For shafts with a large ratio of length to diameter, the existing measurement method mainly uses a contact coordinate machine. But machining errors have a strong influence on the offline measurement results, and the accumulation errors of the measurement system also make the measurement datum difficult to identify. For this reason, a new on-machine measuring method is proposed based on the spatial analytical geometry theory to achieve the measurement of the shape and position tolerance of shafts. Through the method, the measurement system combines the line laser measuring instrument and the laser displacement sensor together. Then, the ideal central axis of the workpieces can be obtained and serve as a datum. Finally, the on-machine non-contact measurement of large-size shafts with geometric errors is realized with high measurement accuracy (<0.01 mm), high measurement efficiency (time <10 mins), and strong robustness (insensitive to installation error and measuring environment).

对于长径比大的轴，现有的测量方法主要使用接触坐标机。但是加工误差对离线测量结果有很大的影响，并且测量系统的累积误差也使测量基准难以识别。因此，基于空间解析几何理论，提出了一种新的在线测量方法，以实现对轴的形状和位置公差的测量。通过该方法，测量系统将线激光测量仪和激光位移传感器结合在一起。然后，可以获得工件的理想中心轴并将其用作基准。最后，实现了具有几何误差的大型轴的机上非接触式测量，测量精度高（<0。