给定精度条件下三维激光扫描距离及有效覆盖范围选取方法

Method for Selecting 3D Laser Scanning Distance and Effective Coverage Range under Specified Accuracy Conditions

摘要: 针对三维激光扫描在给定精度条件下扫描距离及覆盖范围缺乏客观选取依据的问题，提出一套基于标定试验与数据分析的三维激光扫描参数选取方法。以标准板矩阵为标定对象，室内布置标靶球与标准板，采用徕卡RTC360在1~4 m典型距离、近似正射条件下采集点云，利用“同点多次测量平均 + 标准板四边尺寸误差平均”策略获取点位精度指标，绘制不同距离下的点位精度分布图。将单站参数归纳为“扫描距离”和“有效覆盖范围”两个指标，建立目标精度与推荐参数对应关系，并给出≤2 mm、2~3 mm、≥3 mm三类精度需求的典型组合。进一步选取模拟装配构件端面对接特征开展验证，在推荐扫描距离1 m条件下，端面宽度(3个高度)与9条标贴长度的平均误差均控制在2 mm以内。算例表明，该方法能揭示精度随距离和视场位置变化，将参数选取由经验判断转化为可查询规则，适用于预制构件、钢结构等具有精度要求的工程场景。

Abstract: To address the lack of objective criteria for selecting scanning distance and coverage range in three-dimensional laser scanning under specified accuracy requirements, a parameter selection method based on calibration experiments and data analysis is proposed. A matrix of standard plates is used as the calibration object, with target spheres and plates arranged in an indoor environment. Point clouds are acquired using a Leica RTC360 at typical distances from 1 to 4 m under approximately normal incidence. A two-stage averaging strategy, combining repeated measurements at the same point with averaging of dimensional errors along the four edges of each standard plate, is employed to obtain point-wise accuracy indices and derive accuracy distribution maps at different distances. Single-station parameters are then summarized into two indices, namely scanning distance and effective coverage range, and a correspondence is established between target accuracy and recommended parameter combinations for three accuracy levels of ≤2 mm, 2~3 mm and ≥3 mm. An end-face feature measurement test on a simulated assembly component is further conducted, showing that at the recommended 1 m distance, the average errors of the end-face width (three height levels) and nine tape-mark lengths are all within 2 mm. Case study results demonstrate that the method reveals the variation of accuracy with distance and field-of-view position, transforms parameter selection from empirical judgement into a queryable rule set, and is applicable to engineering scenarios such as prefabricated concrete components and steel structures with specified dimensional accuracy requirements.