Abstract of Special Research Report (SRR-No.26)
National Institute of Occupational Safety and Health, Japan
The Development of Comprehensive Safety Control Measures for Production and Construction Systems (Forth Report: Final Reports)
Introduction
SRR-No.26-1 |
Shigeo UMEZAKI |
: As large scale computerized industrial systems such as chemical plants, factory automations and automated building construction systems were used in many industrial field, a comprehensive safety measure for these systems has become great concern for industrial safety. The specific research on "Development of Comprehensive Safety Control Measures for Production and Construction Systems" was conducted from 1997 to 2001 for above reason.
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Study on Search of Human-Error Cases in Accident Database of Chemical Plant (First Report: Development of a Searching Method of Human-Error Cases from Accident Database)
SRR-No.26-2 |
Ou-Sup HAN, Teruhito OTSUKA, Takaaki MIZUTANI and Yasuhiro FUJIMOTO |
: Much information is written in a accident database, such as the situation when accident occurs, the factors which cause accident, the damage information by accident and so on. Such information related to accident provides not only the technical documents in case study of accident, but also the useful knowledge for development of technique to prevent the recurrence of similar accident. Therefore, from the viewpoint of efficient practical use, it would be important to make positive use of information on the accident database. |
Study on Search of Human-Error Cases in Accident Database of Chemical Plant (Second Report: Quantification Analysis on Human-Error Keywords and Accident Reports)
SRR-No.26-3 |
Yasuhiro FUJIMOTO, Teruhito OTSUKA, Takaaki MIZUTANI and Ou-Sup HAN |
: In this paper, the results of the categorization of human-error keywords and accident reports with quantification analysis are reported. The procedures are follows;
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Hazard Evaluation of Scaffolds Against Wind Load Using Construction-Environmental-Simulator Wind Tunnel
SRR-No.26-4 |
Katsutoshi OHDO, Yasumichi HINO and Songpol PHONGKUMSING |
: Construction accidents caused by wind frequently happen and the workers are often injured and killed. One important problem that leads to the engineering concern nowadays is the accident of the scaffolds. Temporary scaffolds are typically covered with sound barrier panels or plastic sheets to prevent construction materials and debris from falling from scaffolds. In Japan, the design of scaffolds mainly considers wind loads that are directly acting on the exterior surface of the scaffolds. However, due to these sheets and the wind direction, wind entering the gap between the building and scaffolds through the wall openings, etc. results in significant increase of wind load acting on the scaffolds. The increase of wind pressures can affect the stability of the scaffolds and lead to the total collapse of the large scale scaffolds which can cause injury or loss of life as well as economic loss and construction time delay. |
Probabilistic Elastic-Plastic Fracture Analysis of Circumferential Through-Wall-Cracked Pipes Using the First-Order Reliability Method
SRR-No.26-5 |
Tetsuya SASAKI |
: To prevent fractures of pressure vessels and pipes, which are widely used at industrial sites like chemical plants, is essentially important to assure safety of workers and a neighborhood. Since fractures of pressure vessels and pipes usually result from cracks contained in materials, any crack-like defects have not been allowed to exist by regulations. However, it is more economical to continue to operate plants ignoring small cracks contained in materials as long as they are not critical, and the recent development of fracture mechanics has already made it possible to realize such damage tolerant operation. In making such economical and technical circumstance to be a background, so-called fitness-forservice standards for pressure vessels and pipes have being developed in the United States, EU countries and Japan. These fitness-for-service standards tend to adopt the two-parameter approach to evaluate structural integrity of components with crack-like flaws. Some probabilistic methods have also been developed to make quantitative assessments of structural reliability based on the two-parameter approach because there exist a large amount of uncertainties in the assessment parameters. However, most of them employ restricted numerical integration or tedious Monte Carlo simulation methods to calculate failure probabilities, and it is difficult to efficiently assess the reliability of many components included in the large-scale system using such methods. In this paper, making use of the first-order reliability method (FORM) is suggested to efficiently and generally compute failure probabilities of circumferential through-wall-cracked pipes subject to bending based on the two-parameter approach. The fracture of a circumferential through-wall-cracked pipe is one of the most important fractures which must be considered to ensure the plant safety. To confirm adequacy of employing FORM, the failure probabilities are computed by FORM and Monte Carlo simulation methods considering uncertainties in major parameters of the two-parameter approach such as crack size, tensional stress, yield stress and fracture toughness. The results show that FORM provides satisfactory estimates for the wide range of fracture mechanics parameters. The effect of a correlation of yield stress and fracture toughness on the failure probability is also investigated. It is revealed that a positive correlation between yield stress and fracture toughness results in the increase of the failure probability. |
Study on Risk Reduction Process and Safety Designing for Construction Robots
SRR-No.26-6 |
Hiroyasu IKEDA, Shoken SHIMIZU, Tsuyoshi SAITO, Jian LU and Masanori ONISHI |
: For the industrial robots with the fixed movable space, the safety measures have already been specifically stipulated by the relevant international safety standards. However, since these standards are not applicable to the mobile robots due to impossibilities to prepare fixed guards, the application of the safety design principles for general machines to the mobile robots is tried. In this research, for designing a construction robot categorized as a mobile robot, a concept of the safety designing based on risk assessment and procedure for realizing such concept are proposed. |
Development of Navigation Vision System for Construction Robots
SRR-No.26-7 |
Jian LU, Hiroyasu IKEDA and Katsumi YASUDA |
: In this paper, a navigation vision system is proposed for the industrial mobile robots that are mainly used in unfixed work place, or planned to travel along changeable routes. Instead of the traditional navigation method in which magnetic tags or lanes are constructed on the floor to indicate the route, a series of navigation-signs (briefed as signs in the following) are placed along the route. By change the order and the types of signs in the series, the route can be planned and adjusted simply and flexibly on the spot. The navigation vision system recognizes these signs, detects large non-sign objects as obstacles, and sends these results to the travel control system.
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Development of a Construction Robots Immunity System Simulating Conducted Disturbances on the Shop Floor
SRR-No.26-8 |
Hajime TOMITA and Toshiyuki UEKI |
: Electric and electronic devices, equipment, or systems are exposed to various kinds of electromagnetic disturbances on the shop floor, such as static electricity and industrial electromagnetic sources, bursts, and surges. To prevent these devices, equipment, and systems from producing improper operating signals due to those electromagnetic disturbances, immunity tests are commonly carried out by the manufacturer before distribution. |
The Basic Study on the Construction Method of the Safety Control System Considering the Coexistence of Availability and Safety
SRR-No.26-9 |
Shigeo UMEZAKI and Shoken SHIMIZU |
: The coexistence of availability and safety is a very important problem in the field of the industrial safety. However, the availability is sometimes decreased by improving safety when a trade-off model is established in the relation between safety and availability. The self developing spiral model was proposed for replacing the conventional trade-off model.
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Development of the Safety Design Supporting System for the Purpose of the Optimum Design of Man-Machine System
SRR-No.26-10 |
Shoken SHIMIZU and Shigeo UMEZAKI |
: This report proposes a new safety design supporting system which is called the "information shared development model". The conventional safety design process depended on intuition and experience of the personal. Safety measures were sometimes not proper in this case for that reason. The new systematic safety design supporting system was developed for that purpose. |
Conclusions
SRR-No.26-11 |
Shigeo UMEZAKI |
: This specifc research report proposed the new safety technology for large scale industrial systems such as chemical plants, construction sites, construction robots or factory automations. Results obtained from this research are summarized as follows:
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