According to the elaborate analysis on friction at home and abroad, a dynamic friction compensation method is proposed to compensate the system ’ s friction force at low velocity . a dynamic friction model is build and a friction observer is designed for ordinary position servo system 在对国内外研究现状进行深入分析的基础上,提出了系统低速运行时摩擦力的动态补偿方法,并针对常见的电液位置伺服系统建立摩擦模型、设计摩擦观测器。