电液负载模拟器摩擦参数辨识及补偿

针对摩擦干扰在电液负载模拟器控制中的影响，提出了将被试件简化为自由伸缩刚性杆的摩擦力作用模型。模型中采用能全面反应摩擦特性的LuGre模型描述摩擦力大小。LuGre的静力摩擦系数和动力摩擦系数依托两种特殊工作状态进行辨识，相应的辨识数据验证了所求系数的准确性。摩擦补偿具体实施时，利用结构不变性原理，求解出摩擦补偿控制器。在此基础上，对负载模拟器开展了位移伺服、力矩伺服、多余力等方面的摩擦力补偿实验。实验结果表明，所求解的LuGre模型及摩擦补偿控制器可以较好地消除摩擦力对负载模拟器控制的影响。

Friction parameter identification and compensation for electro-hydraulic load simulator

Due to the interference of friction while controlling the electro-hydraulic load simulator, a new model with the consideration of friction was presented. In this model, the test sample was simplified as retractable rigid rods and LuGre model was used to describe the friction. The friction coefficients of LuGre model could be identified based on two specific working conditions and the accuracy of coefficients can be verified by virtue of the corresponding identification data. In order to validate the feasibility of proposed model, the friction compensation controller was deduced on the basic of structural invariance principle. Then a large number of experiments including displacement servo, torque servo, redundant force et al, were carried out. Experimental results show the friction acting on load simulator can be eliminated with the employment of LuGre model and friction compensation controller.