针对摩擦非线性影响直流伺服系统控制性能的问题，提出了一种基于LuGre模型的变增益自抗扰控制（VGADRC）方法。建立了含LuGre模型的直流伺服系统微分方程模型。基于该模型设计摩擦补偿与自抗扰控制(ADRC)相结合的复合控制器。该控制器在不增大观测器增益的前提下，利用LuGre模型前馈补偿系统中的摩擦非线性，同时减小量测噪声对系统的影响。此外，为抑制传统线性扩张状态观测器（LESO）初始时刻引起的峰值问题，采用三阶变增益线性扩张状态观测器(VGLESO)对系统中的总扰动进行估计。最后仿真结果表明，采用所提控制方案能有效提高系统的低速跟踪性能和动态性能。

The friction nonlinearity affects the control performance of the DC servo system. To solve this problem, a variable gain active disturbance rejection control (VGADRC) method is proposed. A differential equation model of the DC servo system with the LuGre model is established. Based on this model, a composite controller combining the friction compensation and the active disturbance rejection control (ADRC) is designed. Without increasing the observe gain, the LuGre model of the controller is used to feedforward compensate for the friction nonlinearity in the system. At the same time, the effect of measurement noise on the system is reduced. In addition, to suppress the initial moment peaking of the conventional linear extended state observer (LESO), the third-order variable gain linear extended state observer (VGLESO) is used to estimate the total disturbance in the system. Finally, the simulation results demonstrate that the proposed control method can effectively improve the low-speed tracking performance and dynamic performance of the system.