A Preliminary Design Method of High-Power Electro-Hydrostatic Actuators Considering Design Robustness

Electro-hydrostatic actuators (EHAs) are expanding their application fields due to their combined advantages of electric and hydraulic actuation. However, the control performance, the weight, and the efficiency turn out to be more challenging requirements when the EHA power level increases to over 30 kW. Therefore, a preliminary design dedicated to trading off the system-level EHA performance based on multi-domain coupling analysis is necessary considering the comprehensive performance requirements and the parameter uncertainties. However, the existing methods are deficient in responding to all these design challenges. In this paper, an EHA preliminary design method is proposed to achieve the optimum system-level performance with robustness. First, the design parameters are analyzed and selected. Second, an optimization design of EHAs is realized by developing multi-disciplinary performance simulation models. The robustness is also considered during the optimization design. Third, the optimization results are evaluated by a specifically built EHA model, which realizes high fidelity than the models used for optimization. As a result, the general high-power EHA requirements are fully considered during the preliminary design and an optimum EHA performance is achieved. The proposed method is demonstrated in a design case of a 30 kW EHA for aerospace applications, which achieved the optimum performance of 8 Hz bandwidth and 69.92 kg weight. The preliminary design results also outline the input information for the following detailed design. Therefore, the proposed method demonstrated its applicability for delivering robust EHA design results for engineering applications.