Abstract: In order to meet the requirements of high precision for two-axis direct drive servo feed systems, based on friction compensation, an adaptive nonlinear sliding mode contour control(ANSMCC) method was proposed to take into account the requirements of machining precision and response speed. An equivalent contour error model suitable for large curvature contour machining was established, and considering the influences of uncertain dynamics in the system, an improved LuGre nonlinear friction dynamic model with accurate and real-time compensation was established. In order to improve the contour performance of the two-axis direct drive servo feed systems, an ANSMCC method was designed based on the nonlinear sliding mode surface, where the nonlinear sliding mode surface contained the contour error components. By changing the values of the gain matrix in the nonlinear sliding mode surface, the damping ratio of the system might be changed in real time, so as to coordinate the relationship between the contour errors and the system response speeds. The experimental results show that the proposed method may overcome the dynamic influences of uncertainty in the operation of system, accurately track the large curvature contour curves, improve the contour machining accuracy.

Key words: two-axis direct drive servo feed system, friction compensation, nonlinear sliding mode surface, contour error

摘要： 为满足两轴直驱伺服进给系统的高精度加工要求，提出一种基于摩擦补偿的自适应非线性滑模轮廓控制(ANSMCC)方法，以兼顾加工精度和响应速度要求。建立适用于大曲率轮廓加工的等效轮廓误差模型，同时考虑系统中存在的不确定性动态的影响，建立准确且能实时补偿的改进LuGre非线性摩擦力动力学模型。为提升两轴直驱伺服进给系统轮廓性能，设计基于非线性滑模面的ANSMCC方法，其中非线性滑模面包含轮廓误差分量，通过改变非线性滑模面中增益矩阵值的大小可实时改变系统的阻尼比，从而协调轮廓误差与系统响应速度的关系。实验结果表明，所提方法可以克服系统运行过程中不确定性动态的影响，准确跟踪大曲率轮廓曲线，提高轮廓加工精度。

关键词: 两轴直驱伺服进给系统, 摩擦补偿, 非线性滑模面, 轮廓误差