Resource Holons Research Articles

Digital Twin Based SUDIHA Architecture to Smart Shopfloor Scheduling

Standing on the brink of the fourth industrial revolution, Cyber Physical Systems (CPS) are considered the basic components of the Smart Factory. One important challenge in cyber physical production systems is dynamic scheduling that can handle random disruptions such as failures, raw material shortages and quality defects. To achieve dynamic scheduling, we have proposed a Supervised and Distributed Holonic architecture we called SUDIHA. This architecture incorporates three Holons: Product Holon, Resource Holon and Order Holon and combines global supervision, achieved by Product Holon, with dynamic local control, achieved by Resource Holon. The Digital Twin (DT) concept is generally used to design CPS; it is virtual copies of the system that can interact with the physical counterparts in a bi-directional way. It seems to be promising to tackle the complexity and increase manufacturing system flexibility. In this paper, we use a DT Model to improve the SUDIHA architecture. We propose a Digital Twin based SUDIHA architecture (DT-SUDIHA). The paper will describe Digital Twins’ configuration of each Holon of the SUDIHA Architecture, and the intelligent and real time data driven operation control of this architecture. A case study is carried out at the ENSAM-Meknes flexible workshop to prove the effectiveness of the proposed approach.

An architecture to facilitate the integration of human workers in Industry 4.0 environments

While Industry 4.0 research has predominantly focussed on the connection of machines and digital systems and solutions, it is important to consider the role of human workers within the envisaged Industry 4.0 environments. This paper presents the concept of a digital administration shell to support the integration of humans in Industry 4.0 environments and an architecture for the development of such an administration shell. The Biography-Attributes-Schedule-Execution (BASE) architecture builds on holonic systems principles and is guided by the requirements and responsibilities of the Resource Holon, as developed in the Holonic Manufacturing Systems paradigm. The functionality and value of the BASE architecture administration shell is demonstrated by means of a case study implementation.

Handling machine breakdown for dynamic scheduling by a colony of cognitive agents in a holonic manufacturing framework

Article history: Received March 29, 2015 Received in revised format: May 12, 2015 Accepted May 22, 2015 Available online May 22 2015 There is an ever increasing need of providing quick, yet improved solution to dynamic scheduling by better responsiveness following simple coordination mechanism to better adapt to the changing environments. In this endeavor, a cognitive agent based approach is proposed to deal with machine failure. A Multi Agent based Holonic Adaptive Scheduling (MAHoAS) architecture is developed to frame the schedule by explicit communication between the product holons and the resource holons in association with the integrated process planning and scheduling (IPPS) holon under normal situation. In the event of breakdown of a resource, the cooperation is sought by implicit communication. Inspired by the cognitive behavior of human being, a cognitive decision making scheme is proposed that reallocates the incomplete task to another resource in the most optimized manner and tries to expedite the processing in view of machine failure. A metamorphic algorithm is developed and implemented in Oracle 9i to identify the best candidate resource for task re-allocation. Integrated approach to process planning and scheduling realized under Multi Agent System (MAS) framework facilitates dynamic scheduling with improved performance under such situations. The responsiveness of the resources having cognitive capabilities helps to overcome the adverse consequences of resource failure in a better way. Growing Science Ltd. All rights reserved. 5 © 201

Performance evaluation of holonic-based online scheduling for a switch arrival system

Hybrid system class, which includes systems with piecewise continuous evolution and whose changes are related to the evolution of discrete variables are classically structured in three different levels, the controller, the system and the interface. This kind of system is usually modeled through commutation models representing the whole system. Any reconfiguration process is therefore highly complex, as the calculation times are strongly linked to the size of the system. An adaptation of a holonic reference architecture on a hybrid system is proposed, this proposed model is composed of the union of the hybrid model and the holonic model, where the controller is represented by the product holon and the order holon, the interface is represented by the logical part of the resource holon, and finally the system is represented by the physical part of the resource holon. The aim of this paper is to evaluate the performance of a simple predictive-reactive control using a holonic approach applied to a switch arrival system. Four configurations of study case are studied in simulation in order to evaluate the number of switches, whose optimal value is obtained thanks to a MILP model.

Implementation of agent based holonic control in discrete manufacturing

A B S T R A C T A R T I C L E I N F O The present paper is aimed at implementation of agent based holonic man ufacturing control, a Distributed Problem Solving (DPS) approach that relies on the principle of dynamic team formation through negotiation and cooperation by a group of intelligent system entities. A holonic system comprising product holon, resource holon, and integrated process planning and scheduling holon is developed to execute a customer order where negotiation based task allocation and scheduling is accomplished by Contract Net Protocol (CNP). The bids submitted by the resources are evaluated by Simple Additive Weight (SAW) technique under Fuzzy Multi Criteria Decision Making (FMCDM) environment. The priority of the products is established by the critical ratios (CR) to form the basis of scheduling rule. The necessary message based communication is accomplished using eXtensible Markup Language (XML) having specific Document Type Definition (DTD). The control is implemented by Linux operating system with Java.

Collaborative composition of processes in holonic manufacturing systems

Although it provides a flexible architecture to deal with changes and uncertainties, holonic manufacturing systems (HMS) also pose challenges in design and implementation. A challenge is to design a problem solving environment to guide the holons in HMS such that the decisions made by the individual holons as a whole collaboratively compose the production processes for the tasks. The objective of this paper is to propose a problem solving environment for the composition of minimal cost processes in HMS. Given a specific product type and due date, the problem is to dynamically compose a complete process in HMS to process the product by the due date. To achieve the objective, we combine multi-agent systems technology with Petri nets in this paper. We first propose architecture and a two-layer contract net protocol to describe the negotiation between order holons, product holons and resource holons in HMS. To determine whether it is feasible for a set product holons and resource holons to compose a process for an order holon, we propose Petri net models to capture the workflows and activities in product holons and resource holons, respectively. To optimize the cost in the composed manufacturing process, the concept of activity-based costing is adopted to assign the cost of the activities to Petri nets. The advantages of our design methodology include specification of workflows and resource activities with PNML to minimize the cost. To realize the two-layer contract net protocol relies on a mechanism for a holon to discover the services provided by other holons. We proposed a scheme for publication and discovery of holon services based on FIPA compliant multi-agent system platform. Based on the service publication and discovery scheme, interactions between holons with the two-layer contract net protocol can be realized. We develop a HMS system to solve the process composition problem.

Design of reconfiguration mechanism for holonic manufacturing systems based on formal models

One of the key design issues of holonic manufacturing systems (HMS) is to effectively respond to resource failures based on the flexible holonic architecture. The objective of this paper is to propose a viable design methodology to implement reconfiguration mechanism in HMS. A reconfiguration mechanism is developed to accommodate changes based on collaboration of holons without leading to chaos at the shop floor. To deal with resource failures in HMS, an impact function is defined to characterize the impact of resource failures on different holons in a holarchy. A collaborative reconfiguration mechanism based on an impact function is proposed to effectively reconfigure the systems to achieve minimal cost solutions. The design and implementation methodology combines contract net protocol for negotiation of holons, Petri net for the representation of individual product holons and resource holons and FIPA-compliant agent platform for publication/discovery of holons. A simulation system is developed to verify the proposed reconfiguration mechanism.

Holonic Control Metamodel

Current production leanings, such as high product variability, demand advanced manufacturing systems (MSs). An example is the holonic MS (HMS) in which entities (e.g., resources and products) are ldquosmart.rdquo These entities are called holons (HLs), and their interactions are coordinated by holonic control (HC). Indeed, the complexity of HMS has required new design and test tools. In this context, this paper presents an HC metamodel, which was applied to a particular simulator. In this control solution, causal knowledge is enclosed in Rule HLs, which receive facts about Resource HLs and deliberate about the actions to be executed. The inference happens by means of an innovative net of notifications built from expert knowledge, in the form of (Sub)-HLs, which allows high reactivity, HL decoupling, conflict handling, coherent control expression and execution, and easy control adaptations. This solution still considers other issues, namely, the product-driven manufacturing: a tendency related to customized production in which Product HLs negotiate with Resource HLs aiming at adaptability and reactivity. In this case, Rule HLs intermediate and organize the collaborations of Product HLs and Resource HLs. This paper proposes to use the metamodel to compose a process-driven control and a product-driven control applied to a similar simulated HMS, highlighting their differences and advantages.

A holonic approach for manufacturing execution system design: An industrial application

In the age of globalisation and virtual enterprises, industrial firms are challenged by a volatile and demanding market as well as an everyday more competitive environment. As a main actor of the enterprise integration, manufacturing control systems should be designed in order to answer these necessities of reactivity and profitability in a flexible way. Holonic manufacturing system (HMS) proposes a structure organized as a loosely coupled network of communicating and cooperating agents to solve this problem. Such approach offers concrete solutions to reconfigurability and evolvability issues of manufacturing control systems. This paper presents a manufacturing execution system (MES), using the HMS concepts, and illustrates this approach on a real industrial application. 1 1 American Glass Product (AGP; www.agpglass.com) supports and partially finances this project. Such a structure is based on a typology of manufacturing system elements (products, resources, orders). Roles and behaviours for these manufacturing control elements are proposed. Product holons own reference models of products, for manufacturing execution and quality control. Resources holons are components used as bricks with local intelligent decision-making system embedded. Based on characteristics of the tasks they perform, a specialisation of resource holons is proposed. Specific heuristics are suggested for each class of resource holon. Finally, order holons are related to product demand, manufacturing task and product item. They own models of product item and a time model of the manufacturing task. Mechanisms are proposed to synchronize the execution of manufacturing tasks. These mechanisms guarantee the availability of components and enable to impose time constraints on task scheduling. This MES implements a product-centred approach, as shown by the active and opportunistic behaviour of order holons.

A Petri net model of distributed control in a holonic Manufacturing Execution System

In a holonic manufacturing execution system, operations assignment and scheduling can be decided in real time by automatic negotiation between order holons and resource holons. Negotiation is used to conciliate the goals pursued by the software agents who constitute the control part of the holons. This paper proposes mathematical criteria to represent the agents’ goals, a game theoretic approach to analyze the possible outcomes of the negotiation process, and a Petri net model to represent the interaction protocols between order and resource agents. This model is analyzed in view of verifying the required properties of the protocol. In particular, certain conditions are proposed under which the following requirements are verified: no-blocking, selection of exactly one resource for each order, protocol termination in a bounded time.

A Study on Real-Time Scheduling of Holonic Manufacturing Systems (5th Report, Estimation Method of Future Status Without Decision Criteria of Other Holons)

This paper deals with a real-time scheduling system of the holonic manufacturing systems (HMS). In the previous papers, real-time scheduling processes have been proposed based on the utility values of the candidate holons. A simulation based procedure has also been implemented to estimate the future status of HMS and to determine the utility values based on the estimated future status. However, it was assumed that the simulation models for estimation include the model representing the decision criteria of all the holons. A new simulation based real-time scheduling method is proposed, in the present paper, to improve the estimation process, which enable all the holons to estimate the future status of the HMS without decision criteria of other holons. An estimation process is developed for the individual job holons and resource holons to estimate the future status of HMS through the simulation. Some case studies of the real-time scheduling are carried out to verify the effectiveness of the proposed method. It is shown, through case studies, that the proposed methods are effective to improve the objective function values of the individual holons.

A Study on Real-Time Scheduling of Holonic Manufacturing Systems (3rd Report, Modeling of Decision Criteria of Utility Values for Estimation of Future Status of HMS)

This paper deals with a real-time scheduling system of HMS (Holonic Manufacturing System). Simulation based procedures have been proposed and implemented to estimate the future status of HMS and to determine the utility values, in the previous paper. The objective of this research is to improve the estimation procedure of the future status of HMS. A neural network model is proposed to represent the decision criteria of the utility values of the job holons and the resource holons. The neural network model proposed here is used by the job holons and the resource holons, in order that a holon estimates the future status of the HMS for selecting its suitable utility values in the real-time scheduling process. Some case studies are carried out for verifying the effectiveness of the proposed model.

201 ホロニック生産システムにおける強化学習を用いたリアルタイムスケジューリング手法(S81 生産システムの新展開I,S81 生産システムの新展開I)

This paper deals with a real-time scheduling system of the Holonic Manufacturing Systems (HMSs). In the previous papers, real-time scheduling method based on the utility values have been proposed and applied to the HMSs. In this method, individual job holons and resource holons determine the utility values for the next machining operation based on their own decision criteria. Reinforcement learning is applied to the job holons, in the paper, in order to make the suitable decision criteria for determination of utility values. Some case studies of the real-time scheduling are carried out to verify the effectiveness of the proposed method.

ANALYSIS OF HOLONIC MANUFACTURING SYSTEMS BASED ON NON-ORDINARY COLLABORATIVE PETRI NETS

Holonic manufacturing systems (HMS) provide a flexible and decentralized manufacturing environment to accommodate changes and to meet customers' requirements dynamically. HMS is based on the notion of holon, an autonomous, co-operative and intelligent entity able to collaborate with other holon to process the tasks. It enables the construction of very complex systems that are nonetheless efficient in the use of resources, highly resilient to disturbances and adaptable to changes in the environment. To perform a task in HMS requires a minimal set of holons to form a collaborative network. As individual holons may be unreliable, this adds complexity in modeling and analysis of HMS. How to dynamically form a minimal cost collaborative network for a task and analyze the effects of resource failures on the system operation are challenging issues. In this paper, we consider holonic assembly/disassembly systems with unreliable resource holons. We propose a Petri net to model a collaborative network and study its robustness. Robustness analysis concerns with the ability for a system to maintain operation in case of resource failures. Existing results on robustness analysis are developed based on ordinary Petri net models. However, non-ordinary controlled Petri nets have the advantages to compactly model assembly/disassembly systems where multiple identical resources may be required to perform an operation. This motivates us to propose a non-ordinary collaborative Petri net (NCPN) for this class of systems and extend the robustness analysis to NCPN.

A Study on Real-Time Scheduling of Holonic Manufacturing Systems (4th Report, Multi-objective Optimization Process for Individual Holons and Whole HMSs)

This paper deals with a real-time scheduling system of HMSs (Holonic Manufacturing Systems). A scheduling process based on the utility values have been proposed and applied to the realtime scheduling problems of the HMSs in the previous report. It was shown that the proposed methods generate suitable schedules from the view point of the objective functions of the individual holons in the HMSs. A new real-time scheduling method is proposed, in the paper, to consider both the objective functions of the individual holons and the whole HMSs. In this method, all the pareto optimal combinations of the resource holons and the job holons are generated based on the objective function values of the individual holons. Following this, a most suitable combination is selected from the pareto optimal ones, based on the objective functions of the whole HMSs, such as total make span and total tardiness. It is shown, through case studies, that the proposed method is effective to improve the production schedules from the viewpoint of the objective functions of the whole HMSs in comparison with the previous method.

Reference architecture for holonic manufacturing systems: PROSA

Future manufacturing systems need to cope with frequent changes and disturbances. As such, their control requires constant adaptation and high flexibility. Holonic manufacturing is a highly distributed control paradigm that promises to handle these problems successfully. It is based on the concept of autonomous co-operating agents, called `holons'. This paper gives an overview of the holonic reference architecture for manufacturing systems as developed at PMA-KULeuven. This architecture, called PROSA, consists of three types of basic holons: order holons, product holons, and resource holons. They are structured using the object-oriented concepts of aggregation and specialisation. Staff holons can be added to assist the basic holons with expert knowledge. The resulting architecture has a high degree of self-similarity, which reduces the complexity to integrate new components and enables easy reconfiguration of the system. PROSA shows to cover aspects of both hierarchical as well as heterarchical control approaches. As such, it can be regarded as a generalisation of the two former approaches. More importantly, PROSA introduces significant innovations: the system structure is decoupled from the control algorithm, logistical aspects can be decoupled from technical ones, and PROSA opens opportunities to achieve more advanced hybrid control algorithms.