Method for Constructing Decentralized Interlocking System Operating on Per-Track-Circuit Basis

A decentralized interlocking system is proposed that assigns a unit to each track circuit and wires the units according to the track topology to achieve the function required of the entire system. The functions of each unit are represented by monotonic logic functions. The units are characterized in that they themselves can accomplish fail-safe error characteristics. The system consists of safety-related and non-safety related functional parts. The control requirements of signal aspects and switches are assigned to the non-safety-related parts, and the safety-related parts perform safety confirmation processing to judge whether or not the requirements are acceptable. This separation and the introduction of duality conversion help to achieve the safety confirmation desired of the interlocking system by the monotonic logic functions.