附加物方长度约束的三维坐标交会测量

Intersection measurement of 3D coordinates with object length constraints

大型粒子加速器等精密工程在加工制造及设备安装等方面对空间三维坐标精度提出了极高的要求,在利用多路绝对激光测距仪进行多边交会测量空间点三维坐标的基础上,在物方(目标点所在物体)上附加高精度长度约束以进一步提高点位精度。以多路绝对激光测距仪的高精度绝对测距性能为基础,通过已建立的三维测边网及免自标定的激光多边交会测量平差模型,得到高精度的目标点空间三维坐标。在此基础上,附加涵盖目标点信息的物方长度约束,建立对应的附有条件的参数平差模型,进行平差解算。实验分析表明,在多边交会测量基础上附加物方长度约束,可提高物方目标点坐标的精度,在8 m×3.5 m×2.5 m的整体实验范围内,点位精度最高提升0.74μm,较原精度提升27.0%。该方法可操作性强,可用于现代装备制造业中高精度大尺寸坐标测量。

Precision engineering such as large-scale particle accelerators has high requirements for the accuracy of 3D coordinates in processing and equipment installation.To further improve the point measurement accuracy,high-precision length constraints are added to the object where the target points are located in carrying out the multi-lateral intersection measurement of the 3D coordinates by using a multi-channel absolute distance measurement system.Based on the high-precision absolute distance measurement performance of the multi-channel absolute laser diastimeter,the high-precision spatial 3D coordinates of the target points were obtained in this study by using the established 3D edge measurement network and the adjusted model of self-calibration free multilateral laser intersection measurement.The object length constraints covering the information about target points were added and a corresponding conditional parameter adjustment model was established to implement the adjustment operation.The experimental results show that adding object length constraints based on multilateral intersection measurement can improve the accuracy of target point coordinates.Within the overall experimental range of 8 m×3.5 m×2.5 m,the point accuracy can be increased by 0.74μm,which is 27.0%higher than the original accuracy.The proposed method is easy to operate and can be used for high-precision and large-size coordinate measurement in modern equipment manufacturing industries.