In its i-Construction policy, the Ministry of Land, Infrastructure, Transport and Tourism has stipulated a manual for public surveying using by UAV photogrammetry with the aim of improving ...productivity at construction sites. However, UAV photogrammetry requires a huge amount of time to generate point cloud data from photographs, causing a problem that it is difficult to monitor the daily progress of the construction site. There is another problem that it is incapable of taking measurements except daylight hours.Against this backdrop, we have been developing laser scanner units for UAV equipped with LiDAR, IMU and GNSS receiver. Then, we clarified the error factors that are expected to affect the precision prescribed of point cloud data and summarized the requirements for the onboard equipment and the method of generating point cloud data. However, we have not yet proposed nor developed the laser scanner units as well as for generating point cloud data considering these requirements. Thus, in this paper, we developed the laser scanner units and a new method for generating point cloud data within the laser scanner units to optimize the error factors based on these requirements clarified in the existing study.
The Ministry of Land, Infrastructure, Transport and Tourism is promoting the use of three-dimensional models in order to improve the efficiency and sophistication of bridge maintenance. For existing ...bridges, it is not easy to generate a three-dimensional model that conforms to the specifications from paper drawings. There are many bridges for which no drawings are left, and there is a problem that the drawings cannot be referred to during inspection and the inspection results cannot be recorded in the drawings. In this study, we generated the three-dimensional model from the data measured the actual bridge using the terrestrial laser scanner, UAV equipped with a camera, and Mobile Mapping System. It is used as a basis for recording information related to maintenance. We proposed a method to build a three-dimensional model by applying parametric modeling to the point cloud data. The proposed method was verified using the point cloud data acquired by each measuring device, and showed that a three-dimensional model can be constructed even if some of the data is missing.
As Laser measurement technology has made remarkable progress in recent years and the means of measuring the three-dimensional shapes of road spaces as point cloud data have diversified, point cloud ...data has been measured and accumulated throughout Japan. Point cloud data is useful as a means of accurately grasping the present shape and is expected to be utilized for a wide range of purposes with i-Construction as a turning point. Existing efforts have promoted development of new technologies and open data, steadily increasing opportunities to use point cloud data. However, it is difficult to use point cloud data wisely in accordance with its intended purpose because it is merely a vast set of points that indicate locations in space and does not hold information about the features indicated by the points or about their relationships to other points. Therefore, it is essential to develop an environment for utilizing point cloud data. In this study, we develop 3D Point Studio, a platform for utilizing and sharing 3D data including point cloud data by utilizing area data. The usefulness of this research will be confirmed through examples of applications in the actual sites, and its future development will be discussed.
This paper analyzes how to achieve the accuracy of the lidar data processing. In this paper, we analyze the ways about classification of the point cloud data and extraction of the attribute feature ...data. We find a way on attaching attribute information to the point cloud data sets. At last, we use rough set algorithm to excavate clustering rules from a large number of the point cloud data. We achieved the point cloud data clustering by the method of rough set, and completed the recognition of obstacles.
In this study, the authors propose an effective real-time approach for intersection detection and recognition during autonomous driving in an unknown urban environment. The authors approach use point ...cloud data acquired by a three-dimensional laser scanner mounted on the vehicle. Intersection detection and recognition are formulated as a classification problem whereby roads are classified as segments or intersections and intersections are subclassified as T-shaped or +-shaped. They first construct a novel model called a virtual cylindrical scanner for efficient feature-level representation of the point cloud data. Then they use support vector machine classifiers to resolve the classification problem according to the features extracted. A series of experiments on real-world data sets and in a simulation environment demonstrate the effectiveness and robustness of the authors approach, even in highly dynamic urban environment. They also performed simulation experiments to investigate effects of several critical factors on their proposed approach, such as other vehicles on the road and the advance detection distance.
Torso of female lower body feature such as waist, abdomen and hip is the key factor of pants and skirt design so that rules confirm is the important point in the research of automatic generation of ...pants pattern and skirts pattern. In the three-dimensional human body scanner, a certain difference exists of human lower body torso 3D sizes between scanner data and actual measurement data so that research of calculation rules of lower body torso 3D sizes becomes necessity. In this research, 425 female students at Soochow University from 18 to 26 years old were selected as subjects. Point-cloud diagrams can be obtained by using 3D body scanner and be read by using IMAGEWARE software and then each 3D size and width and thickness of each 3D section. Then classification can be done according to the value of thickness and width with 0.05 file and relations between width and girth, between thickness and girth can be analyzed by using SPSS16.0 to obtain calculation modules of each 3D size then its accuracy can be verified to provide the basis for valid application of three dimensional body scanner and lay foundation of the prototype generation of female pants, design of trousers and automatic pattern generation system research.
Under the background of rapid development of geographic information system (GIS) technology, how to effectively describe and process all kinds of three-dimensional information in urban space has ...become an urgent problem to be solved. This paper focuses on the construction of urban 3D modelling system. The point cloud data obtained by laser scanning or photogrammetry can provide accurate spatial information of urban buildings, including the shape, size, location and structure of buildings, etc. Using these point cloud data, the key technologies such as the fully automated extraction of digital elevation model, the representation of architectural model, and the reconstruction of urban 3D geomorphology are investigated. A large number of experiments are carried out to verify the proposed theory and method. The experimental results show that the average deviation of the models for window 1, billboard, door, floor corner and window 2 is 6.2mm, which is much lower than that of BIM (building information modelling) technology and computer vision and point cloud data.
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