Publications

This page contains a complete list of all CPS related publications in the Electonic Systems Group.

J. van Pinxten, M. Geilen, M. Hendriks, and T. Basten, “Parametric Critical Path Analysis for Event Networks with Minimal and Maximal Time Lags,” IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, vol. 37, no. 11, pp. 2697–2708, 2018.
[Abstract] [BibTeX] [ Download] High-end manufacturing systems are cyber-physical systems where productivity depends on the close cooperation of mechanical (physical) and scheduling (cyber) aspects. Mechanical and control constraints impose minimal and maximal time differences between events in the product flow. Sequence-dependent constraints are used by a scheduler to optimize system productivity while satisfying operational requirements. The numerous constraints in a schedule are typically related to a relatively small set of parameters, such as speeds, lengths, or settling times. We contribute a parametric critical path algorithm that identifies bottlenecks in terms of the feasible parameter combinations. This algorithm allows analysis of schedules to identify bottlenecks in terms of the underlying cause of constraints. We also contribute a way to find Pareto-optimal cost-performance trade-offs and their associated parameter combinations. These results are used to quantify the impact of relaxing constraints that hinder system productivity.
```
@article{van2018parametric,
  title = {Parametric Critical Path Analysis for Event Networks with Minimal and Maximal Time Lags},
  author = {van Pinxten, Joost and Geilen, Marc and Hendriks, Martijn and Basten, Twan},
  journal = {IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems},
  volume = {37},
  number = {11},
  pages = {2697--2708},
  year = {2018},
  publisher = {IEEE}
}
```
H. A. Ara, A. Behrouzian, M. Hendriks, M. Geilen, D. Goswami, and T. Basten, “Scalable analysis for multi-scale dataflow models,” ACM Transactions on Embedded Computing Systems (TECS), vol. 17, no. 4, p. 80, 2018.
[Abstract] [BibTeX] [ Download] Multi-scale dataflow models have actors acting at multiple granularity levels e.g. a dataflow model of a video processing application with operations on frame, line and pixel level. The state of the art timing analysis methods for both static and dynamic dataflow types aggregate the behaviours across all granularity levels into one, often large iteration, which is repeated without exploiting the structure within such an iteration. This poses scalability issues to dataflow analysis, because behaviour of the large iteration is analysed by some form of simulation which involves a large number of actor firings. We take a fresh perspective of what is happening inside the large iteration. We take advantage of the fact that the iteration is a sequence of smaller behaviours, each captured in a scenario, that are typically repeated many times. We use the (max, +) linear model of dataflow to represent each of the scenarios with a matrix. This allows a compositional worst-case throughput analysis of the repeated scenarios by raising the matrices to the power of the number of repetitions, which scales logarithmically with the number of repetitions, whereas the existing throughput analysis scales linearly. We moreover provide the first exact worst-case latency analysis for scenario-aware dataflow. This compositional latency analysis also scales logarithmically when applied to multi-scale dataflow models. We apply our new throughput and latency analysis to several realistic applications. The results confirm that our approach provides a fast and accurate analysis.
```
@article{ara2018scalable,
  title = {Scalable analysis for multi-scale dataflow models},
  author = {Ara, Hadi Alizadeh and Behrouzian, Amir and Hendriks, Martijn and Geilen, Marc and Goswami, Dip and Basten, Twan},
  journal = {ACM Transactions on Embedded Computing Systems (TECS)},
  volume = {17},
  number = {4},
  pages = {80},
  year = {2018},
  publisher = {ACM}
}
```
H. A. Ara, M. Geilen, A. Behrouzian, T. Basten, and D. Goswami, “Compositional dataflow modelling for cyclo-static applications,” in 21st Euromicro Conference on Digital System Design (DSD), 2018, pp. 121–129.
[Abstract] [BibTeX] [ Download] Modular design is a common practice when designing complex applications for embedded systems. Another important practice in the embedded systems domain is the use of abstract models to realize predictable behaviour. Modular model-based design allows to construct a modular model of a complex system via model composition. The model of computation considered in this paper is scenario-aware dataflow, a dataflow model that allows for dynamic behaviour. We model applications with behaviour that changes according to a periodic pattern. Composing models with periodic patterns results in a model with a periodic pattern with a common hyper-period. We propose an efficient algorithmic method to compose cyclo-static scenario-aware dataflow models by generating composite patterns in a concise representation. We show that our approach can automatically generate concise models of several real-life image processing applications.
```
@inproceedings{ara2018compositional,
  title = {Compositional dataflow modelling for cyclo-static applications},
  author = {Ara, Hadi Alizadeh and Geilen, Marc and Behrouzian, Amir and Basten, Twan and Goswami, Dip},
  booktitle = {21st Euromicro Conference on Digital System Design (DSD)},
  pages = {121--129},
  year = {2018},
  organization = {IEEE}
}
```
A. Ibrahim, C. B. Math, D. Goswami, T. Basten, and H. Li, “Co-simulation framework for control, communication and traffic for vehicle platoons,” in 21st Euromicro Conference on Digital System Design (DSD), 2018, pp. 352–356.
[Abstract] [BibTeX] [ Download] Vehicle platooning has gained attention for its potential to achieve an increased road capacity and safety, and a higher fuel efficiency. Member vehicles of a platoon wirelessly communicate complying with industrial standards such as IEEE 802.11p. By exchanging information with other members via wireless communication, a platoon member computes its desired acceleration which is then passed on to the engine control system via in-vehicle network to physically realize the acceleration. This leads to a multi-layer control scheme. The upper-layer is influenced by the behavior of 802.11p communication and network congestion due to transmissions by other vehicles in the traffic. The lower-layer engine control loop communicates over the fast and reliable in-vehicle networks (e.g., FlexRay, Ethernet). Design of the overall system therefore depends on (i) the characteristics of 802.11p-based communication (ii) the nature of the traffic (iii) the control algorithms running at the two layers. We present a cosimulation framework consisting of Matlab (for the multi-layer control algorithms), ns-3 (for the 802.11p network) and SUMO (for the traffic behavior). The framework can be used to validate different platooning setups. As an illustrative case study, we consider a multi-layer control strategy where the upper-layer uses Model Predictive Control (MPC) at a rate in compliance with 802.11p and the lower-layer uses statefeedback control at a higher sampling rate in line with in-vehicle networking capabilities. The control strategy is evaluated considering various realistic traffic and network congestion scenarios.
```
@inproceedings{DSD_2018_ai_final,
  title = {Co-simulation framework for control, communication and traffic for vehicle platoons},
  author = {Ibrahim, Amr and Math, Chetan Belagal and Goswami, Dip and Basten, Twan and Li, Hong},
  booktitle = {21st Euromicro Conference on Digital System Design (DSD)},
  pages = {352--356},
  year = {2018},
  organization = {IEEE}
}
```
R. Jonk, J. Voeten, M. Geilen, T. Basten, and R. Schiffelers, “Timing prediction for service-based applications mapped on linux-based multi-core platforms,” in 21st Euromicro Conference on Digital System Design (DSD), 2018, pp. 130–139.
[Abstract] [BibTeX] [ Download] We develop a model-based approach to predict timing of service-based software applications on Linux-based multi-core platforms for alternative mappings (affinity and priority settings). Service-based applications consist of communicating sequential (Linux) processes. These processes execute functions (also called services), but can only execute them one at a time. Models are inferred automatically from execution traces to enable timing optimization of existing (legacy) systems. Our approach relies on a linear progress approximation of functions. We compute the expected share of each function based on the mapping (affinity and priority) parameters and the functions that are currently active. We validate our models by carrying out a controlled lab experiment consisting of a multi-process pipelined application mapped in different ways on a quadcore Intel i7 processor. A broad class of affinity and priority settings is fundamentally unpredictable due to Linux binding policies. We show that predictability can be achieved if the platform is partitioned in disjoint clusters of cores such that i) each process is bound to such a cluster, ii) processes with non real-time priorities are bound to singleton clusters, and iii) all processes bound to a non-singleton cluster have different real-time priorities. For mappings using singleton clusters with niceness priorities only, our model predicts execution latencies (for each pipeline iteration) with errors less than 5% relative to the measured execution times. For mappings using a nonsingleton cluster (with different real-time priorities) relative errors of less than 2% are obtained. When real-time and niceness priorities are mixed, we predict with errors of 7%.
```
@inproceedings{jonk2018timing,
  title = {Timing prediction for service-based applications mapped on linux-based multi-core platforms},
  author = {Jonk, Ruben and Voeten, Jeroen and Geilen, Marc and Basten, Twan and Schiffelers, Ramon},
  booktitle = {21st Euromicro Conference on Digital System Design (DSD)},
  pages = {130--139},
  year = {2018},
  organization = {IEEE}
}
```
S. Mohamed, D. Zhu, D. Goswami, and T. Basten, “Optimising quality-of-control for data-intensive multiprocessor image-based control systems considering workload variations,” in 21st Euromicro Conference on Digital System Design (DSD), 2018, pp. 320–327.
[Abstract] [BibTeX] [ Download] Image-Based Control (IBC) systems have a long sample period. Sensing in these systems consists of computeintensive image processing algorithms whose response times are dependent on image workload. IBC systems are typically designed for the worst-case workload that results in a long sample period and hence suboptimal quality-of-control (QoC). This worst-case based design is further considered for mapping of controller tasks and allocating platform resources, resulting in significant resource over-provisioning. Our design philosophy is to sample as fast as possible to optimise QoC for a given platform allocation, and for this, we present a structured design flow. Workload variations determine how fast we can sample and we model this dynamic behaviour using the concept of workload scenarios. Our choice of scenario-aware dataflow as the formal model for our application enables us to: i) model dynamic behaviour, analyse timing, and optimally map application tasks to the platform for maximising the effective utilisation of allocated resources, ii) relate throughput of the dataflow graph to the sample period, and thus combine dataflow analysis and mapping with control design parameters and QoC to identify system scenarios, and iii) to efficiently implement a run-time mechanism that manages necessary dynamic reconfiguration between system scenarios. Our results show that our design approach outperforms the worst-case based design with respect to optimising QoC and maximising effective resource utilisation.
```
@inproceedings{sajid2018optimising,
  title = {Optimising quality-of-control for data-intensive multiprocessor image-based control systems considering workload variations},
  author = {Mohamed, Sajid and Zhu, Diqing and Goswami, Dip and Basten, Twan},
  booktitle = {21st Euromicro Conference on Digital System Design (DSD)},
  pages = {320--327},
  year = {2018},
  organization = {IEEE}
}
```
B. van der Sanden, M. Geilen, M. Reniers, and T. Basten, “Partial-Order Reduction for Performance Analysis of Max-Plus Timed Systems,” in 18th International Conference on Application of Concurrency to System Design (ACSD), 2018, pp. 40–49.
[Abstract] [BibTeX] [ Download] [ CrossRef] This paper presents a partial-order reduction method for performance analysis of max-plus timed systems. A max-plus timed system is a network of automata, where the timing behavior of deterministic system tasks (events in an automaton) is captured in (max, +) matrices. These tasks can be characterized in various formalisms like synchronous data flow, Petri nets, or real-time calculus. The timing behavior of the system is captured in a (max, +) state space, calculated from the composition of the automata. This state space may exhibit redundant interleaving with respect to performance aspects like throughput or latency. The goal of this work is to obtain a smaller state space to speed up performance analysis. To achieve this, we first formalize state-space equivalence with respect to throughput and latency analysis. Then, we present a way to compute a reduced composition directly from the specification. This yields a smaller equivalent state space. We perform the reduction on-the-fly, without first computing the full composition. Experiments show the effectiveness of the method on a set of realistic manufacturing system models.
```
@inproceedings{8542125,
  author = {{van der Sanden}, B. and {Geilen}, M. and {Reniers}, M. and {Basten}, T.},
  booktitle = {18th International Conference on Application of Concurrency to System Design (ACSD)},
  title = {Partial-Order Reduction for Performance Analysis of Max-Plus Timed Systems},
  year = {2018},
  volume = {},
  number = {},
  pages = {40-49},
  keywords = {automata theory;equivalence classes;manufacturing systems;matrix algebra;state-space methods;performance analysis;max-plus timed system;partial-order reduction method;timing behavior;deterministic system tasks;state-space equivalence;(max, +) state space;manufacturing system models;(max, +) matrices;automata network;Automata;Timing;Performance analysis;Throughput;Task analysis;Semantics;Algebra;max-plus;performance;throughput;latency;partial-order reduction;max-plus automata;max-plus algebra;performance analysis},
  doi = {10.1109/ACSD.2018.00007},
  issn = {1550-4808},
  month = jun
}
```
A. R. Baghban Behrouzian, D. Goswami, T. Basten, M. Geilen, H. Alizadeh, and M. Hendriks, “Firmness Analysis of Real-Time Applications Under Static-Priority Preemptive Scheduling,” in 2018 IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS), 2018, pp. 295–304.
[Abstract] [BibTeX] [ Download] [ CrossRef] (m, k)-firm real-time tasks must meet the deadline of at least m jobs out of any k consecutive jobs to satisfy the firmness requirement. Scheduling of an (m,k)-firm task requires firmness analysis, whose results are used to provide system-level guarantees on the satisfaction of firmness conditions. We address firmness analysis of an (m, k)-firm task that is intended to be added to a set of asynchronous tasks scheduled under a Static-Priority Preemptive (SPP) policy. One of the main causes of deadline misses in periodic tasks running under an SPP policy is interference from higher priority tasks. Since the synchrony between the newly added task and higher priority tasks is unknown, the interference from the higher priority tasks is also unknown. We propose an analytic Firmness Analysis (FAn) method to obtain a synchrony that results in the maximum minimum number of deadline hit jobs in any k consecutive jobs of the task. Scalability of FAn is compared with that of existing work - a brute-force search approach - and a timed-automata model of the problem that is analysed using the reachability check of the Uppaal model checker. Our method substantially reduces the complexity of the analysis.
```
@inproceedings{8430091,
  author = {{Baghban Behrouzian}, A. R. and {Goswami}, D. and {Basten}, T. and {Geilen}, M. and {Alizadeh}, H. and {Hendriks}, M.},
  booktitle = {2018 IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS)},
  title = {Firmness Analysis of Real-Time Applications Under Static-Priority Preemptive Scheduling},
  year = {2018},
  volume = {},
  number = {},
  pages = {295-304},
  keywords = {automata theory;formal verification;reachability analysis;scheduling;firmness requirement;firmness conditions;asynchronous tasks;periodic tasks;deadline hit jobs;static-priority preemptive scheduling;static-priority preemptive policy;analytic firmness analysis method;brute-force search approach;timed-automata model;reachability check;UPPAAL model checker;Task analysis;Real-time systems;Fans;Interference;Time division multiple access;DH-HEMTs;Scalability;Deadline miss;(m;k) firm real time tasks;static priority preemptive},
  doi = {10.1109/RTAS.2018.00037},
  issn = {},
  month = apr
}
```
J. V. Pinxten, U. Waqas, M. Geilen, T. Basten, and L. Somers, “Online scheduling of 2-re-entrant flexible manufacturing systems,” ACM Transactions on Embedded Computing Systems (TECS), vol. 16, no. 5s, p. 160, 2017.
[Abstract] [BibTeX] [ Download] Online scheduling of operations is essential to optimize productivity of flexible manufacturing systems (FMSs) where manufacturing requests arrive on the fly. An FMS processes products according to a particular flow through processing stations. This work focusses on online scheduling of re-entrant FMSs with flows using processing stations where products pass twice and with limited buffering between processing stations. This kind of FMS is modelled as a re-entrant flow shop with due dates and sequence-dependent set-up times. Such flow shops can benefit from minimization of the time penalties incurred from set-up times. On top of an existing greedy scheduling heuristic we apply a meta-heuristic that simultaneously explores several alternatives considering trade-offs between the used metrics by the scheduling heuristic. We identify invariants to efficiently remove many infeasible scheduling options so that the running time of online implementations is improved. The resulting algorithm is much faster than the state of the art and produces schedules with on average 4.6%shorter makespan.
```
@article{pinxten2017online,
  title = {Online scheduling of 2-re-entrant flexible manufacturing systems},
  author = {Pinxten, Joost Van and Waqas, Umar and Geilen, Marc and Basten, Twan and Somers, Lou},
  journal = {ACM Transactions on Embedded Computing Systems (TECS)},
  volume = {16},
  number = {5s},
  pages = {160},
  year = {2017},
  publisher = {ACM}
}
```
R. Medina, S. Stuijk, D. Goswami, and T. Basten, “Exploring the Trade-off Between Processing Resources and Settling Time in Image-based Control Through LQR Tuning,” in Proceedings of the Symposium on Applied Computing, New York, NY, USA, 2017, pp. 1456–1459.
[Abstract] [BibTeX] [ Download] [ CrossRef] Image-Based control systems extract information by a camera and an image processing algorithm. The challenge of such controllers is that the sensing latency deteriorates the control performance. Multi-core technology can be used to implement the sensing algorithm in a pipelined fashion. More processing resources potentially lead to better settling time. This results in a trade-off between resources and performance. We present a method to analyse this trade-off.
```
@inproceedings{p1456-medina,
  author = {Medina, R\'{o}binson and Stuijk, Sander and Goswami, Dip and Basten, Twan},
  title = {Exploring the Trade-off Between Processing Resources and Settling Time in Image-based Control Through LQR Tuning},
  booktitle = {Proceedings of the Symposium on Applied Computing},
  series = {SAC '17},
  year = {2017},
  isbn = {978-1-4503-4486-9},
  location = {Marrakech, Morocco},
  pages = {1456--1459},
  numpages = {4},
  url = {http://doi.acm.org/10.1145/3019612.3019862},
  doi = {10.1145/3019612.3019862},
  acmid = {3019862},
  publisher = {ACM},
  address = {New York, NY, USA},
  keywords = {LQR tuning, image-based control, particle swarm optimization, pipelined sensing control, trade-off analysis}
}
```
R. Medina, S. Stuijk, D. Goswami, and T. Basten, “Reconfigurable pipelined sensing for image-based control,” in 11th International Symposium on Industrial Embedded Systems, 2016.
[Abstract] [BibTeX] [ Download] Image-based control systems are becoming com- mon in domains such as robotics, healthcare and industrial automation. Coping with a long sample period because of the latency of the image processing algorithm is an open challenge. Modern multi-core platforms allow to address this challenge by pipelining the sensing algorithm. Often, such systems share the resources with other tasks. We show that the performance of an image-based controller can be improved by pipelining the image processing algorithm on unallocated cores. It can be further improved by dynamically allocating (i.e. reconfiguring) cores that are temporarily not used by other tasks to the sensing pipeline. We present a state-based modelling strategy for pipelined and reconfigurable pipelined sensing. We introduce a control design strategy for reconfigurable pipelined systems that assures stability and shows improvement in the control performance.
```
@inproceedings{medina2016sies,
  title = {Reconfigurable pipelined sensing    for image-based control},
  author = {Medina, Robinson and Stuijk, Sander and Goswami, Dip and Basten, Twan},
  booktitle = {11th International Symposium on Industrial Embedded Systems},
  year = {2016},
  month = {in press},
  publisher = {IEEE}
}
```
J. van Pinxten, M. Geilen, T. Basten, U. Waqas, and L. J. Somers, “Online heuristic for the Multi-Objective Generalized traveling salesman problem,” in Design, Automation & Test in Europe Conference Exhibition, DATE, Dresden, Germany, March 14-18, 2016, pp. 822–825.
[Abstract] [BibTeX] [ Download] Today’s manufacturing systems are typically complex cyber-physical systems where the physical and control aspects interact with the scheduling decisions. Optimizing such facilities requires ordering jobs and configuring the manufacturing system for each job. This optimization problem can be described as a Multi-Objective Generalized TSP where conflicting objectives lead to a trade-off space. This is the first work to address this TSP variant, introducing a compositional heuristic suitable to online application.
```
@inproceedings{pinxten2016mogtsp,
  author = {van Pinxten, Joost and Geilen, Marc and Basten, Twan and Waqas, Umar and Somers, Lou J.},
  title = {Online heuristic for the Multi-Objective Generalized traveling salesman
      problem},
  booktitle = {Design, Automation {\&} Test in Europe Conference {\&}
      Exhibition, {DATE}, Dresden, Germany, March 14-18},
  pages = {822--825},
  year = {2016}
}
```
B. van der Sanden et al., “Compositional Specification of Functionality and Timing of Manufacturing Systems,” in Forum on Specification and Design Languages (FDL), Bremen, Germany, 2016.
[Abstract] [BibTeX] [ Download] This paper introduces a formal modeling approach for compositional specification of both functionality and timing of manufacturing systems. Functionality aspects can be considered orthogonally to timing aspects. The functional aspects are specified using two abstraction levels; high-level activities and lower level actions. Design of a functionally correct controller is possible by looking only at the activity level, abstracting from the different execution orders of actions and their timing. As a result, controller design can be performed on a much smaller state space compared to an explicit model where timing and actions are present. The performance of the controller can be analyzed and optimized by taking into account the timing characteristics. Since formal semantics are given in terms of a (max,+) state space, various existing performance analysis techniques can be used. We illustrate the approach, including performance analysis, on an example manufacturing system.
```
@inproceedings{sanden2016fdl,
  author = {van der Sanden, Bram and Bastos, Jo\~ao and Voeten, Jeroen and Geilen, Marc and Reniers, Michel and Basten, Twan and Jacobs, Johan and Schiffelers, Ramon},
  title = {Compositional Specification of Functionality and Timing of Manufacturing Systems},
  booktitle = {Forum on Specification and Design Languages (FDL)},
  month = sep,
  year = {2016},
  address = {Bremen, Germany}
}
```
A. R. B. Behrouzian, D. Goswami, T. Basten, M. Geilen, and H. A. Ara, “Multi-Constraint Multi-Processor Resource Allocation,” in International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation (SAMOS), 2015, pp. 338–346.
[Abstract] [BibTeX] [ Download] This work proposes a Multi-Constraint Resource Allocation (MuCoRA) method for applications from multiple domains onto multi-processors. In particular, we address a mapping problem for multiple throughput-constrained streaming applications and multiple latency-constrained feedback control applications onto a multi-processor platform running under a Time-Division Multiple-Access (TDMA) policy. The main objective of the proposed method is to reduce resource usage while meeting constraints from both these two domains (i.e., throughput and latency constraints). We show by experiments that the overall resource usage for this mapping problem can be reduced by distributing the allocated resource (i.e., TDMA slots) to the control applications over the TDMA wheel instead of allocating consecutive slots.
```
@inproceedings{behrouzian2015multi,
  title = {Multi-Constraint Multi-Processor Resource Allocation},
  author = {Behrouzian, Amir RB and Goswami, Dip and Basten, Twan and Geilen, Marc and Ara, Hadi Alizadeh},
  booktitle = {International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation (SAMOS)},
  pages = {338--346},
  year = {2015},
  organization = {IEEE}
}
```
U. Waqas et al., “A re-entrant flowshop heuristic for online scheduling of the paper path in a large scale printer,” in Design, Automation Test in Europe Conference Exhibition (DATE), 2015, pp. 573–578.
[Abstract] [BibTeX] [ Download] A Large Scale Printer (LSP) is a Cyber Physical System (CPS) printing thousands of sheets per day with high quality. The print requests arrive at run-time requiring online scheduling. We capture the LSP scheduling problem as online scheduling of re-entrant flowshops with sequence dependent setup times and relative due dates with makespan minimization as the scheduling criterion. Exhaustive approaches like Mixed Integer Programming can be used, but they are compute intensive and not suited for online use. We present a novel heuristic for scheduling of LSPs that on average requires 0.3 seconds per sheet to find schedules for industrial test cases. We compare the schedules to lower bounds, to schedules generated by the current scheduler and schedules generated by a modified version of the classical NEH (MNEH) heuristic [1], [2]. On average, the proposed heuristic generates schedules that are 40% shorter than the current scheduler, have an average difference of 25% compared to the estimated lower bounds and generates schedules with less than 67% of the makespan of schedules generated by the MNEH heuristic.
```
@inproceedings{waqas2015flowshop,
  author = {Waqas, U. and Geilen, M. and Kandelaars, J. and Somers, L. and Basten, T. and Stuijk, S. and Vestjens, P. and Corporaal, H.},
  booktitle = {Design, Automation Test in Europe Conference Exhibition (DATE)},
  title = {A re-entrant flowshop heuristic for online scheduling of the paper path in a large scale printer},
  year = {2015},
  month = mar,
  pages = {573-578},
  keywords = {flow shop scheduling;integer programming;minimisation;printers;CPS;LSP scheduling problem;MNEH heuristic;cyber physical system;large scale printer;makespan minimization;mixed integer programming;online paper path scheduling;online reentrant flowshop scheduling;reentrant flowshop heuristic;relative due dates;sequence dependent setup times;Job shop scheduling;Printers;Printing;Processor scheduling;Productivity;Schedules}
}
```
B. van der Sanden et al., “Modular Model-Based Supervisory Controller Design for Wafer Logistics in Lithography Machines,” in Proceedings of MODELS, 2015.
[Abstract] [BibTeX] [ Download] Development of high-level supervisory controllers is an important challenge in the design of high-tech systems. It has become a significant issue due to increased complexity, combined with demands for verified quality, time to market, ease of development, and integration of new functionality. To deal with these challenges, model-based engineering approaches are suggested as a cost-effective way to support easy adaptation, validation, synthesis, and verification of controllers. This paper presents an industrial case study on modular design of a supervisory controller for wafer logistics in lithography machines. The uncontrolled system and control requirements are modeled independently in a modular way, using small, loosely coupled and minimally restrictive extended finite automata. The multiparty synchronization mechanism that is part of the specification formalism provides clear advantages in terms of modularity, traceability, and adaptability of the model. We show that being able to refer to variables and states of automata in guard expressions and state-based requirements, enabled by the use of extended finite automata, provides concise models. Additionally, we show how modular synthesis allows construction of local supervisors that ensure safety of parts of the system, since monolithic synthesis is not feasible for our industrial case.
```
@inproceedings{sanden2015modeling,
  author = {van der Sanden, B. and Reniers, M. and Geilen, M. and Basten, T. and Jacobs, J. and Voeten, J. and Schiffelers, R.},
  booktitle = {Proceedings of MODELS},
  title = {Modular Model-Based Supervisory Controller Design for Wafer Logistics in Lithography Machines},
  year = {2015}
}
```
S. Adyanthaya et al., “xCPS: A tool to eXplore Cyber Physical Systems,” in Workshop on Embedded and Cyber-Physical Systems Education (WESE), New York, NY, USA, 2015, pp. 3:1–3:8.
[Abstract] [BibTeX] [ Download] Cyber-Physical Systems (cps) play an important role in the modern high-tech industry. Designing such systems is a challenging task due to the multi-disciplinary nature of these systems, and the range of abstraction levels involved. To facilitate hands-on experience with such systems, we develop a cyber-physical platform that aids in research and education on cps. This paper describes this platform, which contains all typical cps components. The platform is used in various research and education projects for bachelor, master, and PhD students. We discuss the platform and a number of projects and the educational opportunities they provide.
```
@inproceedings{2015-esweek-abehrouzian-xcps_tool,
  author = {Adyanthaya, Shreya and Ara, Hadi Alizadeh and Bastos, Jo\~{a}o and Behrouzian, Amir and S\'{a}nchez, R\'{o}binson Medina and van Pinxten, Joost and van der Sanden, Bram and Waqas, Umar and Basten, Twan and Corporaal, Henk and Frijns, Raymond and Geilen, Marc and Goswami, Dip and Stuijk, Sander and Reniers, Michel and Voeten, Jeroen},
  title = {{xCPS: A tool to eXplore Cyber Physical Systems}},
  month = oct,
  year = {2015},
  booktitle = {Workshop on Embedded and Cyber-Physical Systems Education (WESE)},
  pages = {3:1--3:8},
  publisher = {ACM},
  address = {New York, NY, USA}
}
```
U. Waqas et al., “A Fast Estimator of Performance with respect to the Design Parameters of Self Re-entrant Flowshops.”
[Abstract] [BibTeX] [ Download] Self re-entrant flowshops consist of machines which process jobs several times. They are found in applications like TFT-LCD assembly, LED manufacturing and industrial printing. The structure of a self re-entrant flowshop influences its performance. To get better performance while reducing costs a fast performance estimation method can be used to explore the trade-offs between the structure and the performance during the design process. We present a novel performance estimator that uses the information in the jobs being processed to analyse the trade-offs. We study the impact of the design parameters of an industrial printer using the performance estimator with an average estimation time of 1.1 milliseconds per job and with an average accuracy of not less than 96%.
```
@unpublished{waqas2016dsd,
  author = {Waqas, U. and Geilen, M. and Stuijk, S. and Pinxten, J.V. and Basten, T. and Somers, L. and Corporaal, H.},
  title = {A Fast Estimator of Performance with respect to the Design Parameters of Self Re-entrant Flowshops},
  note = {DSD},
  optmonth = {September},
  optyear = {2016}
}
```