Naruo Kano

Application of location information by stereo camera images to project progress monitoring

In this paper, the authors discussed the overview of a method for estimating the 3-D coordinated data for development of a project control system with stereo camera images. The information for control project with location information in the 3-dimensional space of time series from images is proposed. SFM (Structure From Motion) is used for collection of camera motion and 3-D object data. The image collection on actual construction site was performed and 3D structure from stereo camera images was evaluated. According to the result, the possibility of the monitoring and the factors necessary to development for practical were proposed.

A Location System with RFID Technology in Building Construction Site

In this paper, the authors explained the overview of data sampling method for development of a location system for workers using RFID technology. Data is the RSSI (Receive Signal Strength Indication) from RFID tag attached to the worker installing a rolling shutter, and was obtained from antennas and RFID readers set around the construction site. Discriminant analysis was done using RSSI collected and the area where worker is performing a task, and a estimation model of the working area was prepared. The model had a range of the percentage of correctly classified from 3% to 30%. The authors suggested the method to make estimate by using integrated models prepared in respect of RFID readers, and showed the percentage of correctly classified of 43.2%. According to the result, the authors confirmed the possibility of the location system with RFID technology, and mentioned the factors necessary to develop for further practical use.

Comparison of construction photograph and VR image in construction progress

Abstract—A photograph always makes an image of objects as they are without any alteration, so that a photograph is recognized as highly accurate information. Thus the photograph has been widely used as a record of site, routine work particularly for construction control and inspection. As a characteristic of photograph, the point of view for a photo image is identical to that of a VR image which can be created based on 3-dimensional CAD. In other words, matching of the photo image and the VR image provides a convenient way to examine the difference between the actual situation in a job site and the design drawing for the building. This paper suggests the method for determination of the 3-dimensional viewpoint and the direction vector of a construction photograph to perform comparison of the construction photograph and the corresponding VR image. In addition, through a case study in which acquisition of construction photographs and comparison of construction photographs and VR images according to the elapsed time have been carried out, the validity of proposed methods has been well proved.

An Estimating Method of Worker's Task with 6-DOF Sensors

Recently construction workers tend to work alone and are getting older. In such working atmosphere, monitoring their works at the site is necessary for keeping task performance quality and accuracy. However, the management and evaluation of workers’ performance can only be done by supervisors’ physical observation. Understanding of their works will be easier if the data that shows what kind of task is performed can be estimated from their body positions and movement, and that enable monitoring by data obtained concurrently. Data for body positions and movements of workers was obtained and measured by using 6-DOF motion sensors, and the method to estimate the type of task by using neural network is described. Finally the authors developed the method to monitor the work at the site using the data obtained by 6-DOF motion sensors and systemized the estimation procedure.

Laser Marking System Based on 3D CAD Model

In many cases of renovation work, it is very difficult to gain sufficient information about the existing building such as the positions and dimensions of the frame, interior and equipment because of incomplete or missing drawings. As a result, it is necessary to fabricate the parts on the construction site. We have been developing a system for measuring existing buildings precisely using a 3D laser scanner before renovation work, fabricating the parts in factories and assembling them on site. This system will increase productivity and eliminate construction waste. The system requires a function for positioning of the parts and marking precisely on the site. Our developed marking system determines positions from 3D-CAD data and indicates them with a motor-driven Total Station. The position data is produced from objects such as points and lines stored in a design file, and is saved as a marking data file. The Total Station reads the data file and marks the positions by laser automatically and precisely. This report describes the function to produce the position data file and to mark the positions with the Total Station. It also shows the results of a field test at an actual construction site. This research was carried out with a grant from the Ministry of Land, Infrastructure, Transport and Tourism.

A Study on the Application of VR Technique to Building Construction - Comparisons of Site Photo and VR Image in Construction Progress

Photo taking at an actual job site provides a very useful tool for the record of construction progress and the inspection of built-up members. The photos are also utilized as essential data to carry out the control of construction progress in virtual space. Besides, the situation of construction progress at an actual site might well encounter a conflict with the construction plan that was prepared before the beginning of construction. This invokes the importance of use of site photos in VCS(Virtual Reality Construction Site) that enable the real time construction control by comparing themselves to the images from virtual reality. In this study the comparison between the site photo taken at an actual job site and the virtual images corresponding to them was carried out to estimate validity of the proposed VCS. Particularly this paper demonstrates the possible troubles during development of a prototype system by acquisition of the site photos from an actual job site.

Construction Management Tools Using 3D-CAD, Virtual Reality, RFID, and Photography Technologies

Since the development of the PERT/CPM method in 1958, many planning and controlling tools have been developed; however, no method has exceeded the PERT/CPM to make an epoch-making impact on the methodology for planning and controlling at a construction site. The advanced technologies are strongly expected to serve as platforms for the development of new planning and controlling tools. 3D-CAD, Virtual Reality and RFID technologies with conventional photography technology are expected to be key technologies to change the way of planning and controlling. This paper discusses the significance of these four technologies in construction management. Through the case studies carried out at Waseda University, the author pursues the feasibility of new tools for construction management.

Development of an adaptable system for effective utilization of architectural space

In this paper, the authors referred to the development of the suitable modification technology of architectural space in alignment with change in circumstance surrounding lifestyle of residents as necessary. A design method of architectural space and building elements, and a handling method of structural objects of having used robotic technology are proposed as a proposal of adaptability of building. The development and design of a Floor Adaptable System (FAS), which can modify architectural space by moving up and down of floor units, was performed. The Floor Adaptable System installation and test operation was done in WABOT-HOUSE, and showed the operation process. According to the result, the authors confirmed the possibility of the Floor Adaptable System with hydraulic jacks, and mentioned the factors necessary to develop for further practical use.

A study on measuring of reinforced-concrete structure by 3D laser scanner and making design of pre-cut interior finishing components with polygon model

To achieve renovation work without noise, the authors developed techniques of manufacturing pre-cut interior finishing components for renovation work. In this paper, to achieve the system of pre-cut interior finishing components, the authors describe a measuring method of reinforced-concrete structure by 3D laser scanner and then describe a method of making a design of pre-cut interior finishing components with the polygon model. Using these two methods, the steps of manufacturing pre-cut interior finishing components consist of the following four steps: First, measure the building shape using a 3D laser scanner. Secondly, integrate a point cloud data and retrieve the markings on the floor. Then, create a polygon model of the building based on the point cloud data. Lastly, make a drywall design using a polygon model. To evaluate the technique feasibility of manufacturing pre-cut interior finishing components, the authors have conducted an experiment of the finishing interior work of the drywall. Using pre-cut interior finishing components, the authors have been able to achieve interior finishing work without noise.

A study on the optimization method for panel layout problem in drywall

This study is aimed at developing methods to optimize the material yield of drywall panels. In this paper, the authors describe the drywall panel layout optimization method which consists of the following three steps: first, to generate possible alternative patterns of drywall panel layout in a wall; second, for each alternative pattern, to find out the best combination of panel parts to be cut from a panel of standard size; third, to solve the cutting length of panels, the waste volume of panels and the length of panel joints in each layout pattern. The authors applied this method to minimize the cost of drywall using plaster board (1820×910mm). The method generates possible patterns of drywall panel layout in the wall and acquires the best combination of panels to be cut from a standardsize panel, then estimates the cost of drywall works in each pattern.