Percorrer por autor "Jimenez, Jose Fernando"
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- Analysing the impact of rescheduling time in hybrid manufacturing controlPublication . Jimenez, Jose Fernando; Zambrano-Rey, Gabriel; Bekrar, Abdelghani; Trentesaux, Damien; Leitão, PauloHybrid manufacturing control architectures merge the benefits of hierarchical and heterarchical approaches. Disturbances can be handled at upper or lower decision levels, depending on the type of disturbance, its impact and the time the control system has to react. This paper focuses particularly on a disturbance handling mechanism at upper decision levels using a rescheduling manufacturing method. Such rescheduling is more complex that the offline scheduling since the control system must take into account the current system status, obtain a satisfactory performance under the new conditions, and also come up with a new schedule in a restricted amount of time. Then, this paper proposes a simple and generic rescheduling method which, based on the satisfying principle, analyses the trade-off between the rescheduling time and the performance achieved after a perturbation. The proposed approach is validated on a simulation model of a realistic assembly cell and results demonstrate that adaptation of the rescheduling time might be beneficial in terms of overall performance and reactivity.
- An approach for characterizing the operating modes in dynamic hybrid control architecturesPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Trentesaux, Damien; Leitão, PauloNowadays, manufacturing control system faces the challenge of featuring optimal and reactive mechanisms to respond to volatile environments. In automation domain, hybrid control architectures solve these requirements as it allows coupling predictive/proactive and reactive techniques in manufacturing operations. However, to include dynamic coupling features, it is necessary to characterize the possible new operating modes and visualize its potential when a switching is needed. This paper presents an approach to characterize the operating modes of dynamic hybrid control architectures to support the dynamic switching process. The results, obtained through a simulation in a multi agent platform of flexible manufacturing systems, showed the interest of our approach in terms of including the characterization of operating modes as decisional criteria towards a system switching.
- A dynamic hybrid control architecture for sustainable manufacturing controlPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Giret, Adriana; Leitão, Paulo; Trentesaux, DamienManufacturing systems face the challenge of accomplishing the productive effectiveness and sustainable efficiency goals at operational level. For this, manufacturing control systems must incorporate a mechanism that balances the trade-off between effectiveness and efficiency in perturbed scenarios. This paper proposes a framework of a dynamic hybrid control that manages and balances the trade-off between effectiveness and efficiency objectives. Our proposal integrates this trade-off in three different locations: the predictive-offline scheduling component, the reactive-online control component, and the switching mechanism that changes dynamic architecture. To show the contribution of our approach and the progress of our research, a case study dealing with energy-aware manufacturing control is presented.
- Governance mechanism in control architectures for Flexible Manufacturing SystemsPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Trentesaux, Damien; Zambrano-Rey, Gabriel; Leitão, PauloManufacturing systems, and specifically Flexible Manufacturing Systems (FMS), face the challenge of accomplish global optimal performance and reactiveness at dynamic manufacturing environments. For this reason, manufacturing control systems must incorporate mechanisms that support dynamic custom-build responses. This paper introduces a framework that includes a governance mechanism in control system architectures that dynamically steers the autonomy of decision-making between predictive and reactive approaches. Results from experiments led in simulation show that it is worth studying in depth a governance mechanism that tailors the structure and/or behaviour of a manufacturing control system and, at the same time, potentiate the reactivity required in manufacturing operations.
- A nervousness regulator framework for dynamic hybrid control architecturesPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Trentesaux, Damien; Leitão, PauloDynamic hybrid control architectures are a powerful paradigm that addresses the challenges of achieving both performance optimality and operations reactivity in discrete systems. This approach presents a dynamic mechanism that changes the control solution subject to continuous environment changes. However, these changes might cause nervousness behaviour and the system might fail to reach a stabilized-state. This paper proposes a framework of a nervousness regulator that handles the nervousness behaviour based on the defined nervousness-state. An example of this regulator mechanism is applied to an emulation of a flexible manufacturing system located at the University of Valenciennes. The results show the need for a nervousness mechanism in dynamic hybrid control architectures and explore the idea of setting the regulator mechanism according to the nervousness behaviour state.
- Pollux: a dynamic hybrid control architecture for flexible job shop systemsPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Zambrano-Rey, Gabriel; Trentesaux, Damien; Leitão, PauloNowadays, manufacturing control systems can respond more effectively to exigent market requirements and real-time demands. Indeed, they take advantage of changing their structural and behavioural arrangements to tailor the control solution from a diverse set of feasible configurations. However, the challenge of this approach is to determine efficient mechanisms that dynamically optimise the configuration between different architectures. This paper presents a dynamic hybrid control architecture that integrates a switching mechanism to control changes at both structural and behavioural level. The switching mechanism is based on a genetic algorithm and strives to find the most suitable operating mode of the architecture with regard to optimality and reactivity. The proposed approach was tested in a real flexible job shop to demonstrate the applicability and efficiency of including an optimisation algorithm in the switching process of a dynamic hybrid control architecture.
- State of the art and future trends of optimality and adaptability articulated mechanisms for manufacturing control systemsPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Trentesaux, Damien; Montoya-Torres, Jairo; Leitão, PauloNowadays, manufacturing control systems have evolved from reactive and informative decision support system to a proactive and intelligent manufacture management mechanism. Industries require both optimal and adaptive manufacturing processes in order to respond competitively to market requirements. In response, advanced manufacturing control systems are configured as artificial intelligence distributed architectures capable to support environment disturbances. However, these techniques, specifically Multi-agent systems and Holonic Manufacturing Systems, are weak supporting optimal performance. Conversely, Operational Research decision support systems achieve optimality under centralized architectures. Still, these are weak supporting adaptable processes under environmental disturbances. Consequently, researchers recently have focused in articulating optimality and adaptation paradigms in order to construct a robust optimal-wise and adaptable mechanism. This paper surveys the literature in manufacturing control systems that use these articulated adaptable optimal mechanism, constructs a proposal typology according structural features and discusses future possibilities for balancing optimality and adaptability characteristics.
- A switching mechanism framework for optimal coupling of predictive scheduling and reactive control in manufacturing hybrid control architecturesPublication . Jimenez, Jose Fernando; Bekrar, Abdelghani; Trentesaux, Damien; Leitão, PauloNowadays, manufacturing systems are seeking control architectures that offer efficient production performance and reactivity to disruptive events. Dynamic hybrid control architectures are a promising approach as they are not only able to switch dynamically between hierarchical, heterarchical and semi-heterarchical structures, they can also switch the level of coupling between predictive scheduling and reactive control techniques. However, few approaches address an efficient switching process in terms of structure and coupling. This paper presents a switching mechanism framework in dynamic hybrid control architectures, which exploits the advantages of hierarchical manufacturing scheduling systems and heterarchical manufacturing execution systems, and also mitigates the respective reactivity and optimality drawbacks. The main feature in this framework is that it monitors the system dynamics online and shifts between different operating modes to attain the most suitable production control strategy. The experiments were carried out in an emulation of a real manufacturing system to illustrate the benefits of including a switching mechanism in simulated scenarios. The results show that the switching mechanism improves response to disruptions in a global performance indicator as it permits to select the best alternative from several operating modes.