为精确得到模型的动静态参数,提出了以稳态误差分析为基础的模型参数辨识方法.首先,确立了伺服系统的稳态误差与其输入信号、干扰信号的关系,并以此为基础消除了转矩纹波对摩擦模型参数辨识的干扰;然后,利用稳态误差推导摩擦力矩,采用遗传算法辨识动静态参数;最后,利用辨识后的模型进行摩擦补偿,分析其补偿效果.实验结果表明,补偿后的稳态误差明显减小,匀速运动时由36 μm减小到±3 μm,匀加速运动时由34 μm减小到±3 μm,正弦运动时由±35 μm减小到±7 μm.本文提出的辨识方法能够精确地得到LuGre摩擦模型的动静态参数.基于辨识后的模型可有效地提高伺服系统的跟踪精度.%To get accurate parameters in both static and dynamic models, an identification method of model parameters based on the analysis of steady state error was presented. Firstly, the relationship between steady state errors and input and interference signals in a servo system was determined, and the influence of torque ripples on the parameter identification was eliminated based on the study above. Then, the friction torque was deduced by using the steady state error, and the static and dynamic parameters were identified through the genetic algorithm. Finally, the friction torque was compensated according to the identified model, and the compensated effect was analyzed. The experimental results show that the steady state error of uniform motion has decreaseed from 36 μm to ±3 μm,that of uniformly accelerated motion decreased from 34 μm to ±3 μm, and that of sinusoidal motion decreased from 35 m to ±7 μm. It concludes that the dynamic and static parameters of LuGre can be preciseJy obtained by this identification mctlhod, and thc tracking accuracy of the scrvo systenm can also be improved through friction compensation on the basis of the proposed model.
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