Apparatus and method for verifying the dynamic stiffness capability of hydraulic servo actuators

A method for assessing the dynamic stiffness of a flight control actuator, said method comprising the steps of:

• providing an actuator control system having an actuator coupled to an aircraft control surface;
• providing actuator control electronics operably coupled to the actuator control system;
• providing a digital flight computer operably coupled to the actuator control system;
• applying a command signal to the actuator control system, wherein the command signal causes a pressure spike to be applied to the actuator, wherein the pressure spike causes an acceleration of the aircraft control surface coupled to the actuator;
• measuring a pressure differential generated across the actuator by the pressure spike;
• processing the pressure differential with the actuator control electronics to produce a processed pressure differential signal;
• transmitting the processed pressure differential signal to the digital flight computer for comparison to known actuator-control surface pressure differential values;
• and
• determining the acceptability of the actuator to provide dynamic stiffness for limiting control surface flutter based on the comparison to known actuator-control surface pressure differential values.

An apparatus for assessing the dynamic stiffness of a flight control actuator, comprising:

• an aircraft control surface;
• an actuator control system that includes an actuator having a portion thereof coupled to the aircraft control surface;
• and
• a processor in operable communication with the actuator control system, the processor configured to:
• generate a command signal for the actuator control system that causes the production of a pressure differential across the actuator, which is based on the ability of the actuator to react to an inertial toad generated by an attempted acceleration of the aircraft control surface;
• process a pressure signal representative of the pressure differential produced across the actuator;
• and
• compare the pressure signal to known pressure differential values produced under similar conditions for specific actuator and specific control surface combinations.