Recently, quantitative and repetitive inspections of the old urban area were conducted because many structures exceed their designed lifetime. The health of a building can be validated from the condition of the outer wall, while the slant angle of the wall widely serves as an indicator of urban regeneration projects. Mostly, the inspector directly measures the inclination of the wall or partially uses 3D point measurements using a static light detection and ranging (LiDAR). These approaches are costly, time-consuming, and only limited space can be measured. Therefore, we propose a mobile mapping system and automatic slant map generation algorithm, configured to capture urban environments online. Additionally, we use the LiDAR-inertial mapping algorithm to construct raw point clouds with gravity information. The proposed method extracts walls from raw point clouds and measures the slant angle of walls accurately. The generated slant angle map is evaluated in indoor and outdoor environments, and the accuracy is compared with real tiltmeter measurements.

中文翻译：

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使用 3D 点云自动生成墙倾斜角度图

近期，由于许多结构超过了设计寿命，对旧城区进行了定量和重复检查。建筑物的健康状况可以从外墙的状况来验证，而墙的倾斜角度则广泛用作城市更新项目的指标。大多数情况下，检查员使用静态光检测和测距 (LiDAR) 直接测量墙壁的倾斜度或部分使用 3D 点测量。这些方法成本高、耗时长，而且只能测量有限的空间。因此，我们提出了一种移动地图系统和自动倾斜地图生成算法，配置为在线捕捉城市环境。此外，我们使用 LiDAR 惯性映射算法构建具有重力信息的原始点云。所提出的方法从原始点云中提取墙壁并准确测量墙壁的倾斜角度。生成的倾斜角图在室内和室外环境中进行评估，并将精度与真实倾斜仪测量值进行比较。