Date of Original Version



Conference Proceeding

Abstract or Description

This study presents new risk analysis tools and demonstrates the feasibility and applicability of these tools in the design verification of railway interlocking control systems and deadlock prevention in automated manufacturing systems. Our verification methodology consists of the following stages. First, we analyze the rules executed by the controller and extract a state machine model of the controller. Second, we compose safety, reliability, and operability system specifications using a propositional temporal logic. Finally, we use the model checker to check the state machine model of the system against its requirements. The verification approach allows an exhaustive search of all possible behaviors and scenarios. We verified two real railway interlocking control applications with 125 and 452 constraints respectively. Checking two opposing signal protection specifications involving 3 signals ranged between 74 and 1223 seconds depending on the size and the complexity of the interlocking. Traditional verification methods typically require several person weeks