Multidisciplinary optimization and motion control method of electromagnetic linear actuator for electro-hydrostatic system

In this paper, a novel electro-hydraulic system (EHS) with a direct-drive pump based on a high power-density moving-coil electromagnetic linear actuator (EMLA) is proposed. Based on the analysis of the EHS, a multidisciplinary optimization method based on the multi-objective game theory is proposed to optimize the static and dynamic performance of the EMLA concurrently. Aiming at the continuous disturbance of the EHS, an improved terminal sliding mode control (ITSMC) based on the improved exponential reaching law is designed. The robust differentiator and super-twisting disturbance observer are combined to compensate for the system. The result proves the feasibility of the novel EHS. The multidisciplinary optimization method is effective. The maximum electromagnetic force increased by 17.91%, and the electromagnetic force fluctuation rate decreased by 5.91% compared with the single discipline scheme, respectively. Compared with NTSMC method and PID method, the ITSMC method has higher response speed and control accuracy under the condition of nonlinear force disturbance and signal noise. The ITSMC method effectively improves the robustness of the control system under complex conditions.