摘要
挖掘臂的液压缸摩擦力使系统动态特性恶化,对其进行有效的摩擦补偿是提高控制性能的关键。为获得液压缸的精确摩擦模型,建立了铲斗关节动力学方程,方程中分别采用了库仑摩擦、库仑+黏性摩擦及Stribeck摩擦模型。针对系统中存在的有色噪声,采用了改进的递推最小二乘法辨识未知参数。将辨识的三种摩擦模型进行对比分析表明,Stribeck摩擦模型精度最高,能很好地预测液压缸驱动力。其中,Stribeck摩擦模型的辨识误差比库仑+黏性摩擦及库仑摩擦分别减少约8%与18%。
The friction force of the hydraulic cylinder of an excavator arm deteriorates its dynamic properties. Therefore, the effective friction compensation for the hydraulic cylinder is important for improving its control per formance. In order to construct a precise friction model of the hydraulic cylinder, we build the dynamic function for the bucket joint and use in it the coulomb friction, the coulombviscous friction and the stribeck friction respective ly. Due to the colored noise in the hydraulic cylinder, we use the improved recursive least squares method to esti mate the unknown parameters. The comparison results on the three friction models show that the identified Stribeck model is the most accurate one and that it can effectively predict the actuation force of the hydraulic cylinder. The identification errors of the stribeek model are about 8% and 18% less than those of the coulombviscous model and the coulomb model.
出处
《机械科学与技术》
CSCD
北大核心
2013年第6期814-818,共5页
Mechanical Science and Technology for Aerospace Engineering
基金
国家自然科学基金项目(51175511)资助
关键词
挖掘臂
液压缸
摩擦
辨识
递推最小二乘法
mathematical models
least squares approximations
functions
excavator arm
hydraulic cylinder
friction force
identification error
recursive least squares method
friction model
dynamic function
