Electric control surface actuation • Goal: Retrofit of the hydraulic control surface actuators with

electromechanical systems

Retrofit Actuator Package

Hydraulic system

Electromechanical system

Figure 1: Existing hydraulic actuation system [2] and prototype electromechanical system. Adapted from Ref. [9]

• Cons of electrical retrofit • Power consumption during holding

maneuvers • Strenuous loading demands

• Benefits of electrical retrofit • Reduced whole lifecycle

expenses • Maintainability • Energy conversion efficiency

Synthesis Methodology - Overview

System model for synthesis • Linearized 2-port impedance model

• Dynamics of interest for ocean disturbance rejection

Derived via transmission matrices

Specifications on Response • Reject Pierson-Moskowitz wave spectrum induced torques

• Desired rejection response produced by attenuating natural response over wave spectrum frequencies

Resulting impedance function

• Positive real – Purely passive realization exists • Brune Elements – Requires complex transformers • Further options for physical realization

• Model reduction (balanced realization) • Active and passive components (functional expansion)

Physical Realization of Impedance • Purely active realization – actuator as impedance

• Passive and active hybrid architecture

Design energy consumption comparison • Energy consumption as metric for design selection

• Simulated actuator energy required for regulation control • Ocean disturbances imposed

• For this design iteration, active impedance control in actuator consumed minimal energy

• Purely passive realization would minimize energy for rejection