Verification and Validation of a Theoretical Model of a Direct Drive Valve-Controlled Electrohydrostatic Actuator for Primary Flight Control

In this work, a theoretical parametric nonlinear model for a hybrid variable pressure actuator was verified through dynamic system modeling techniques and validated using experimental data. The hybrid configuration under investigation combines design features of a valve-controlled hydraulic actuator and an electrohydrostatic actuator resulting in a variable pressure hydraulic actuator. A comparison analysis is conducted to determine the performance and, more specifically, power characteristics of the hybrid configuration relative to the two types of conventional flight control actuation---valve-controlled actuators and electrohydrostatic actuators. The hybrid configuration is unique in the sense that it allows for independent localized hydraulic system pressure control. In this analysis, bang-bang control is implemented by defining low-pressure and high-pressure thresholds resulting in active-passive electrical power consumption. The hybrid configuration was shown to exhibit power input superiority due to duty-cycle behavior of the electrical power element during high-load low-rate scenarios when compared to traditional actuation configurations.