Strict Minimal Siphon-Based Colored Petri Net Supervisor Synthesis for Automated Manufacturing Systems With Unreliable Resources

Abstract

Various deadlock control policies for automated manufacturing systems with reliable and shared resources have been developed, based on Petri nets. In practical applications, a resource may be unreliable. Thus, the deadlock control policies proposed in previous studies are not applicable to such applications. This paper proposes a two-step robust deadlock control strategy for systems with unreliable and shared resources. In the first step, a live (deadlock-free) controlled system that does not consider the failure of resources is derived by using strict minimal siphon control. The second step deals with deadlock control issues caused by the failures of the resources. Considering all resource failures, a common recovery subnet based on colored Petri nets is proposed for all resource failures in the Petri net model. The recovery subnet is added to the derived system at the first step to make the system reliable. The proposed method has been tested using an automated manufacturing system deployed at King Saud University.INDEX TERMS Automated manufacturing system, colored Petri nets, deadlock prevention, siphon.

Intelligent Colored Token Petri Nets for Modeling, Control, and Validation of Dynamic Changes in Reconfigurable Manufacturing Systems

“…Traditional Petri nets are popularly used to model, simulate, control, and analyze automated manufacturing systems (AMSs). Existing traditional Petri net studies assumed one or more of the following: (1) the system configuration is recognized and does not change throughout the operation, (2) there is no addition of new machines and no removal of old machines, and machine failures are not addressed, (3) rework is not required, and (4) products to be manufactured are identified, their process routes are specified, and the addition of new products is not applicable [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. This means that traditional Petri net models do not undergo dynamic configurations, such as processing failures and rework, machine breakdowns, addition of new machines, addition of new products, removal of old machines, or change processing routes induced by the competitive global market.…”

Petri Net Model Based on Neural Network for Deadlock Control and Fault Detection and Treatment in Automated Manufacturing Systems

“…This section concentrates on the relation between the controlled system in Algorithm 1 and resource failures. Definition 31 [6]: Let (NCN, MCNo) be a controlled colored S 3 Step 1: for each ru ∈ PUR do Step 3: End…”

“…They are convenient for describing characteristics and behaviors such as synchronization, causal dependence, conflict, concurrency, and sequencing in AMSs. Petri nets can also be used to provide behavioral features, such as boundedness and liveness [5,6]. From a technical perspective, several policies based on Petri nets have been proposed; these policies are based on three strategies: (i) deadlock detection and recovery, (ii) deadlock avoidance, and (iii) deadlock prevention [5,7].…”

“…Liu et al [33] proposed a deadlock control strategy for GS 3 PRs with unreliable resources, based on elementary siphons theory [34,35] and the max′-controlled siphon control approach presented in [36]. Al-Ahmari et al [37] proposed a robust deadlock state feedback control strategy, which consisted of a two-step system with unreliable and shared resources for S 3 PRs. In the first step, a controlled system (deadlock-free) was obtained using a strict minimal siphon, which did not consider resource failures.…”

“…The second step addresses issues of deadlock control caused by resource failures. For all the resource failures in the Petri net model, a common recovery subnet based on colored Petri nets is proposed [6]. This recovery subnet is applied to the obtained system from the first step to ensure that the system is reliable.…”