Nonblocking Supervisory Control of Flexible Manufacturing Systems Based on State Tree Structures

2013 ◽  
pp. 1-19 ◽  
Author(s):  
Wujie Chao ◽  
Yongmei Gan ◽  
W. M. Wonham ◽  
Zhaoan Wang
Keyword(s):  
Supervisory Control ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Discrete Event ◽  
Control Logic ◽  
Tree Structures ◽  
Powerful Approach ◽  
State Tree ◽  
Controllable Event

Much research has been addressed to nonblocking supervisory control of Discrete-Event Systems (DES) such as Flexible Manufacturing Systems (FMS), and a variety of approaches have been developed. One especially powerful approach, due to Chuan Ma, is based on DES representation by means of State Tree Structures (STS). Using STS, this chapter develops nonblocking supervisory control of a well-known benchmark FMS example taken from the literature, for which the description was given originally as a Petri net. The authors straightforwardly obtain the optimal (maximally permissive) and nonblocking supervisory control, and display the control logic for each (controllable) event transparently as a binary decision diagram.

scholarly journals Improving Just-in-Time Delivery Performance of IoT-Enabled Flexible Manufacturing Systems with AGV Based Material Transportation

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6333 ◽  
Author(s):  
Fengjia Yao ◽  
Bugra Alkan ◽  
Bilal Ahmad ◽  
Robert Harrison
Keyword(s):  
Decision Making ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Discrete Event ◽  
Mixed Integer ◽  
Shop Floor ◽  
Just In Time ◽  
Delivery Performance ◽  
Material Transportation

Autonomous guided vehicles (AGVs) are driverless material handling systems used for transportation of pallets and line side supply of materials to provide flexibility and agility in shop-floor logistics. Scheduling of shop-floor logistics in such systems is a challenging task due to their complex nature associated with the multiple part types and alternate material transfer routings. This paper presents a decision support system capable of supporting shop-floor decision-making activities during the event of manufacturing disruptions by automatically adjusting both AGV and machine schedules in Flexible Manufacturing Systems (FMSs). The proposed system uses discrete event simulation (DES) models enhanced by the Internet-of-Things (IoT) enabled digital integration and employs a nonlinear mixed integer programming Genetic Algorithm (GA) to find near-optimal production schedules prioritising the just-in-time (JIT) material delivery performance and energy efficiency of the material transportation. The performance of the proposed system is tested on the Integrated Manufacturing and Logistics (IML) demonstrator at WMG, University of Warwick. The results showed that the developed system can find the near-optimal solutions for production schedules subjected to production anomalies in a negligible time, thereby supporting shop-floor decision-making activities effectively and rapidly.

Distributed Computation of Liveness-Enforcing Supervisory Control of Flexible Manufacturing Systems

2017 ◽  
Vol 16 (01) ◽  
pp. 1-15 ◽  
Author(s):  
Fatemeh Jafarinejad ◽  
Ali A. Pouyan
Keyword(s):  
Supervisory Control ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Large Scale ◽  
Deadlock Prevention ◽  
Prevention Policy ◽  
Synthesis Procedure ◽  
Essential Set ◽  
Time And Space Complexity

This paper presents a modular deadlock prevention policy for large-scale flexible manufacturing systems. It can find maximally permissive liveness-enforcing supervisory control in an efficient computational complexity manner. A vector covering approach is used to minimize essential set of legal markings and first-met bad markings. Providing that modules of system interact using choice, we will prove that monitor-based supervisory control methods can be applied distributedly. Then, choice operator of Petri net will be used to synthesis subsystems. Even if such assumption limits the application of modular monitor-based supervisory control, the proposed results constitute a primary step towards a synthesis procedure that overcomes time and space complexity of monitor-based deadlock prevention policies.

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