Coulomb干摩擦模型与LuGre摩擦模型的分析与比较

An Analysis and Comparison of Coulomb Dry Friction Model and LuGre Friction Model

分析比较Coulomb干摩擦模型和LuGre摩擦模型的特点。Coulomb干摩擦模型形式简单,能较好地反映stick-slip运动状态的切换,但不能反映对系统动态响应有直接影响的不同的摩擦现象,且其不连续性也给数值仿真带来了困难。LuGre摩擦模型能捕捉滑动速度变化时摩擦力的变化,使其适用于stick-slip运动的研究,然而其参数的确定十分困难,且在数值计算时需要取较小的步长才能进行求解,计算效率较低。分别应用这两种模型仿真分析含摩擦滑移铰平面刚体的stick-slip现象,通过具体算例对数值方法进行说明,并给出了结论。

An analysis and comparison are carried out to show the characteristics of the Coulomb dry friction model and LuGre friction model.The Coulomb dry friction model is simple and can better reflect the switching of stick-slip motion.However,this model cannot reflect different friction phenomena that have direct influence on the dynamic response of the sys＇ em.This model is not continuous,which leads to numerical simulation difficulties.The LuGre friction model can capture the variation of friction force with slip velocity,thus making it suitable for studies on stick-slip motions.However,the model parameters of the LuGre frictional model can hardly be determined from any experiment.It is necessary to take small time step sizes to solve the numerical calculation,and the computation efficiency is low.The Coulomb friction model and the LuGre friction model are applied respectively to analyze the stick-slip phenomenon of the plane rigid body with friction-affected sliding joints.The numerical examples are given to illustrate the numerical method,andthe conclusion is summarized.