Abstract of Special Research Report (SRR-No.21)
National Institute of Occupational Safety and Health, Japan
Development of Comprehensive Safety Control Measures for Production and Construction Systems (Second Report; Development of Hazard Evaluation Methods for Large Scale Industrial Systems and Safety Control Measures for Construction Robots)
: As large scale computerized industrial systems such as chemical plants, factory automations and automated building construction systems has been used in many industrial fields, a comprehensive safety measure for these systems has become great concern for industrial safety.
Hazard Evaluation for Collapse of Scaffolds due to Wind
|Katsutoshi OHDO, Yasumichi HINO and Yoshinori YONEYAMA|
: Temporary scaffolds are typically covered with plastic sheets in Japan to prevent construction equipment from falling from the scaffolds. However, wind loads which act on the scaffolds are significant due to these sheets. This seriously impacts safety because wind loads have a large effect on the stability of the scaffolds due to the scaffolds' inherent instability under horizontal loads. In fact, the scaffolds often collapse under strong winds during construction and many people have been injured and killed.
Improvement of a Non-Linear Optimization Algorithm for Structural Reliability Analyses
: Recently, the structures are becoming more complex and performance requirements are becoming more ambitious. On the other hand, the requirements for safety and cost reduction are also becoming more demanding. To balance these inconsistent requirements, the need for a structural reliability analysis, which employs probabilistic information of loads, material properties and geometry of components, has been growing. In general, a structural reliability analysis requires the failure probability of the structure which is defined by the multi-dimensional integral of the joint probability density function of basic probabilistic variables. However, it is usually difficult to directly compute this multi-dimensional integral because of the arbitrary nature of the integration domain and typically high dimension of the problem. To overcome these difficulties, indirect methods such as the first-order reliability method (FORM) or the second-order reliability method (SORM) has been proposed as well as the Monte Carlo simulation methods.
Development of a Human-error Prediction Estimator
|Jian LU, Shigeo UMEZAKI and Kiyoshi FUKAYA|
: As for recent labor accidents, it is said that, while the accidents which originate from equipment defects decrease relatively, the accidents which originate from human factor such as the human-error of the worker increase. However, even as for the accidents that seem to originate from human error, it is not rare that the equipment defects are found still to be the basic reason, after some detailed investigation.
Report of the Investigation Meetings on the Safety Control Technology for Construction Robots and Research Subjects
|Hiroyasu IKEDA, Shigeo UMEZAKI, Tetsuya SASAKI, Shoken SHIMIZU, Hajime TOMITA, Jian LU, Katsutoshi OHDO and Seiji TAKANASHI|
: In many cases, the construction industry is, unlike production industry at large, comparatively dependent on manual work based on judgments by workers as there are a few repetitive work For this reason, industrial robots used in manufacturing are not adequate to be applied construction sites. In fact, the construction robots are required to have transfer technology and high-grade intelligence, which are beyond the technological category of the current industrial robots, but the current construction robots have not yet reached such a high technological level. Particularly, as to the robots moving around in an environment in which they are working jointly with human workers unless the safety technology for assuring safety for the human workers has been established, the construction robots would not easily spread.
Development of the Safety Control System for Construction Robots --Inherently Safe Manipulator and Hierarchized Sensing System--
|Hiroyasu IKEDA, Noboru SUGIMOTO, Shoken SHIMIZU and Jian LU|
: Recently, the introduction of robots into construction work, in which automatization and labor savings are in rapid promotion, has been strongly desired. In building interior construction work, for example, as it involves a lot of manual labor, simple machines are used to ease the heavy, muscular labor of human workers. A system for enabling robots to collaborate with human workers in similar construction work is under research for future realization. However, according to this system, safety is not ensured for human workers in coexistence with robots, and safety work cannot be realized by merely taking measures to prevent human workers from approaching the danger condition, which is the basis of safety assurance under the conventional safety standards.