基于等效元素法的机电作动器传动机构动力学建模与分析

Dynamics Analysis on the Transmission Mechanism of Electro-Mechanical Actuators Based on Equivalent Finite Element Method

关键词:  机电作动器  单元等效  雅克比矩阵  动力学方程  ADAMS动力学分析

Key words:  Electro-mechanical actuators  Equivalent finite element  Jacques matrix  Dynamic equation  ADAMS dynamics analysis

摘要:

目前机电作动器传动机构存在刚体数目多、传动链长、动力学模型难以建立的问题。通过引入规范化的动力学建模方法——集中质量等效元素法，建立了某机电作动器传动机构的动力学模型，包括等效系统质量阵、等效系统力系和系统自由坐标与广义坐标之间的雅克比关系阵，并得到了其解析动力学方程；结合方程在ADAMS平台进行动力学逆求解仿真，得到了30°大行程位移信号和8Hz频率信号两种工况下的系统载荷响应曲线。随着负载转动惯量增加，电机动载系数达到1.34，丝杠动载系数达到1.55；外部负载不变时，随着驱动信号幅值增加，电机动载最大系数达到1.23。分析表明随着机电作动器系统外部惯性负载及系统运动速度的提高，由外部惯性负载及自身传动机构产生的动载效应明显，为机电作动器传动机构优化设计提供了理论依据。

Abstract:

As it's difficult to establish the dynamic model of the transmission mechanism for the large number of rigid bodies and long transmission chain of electro-mechanical actuators, a normalized dynamic modeling method called Equivalent Finite Element Method is introduced. The dynamics model of electro-mechanical actuators is established based on Equivalent Finite Element Method，which consists of equal system mass matrix, equal system force matrix and Jacobean matrix between free coordinate system and generalized coordinate system. The motive differential equation of the system is acquired. Combining with the equation, the form of solution is given and simulated on ADAMS, which acquires dynamics response curves of the system when inputting 30 degree step and 8Hz frequency signal. The result shows that the inertia load effect is obvious while the moment of inertia and the drive signal amplitude increase, the dynamic factor Kv becomes 1.34 and 1.23. It could offer reference to the control and optimal design for electro-mechanical actuators.