移位法和双测头法直线度误差分离的精度分析

An Accuracy Analysis of the Straightness Error Separation by the Displacement Method and the Double-probe Method

讨论了目前一直在工程实践中应用的移位法和双测头法直线度误差分离中存在的一些问题，并与两步法圆度误差分离技术进行了对比，认为：移位法直线度误差分离的精度对移位时的微量角位移十分敏感，工程应用中精度较难保证；双测头法直线度误差分离存在较大的理论误差。

Theerror separating technique is widyuscd to reduce the dependency of the measuringaccuracy of straightness and roundness on the data accuracy.Some problems concerning thedisplacement method and the double-probe method used in engineering practice to separatethe straightness error from data error are discussed.By drawing an analogy to the results oftheoretical analysis obtained in roundness error separation by the two-step method,it is con-clude that:(a)The accuracy of straightness error separation by the displacement method isvery sensitive to microangular displacement and so it is doubtful if the accuracy can be guar-anteed in practice;(b)There exists another great theoretical error in double-probe methodstraightness error separation,especially in the case where there is a long section that appearsto be convex or concave,Therefore,great care should be taken if it is to be used.