Zdeněk Hanzálek

Zdeněk Hanzálek
Czech Technical University in Prague | ČVUT · Czech Institute of Informatics, Robotics and Cybernetics

Ph.D.

About

184
Publications
42,473
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1,574
Citations
Additional affiliations
January 2005 - present
January 1998 - December 2011
České vysoké učení technické v Praze

Publications

Publications (184)
Preprint
Full-text available
The problem of path planning for automated parking is usually presented as finding a collision-free path from initial to goal positions, where three out of four parking slot edges represent obstacles. We rethink the path planning problem for parallel parking by decomposing it into two independent parts. The topic of this paper is finding optimal pa...
Article
Due to the outbreak of the COVID-19 pandemic, the manufacturing sector has been experiencing unprecedented issues, including severe fluctuation in demand, restrictions on the availability and utilization of the workforce, and governmental regulations. Adopting conventional manufacturing practices and planning approaches under such circumstances can...
Article
Full-text available
Mixed-criticality scheduling addresses the problem of sharing common resources among jobs of different degrees of criticality and uncertain processing times. The processing time of jobs is observed during the online execution of the schedule with the prolongations of critical jobs being compensated by the rejection of less critical ones. One of the...
Conference Paper
In many safety-critical applications, Multi-Processor Systems-on-Chip (MPSoC) must operate within a given thermal envelope under harsh environmental conditions. Meeting the thermal requirements often requires using advanced task allocation and scheduling techniques that are guided by detailed power models. This paper introduces a method that has th...
Conference Paper
This paper describes an entire automated vehicle platform for software prototyping and demonstration. The project is build up with the cooperation of the Czech Technical University and Porsche Engineering Services company. The platform is based on a serial production car Porsche Panamera. The aim of this prototype is to close perception - planning...
Conference Paper
Autonomous cars represent the future of human transportation. We contribute to this course by cooperation with the automotive industry on making a Porsche Panamera car drive autonomously. Unfortunately, performing experiments with real cars is expensive, potentially dangerous, and sometimes not convenient. For this reason, we prototype many of the...
Chapter
Full-text available
Additive manufacturing (AM) is a promising technology for the rapid prototyping and production of highly customized products. The scheduling of AM machines has an essential role in increasing profitability and has recently received a great deal of attention. This paper investigates the scheduling of batch processing of parallel 3d-printing machines...
Chapter
The reconfigurable manufacturing system (RMS) has been acknowledged as an effective manufacturing paradigm to tackle high volatility in demand types and amounts. However, the reconfiguration needs an amount of time and leads to some level of resource wastage. Accordingly, a high frequency in the system’s reconfiguration may have a negative impact o...
Article
This paper addresses a single machine scheduling problem minimizing the weighted number of tardy jobs, where each job is characterized by processing time, due date, deadline, and weight. It is known from the existing literature that so-called strongly correlated instances, i.e., instances where each job has the weight equal to its processing time p...
Article
The real-time and safety-critical demands posed in a variety of industrial systems can now be handled on the Ethernet architecture by virtue of the IEEE Time-Sensitive Networking task group. In particular, deterministic nature and timeliness guarantees can be achieved by time-triggered communication schedules that are enabled by the IEEE 802.1Qbv s...
Article
Full-text available
The deterministic behavior of real-time communication networks is achieved by time-triggered periodic schedules for critical data traffic. Calculating such a schedule requires satisfying a lot of constraints, which in practice may be difficult due to the increasing number of data flows in the network. In the current approaches, the routes of flows...
Conference Paper
Full-text available
Convergecast and broadcast operations in WSN-based applications impose demands in terms of energy efficiency, reliability, and timeliness QoS properties which existing protocols struggle to fulfill. The Deterministic Synchronous Multi-channel Extension (DSME) mechanism introduced in the IEEE 802.15.4e standard constitutes a promising solution to ad...
Article
We consider a stochastic parallel machine scheduling problem, where the jobs have uncertain processing time described by a normal probability distribution. The objective is to maximize the probability that all the jobs are completed before a common due date. The considered problem has many practical applications, but it is notoriously known to be d...
Article
This work studies a discrete manufacturing scheduling problem faced by companies with energy-intensive processes. A scheduling environment with parallel dedicated machines is considered, where each machine consumes electric energy while processing a job. Usually, the manufacturing companies have a contract with an electric utility that specifies th...
Article
This survey covers the basic principles and related works addressing the time-triggered scheduling of periodic tasks with deadlines. The wide range of applications and the increasing complexity of modern real-time systems result in the continually growing interest in this topic. However, the articles in this field appear without systematic notation...
Chapter
This chapter considers the two-echelon supply chain network design with unreliable facilities when nodes related to facilities in both echelons fail under disruptions. A new mixed-integer programming (MIP) model is proposed for a reliable facility location with possible customer reassignment in different probabilistic scenarios. The maintaining of...
Article
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 transiti...
Chapter
Periodic scheduling problems (PSP) are frequently found in a wide range of applications. In these problems, we schedule a set of tasks on a set of machines in time, where each task is to be executed repeatedly with a given period. The tasks are assigned to machines, and at any moment, at most one task can be processed by a given machine. Since no e...
Article
Full-text available
This paper addresses a single machine scheduling problem with non-preemptive jobs to minimize the total electricity cost. Two latest trends in the area of the energy-aware scheduling are considered, namely the variable energy pricing and the power-saving states of a machine. Scheduling of the jobs and the machine states are considered jointly to ac...
Preprint
This paper is motivated by periodic data transmission in autonomous cars. We considered periodic tasks (with different periods) on one or several machines. After reviewing the literature on the subject, we managed to generalize a result of Lukasiewicz et al. (i.e., the equivalence of periodic scheduling with the power of two periods and special 2D...
Presentation
Full-text available
Presentation slides created for CPAIOR 2020 conference presenting a new modeling approach for scheduling problem 1|TOU,states|TEC. Presentation video is available on YouTube: https://youtu.be/cSPShs-Q1Wk For manuscript see https://www.researchgate.net/publication/337781297_Power_of_Pre-Processing_Production_Scheduling_with_Variable_Energy_Pricing...
Conference Paper
Full-text available
Many modern computing platforms in the safetycritical domains are based on heterogeneous Multiprocessor System-on-Chip (MPSoC). Such computing platforms are expected to guarantee high-performance within a strict thermal envelope. This paper introduces a testbed for thermal and performance analysis. The testbed allows the users to develop advanced s...
Article
Rooted from the Industry 4.0 principles, Cloud Manufacturing (CMfg) is a novel customer-oriented manufacturing norm, which can assist enterprises to withstand in the nowadays highly volatile and competitive market. CMfg systems comprise two separate parties, namely, customers and factories, with independent individuals. In this regard, considering...
Article
Full-text available
Thanks to the standards being developed by IEEE Time-Sensitive Networking (TSN) Task Group, the classical IEEE 802.1 Ethernet architecture is now enhanced to accommodate real-time and safety-critical requirements emerging in various cyber-physical systems. The deterministic nature of the communication is achieved through the time-triggered traffic,...
Article
Full-text available
This paper is motivated by the repetitive and periodic transmission of messages in Wireless Sensor Networks (WSNs) given by the ZigBee standard. In order to save energy, communication tasks are grouped in time. The WSN applications, such as control loops used in production lines, impose deadlines on the message delivery time. By introducing a group...
Preprint
Full-text available
The FlexRay bus is a modern standard used in the automotive industry.It offers deterministic message transmission with zero jitter while using time-triggered scheduling in the static segment. When several vehicle variants (i.e. different models and their versions) share the same signal, the car manufacturers require to schedule such signal at the s...
Preprint
Full-text available
The reliability of the increasing number of modern applications and systems strongly depends on interconnecting technology. Complex systems which usually need to exchange, among other things, multimedia data together with safety-related information, as in the automotive or avionic industry, for example, make demands on both the high bandwidth and t...
Article
The complexity of modern automotive systems grows with increasing user demands. A wide range of functionalities that these systems comprise is implemented as multiple control applications sharing platform resources. To ensure safe operation of the system, the applications must be executed periodically and deterministically in time. Although the app...
Preprint
Full-text available
In this paper, we investigate the use of deep learning for solving a classical NP-Hard single machine scheduling problem where the criterion is to minimize the total tardiness. Instead of designing an end-to-end machine learning model, we utilize well known decomposition of the problem and we enhance it with a data-driven approach. We have designed...
Preprint
Full-text available
This paper, inspired by a real production process of steel hardening, investigates a scheduling problem to minimize the idle energy consumption of machines. The energy minimization is achieved by switching a machine to some power-saving mode when it is idle. For the steel hardening process, the mode of the machine (i.e., furnace) can be associated...
Preprint
Full-text available
Finding a collision-free path for autonomous parking is usually performed by computing geometric equations, but the geometric approach may become unusable under challenging situations where space is highly constrained. We propose an algorithm based on Rapidly-Exploring Random Trees Star (RRT*), which works even in highly constrained environments an...
Chapter
Full-text available
The paper deals with a parallel machines scheduling problem with dedicated tasks with sequence-dependent setup times that are subject to the non-overlapping constraint. This problem emerges in the productions where only one machine setter is available on the shop floor. We consider that setups are performed by a single person who cannot serve more...
Conference Paper
Full-text available
In this paper, we investigate the use of deep learning for solving a classical NP-Hard single machine scheduling problem where the criterion is to minimize the total tardiness. Instead of designing an end-to-end machine learning model, we utilize well known decomposition of the problem and we enhance it with a data-driven approach. We have designed...
Conference Paper
This paper, inspired by a real production process of steel hardening, investigates a scheduling problem to minimize the idle energy consumption of machines. The energy minimization is achieved by switching a machine to some power-saving mode when it is idle. For the steel hardening process, the mode of the machine (i.e., furnace) can be associated...
Preprint
Full-text available
Accepted to upcoming 17th International Conference on the Integration of Constraint Programming, Artificial Intelligence, and Operations Research (CPAIOR2020) This paper addresses a single machine scheduling problem with non-preemptive jobs to minimize the total electricity cost. Two latest trends in the area of the energy-aware scheduling are con...
Article
Many scheduling problems that can be identified inside safety-critical applications, such as in autonomous cars, tend to be mixed-critical. Such scheduling problems consider tasks to have different criticalities depending on the safety levels (activation of brakes vs. activation of air-conditioning). The biggest challenge in those scheduling proble...
Preprint
Full-text available
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 transiti...
Article
Full-text available
The design of Medium Access Control (MAC) protocol for Wireless Sensor Networks (WSNs) with both limited energy consumption and data delivery time is crucial for industrial and control applications. Since Time Division Multiple Access (TDMA) MAC eliminates the collision occurrence and seeks the minimization of the number of time-slots assigned to e...
Conference Paper
Many real-world scheduling problems are characterized by uncertain parameters. In this paper, we study a classical parallel machine scheduling problem where the processing time of jobs is given by a normal distribution. The objective is to maximize the probability that jobs are completed before a given common due date. This study focuses on the com...
Conference Paper
Full-text available
Finding a collision-free path for autonomous parking is usually performed by computing geometric equations, but the geometric approach may become unusable under challenging situations where space is highly constrained. We propose an algorithm based on Rapidly-Exploring Random Trees Star (RRT*), which works even in highly constrained environments an...
Article
Full-text available
Many applications require both high performance and predictable timing. High-performance can be provided by COTS Multi-Core System on Chips (MPSoC), however, as cores in these systems share main memory, they are susceptible to interference from each other, which is a problem for timing predictability. We achieve predictability on multi-cores by emp...
Article
Full-text available
The portfolio of models offered by car manufacturing groups often includes many variants (i.e., different car models and their versions). With such diversity in car models, variant management becomes a formidable task. Thus, there is an effort to keep the variants as close as possible. This simple requirement forms a big challenge in the area of co...
Article
Nowadays, robotic cells are mostly designed with the main goal to meet the desired production rate without any consideration of the energy efficiency, therefore, it is often possible to achieve significant energy savings without downsizing the production. In our previous study, we established the mathematical formulation of the energy optimization...
Chapter
Full-text available
This study addresses optimization of production processes where machines have high energy consumption. One efficient way to reduce the energy expenses in production is to turn a machine off when it is not being used or switch it into an energy-saving mode. If the production has several machines and production demand that varies in time, the energy...
Article
Full-text available
This paper introduces a novel scheduling problem, where jobs occupy a triangular shape on the time line. This problem is motivated by scheduling jobs with different criticality levels. A measure is introduced, namely the binary tree ratio. It is shown that the greedy algorithm solves the problem to optimality when the binary tree ratio of the input...
Article
Full-text available
Due to some technical issues with article HTML, Algorithm 1 appeared twice and there was no ILP formulation.
Article
Full-text available
This study presents a widely applicable approach to accelerate the computation time of the Branch-and-Price (BaP) algorithm, which is a very powerful exact method used for solving complex combinatorial problems. Existing studies indicate that the most computationally demanding element of the BaP algorithm is the pricing problem. The case-studies pr...
Conference Paper
Many applications require both high performance and predictable timing. High-performance can be provided by COTS Multi-Core System on Chips (MPSoC), however, as cores in these systems share the memory bandwidth they are susceptible to interference from each other, which is a problem for timing predictability. We achieve predictability on multi-core...
Conference Paper
The research presented in this paper is focused on the scheduling problem with alternative process plans where the goal is to minimise the sum of all the performed setup times in the schedule. The setup times play an important role in scheduling problems, yet they are, in most cases, considered only as an additional constraint, not as a part of the...
Article
Full-text available
In this work, we consider a scheduling problem faced by production companies with large electricity consumption. Due to the contract with the electric utility, the production companies are obligated to comply with the total energy consumption limits in the specified time intervals (usually 15-min long); otherwise, the companies pay substantial pena...
Chapter
Full-text available
A novel mathematical formulation of the energy optimisation problem for robotic lines is presented, which allows minimising the energy consumption in a robotic cell while keeping the required production cycle time. Different energy saving modes of the robots are utilised as well as the fact that the robot energy consumption during its movement depe...
Article
Full-text available
Cluster scheduling respecting collision avoidance is a complex problem in cluster-tree Wireless Sensor Networks (WSNs). The difficulty of the problem also increases significantly when the traffic is organized as time-constrained data flows with opposite directions. Thus, in this paper we seek for collision-free cluster schedule that meets all the d...
Conference Paper
Full-text available
In this paper, we address the problem of developing TDMA scheduling algorithm for tree topology WSNs. The data transmissions are organized into periodic data flows that may have opposite directions since they are carrying sensor and actuator values for feedback control. It is required to determine a periodic and collision-free allocation of the tim...
Article
Full-text available
The complexity of embedded application design is increasing with growing user demands. In particular, automotive embedded systems are highly complex in nature, and their functionality is realized by a set of periodic tasks. These tasks may have hard real-time requirements and communicate over an interconnect. The problem is to efficiently co-schedu...
Article
This paper deals with a mixed-criticality scheduling problem: each job has a criticality level depending on its importance. In addition, each job has a finite set of possible processing times, and a known probability for each of them. Every job must be processed between its release date and its deadline. Moreover, each job has a weight correspondin...
Article
Full-text available
The paper studies a lacquer production scheduling problem formulated as a resource constrained project scheduling problem with general temporal constraints (i.e., positive and negative time-lags). This real-world scheduling problem requires so-called take-give resources that are needed from the beginning of an activity to the completion of another...
Article
This study focuses on the energy optimization of industrial robotic cells, which is essential for sustainable production in the long term. A holistic approach that considers a robotic cell as a whole toward minimizing energy consumption is proposed. The mathematical model, which takes into account various robot speeds, positions, power-saving modes...
Article
Full-text available
In this paper, we study an NP-hard problem of a single machine scheduling minimizing the makespan, where the mixed-critical tasks with an uncertain processing time are scheduled. We show the derivation of F-shaped tasks from the probability distribution function of the processing time, then we study the structure of problems with two and three crit...
Conference Paper
The current research in real-time scheduling focuses mostly on the certification of functionalities with respect to safety requirements under conservative assumptions or to achieve efficient resource utilization but with optimistic assumptions. With growing system complexity, the safety certification is becoming hard, especially in event-triggered...