Functional failure modes cause-consequence logic suited for mobile robots used at scientific facilities

The scientific facilities emitting ionizing radiation may have some significant failures and hazard issues, in and around their infrastructure. Significantly, this will also cause risks to workers and environment, which has led engineers to explore the use and implementation of mobile robots (MR), in order to reduce or eliminate such risks concerned with safety issues. Safe functioning of MR and the systems working at hazardous facilities is essential and therefore all the systems, structures and components (SSC) of a hazardous facility have to correspond to high reliability, availability, maintainability and safety (=RAMS) demands. RAMS characteristics have a causal relationship with the risks related to the facility systems availability, safety and life cycle costs. They also form the basis for the operating systems and MR performance, to carry out the desired functions. In this paper we have developed and presented a method for how to consider and model a SSC with respect to its desired functions and also the computer-supported modeling and analysis of functional failure modes cause-consequence logic of a complex system, to ensure its RAMS characteristics during design and development phase, with an application approach to MR power outage. On the basis of experience and assisted by the modeled cause consequence logic it becomes possible to identify the problem areas, which during the design and development phase may reduce the RAMS performance and delay its design and development time.