A switching mechanism framework for optimal coupling of predictive scheduling and reactive control in manufacturing hybrid control architectures

Abstract

Nowadays, 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.

Pollux: a dynamic hybrid control architecture for flexible job shop systems

“…The architecture of Pollux features different operating modes and includes a switching mechanism that efficiently manages the changing of operating modes according to manufacturing needs. This approach is an extension of the work proposed in Jimenez et al (2015Jimenez et al ( , 2016. Although this architecture is developed to be used in any control system (i.e.…”

Analysing the Impact of Rescheduling Time in Hybrid Manufacturing Control

“…The main benefit of complete/partial scheduling repair is that it re-evaluates the conditions of the system and optimises the performance given the restrictions and degradation caused by disruption. However, besides the need of defining a strategy of execution while the schedule is being recalculated, it has synchronization issues when the solution is going to be applied [16]. The main benefit of fully reactive configurations is the instantaneous reaction and thus the capability of the system to deal with various types of perturbations, dropping the rescheduling time to zero and passing to online/real-time rescheduling.…”

Dynamic Switching Mechanism to Support Self-organization in ADACOR Holonic Control System

“…Since the use of flat control architectures introduces good reaction to disturbances but degrades the global production optimization, the challenge is to combine their best features with the best characteristics of hierarchical structures, aiming to achieve agility to emergency without compromising the global optimization. In the last years, several approaches aiming this challenge were reported in the research literature, namely ADACOR (Leitão and Restivo, 2006), ORCA-FMS (Pach et al, 2014) and Pollux (Jimenez et al, 2016). In these evolvable architectures, a crucial issue is the switching mechanism that supports the evolution of the organizational structure.…”