Unified Pressurization and Valving for Smart-Material Based Electrohydrostatic Actuators (EHAs)

Smart materials have shown promise for fluid power generation within electrohydrostatic actuators (EHAs). The smart material pumps have been successfully built to operate at high frequencies, but valve limitations have consistently reduced overall performance. Both passive and active valve concepts have been designed and tested, but these approaches have resulted in bandwidth limitations and added weight, respectively. A new unified pressurization and valving approach makes use of existing architecture in the pressurization systems, employing piezoelectric, magnetostrictive, or similar smart materials, and couples compact valve sets to the assembly. A current design, which links the valve motion to that of the reciprocating prime mover, has been developed and tested with promising results, including an increase in the optimal drive frequency. Additional design, testing, and analysis are proposed for a Phase 2 effort to further increase the functional bandwidth of the valves and the power density of the actuators. The valves will be incorporated into multiple EHAs that will be built and laboratory tested. The EHAs will then be integrated into the Insitu A-20 unmanned air vehicle (UAV) for flight test and separately into a laboratory morphing wing demonstration to validate the flightworthiness and applicability of the technology.