复杂曲面零件加工精度的原位检测误差补偿方法

为提高复杂曲面零件的数控机床原位检测精度，分析影响接触式检测系统精度的各项因素及其误差补偿方法。对检测系统的主要误差来源如机床几何误差、测头预行程误差和测头半径误差进行分析研究。在对数控机床的几何误差进行分析和建模的基础上，采用激光干涉仪进行三轴数控机床的单项误差测量和补偿；针对测头检测过程中存在的预行程误差，提出基于径向基函数(Radial basis function, RBF)的预行程误差预测方法，获得测头预行程误差分布图，并对检测系统进行实时预行程误差的补偿；提出改进的三角网格模型顶点法矢计算方法，有效进行三维测头的半径补偿。通过实例零件的加工精度原位检测试验及其与三坐标测量机CMM检验结果的比较，验证了原位检测方法的有效性。

In-situ Inspection Error Compensation for Machining Accuracy Improvement of Complex Components

In order to improve in-situ inspection accuracy of complex surface components, error factors influencing the inspection accuracy of the on-machine inspection system are discussed and error compensation methods are studied. The main errors of the inspection system are analyzed which contain geometric error of machine tools, pre-travel error of the inspection system and radius error of measuring probe. The geometric error model of a three-axis numerical control machine tool is established and each individual error value is identified and obtained through laser interferometer. For the pre-travel error of the inspection system, a radial basis function algorithm based prediction method is proposed and implemented. Based on the distribution of the pre-travel probe error obtained, an real-time compensation of the error can be performed during the actual inspection process. Considering the probe radius and its compensation of the contact-type measuring system4, a new algorithm is developed to improve the calculation accuracy of the normal vector which will affect the compensation accuracy. To verify the effectiveness of the proposed method, a complex part is exampled. Through the comparison of the in-situ inspection result with that of the CMM measurement, the proposed inspection system can achieve a great improvement of the inspection accuracy.