凸轮轴磨削加工轮廓误差的自适应控制

Adaptive Control of Cam Contour Error in Camshaft Grinding Process

凸轮轮廓误差的大小直接反映了凸轮磨削加工的精度,由于磨削过程中凸轮轮廓误差不能通过测量获得,该文推导了一种在极坐标系下凸轮轴磨削加工轮廓误差的表达式;采用两轴交叉耦合误差补偿模型,保证砂轮进给和工件旋转运动之间的数学关系;由于磨削力扰动、非线性因素及动力学模型的不准确等会降低轮廓精度,结合交叉耦合轮廓控制器,采用了模型参考自适应控制技术,通过在线计算轮廓误差,调节进给量,使实时轮廓误差满足精度要求。

Cam contour error reflects the cam grinding process precision directly.Based on the fact that the Cam contour error can＇t be real-timely measured,this paper deduces a cam contour error expression in camshaft grinding process in polar coordinates.The cross-coupled biaxial error compensation model has been established to ensure the mathematics relationship between the grinding wheel feeding movement and the work piece rotating movement.For that the factors such as grinding force disturbance,non-linearity and non-veracity of dynamics model will reduce contour precision,a model-referenced adaptive control with cross-coupled contour controller is adopted to adjust feed rate on line,which process is that the online error information is estimated by terms of contour error in order that the interpolation controller calculates the biaxial command value.Therefore,the grinding process precision is advanced highly.