转速负反馈在伺服系统机械谐振抑制中的应用研究

Application Research on Speed Negative Feedback in Mechanical Resonance Suppression in Servo System

伺服电机驱动系统中的弹性连接装置会引发机械谐振。该文提出基于转速负反馈的机械谐振抑制方法,该方法将转速中包含谐振频率的频率分量反馈补偿给电磁转矩处,使得系统阻尼系数增大的同时能够保证系统动态响应性能。并给出参数设计方法,首先利用负载转速/电磁转矩间传递函数、负载转速/给定转速间传递函数分析反馈系数对机械谐振抑制效果的影响,为了得到最优控制性能,提出利用权衡系数对反馈系数进行评估,权衡抑制效果和系统整体响应性能而得出反馈系数最优取值范围;利用转速增量与输出电磁转矩增量的相位关系,得出滤波时间常数取值范围与轴系刚度系数和谐振频率的定量关系,证明了转速负反馈抑制方法对负载惯量变化的鲁棒性,为该方法工程应用提供理论指导。仿真与实验研究表明按照该文提出的参数设计方法设计的转速负反馈能有效抑制机械谐振,该方法对负载惯量变化具有强鲁棒性。

The elastic connection devices in the Servo motor drive system lead to mechanical resonance.This paper proposes a mechanical resonance suppression method based on speed negative feedback.This method compensates the speed including high-frequency components of resonance frequency to the electromagnetic torque,increasing the system damping coefficient and ensuring system performance simultaneously.The parameter design method is given in the paper,analyzing the influence of the feedback coefficient on the mechanical resonance suppression by using the transfer function of load speed/electromagnetic torque and the transfer function of load speed/given speed firstly.In order to obtain the optimal control performance,this paper proposed the use of trade-off coefficient to evaluate the feedback coefficient,weigh the suppression effect and the overall response of the system to obtain the optimal range of feedback coefficient;based on the phase relationship between the increment of speed and output electromagnetic torque,the quantitative relationship between the range of constant filter time and the stiffness coefficient of the shaft and the resonance frequency is obtained.The robustness of the speed negative feedback suppression method to load inertia change is proved,which provides theoretical guidance for engineering application of the method.The results of simulation and experiment show that the speed negative feedback can effectively suppress the mechanical resonance according to the parameter design method proposed in this paper,and the method has strong robustness to the change of load inertia.