A seventh-order model for dynamic response of an electro-hydraulic servo valve

• Published in: Chinese journal of aeronautics 2014-12, Vol.27 (6), p.1605-1611
• Main Authors: Liu, Changhai, Jiang, Hongzhou
• Format: Article
• Language: English
• Subjects: AMESim; Computational fluid dynamics; Computer simulation; Dynamic response; Fluid flow; Fluids; Hydraulic control systems; Mathematical models; Nozzle–flapper; Servo valve; Servomechanisms; Torque motor; Transfer function; Valves; 仿真模型; 低阶模型; 动态响应; 模型推导; 流体性质; 物理参数; 电液伺服阀
• ISSN: 1000-9361
• DOI: 10.1016/j.cja.2014.10.029

In this paper, taking two degrees of freedom on the armature–flapper assembly into account, a seventh-order model is deduced and proposed for the dynamic response of a two-stage electro-hydraulic servo valve from nonlinear equations. These deductions are based on fundamental laws of electromagnetism, fluid, and general mechanics. The coefficients of the proposed seventhorder model are derived in terms of servo valve physical parameters and fluid properties explicitly.For validating the results of the proposed model, an AMESim simulation model based on physical laws and the existing low-order models validated by other researchers through experiments are used to compare with the seventh-order model. The results show that the seventh-order model can reflect the physical behavior of the servo valve more explicitly than the existing low-order models and it could provide guidance more easily for a linear control design approach and sensitivity analysis than the AMESim simulation model.