Robust supervision using shared-buffers in automated manufacturing systems with unreliable resources

• Try to resolve deadlock issues in a class of AMSs with unreliable resources.
• Our policy is of the so-called distributing type.
• Our policy is capable of handling simultaneous multi-resource failures.

It has been an active area of research to solve the modeling, analysis, and deadlock control problems for automated manufacturing systems (AMSs). So far, all the system resources are assumed to be reliable in most of the existing approaches for deadlock-free and nonblocking supervisory control. However, many resources of AMSs are subject to failure in the real world. In order to develop a more practical and applicable supervisor, this work takes into consideration of multiple unreliable resources in a class of AMSs. On the basis of two variants of Banker’s Algorithm, this paper presents a robust supervisory control policy to avoid deadlock and blocking in these systems. The policy tries to make the best use of buffers of the shared resources to achieve the control objectives. Our controller is qualified to handle simultaneous multi-resource failures. By using formal language and automata theory, we establish its correctness. Moreover, our proposed method is verified via an AMS example, and we make comparison studies between our policy and some of the other similar type of policies in the literature.