摩擦现象的存在将直接影响到非线性伺服系统的跟踪性能，进而影响到系统的稳定性和可靠性。目前，大多数非线性伺服系统摩擦建模和补偿控制研究主要存在两方面的问题：首先，现有的摩擦模型大多只是针对低速摩擦的情况而提出的，当伺服系统具有较高的运动速度和加速度要求、需要频繁进行速度换向时，单一的低速摩擦建模方法将会变得不够准确；其次，非线性伺服系统常常会受到模型不确定和外部干扰的影响，使得摩擦辨识和补偿精度大大降低。本项目拟研究一种新的分段参数化摩擦动态模型，建立非线性伺服系统在高、低速运动中摩擦动态的统一辨识模型，提高摩擦建模的精度。通过采用扩张状态观测器技术，补偿伺服系统的不确定因素，降低控制性能对摩擦建模精度的依赖性。此外，结合有限时间控制方法和协同控制理论设计有限时间协同控制器，提高伺服系统的响应速度和鲁棒性。因此，本项目的研究具有重要的科研价值和实际应用前景。

The existence of friction phenomenon will directly affact the tracking performance of noninear servo systems, and even affect the system stability and reliability. Presently, most research approaches on friction modeling and compensation control for nonlinear servo systems mainly have two main issues: First, the existing friction models are proposed only for low-speed friction situations, however, the single low-speed friction modeling method will become not precise any more in the case that the servo system requires higher motion velocity and acceleration, and the velocity direction needs to be changed frequently. Secondly, model uncertainties and external disturbances always exist in nonlinear servo systems so that the friction identification and compensation accuracy will be much deteriorated. In this project, a novel piecewise parameterized friction model is proposed, and an unified identification model of the friciton dynamic is built for nonliear servo systems in high-speed and low-speed motion processes to improve the friciton modeling accuary. By employing the extended state observer (ESO) technique, the uncertainties existing in servo systems can be compensated and thus the dependence of control performance on modeling accuracy is reduced. Moreover, a finite-time synergetic controller is designed to improve the response speed and robustness of servo systems by combining the finite-time control method with the synergetic control theory. Therefore, the research of this project has important scientific research value and practical application prospect.