Supervisory Control of Modular Discrete-Event Systems Under Partial Observation: Normality

• 成果类型: Article
• 署名作者: Komenda, Jan; Masopust, Tomas
• 署名单位: Czech Academy of Sciences; Institute of Mathematics of the Czech Academy of Sciences; Palacky University Olomouc
• 刊物名称: IEEE TRANSACTIONS ON AUTOMATIC CONTROL
• ISSN/ISSBN: 0018-9286
• DOI: 10.1109/TAC.2023.3333792
• 发表日期: 2024
• 页码: 3796-3807
• 关键词: Supervisory control; Behavioral sciences; observability; CONTROLLABILITY; Closed loop systems; observers; Discrete-event systems; Discrete-event system (DES); modular control; normality; observation consistency

摘要

Complex systems are often composed of many small communicating components called modules. We investigate the synthesis of supervisory controllers for modular systems under partial observation that, as the closed-loop system, realize the supremal normal sublanguage of the specification. Such controllers are called maximally permissive normal supervisors. The challenge in modular systems is to find conditions under which the global nonblocking and maximally permissive normal supervisor can be achieved locally as the parallel composition of local normal supervisors. We show that a structural concept of hierarchical supervisory control called modified observation consistency (MOC) is such a condition. However, the algorithmic verification of MOC is an open problem, and therefore it is necessary to find easily verifiable conditions that ensure MOC. We show that the condition that all shared events are observable is such a condition. Considering specifications, we examine both local specifications, where each module has its own specification, and global specifications. Combining our results for normality with the existing results for controllability yields the local synthesis of the nonblocking and maximally permissive controllable and normal supervisor. Finally, we illustrate the results on an industrial case study of the patient table of an MRI scanner.