This paper considers partially-observed discrete-event systems modeled by finite-state automata. The observation of event occurrences is associated with the transitions of the automaton model. That is, whether or not an event occurrence is observed is state-dependent, i.e., it depends on the transition in which the event label appears. This is in contrast to the case when observations are static and an event is either observed or not observed at every state in which it can occur. We refer to the set of transitions whose associated events are observed as an observation policy. Given an automaton model and an observation policy, we consider the problem of computing a deterministic generator of the language of event sequences that are observed using the automaton model and observation policy (i.e., an observer). Such a generator is useful, e.g., in problems of sensor activation for providing a deterministic mapping from event observations to sensor activation decisions when the decision to activate an event’s sensor is initially modeled as an observation policy. We propose an abstraction of the automaton model that may be used to represent an observer in certain cases. We illustrate cases where this abstraction accurately represents an observer when there is no ambiguity as to which event occurrences are observed following two observationally-identical strings. For the most general case considered, we demonstrate that verifying if the case holds is PSPACE-complete.

中文翻译：

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从离散事件系统中的观察策略计算观察者

本文考虑了由有限状态自动机建模的部分观测离散事件系统。事件发生的观察与自动机模型的转换相关联。也就是说，是否观察到事件发生是状态相关的，即取决于事件标签出现的转换。这与观察是静态的并且事件在它可能发生的每个状态下都被观察到或不被观察到的情况相反。我们将其相关事件被观察到的一组转换称为观察策略。给定自动机模型和观察策略，我们考虑计算使用自动机模型和观察策略（即观察者）观察到的事件序列的语言的确定性生成器的问题。这种发生器很有用，例如，在传感器激活问题中，当激活事件传感器的决定最初被建模为观察策略时，提供从事件观察到传感器激活决策的确定性映射。我们提出了自动机模型的抽象，在某些情况下可用于表示观察者。我们举例说明了当在两个观察相同的字符串之后观察到哪些事件发生没有歧义时，这种抽象准确地表示观察者的情况。对于考虑的最一般情况，我们证明验证情况是否成立是 PSPACE 完整的。我们提出了自动机模型的抽象，在某些情况下可用于表示观察者。我们举例说明了当在两个观察相同的字符串之后观察到哪些事件发生没有歧义时，这种抽象准确地表示观察者的情况。对于考虑的最一般情况，我们证明验证情况是否成立是 PSPACE 完整的。我们提出了自动机模型的抽象，在某些情况下可用于表示观察者。我们举例说明了当在两个观察相同的字符串之后观察到哪些事件发生没有歧义时，这种抽象准确地代表观察者的情况。对于考虑的最一般情况，我们证明验证情况是否成立是 PSPACE 完整的。