Today＇s production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industr...Today＇s production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industrial turbulent environments. Flexible automated systems are requested in order to improve dynamic production efficiency, e.g. robot-based hardware and PC-based controllers, but these usually induce a significantly higher production complexity, whereby the efforts for planning and programming, but also setups and reconfiguration, expand. In this paper a definition and some concepts of self-optimizing assembly systems are presented to describe possible ways to reduce the planning efforts in complex production systems. The concept of self-optimization in assembly systems will be derived from a theoretical approach and will be transferred to a specific application scenario---the automated assembly of a miniaturized solid state laser--where the challenges of unpredictable influences from e.g. component tolerances can be overcome by the help of self-optimization.展开更多
With the increasing concerns about energy consumption and environmental protection, minimizing energy consumption while ensuring desired productivity becomes more and more important in flexible assembly systems(FASs) ...With the increasing concerns about energy consumption and environmental protection, minimizing energy consumption while ensuring desired productivity becomes more and more important in flexible assembly systems(FASs) design and operation. However, because of the complexity of deadlock-prone FASs, only a few researchers have addressed their scheduling problems. Besides, no existing literature in the field of scheduling of deadlock-prone FASs takes energy consumption minimization as the optimization criterion to our best knowledge. This paper presents an A^(*)-based hybrid heuristic search algorithm to minimize the total energy consumption of FASs with tool change processes. Based on a developed Petri net(PN) model, two energy functions are proposed to calculate the energy consumption of FASs. To achieve better performance, six new heuristic functions are designed to guide the search process by considering the features of FASs. Besides, two selection functions are proposed to evaluate the prospects of vertexes and choose the promising ones.Moreover, a dynamic window is applied in the algorithm to limit the search space, and a deadlock prevention policy is used to ensure feasible schedules. Experimental results show that the proposed algorithm can effectively find feasible schedules for FASs,and a well-designed heuristic function is likely to obtain schedules to meet industrial application requirements.展开更多
文摘Today＇s production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industrial turbulent environments. Flexible automated systems are requested in order to improve dynamic production efficiency, e.g. robot-based hardware and PC-based controllers, but these usually induce a significantly higher production complexity, whereby the efforts for planning and programming, but also setups and reconfiguration, expand. In this paper a definition and some concepts of self-optimizing assembly systems are presented to describe possible ways to reduce the planning efforts in complex production systems. The concept of self-optimization in assembly systems will be derived from a theoretical approach and will be transferred to a specific application scenario---the automated assembly of a miniaturized solid state laser--where the challenges of unpredictable influences from e.g. component tolerances can be overcome by the help of self-optimization.
基金supported in part by the National Natural Science Foundation of China(62003265)2023 Suzhou Innovation and Entrepreneurship Leading Talents Program (Young Innovative Leading Talents)(ZXL2023178)+2 种基金Natural Science Basic Research Program of Shaanxi (2025JC-YBMS-656)Tongxiang Institute of Artificial General Intelligence (TAGI2-A-2024-0006)the Deanship of Scientific Research (DSR) at King Abdulaziz University,Jeddah,Saudi Arabia (GPIP:908-135-2024)
文摘With the increasing concerns about energy consumption and environmental protection, minimizing energy consumption while ensuring desired productivity becomes more and more important in flexible assembly systems(FASs) design and operation. However, because of the complexity of deadlock-prone FASs, only a few researchers have addressed their scheduling problems. Besides, no existing literature in the field of scheduling of deadlock-prone FASs takes energy consumption minimization as the optimization criterion to our best knowledge. This paper presents an A^(*)-based hybrid heuristic search algorithm to minimize the total energy consumption of FASs with tool change processes. Based on a developed Petri net(PN) model, two energy functions are proposed to calculate the energy consumption of FASs. To achieve better performance, six new heuristic functions are designed to guide the search process by considering the features of FASs. Besides, two selection functions are proposed to evaluate the prospects of vertexes and choose the promising ones.Moreover, a dynamic window is applied in the algorithm to limit the search space, and a deadlock prevention policy is used to ensure feasible schedules. Experimental results show that the proposed algorithm can effectively find feasible schedules for FASs,and a well-designed heuristic function is likely to obtain schedules to meet industrial application requirements.
