惯性质量对齿轮齿条式作动器阻尼特性的影响

Influence of inertial mass on rack and pinion actuator′s damping characteristic

设计了一种基于伺服电机和齿轮齿条结构的作动器,理论分析了作动器输出阻尼力的两个组成部分:机械摩擦阻尼力和惯性力,并给出了各自的计算方法。采用典型的正弦激励,通过与传统减振器被动阻尼的对比,分析了引入惯性质量对作动器阻尼特性的影响,并通过台架试验进行了验证。结果表明:作动器阻尼力的计算方法是合理的,能够较好地拟合作动器阻尼力的实际值;同时,作动器的惯性质量会导致最大阻尼力增大、阻尼非线性特性增强,不利于其主动控制;结构空程间隙导致作动器高频换向时阻尼力波动明显,在作动器的结构设计过程中,应通过优化设计减小其惯性质量和空程。

An actuator based on the structure of servo motor and rack and pinion is designed.The two components of actuator damping force are analyzed theoretically,which are mechanical friction damping force and inertia force,and their calculation methods are given respectively.Compared with the traditional passive damping force,the influence of the inertial mass on the damping characteristics of the actuator is analyzed through typical sinusoidal excitation,and further verified by bench test.The test results show that the calculation method of damping force is reasonable,can match the actual damping force of the actuator well.However,it is also found that the inertial mass of the actuator results in the rise of the maximum damping force and the nonlinear characteristic which goes against its active control.Moreover,the idle stroke of the structure leads to obvious fluctuation of the damping force in the process of high frequency reversing.So,in the process of actuator structure design,it should be considered to reduce the inertial mass and idle stroke by optimal design.