Presents a method for deadlock avoidance algorithm used in Flexible Manufacturing System(FMS). This method is an improvement of the Banker algorithm. The Banker algorithm is commonly used in the Operating System (OS),...Presents a method for deadlock avoidance algorithm used in Flexible Manufacturing System(FMS). This method is an improvement of the Banker algorithm. The Banker algorithm is commonly used in the Operating System (OS), but some improvements will have to be made on the algorithm if this algorithm is used in FMS. The difference between the process in operating system and the job in the FMS is fully discussed. Based on this difference, the improvement is made. In order to improve the algorithm, formal methods are adopted to the manufacturing systems. The simulation model is translated into a format suitable for model checking. That is, the model is written into PROMELA, the input language of the popular model checker SPIN. After that, SPIN is used to verify that the model does not have deadlock. This algorithm proves to be highly effective in practice.展开更多
This paper presents the possibilities of job optimization in waterway with multiple locks and canals, in order to increase the system productivity. Safe navigation in such complex waterway system is very demanding. So...This paper presents the possibilities of job optimization in waterway with multiple locks and canals, in order to increase the system productivity. Safe navigation in such complex waterway system is very demanding. Some of the problems that need to be solved are： How to control traffic in a way that vessels move in opposite directions; How to resolve possible conflicts in case that more vessels try to acquire particular lock at the same time; How to avoid possible deadlocks; How to ensure the vessel passage in the shortest possible time？ It is necessary to apply adequate control policy to avoid deadlocks and blocks the vessels＇ moving only in the case of dangerous situation. The motion of vessels can be described as the set of discrete events and states. Herein we propose deadlock avoidance algorithm for complex waterway system with multiple key resources and we use multiple re-entrant flowlines class of Petri net （MRF^PN）. The solution represents deadlock prevention supervisor in a sense that vessels are stopped only in a case of immediate dangerous situation in dense traffic. The goal of this paper is to find optimal, conflict and deadlock free job schedule in CWS. In this sense, the authors developed the algorithm which integrates MRF^PN with a genetic algorithm. The algorithm deals with multi-constrained scheduling problem with shared resources. The final goals are minimization the total travel time of vessels through the waterway system.展开更多
文摘Presents a method for deadlock avoidance algorithm used in Flexible Manufacturing System(FMS). This method is an improvement of the Banker algorithm. The Banker algorithm is commonly used in the Operating System (OS), but some improvements will have to be made on the algorithm if this algorithm is used in FMS. The difference between the process in operating system and the job in the FMS is fully discussed. Based on this difference, the improvement is made. In order to improve the algorithm, formal methods are adopted to the manufacturing systems. The simulation model is translated into a format suitable for model checking. That is, the model is written into PROMELA, the input language of the popular model checker SPIN. After that, SPIN is used to verify that the model does not have deadlock. This algorithm proves to be highly effective in practice.
文摘This paper presents the possibilities of job optimization in waterway with multiple locks and canals, in order to increase the system productivity. Safe navigation in such complex waterway system is very demanding. Some of the problems that need to be solved are： How to control traffic in a way that vessels move in opposite directions; How to resolve possible conflicts in case that more vessels try to acquire particular lock at the same time; How to avoid possible deadlocks; How to ensure the vessel passage in the shortest possible time？ It is necessary to apply adequate control policy to avoid deadlocks and blocks the vessels＇ moving only in the case of dangerous situation. The motion of vessels can be described as the set of discrete events and states. Herein we propose deadlock avoidance algorithm for complex waterway system with multiple key resources and we use multiple re-entrant flowlines class of Petri net （MRF^PN）. The solution represents deadlock prevention supervisor in a sense that vessels are stopped only in a case of immediate dangerous situation in dense traffic. The goal of this paper is to find optimal, conflict and deadlock free job schedule in CWS. In this sense, the authors developed the algorithm which integrates MRF^PN with a genetic algorithm. The algorithm deals with multi-constrained scheduling problem with shared resources. The final goals are minimization the total travel time of vessels through the waterway system.
