机器人关节传动系统固有特性分析

Analysis of Inherent Characteristics of Robot Joint Transmission System

机器人关节作为机器人的核心部件,主要由驱控系统和多级齿轮传动系统组成,在高转速、高负载下的齿轮传动系统动力学特性更加复杂。以机器人关节中齿轮传动系统为研究对象,采用集中参数法建立了其平移-扭转耦合动力学模型,根据牛顿第二定律建立了各构件动力学方程;分析了该系统的固有频率、模态应变能和模态动能,并研究了系统参数对固有频率的影响。结果表明,对于系统的模态能,在第15阶固有频率下的总应变能最大,此时系统整体变形最大;第24阶固有频率下的总动能最大,系统在该固有频率下的振动最为剧烈;系统参数对固有频率的影响主要体现为:高阶固有频率受影响较为明显;受系统刚度变化的影响,部分固有频率轨迹曲线逐渐接近后在某点附近会以较大的曲率快速分离,出现模态跃迁现象,在遇到频率相近时,会再次跃迁。

As the core component of robots,the robot joint is mainly composed of drive control system and multi-stage gear transmission system.Under high speed and high load,the dynamic characteristics of gear transmission system are more complex.Taking the gear transmission system in the robot joint as the research object,the translation torsion coupling dynamic model is established by using the lumped parameter method,and the dynamic equations of each component are established according to Newton’s second law.Therefore,the natural frequency,modal strain energy and modal kinetic energy of the system are analyzed,and the influence of system parameters on natural frequency is studied.The results show that for the modal energy of the system,the total strain energy is the largest at the 15th natural frequency,the overall deformation of the system is the largest,the total kinetic energy is the largest at the 24th natural frequency,and the vibration of the system is the most intense at this natural frequency;the influence of system parameters on natural frequency is mainly reflected in that higher-order natural frequency is obviously affected;affected by the change of system stiffness,some natural frequency trajectory curves gradually approach,and will quickly separate with large curvature near a certain point,resulting in modal transition.When the frequencies are similar,they will transition again.