安全確認形作業システムの論理的考察

抄録

On the basis of probability, in which accidents are recognized as unavoidable fatal happenings, 'safety' cannot logically be discussed and developed. In this report, logical safety is approached. As safety goes with information indicating the 'safety', the condition for constructing any reasonable safety operation system is that the information (safety information) must be transmitted 'unate'. This means that the extraction of safety information demands introduction of the threshold logic into operational space. In this report, the safety condition is logically defined, and the definition of 'safety control system' is presented on the basis of the condition securing the safe operation. In the defined safety control system, interlocking, as a fundamental element, is logically developed under an energy transmitting model of interlocking. The model defines the condition of the output signal in the interlocking. The interlocking indicates the truth that a practical safety system composes a phased structure, consist of a system in which safety information is transmitted 'unate', and a system in which the safety information is not necessarily transmitted.