基于LuGre模型的气缸摩擦力特性研究  

Analysis of friction characteristics of pneumatic cylinders based on LuGre model

作　　者：孟德远[1] 陶国良[1] 刘昊[1] 陈剑锋[1] 

机构地区：[1]浙江大学流体传动及机电控制国家重点实验室,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2012年第6期1027-1033,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(50775200)

摘　　要：为满足高精度电-气比例/伺服控制系统设计时基于模型的摩擦力补偿需要,基于LuGre模型建立气缸的动态摩擦模型.搭建了一个新型的气缸摩擦力测试台,通过测量活塞匀速运动时摩擦力与活塞速度的关系辨识了模型中的静态参数;针对在时域估计模型动态参数存在诸多困难,提出将活塞的运动方程在平衡点附近线性化,通过测量活塞位移和驱动力之间的频率响应函数来间接估计动态参数值.测试了气缸在不同腔内压力下的摩擦力特性,结果表明:库伦摩擦力、最大静摩擦力和黏性摩擦系数与压力近似成线性关系,而Stribeck速度和模型动态参数基本不受气缸两腔压力变化影响.正弦变化力激励下的活塞位移计算曲线和实验结果对比表明,参数估计准确,该模型能很好的描述气缸的摩擦力特性.The LuGre dynamic friction model was introduced to fulfill the requirement of a good friction model of pneumatic cylinders in applications with high precision positioning and low velocity tracking.An experiment setup used for the friction force measurements was developed and the static and dynamic parameters associated with the model were estimated separately.The static parameters were estimated by construction of the friction-velocity map measured during constant velocity motions.And the second-order description of the linearized LuGre model in the stiction regime was used to perform the frequency domain identification of the dynamic parameters.Furthermore,the friction forces of cylinder with different chamber pressures were tested.The Coulomb friction level,the stiction force level and the viscous friction coefficient increased with the chamber pressure and the pressure difference between the cylinder chambers,while the Stribeck velocity and the dynamic parameters may be considered as independent of the pressure variation in chambers.Experimental results showed that the proposed model with the estimated model parameters can predict the friction force accurately.

关 键 词：气缸摩擦力 LUGRE模型 参数估计 频域分析 

分 类 号：TH117.1[机械工程—机械设计及理论] TH138.51