Abstract: The joint of welding robot is the key component of welding robot, which has variable load, large torque and frequent faults. The dynamic model of welding robot joint is established by using the lumped mass method, and the dynamic equation is established. Based on the Runge-Kutta method, the vibration data under normal and typical fault conditions are obtained by solving the differential equation. The simulation of vibration signal in time domain and frequency domain is carried out by MATLAB, and the results show that the amplitude and frequency conversion band of vibration signal increase when the sun wheel pitting fault occurs, in the case of cycloid wheel pitting fault, the signal energy is concentrated and the amplitude increases at frequency doubling, and the energy is concentrated at frequency doubling when rotor eccentricity fault occurs. It provides theoretical basis and diagnostic basis for condition monitoring and fault diagnosis of welding robot.

Key words: welding robot, RV reducer, fault diagnosis, dynamical model

摘要： 焊接机器人的关节点负载多变、扭矩大、故障多发,是焊接机器人的关键部件,其故障特性研究是焊接机器人工作状态监测的重要环节。采用集中质量法对焊接机器人关节点进行动力学建模,建立动力学方程。基于龙格库塔法求解动力学方程,得到正常状态和典型故障状态下的振动数据。通过MATLAB模拟振动信号的时域和频域,得到太阳轮点蚀故障时振动信号幅值升高、变频带升高,摆线轮点蚀故障时信号在1倍频处能量集中、幅值升高,转子发生偏心故障时能量向2倍频处集中。为焊接机器人状态监测和故障诊断提供理论基础和诊断依据。

关键词: 焊接机器人, RV减速器, 故障诊断, 动力学模型