飞机复杂装配部件的全尺寸数字化综合测量与评估,能为飞机制造质量的持续提升提供重要的数据基础。测量工作要求在没有专用测量工装、不影响后续装配工序、受现场环境限制的情况下进行,具有被测对象外形复杂、存在自身遮挡、各部位测量数据要求不同、数据拼合及模型配准困难等难点。本文提出一种综合采用离散目标点摄影测量、结构光面扫描测量和手持式光笔接触测量的现场测量方案,以相互兼容的视觉目标靶点为不同测量方法之间数据定位融合的桥梁,实现了复杂装配部件的全尺寸现场测量。为使测量数据与CAD数模有高可靠性、高精度的配准,研究了配准点集的约束强度度量指标,以及配准误差的定量分析方法,在此基础上提出了配准约束强度优选参考值和临界阈值,可以有效指导飞机装配部件的现场数字化综合测量和质量评估。运用提出的综合测量方法和配准点选取准则,对某型飞机前机身进行了现场实际测量和数据分析,为复杂装配部件几何精度综合评估提供了有效方法和数据依据。
The 3D measurement and evaluation of aircraft assemblies can provide critical data in the manufacturing process for quality enhancement.It is a complicated task to measure a complex aircraft structure during manufacturing with the requirements of no auxiliary equipment for the measurement,no influence on the assembly process,and numerous other restrictions at the site.Difficulties in the task include measure the object in various ways,realize data alignment with low accumulation error,and get data from obstructed areas.In this paper,we propose an integrated metrology approach which combines photogrammetry,structure light scanning and optical tracking measurement with a handheld probe.The data from the three types of optical measurement is unified into one coordinate system by using some designated reference points.In order to achieve high accuracy in aligning the measurement data with the CAD model,the principles for choosing the registration points are proposed based on the theory of sensitivity analysis.To demonstrate the validity of our method,an aircraft fore fuselage is measured,and the data registration using our proposed principles is performed,which shows that our method is valid and it produces accurate results for the in-process quality evaluation of complex aircraft assemblies.