光学式轴孔内径在线测量方法研究与误差分析

Analysis on Optical Shaft Hole Diameter Online Measurement Method and Error Analysis

轴孔内径尺寸测量是发动机箱体检测中的一项关键技术,是提升发动机性能和质量的必要手段。为提高轴孔内径在线测量水平,同时克服现有方法的局限性,提出一种新型光学式多方向轴孔内径测量方法。该方法借鉴气动量仪的布局,均匀分布激光位移传感器于测棒截面,并根据发动机箱体轴孔的结构特点,匹配测棒长度和测量截面层数。为评价装配误差和测量随机误差对测量精度的影响,利用遗传算法分析内径测量数学模型,寻找影响最终测量误差的关键因素,并以此作为指导测量的依据。结合校准过程,通过比较轴孔内径的测量值和已知检定值,证明该方法内径测量误差优于5μm。试验结果表明该方法可以用于轴孔内径的高精度自动化在线测量。

The measurement of shaft hole diameter is a key technology in the engine box tests, and it is also a necessary mean to enhance the quality of engine production. In order to improve the shaft hole diameter online measurement level, while overcoming the limitations of existing methods, it propose a new type of optical multi-directional shaft hole diameter measurement method. Drawing on the layout of the pneumatic measuring instrument, the method uniformly distributes the laser displacement sensors in the probe cross-section, and in accordance with the structural characteristics of the engine box, matches the probe length and measuring cross-section layers. To evaluate the influence of assembly error and random errors to the measurement accuracy, genetic algorithms is used to analysis of the internal diameter measurement mathematical model to find the key factors affecting the final measurement error which is a basis for guiding measurement. It is compared that the measurement values and test values of the shaft hole diardeters at different positions in the hole by combining with the calibration process, and it is proved that the measurement error of this method is better than 5μm. The result verifies that this method can be used to achieve precision automated online measurement of the shaft hole diameter.