Setting a Complex System to a Known Initial State

摘要

Nowadays nondeterministic models are widely used when describing the behavior of complex systems. Nondeterminism occurs due to various reasons such as physical properties, limited controllability, and/or observability of a system under analysis, abstraction level, etc. [1]. Given a complex system, if its behavior can be described using finite sets of states and transitions between them, then homing experiments with nondeterministic Finite State Machines (FSMs) can be applied in order to set the system into a known initial state [2]. If the technical system behavior is described by a deterministic FSM then such experiments are well established. In particular, a complete deterministic FSM with n pairwise distinguishable states always has a homing sequence of length at most n(n – 1)/2. Moreover, the order of length of the homing sequence cannot be reduced when the next input depends on output responses of a system under experiment to the previous inputs, i.e., the complexity of homing experiments cannot be reduced using adaptive experiments instead of preset. For systems with the nondeterministic behavior, investigations of homing experiments are just beginning to develop [3, 4, 5]. In this paper, we briefly present the novel results obtained in this area under the assumption that the behavior of the system under experiment is described by a complete observable nondeterministic FSM. In other words, the behavior of the system in each state is defined for any input, but there can be several output responses to the same input in some states. For the observable FSM, given an input/output pair and a current state, the next state of the system can be uniquely identified.