基于PSD的长跨度孔系同轴度误差测量系统

以激光作为准直基准,研制了基于位置敏感探测器(PSD)的长跨度孔系同轴度误差测量系统。多功能测头在孔系内通过自定心机构确定各被测截面,测头前端的PSD检测激光光斑位置以确定各孔截面中心坐标,并进而评定出孔系同轴度误差。推导出激光自准直数学模型,根据该模型由四自由度工作台调整激光器位置,实现了激光自准直。使用本测量系统完成了激光自准直实验和孔系同轴度误差测量实验。实验结果表明:经准直后激光束与工件两端孔中心连线之间的偏差在±0.032 mm以内,与三坐标测量机相比,本系统同轴度误差测量的相对误差为8%,具备了较高的准直精度和同轴度误差测量精度。

Error measurement system of coaxiality for long-span holes based on PSD

A measurement system of coaxiality for long-span holes is developed based on position sensitive detector(PSD) and laser collimation.Measured section is determined by self-centering mechanism in holes of multifunctional probe,and the center coordinates of each hole's section are determined after laser spot position is detected by PSD at the front end of probe,by which the coaxiality error can be evaluated.Mathematical model of laser self collimation is deduced and according to the model,the laser position can be adjusted with a four-degree-of-freedom platform.The experiments of laser collimation as well as the measurement of coaxiality are performed.Experimental result shows that the deviation between the laser beam and the center line of both end holes of the workpiece is within ±0.032 mm and the relative error of coaxiality error measurement system is 8 % compared with three coordinate measuring machine,and has high precision of collimation and coaxiality error measurement.