电动舵机模块化建模及动刚度仿真

颤振是一种危险的气动弹性失稳形式，舵机动刚度对舵系统的颤振特性具有不可忽视的影响，因此舵机的精确建模与仿真分析十分有必要。针对此问题，提出了一种电动舵机模块化建模方法及动刚度计算机模拟方法。以“直流电机-减速齿轮-滚珠丝杠-拨叉副”典型结构的电动伺服舵机为对象，将其分解为具备核心功能的子模块，充分考虑了实际结构中可能出现的主要非线性因素，再根据子模块之间的连接关系来搭建整体的舵机模型。基于该舵机模型，提出了利用步进正弦扫频信号激励、最小二乘法数据处理得到动刚度的计算方法，并以某舵机为算例，开展了舵机主要线性参数及非线性因素对舵机动刚度影响的研究。电动舵机模块化建模方法通用性好，便于不同舵机的拓展。电机转子阻尼、减速器的传动比以及输出轴处的阻尼对舵机的动刚度影响很大，间隙、接触刚度和摩擦这3类非线性因素对舵机的动刚度特性也具有重要的影响。 

Modular modeling and dynamic stiffness simulation of electromechanical actuator

Flutter is a dangerous aeroelastic instability form. The influence of actuator dynamic stiffness on the fin-actuator system flutter characteristics cannot be ignored. Therefore, accurate actuator modeling and simulation are necessary. A modular modeling method and dynamic stiffness computer simulation method for electromechanical actuator are proposed. The object is the actuator composed of DC motor, reduction gear and ball screw-fork. It is divided into submodules with core functions. The main nonlinear factors that may appear are fully considered. Then the whole actuator model is built according to the connection between the submodules. Based on the above, a calculation method using step sine sweep signal as excitation and processing the data by least square method is proposed. Taking a certain actuator as an example, the influence of the actuator main linear and nonlinear parameters on the dynamic stiffness is studied. The modular modeling method has good generality, which is convenient for the modeling of different actuators. The damping of the motor rotor, the transmission ratio of the reducer and the damping at the output shaft have a great influence on the dynamic stiffness, and three nonlinear factors, clearance, contact stiffness and friction, also have important influence.