电动静液作动器框图建模与控制

Block diagram modeling and control of electro-hydrostatic actuator

功率电传作动系统是未来飞行控制的发展方向,它取消了传统的中央液压油源.电动静液作动器是功率电传系统的执行机构,在作动器端把电能转化为局部液压能,兼具传统液压系统和直接电力驱动作动器的优点.根据其元部件数学方程,建立非线性框图子模型,构造了一种定排量变转速电动静液作动器,完善了补油回路和摩擦特性的描述.通过考察作动器稳定性、静态刚度和动态性能指标,对单环比例、积分、微分(PID,Proportion IntegrationDifferentiation)、多环PID、全状态反馈控制等方法进行了设计及比较分析.仿真结果表明,结合动态压力反馈策略的全状态反馈控制器能有效改善系统的动、静态性能.

Power-by-wire （PBW） actuation is the future direction of flight control system in which the need for a central hydraulic system is eliminated. The electro-hydrostatic actuator （EHA） is a kind of PBW actuator that converts the electrical power into local hydraulic power and combines the benefits of the conventional hydraulic system and the direct drive electrical actuators. Based on the mathematic equations, all the EHA components were modeled by the block diagrams and assembled to a fixed-displacement variable-speed architecture, which contained the refeeding circuit and the friction. Furthermore, the single proportion integration differentiation （PID） controller, cascade PID controller and state feedback controller are designed for comparison analysis that focused on the system stability, stiffness and dynamic characteristics. The simulation results prove that the state feedback controller along with dynamic pressure feedback strategy efficiently improves the static and dynamic performance of EHA.