Abstract
This article presents a modular automaton-based framework to specify flexible manufacturing systems and to optimize the makespan of product batches. The Batch Makespan Optimization (BMO) problem is NP-Hard and optimization can therefore take prohibitively long, depending on the size of the state-space induced by the specification. To tame the state-space explosion problem, we develop an algebra based on automata equivalence and inclusion relations that consider both behavior and structure. The algebra allows us to systematically relate the languages induced by the automata, their state-space sizes, and their solutions to the BMO problem. Further, we introduce a novel constraint-based approach to systematically prune the state-space based on the the notions of nonpermutation-repulsiveness and permutation-attractiveness. We prove that constraining a nonpermutation-repulsing automaton with a permutation-attracting constraint always reduces the state-space. This approach allows us to (i) compute optimal solutions of the BMO problem when the (additional) constraints are taken into account and (ii) compute bounds for the (original) BMO problem (without using the constraints). We demonstrate the effectiveness of our approach by optimizing an industrial wafer handling controller.
Original language | English |
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Article number | 15 |
Number of pages | 26 |
Journal | ACM Transactions on Cyber-Physical Systems |
Volume | 5 |
Issue number | 2 |
DOIs | |
Publication status | Published - 4 Jan 2021 |
Funding
This research is supported by the Dutch NWO-TTW, carried out as part of the Robust Cyber-Physical Systems (RCPS) program, project number 12694. Research leading to these results has received funding from the EU ECSEL Joint Undertaking under grant agreement no 826452 (project Arrowhead Tools). The proofs for all Lemmas and Theorems can be found in an Appendix provided with the supplementary material. Authors’ addresses: J. Bastos, J. Voeten, S. Stuijk, and H. Corporaal, TUe Department of Electrical Engineering, Eindhoven University of Technology, 5612AP Eindhoven, The Netherlands; emails: [email protected], {j.p.m.voeten, s.stuijk, h.corporaal}@tue.nl; R. Schiffelers, ASML Veldhoven, The Netherlands; email: [email protected]. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected]. © 2021 Association for Computing Machinery. 2378-962X/2021/01-ART15 $15.00 https://doi.org/10.1145/3426194
Keywords
- Flexible manufactoring systems
- formal specification
- makespan optimization
- max plus linear systems