A polynomial-time scheduling approach to minimise idle energy consumption: An application to an industrial furnace

0536752 - ÚTIA 2022 RIV NL eng J - Journal Article
Benedikt, O. - Alikoç, B. - Šůcha, P. - Čelikovský, Sergej - Hanzálek, Z.
A polynomial-time scheduling approach to minimise idle energy consumption: An application to an industrial furnace.
Computers & Operations Research. Roč. 128, č. 1 (2021), č. článku 105167. ISSN 0305-0548. E-ISSN 1873-765X
Institutional support: RVO:67985556
Keywords : Scheduling * Energy optimisation * Operational research * Optimal control * Electric furnaces
OECD category: Robotics and automatic control
Impact factor: 5.159, year: 2021
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0305054820302847?via%3Dihub

This article presents a novel scheduling approach to minimise the energy consumption of a machine during its idle periods. In the scheduling domain, it is common to model the behaviour of the machine by defining a small set of machine modes, e.g. ‘‘on”, ‘‘off” and ‘‘stand-by”. Then the transitions between the modes are represented by a static transition graph. In this paper, we argue that this type of model might be too restrictive for some types of machines (e.g. the furnaces). For such machines, we propose to employ the complete time-domain dynamics and integrate it into an idle energy function. This way, the scheduling algorithm can exploit the full knowledge about the machine dynamics with minimised energy consumption encapsulated in this function. In this paper, we study a scheduling problem, where the tasks characterised by release times and deadlines are scheduled in the given order such that the idle energy consumption of the machine is minimised. We show that this problem can be solved in polynomial time whenever the idle energy function is concave. To highlight the practical applicability, we analyse a heat-intensive system employing a steel-hardening furnace. We derive an energy optimal control law, and the corresponding idle energy function, for the bilinear system model approximating the dynamics of the furnace (and possibly other heat-intensive systems). Further, we prove that the idle energy function is, indeed, concave in this case. Therefore, the proposed scheduling algorithm can be used. Numerical experiments show that by using our approach, combining both the optimal control and optimal scheduling, higher energy savings can be achieved, compared to the state-of-the-art scheduling approaches.
Permanent Link: http://hdl.handle.net/11104/0314742