基于微定位工作台的精密磨削过程动力学建模与误差补偿技术

为了消除传统平面磨床砂轮振动对加工精度的影响,提出了采用自行设计的纳米级微定位工作台进行在线动态补偿的方法。为了对平面磨床的动平台上安装有微定位工作台的新型机床磨削过程的特性进行研究,分析了磨头-砂轮-微定位工作台组成系统的动力学行为。运用模态综合理论和拉格朗日方程建立了磨削过程模态坐标下的动力学模型,并利用状态空间方法得到了磨床在模态坐标下振动响应的数值计算公式。由振型叠加原理,得到具有微定位工作台补偿装置的新型平面磨床在物理坐标下的响应。在此基础上分析了磨床系统的动态特性和补偿前后的加工精度。仿真结果表明,采用微定位工作台进行在线振动补偿,可有效地提高加工工件的表面质量。

MODELING OF PRECISION GRINDING PROCESS BASED ON MICRO-POSITIONING TABLE AND ERROR COMPENSATION TECHNOLOGY

In order to eliminate the influence of the wheel vibration on machining precision of the workpiece, a micropositioning workpiece table with nanometer resolution is utilized to implement dynamic compensation. In order to study the characteristics of the grinding machine modulate with micropositioning table, the modal synthesis method and Lagrange's equation are utilized to establish the dynamic equation of the intelligent grinding machine system. According to the fact, the whole system is divided into three subsystems connected by two constrain matrixes. Using the state-space method, the numerical solution is obtained. Then the response of the system can be achieved using the principle of modal superposition. Accordingly, the dynamic characteristics of the system and machining precision before and after compensation are analyzed. The simulation results show that the machining accuracy of the workpiece can be effectively improved by utilizing the micro-positioning workpiece table to implement dynamic compensation.