Dependent claims

In a helicopter rotor blade arrangement including a rotor blade body, a flap that is pivotable relative to said rotor blade body, a piezoelectric actuator, a force transmitting linkage connected from an actuator output of said piezoelectric actuator to said flap, and a control arrangement that is connected and provides a control signal to a control input of said piezoelectric actuator,

an improvement in said control arrangement comprising:
a primary control with a primary feedback input and a primary control output;
a flap position sensor that is arranged to sense an actual position of said flap, and that has a position sensor output which is connected to said primary feedback input and which is adapted to provide a flap position signal responsive and corresponding to said actual position of said flap;
a secondary control with a secondary reference input, a secondary feedback input and a secondary control output, wherein said secondary control output is connected and provides said control signal to said control input of said piezoelectric actuator, and wherein said primary control output is connected to said secondary reference input;
and
a measuring element that is coupled with said force transmitting linkage and that has a measuring element output which is connected to said secondary feedback input.

3 more elements

A method of actuating a pivotable flap that is pivotally connected to a helicopter rotor blade, using a piezoelectric actuator connected to said flap by a force transmitting linkage, comprising the following steps:

a) operating said piezoelectric actuator to transmit an actuating force through said force transmitting linkage to said flap so as to pivot said flap relative to said rotor blade;
b) sensing an actual position of said flap relative to said blade and generating an actual flap position signal corresponding to said actual position of said flap;
c) sensing an actual force value of said actuating force being transmitted through said force transmitting linkage and generating an actuating force signal corresponding to said actual force value;
d) forming an actuator control signal responsive to and dependent on said actual flap position signal and said actuating force signal;
and
e) controlling said operating of said piezoelectric actuator by providing said actuator control signal to said piezoelectric actuator.

3 more elements

Dependencies are inferred from the claim text.