1. 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

2. Synthesis Methodology - Overview

3. System model for synthesis
• Linearized 2-port impedance model
• Dynamics of interest for ocean disturbance rejection
Derived via transmission matrices

4. Specifications on Response
• Reject Pierson-Moskowitz wave spectrum induced torques
• Desired rejection response produced by attenuating natural response
over wave spectrum frequencies

5. 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)

6. Physical Realization of Impedance
• Purely active realization – actuator as impedance
• Passive and active hybrid architecture

7. 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