Abstract of Special Research Report (SRR-No.24)
National Institute of Occupational Safety and Health, Japan
The Development of Comprehensive Safety Control Measures for Production and Construction Systems (Third Report: The Development of Safety Control Technology for Large Scale Industrial Systems
Introduction
SRR-No.24-1 |
Shigeo UMEZAKI |
: As large scale computerized industrial systems such as chemical plants, factory automations and automated building construction systems are being used in many industrial fields, comprehensive safety measures for these systems have become great concern for industrial safety. The specific research on "The Development of Comprehensive Safety Control Measures for Production and Construction Systems" was conducted from 1997 to 2001 for this reason.
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The Basic Consideration on the Optimum Design Method of the Safety Control System Using Programmable Electronic Equipment
SRR-No.24-2 |
Shigeo UMEZAKI, Hiroyasu IKEDA, Tsuyoshi SAITO and Noboru SUGIMOTO |
: In the safety system using programmable electronic equipment, labor accidents may arise due to program bugs, troubles of electronic equipment, electro-magnetic noise effects, etc.. Therefore, countermeasures such as dualization of CPUs and installation of the self checking mechanism have recently been proposed in the industrial field. However, the safety of such control systems greatly depends on independence, redundancy, existence of the self checking mechanism and check intervals for elements of the safety system. The accident occurrence rate was quantitatively examined according to the degree of redundancy and diversity, and the intervals of self checking for the programmable safety system. The allowable accident occurrence rate was assumed under 10-11/hour.
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The Development and Evaluation of the Two Dimensions Blanking System for the Purpose of Distinguishing between Human Bodies and Objects with the Solid Shape
SRR-No.24-3 |
Shigeo UMEZAKI, Shoken SHIMIZU, Shigenobu KOBAYASHI, Shinji KAWADO, Kenji TAGAMI, Bunji ISHIZAKI, Jyunji MATUI and Tuneo SUZUKI |
: This report proposes a new safety system for distinguishing between human bodies and objects with the solid shape. Common photo-electric safety devices are not available for this system because the object obstructs some light beams. In order to solve this problem, a blanking system with the fail-safe teaching function was developed in this study.
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The Development and Evaluation of the Floating Systems for the Purpose of Distingushing between Human Bodies and Objects with the Plane Shape
SRR-No.24-4 |
Shigeo UMEZAKI, Shoken SHIMIZU, Shigenobu KOBAYASHI and Ichiro WASHIZAKI |
: This report proposes a new safety system for distinguishing between human bodies and objects with the plane shape. An operator of a rollermill often carries out supplies of sheets and cleaning of the roll continuing actuating the roll. Safety measures by fences or enclosures are difficult to use for such works, because the operator approaches the rollermill very closely. The new safety system was developed to solve these problems.
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The Development and Evaluation of the Laser System Safety Equipment for the Purpose of the Safe Confirmation in Large Scale Working Areas
SRR-No.24-5 |
Shigeo UMEZAKI |
: This report proposes a laser sensor using new pattern matching methods to confirm safety and normality. The searching area of this sensor was divided into three portions, that is a safe confirmation area, a normal confirmation area and an unidentified area.
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The Development and Evaluation of the Safe Confirmation System for Many Operators Cooperating in Large Scale Working Area
SRR-No.24-6 |
Shigeo UMEZAKI |
: This report proposes a new safety system for counting the number of operators in the moving area of the machine. It was very difficult to create such a system because the operator could enter into the machine moving area without pulling out of the interlocking key, and there were not only nominated operators but also non-nominated operators, passers-by, or observers in the actual field. Therefore, the system which can recognize the presence position of operators by the movement of interlocking keys was developed in this study.
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The Development and Evaluation of the Turning Angle Monitor for the Purpose of the Application to Industrial Robots
SRR-No.24-7 |
Shigeo UMEZAKI, Shigenobu KOBAYASHI, Kenjiro HAMADA and Kazushi FUJIWARA |
: This report proposes a new turning angle monitor for the purpose of its application to industrial robots. The conventional robot systems sometimes use limit switches to detect the position of the robot. However, it was difficult to detect the accurate angle of the robot because the limit switch could not detect any angles. The new turning angle monitor which can generate the analog output voltage in proportion to the turning angle of the robot was developed for the purpose.
As this study is under execution at present, the reliability test of power reed switches to switch over two hundred million times will be carried out, and the safe performance under the actual environment will be confirmed. |
The Development and Evaluation of the Stop-Hold Monitor for the Purpose of the Application to Industrial Robots
SRR-No.24-8 |
Shigeo UMEZAKI, Shigenobu KOBAYASHI, Kenjiro HAMADA and Kazushi FUJIWARA |
: This report proposes a new stop-hold monitor for the purpose of its application to industrial robots. The operator sometimes makes the robot stop-hold state, and carries out the maintenance or trouble shooting by approaching the robot very closely. These cases may cause an accident if the robot becomes runaway due to noise or malfunction.
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The Development and Evaluation of Safety Control System for the Logic Machinery Considering Life Cycle Cost and Safety —The Proposal of Distributed Safety Bus Control—
SRR-No.24-9 |
Shigeo UMEZAKI |
: This report proposes a new safety bus system for logistic machineries considering high level safety and life cycle cost. The cost reduction for safety control systems is a very important problem in the industrial engineering, especially design process, manufacturing process, maintenance or remodeling. In addition, the high level safety is required for logistic machineries because they sometimes cooperate with the human. The comprehensive solution of these problems was tried by the proposal of the "distributed and safety bus control".
As this study is under execution at present, the quantitative evaluation method for the life cycle cost will be developed, and the safe performance under the actual environment will be examined. |
Conclusions and Future Problems
SRR-No.24-10 |
Shigeo UMEZAKI |
: This specific research report proposed the new safety control technology using the programmable electronic equipment with triple redundancy, diversity and the self checking mechanism.
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