Structural 3D Reconstruction of Indoor Space for 5G Signal Simulation with Mobile Laser Scanning Point Clouds

石莹 2021-08-08 浏览

摘要

室内三维模型重建在智慧城市中有着重要的应用，例如：建筑信息模型（BIM）、空间位置服务、能耗估算、信号模拟等。基于激光点云快速、稳健地重建三维模型已经引起了广泛的研究兴趣。然而，由于室内环境复杂，自动化重建高精度三维模型仍然是一个严峻的挑战。针对这些问题，本论文提出融合结构线要素和三维几何面要素的方法，实现了基于移动激光扫描点云自动化重建三维模型。首先，我们基于语义约束构建多标记图割模型将无序的点云自动化分割为单个房屋，解决了长廊中过分割的问题。然后，将单个房屋点云的水平切片投影到平面生成二值图像，在二值图像中提取直线，并进行线要素的规则化，以此生成结构线的平面图。我们将分割房屋点云、提取线、面要素作为语义约束，利用图优化的方法重建三维结构化模型。最后，利用基于重建的结构化模型进行了5G信号仿真，旨在服务于未来大范围室内场景中5G小基站优化选址。我们利用手持和背包移动激光扫描设备采集的四组室内点云数据对本文提出的方法进行精度评价，结果表明，该方法能够在复杂的室内场景中准确有效地重建出高精度的结构化模型。

成果介绍

图1 方法流程图

 

（a）利用手持激光点云数据（benchmark）重建多楼层室内模型

 

（b）利用深圳大学背包激光扫描点云数据重建室内弯曲走廊模型

 

（c）利用厦门大学背包激光点云数据重建室内弯曲走廊模型

（d）利用厦门大学背包激光点云重建地下停车场模型

图2 基于移动激光扫描点云重建三维室内结构化模型

图3 重建室内模型的精度评价

 

（a）仿真5G信号多路径传播 （一楼）（b）信号强度水平剖面图（一楼）

 

（c）仿真5G信号多路径传播 （二楼）（d）信号强度水平剖面图 （二楼）

图4 基于重建结构化模型的5G信号强度仿真

Abstract

3D modelling of indoor environment is essential in smart city applications such as building information modelling (BIM), spatial location application, energy consumption estimation, and signal simulation, etc. Fast and stable reconstruction of 3D models from point clouds has already attracted considerable research interest. However, in the complex indoor environment, automated reconstruction of detailed 3D models still remains a serious challenge. To address these issues, this paper presents a novel method that couples linear structures with three-dimensional geometric surfaces to automatically reconstruct 3D models using point cloud data from mobile laser scanning. In our proposed approach, a fully automatic room segmentation is performed on the unstructured point clouds via multi-label graph cuts with semantic constraints, which can overcome the over-segmentation in the long corridor. Then, the horizontal slices of point clouds with individual room are projected onto the plane to form a binary image, which is followed by line extraction and regularization to generate floorplan lines. The 3D structured models are reconstructed by multi-label graph cuts, which is designed to combine segmented room, line and surface elements as semantic constraints. Finally, this paper proposed a novel application that 5G signal simulation based on the output structural model to aim at determining the optimal location of 5G small base station in a large-scale indoor scene for the future. Four datasets collected using handheld and backpack laser scanning systems in different locations were used to evaluate the proposed method. The results indicate our proposed methodology provides an accurate and efficient reconstruction of detailed structured models from complex indoor scenes.