BP网络在进给系统定位误差预测中的运用

针对机床进给伺服系统定位精度预测的难点,分析了进给伺服系统机械传动系统定位误差增长的原因,提出了一种定位误差预测的方法。在Adams中建立进给伺服系统动力学仿真模型,得到不同初始状态下的定位误差值,基于BP神经网络建立工作台与螺母座间隙、滚珠丝杠倾斜度、工件负载与定位误差之间的映射模型,根据映射模型提出对定位误差预测的方法。利用所建立的精密运动可靠性试验平台进行验证,证明了该方法的正确性和有效性。

A Forecasting Method of Positioning Accuracy for CNC Machine Tools Feed System Based on BP Neural Network

Aimed at the difficulty in forecasting the positioning accuracy of machine tool feed system,a new model has been established, analyzing the positioning accuracy degradation of the mechanical transmission system of feed system. Firstly, a computer numerical control(CNC) machine tool feed system model is made using a dynamic simulation software Adams to obtain positioning accuracy values for different initial state. Then, a mapping model is set up between the positioning accuracy and the gap, the ball tilt and the workpiece loading by BP neural network. According to the mapping model, the prediction method of the positioning accuracy is discussed in detail. Finaly, the method is proved to be correct and effective by conducting the test experiment of positioning accuracy on the test platform of precision motion reliability.