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Abstract

During implementation of construction projects, durations of activities are affected by various factors. Because of this, both during the planning phase of the project as well as the construction phase, managers try to estimate, or predict, the length of any delays that may occur. Such estimates allow for the ability to take appropriate action in terms of planning and management during the execution of construction works. This paper presents the use of the non-deterministic concept for describing the uncertainty of estimating works duration. The concept uses the theory of fuzzy sets. The author describes a method for fuzzy estimations of construction works duration based on the fact that uncertain data is an inherent factor in the conditions of construction projects. An example application of the method is presented. The author shows a fuzzy estimation for the duration of an activity, taking into consideration the distorting influence caused by malfunctioning construction equipment and delivery delays of construction materials.

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Authors and Affiliations

N. Ibadov
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Abstract

Construction projects, even exemplarily planned and organized, bear a risk of unforeseen events and problems which can result in completion of the works after the deadline, that is delays. The construction of bridges is an inseparable part of road and rail projects and construction and expansion of the transport network. The paper aims at finding a relationship between the independent variables characterizing bridge projects and the delays during their implementation. Two alternative models were proposed to solve the problem: logit and probit. The data set comprising road and rail bridges built in Poland in the last 12 years (2005–2017) was used to build the models. The evaluation, quality and accuracy parameters of proposed models were determined in the final part of the paper.

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Authors and Affiliations

A. Leśniak
M. Juszczyk
G. Piskorz
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Abstract

The problems in the Covid-19 pandemic have a major influence on the field of education with the use of technology to support the teaching and learning process to facilitate students who do home learning activities. The proposed concept of freedom of learning is a more comprehensive concept such as portfolio and assignments such as group assignments, writings, and so on that are done in full online by adding additional features such as Teaching and Learning Activities and Assessment through information technology media. (E-Learning / Learning Management System). The method proposed in this research is the Peer Connection Queue (PCQ) method on mikrotik operating systems. PCQ method is a program to manage network traffic in Quality of Services (QoS). Bandwidth management methods. The hypothesis formulated is to create bandwidth management with PCQ so that bandwidth sharing is automatically and evenly distributed to multi clients. Therefore, in this research finally formulated into the goal of E-Learning effectiveness analysis using bandwidth management analysis method, which will be measured and analyzed in this research is throughput, delay, jitter, and packet loss. So that the final result of this research obtained the feasibility of the teaching and learning process that is carried out effectively.
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Bibliography

[1] M. Giatman, S. Siswati, I.Y. Basri, “Online Learning Quality Control in the Pandemic Covid-19 Era in Indonesia,” Journal of Nonformal Education, 6(2), 2020, 168-175.
[2] A. Purwanto, M. Asbari, M. Fahlevi, A. Mufid, E. Agistiawati, Y. Cahyono, P. Suryani, “Impact of Work From Home (WFH) on Indonesian Teachers Performance During the Covid-19 Pandemic: An Exploratory Study,” International Journal of Advanced Science and Technology, 2020, 29(05), 6235-6244.
[3] Y. Wiratomo, F. Mulyatna, “Use of learning management systems in learning efforts during a pandemic,” Journal of Mathematical Pedagogy (JoMP), 2020, 1(2).
[4] Y. K. Dwivedi, D. L. Hughes, C. Coombs, I. Constantiou, Y. Duan, J. S. Edwards, R. Raman, “Impact of COVID-19 pandemic on information management research and practice: Transforming education, work and life,” International Journal of Information Management, 2020, 55, 102211.
[5] N. Kapasia, P. Paul, A. Roy, J. Saha, A. Zaveri, R. Mallick, P. Chouhan, “Impact of lockdown on learning status of undergraduate and postgraduate students during COVID-19 pandemic in West Bengal, India,” Children and Youth Services Review, 2020. 116, 105194.
[6] S. Sundarasen, K. Chinna, K. Kamaludin, M. Nurunnabi, G.M. Baloch, H.B. Khoshaim, A. Sukayt, “Psychological impact of COVID-19 and lockdown among university students in Malaysia: implications and policy recommendations,” International Journal of Environmental Research and Public Health, 2020, 17(17), 6206. [7] https://kampusmerdeka.kemdikbud.go.id/news/kampus-merdeka-ala-mas-menteri-nadiem-makarim-seperti-apa-konsepnya
[8] https://www.kemdikbud.go.id/main/blog/2020/10/ditjen-dikti-luncurkan-buku-panduan-kurikulum-dikti-dan-aplikasi-merdeka-belajarkampus-merdeka
[9] Menteri Pendidikan, Surat Edaran Nomor 1 Tahun 2020 Tentang Kebijakan Merdeka Belajar dalam Penentuan Kelulusan Peserta Didik, dan Pelaksanaan Penerimaan Peserta Didik Baru Tahun Ajaran 2020/2021, Surat Edaran MENDIKBUD RI, 2020.
[10] Menteri Pendidikan, Surat Edaran Nomor 2 Tahun 2020 Tentang Pencegahan Dan Penanganan Corona Virus Disease (COVID-19) di Kementerian Pendidikan Dan Kebudayaan. Surat Edaran MENDIKBUD RI, 2020.
[11] Menteri Pendidikan, Surat Edaran Nomor 3 Tahun 2020 Tentang Pencegahan COVID-19 pada Satuan Pendidikan. Surat Edaran MENDIKBUD RI, 2020.
[12] Menteri Pendidikan, Surat Edaran Nomor 4 Tahun 2020 Tentang Pelaksanaan Kebijakan Pendidikan dalam Masa Darurat Penyebaran Covid-19. Surat Edaran MENDIKBUD RI, 2020.
[13] A.D. Alharthi, M. Spichkova, M. Hamilton, “Sustainability requirements for eLearning systems: a systematic literature review and analysis,” Requirements Engineering, 2019, 24(4), 523-543.
[14] F.J. García-Peñalvo, (2021), “Avoiding the dark side of digital transformation in teaching. An institutional reference framework for eLearning in higher education”, Sustainability, 13(4), 2023.
[15] Al Fadjri, M. K. N., Ritzkal, R., & Hendrawan, A. H., “Computer Network Analysis Using The Queue System In Mikrotik: Computer Network Analysis Using The Queue System,” In Mikrotik, Jurnal Mantik, 2020, 4(1), 483-488.
[16] Ramady, G. D., Hidayat, R., Mahardika, A. G., & Hidayat, W., December) “Optimizing Wireless Distribution System Network Infrastructure in Hybrid Topology using PCQ Method,” In Journal of Physics: Conference Series, 2019, Vol. 1424, No. 1, p. 012026. IOP Publishing.
[17] Pratama, Y., Ependi, U., & Suroyo, H., (“Optimization of Wireless Network Performance Using the Hierarchical Token Bucket (Case Study: Muhammadiyah University of Palembang),” Journal of Information Systems and Informatics, 2019, 1(1), 49-59.
[18] Hafiz, A., Afriansyah, D., Ikhsan, F. K., Suprapto, B., & Pratama, I. W., (2019) “Measuring quality of wireless local area network using quality of service framework,” IJISCS (International Journal of Information System and Computer Science), 3(3), 90-97.
[19] Sutanto, I., Wahjuni, S., Prianggono, J., & Guritman, S., (2019) “Optimization Distance Learning Computer of Network,” Computer Engineering and Applications Journal, 8(1), 65-76.
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[21] A. L. I. A. A.Ramadhan, R. E. Indrajit, N. Rokhman, E.W. Subanar, P.S. Kumar, B.T. Rao, M. Ola, “Analysis of effectiveness of using simple queue with per connection queue (PCQ) in the bandwidth management (A case study at the academy of information management and computer mataram (AMIKOM) mataram),” Journal of Theoretical and Applied Information Technology, 2016, 83(3).
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[26] Budiyanto, S., & Pratama, I., “Classification of Network Status in Academic Information Systems using Naive Bayes Algorithm Method,” In 2020 2nd International Conference on Broadband Communications, Wireless Sensors and Powering (BCWSP), IEEE, 2020, September , pp. 107-112.
[27] Praptodiyono, S., Firmansyah, T., Murugesan, R. K., Alaydrus, M., Aprilia, R., & Leau, Y. B.,” Improving the security of mobile IPV6 signalling using KECCAK/SHA-3,” Journal of Engineering Science and Technology, 2021, 16(3), 2312-2325.
[28] Ramadhan, E., Firdausi, A., & Budiyanto, S., “Design and analysis QoS VoIP using routing Border Gateway Protocol (BGP),” In 2017 International Conference on Broadband Communication, Wireless Sensors and Powering (BCWSP), IEEE, 2017, November, (pp. 1-4).

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Authors and Affiliations

Setiyo Budiyanto
1
Lukman Medriavin Silalahi
1
Freddy Artadima Silaban
1
Henry Binsar Hamonangan Sitorus
2
Agus Dendi Rochendi
3
Mochamad Furqon Ismail
4

  1. Department of Electrical Engineering, Universitas Mercu Buana, Indonesia
  2. Department of Electrical Engineering, Universitas Pembangunan Nasional “Veteran” Jakarta , Indonesia
  3. Department of Oceanographic Physics, Lembaga Ilmu Pengetahuan Indonesia, Indonesia
  4. Department of Physical Oceanography, Geomar Helmholtz Centre for Ocean Research Kiel, Germany
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Abstract

This paper deals with the problem of stabilization by an estimated state feedback for a family of nonlinear time-delay Takagi-Sugeno fuzzy parameterized systems. The delay is supposed to be constant where the parameter-dependent controls laws are used to compensate the nonlinearities which are formulated in terms of linear matrix inequalities (LMIs). Based on the Lyapunov- Krasovskii functionals, global exponential stability of the closed-loop systems is achieved. The controller and observer gains are able to be separately designed even in the presence of modeling uncertainty and state delay. Finally, a numerical example is given to show the applicability of the main result.
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Authors and Affiliations

Nizar Hadj Taieb
1
Mohamed Ali Hammami
2
François Delmotte
3

  1. University of Sfax, IPEIS Sfax, Tunisia
  2. University of Sfax, Faculty of Sciences of Sfax, Tunisia
  3. University of Artois, Bethune, France
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Abstract

The main idea of all Active Queue Management algorithms, is to notify the TCP sender about incoming congestion by dropping packets, to prevent from the buffer overflow, and its negative consequences. However, most AQM algorithms proposed so far, neglect the impact of the high speed and long delay links. As a result, the algorithms’ efficiency, in terms of throughput and/or queue stability, is usually significantly decreased. The contribution of this paper is twofold. First of all, the performance of the well known AQM algorithms in high speed and long delay scenarios is evaluated and compared. Secondly, a new AQM algorithm is proposed, to improve the throughput in the large delay scenarios and to exclude the usage of random number generator.
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Authors and Affiliations

Agnieszka Brachman
Łukasz Chrost
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Abstract

In the paper a Lyapunov matrices approach to the parametric optimization problem of a time-delay system with two commensurate delays and a PI-controller is presented. The value of integral quadratic performance index is equal to the value of the Lyapunov functional for the initial function of the time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix. In the paper is presented the example of a scalar system with two delays and a PI controller.

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Authors and Affiliations

Jozef Duda
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Abstract

The practical and asymptotic stabilities of delayed fractional discrete-time linear systems described by the model without a time shift in the difference are addressed. The D-decomposition approach is used for stability analysis. New necessary and sufficient stability conditions are established. The conditions in terms of the location of eigenvalues of the system matrix in the complex plane are given.

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Authors and Affiliations

A. Ruszewski
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Abstract

A simple robust cheap LQG control is considered for discrete-time systems with constant input delay. It is well known that the full loop transfer recovery (LTR) effect measured by error function ∆(z) can only be obtained for minimum-phase (MPH) systems without time-delay. Explicit analytical expressions for ∆(z) versus delay d are derived for both MPH and NMPH (nonminimum-phase) systems. Obviously, introducing delay deteriorates the LTR effect. In this context the ARMAX system as a simple example of noise-correlated system is examined. The robustness of LQG/LTR control is analyzed and compared with state prediction control whose robust stability is formulated via LMI. Also, the robustness with respect to uncertain time-delay is considered including the control systems which are unstable in open-loop. An analysis of LQG/LTR problem for noise-correlated systems, particularly for ARMAX system, is included and the case of proper systems is analyzed. Computer simulations of second-order systems with constant time-delay are given to illustrate the performance and recovery error for considered systems and controllers.

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Authors and Affiliations

D. Horla
A. Krolikowski
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Abstract

The stability analysis for discrete-time fractional linear systems with delays is presented. The state-space model with a time shift in the difference is considered. Necessary and sufficient conditions for practical stability and for asymptotic stability have been established. The systems with only one matrix occurring in the state equation at a delayed moment have been also considered. In this case analytical conditions for asymptotic stability have been given. Moreover parametric descriptions of the boundary of practical stability and asymptotic stability regions have been presented.

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Authors and Affiliations

Andrzej Ruszewski
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Abstract

For many years, a digital waveguide model is being used for sound propagation in the modeling of the vocal tract with the structured and uniform mesh of scattering junctions connected by same delay lines. There are many varieties in the formation and layouts of the mesh grid called topologies. Current novel work has been dedicated to the mesh of two-dimensional digital waveguide models of sound propagation in the vocal tract with the structured and non-uniform rectilinear grid in orientation. In this work, there are two types of delay lines: one is called a smaller-delay line and other is called a larger-delay line. The larger-delay lines are the double of the smaller delay lines. The scheme of using the combination of both smaller- and larger-delay lines generates the non-uniform rectilinear two-dimensional waveguide mesh. The advantage of this approach is the ability to get a transfer function without fractional delay. This eliminates the need to get interpolation for the approximation of fractional delay and give efficient simulation for sound wave propagation in the two-dimensional waveguide modeling of the vocal tract. The simulation has been performed by considering the vowels /ɔ/, /a/, /i/ and /u/ in this work. By keeping the same sampling frequency, the standard two-dimensional waveguide model with uniform mesh is considered as our benchmark model. The results and efficiency of the proposed model have compared with our benchmark model.

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Authors and Affiliations

Tahir Mushtaq Qureshi
Khalid Saifullah Syed
Asim Zafar
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Abstract

Tea mosquito bugs (TMB; Helopeltis bradyi, Hemiptera, Miridae) are a main pest in tea and cacao plantations worldwide. Pheromone-mediated mating disruption (MD) is a promising strategy to manage TMB populations. Experiments were conducted to evaluate the simultaneous effect of TMB female delayed mating (1, 3 and 5 days delayed mating) and pairing duration (1 day, 5 days, and entire lifespan) on several reproductive parameters. Results showed that female delayed mating obviously affected egg number, egg viability, and offspring number, but male delayed mating did not show such effects. Shortened pairing durations had a significant effect on egg viability and offspring number but not on egg number. Increased delayed mating and pairing duration negatively affected adult longevity. In general, we noted that TMB reproductive performance is vulnerable to delayed mating and shortened pairing durations, thus providing essential guidance for the implementation of MD strategies of TMB in the field.
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Authors and Affiliations

Indriani Feberati Putri
1
Suputa Suputa
1
Alan Soffan
1
ORCID: ORCID

  1. Department of Plant Protection, Universitas Gadjah Mada, Yogyakarta, Indonesia
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Abstract

A novel measurement method and a brief discussion of basic characteristics of measuring the phase shift angle between two sinusoidal signals of the same frequency are presented in this paper. It contains a mathematical model for using conditional averaging of a delayed signal interfered with noise to measure the phase shift angle. It also provides characteristics of conditional mean values and discusses the effect of random interferences on the accuracy of the phase shift measurement. The way to determine the variance of the conditional mean value, together with the assessment of standard and expanded uncertainty, are described. The uncertainty characteristic shows the complementary properties of the discussed angle measurement principle �� for small absolute values |��| (minimum for �� = 0) relative to the correlation principle, where the minimum measurement uncertainty is present for �� = ��/2. |
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Authors and Affiliations

Adam Kowalczyk
1
Anna Szlachta
1

  1. Rzeszow University of Technology, Faculty of Electrical and Computer Engineering, Department of Metrology and Diagnostic Systems, W. Pola 2, 35-959 Rzeszow, Poland
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Abstract

In pursuing numerous construction projects, investors and contractors regularly face construction delay problems, many of which are likely to have been avoidable. There is found that payment delays and project delays are the two most critical effects of risk factors of construction management. The paper presents the practical application of the Earned Value Management method, which was used to estimate the possible extension of the duration of construction works during which realization disturbances occurred on the example of selected construction investment. The realization disturbances are usually an inseparable element in the implementation of construction works. They are the result of, among others: additional works, changes or design defects, as well as a badly adopted logistics strategy regarding the supply of construction materials. Delays or increasing the total cost of investment is a problem often encountered in the implementation of construction investments, despite advanced construction technologies, including system technologies and proven tools supporting the management of the construction process. The EVM method is used to control investments. It allows you to control delays and acceleration of construction works as well as to estimate their cost and completion date. In the analyzed case it was used to determine the scale of delays arising in construction works and related effects with the specification of the participation of individual participants of the investment process for delays. This paper is a continuation and supplementation of the research presented in the article: “The influence of construction works disturbances on the EVM analysis outcomes – case study” [23].
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Bibliography


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[2] K. Park, H.W. Lee, K. Choi, et al., “Project Risk Factors Facing Construction Management Firms”. Int J Civ Eng 17, pp. 305–321 (2019). https://doi.org/10.1007/s40999-017-0262-z
[3] ANSI EIA – 748 Standard – Earned Value Management Systems.
[4] K. Araszkiewicz, and M. Bochenek, “Control of construction projects using the Earned Value Method – case study”, Open Engineering 9 (2019), pp. 186–195. https://doi.org/10.1515/eng-2019-0020
[5] M. Bilal, L.O. Oyedele, H.O. Kusimo, H.A. Owolabi, L.A. Akanbi, A.O. Ajayi, O.O. Akinade, and J.M.D. Delgado, “Investigating profitability performance of construction projects using big data: A project analytics approach”, Journal of Building Engineering, 26 (2019). https://doi.org/10.1016/j.jobe.2019.100850
[6] D.W.M. Chan, T. O. Olawumi, and A. M.L. Ho, “Perceived benefits of and barriers to Building Information Modelling (BIM) implementation in construction: The case of Hong Kong”, Journal of Building Engineering, 25 (2019). https://doi.org/10.1016/j.jobe.2019.100764
[7] R. Charef, S. Emmitt, H. Alaka, and F. Fouchal, (2019). “Building Information Modelling adoption in the European Union: An overview”. Journal of Building Engineering, 25, (2019). https://doi.org/10.1016/j.jobe.2019.100777
[8] T. Chen et al, “How do project management competencies change within the project management career model in large Chinese construction companies?”, International Journal of Project Management, 37 (2019), pp. 485–500. https://doi.org/10.1016/j.ijproman.2018.12.002
[9] U. Dwivedi, “Earned Value Management Explained”, 2019 Project Smart reserved, https://www.projectsmart.co.uk/earned-value-management-explained.php
[10] F. Elghaish, S. Abrishami, M. RR. Hosseini, S. Abu-Samra, and M. Gaterell, “Integrated project delivery with BIM: An automated EVM-based approach”, Automation in Construction, 106, (2019). https://doi.org/10.1016/j.autcon.2019.102907
[11] M. Lendo-Siwicka, M. Poloński, and K. Pawluk, “Identification of the interference in the investment process during the realization of a shopping centre – a case study”, Archives of Civil Engineering, LXII (2016), pp. 159–172. https://doi.org/10.1515/ace-2015-0058
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[13] L. Song, “Earned Value Management: A Global Cross-Industry Perspective on Current EVM Practice”. PMI 2010.
[14] S.T. Matarneha, M. Danso-Amoako, S.T. Matarneh, S. Al-Bizri, M. Gaterell, and R. Matarneh, “Building information modeling for facilities management: A literature review and future research directions”, Journal of Building Engineering, 24 (2019). https://doi.org/10.1016/j.jobe.2019.100755
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[20] E. Papadonikolaki, C. van Oel, and M. Kagioglou, “Organising and Managing boundaries: A structurational view of collaboration with Building Information Modelling (BIM)”, International Journal of Project Management, 37 (2019), pp. 378–394. https://doi.org/10.1016/j.ijproman.2019.01.010
[21] P. Piroozfar, E. R.P. Farr, A.H.M. Zadeh, S.T. Inacio, S. Kilgallone, and R. Jin, “Facilitating Building Information Modelling (BIM) using Integrated Project Delivery (IPD): A UK perspective”, Journal of Building Engineering, 26 (2019). https://doi.org/10.1016/j.jobe.2019.100907
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Authors and Affiliations

Anna Starczyk-Kołbyk
1
ORCID: ORCID
Leopold Kruszka
2
ORCID: ORCID

  1. Military University of Technology, Faculty of Civil Engineering and Geodesy, ul. gen. Sylwestra Kaliskiego 2, 00–908 Warsaw, Poland
  2. Military University of Technology, Faculty of Civil Engineering and Geodesy, ul. gen. Sylwestra Kaliskiego 2,00–908 Warsaw, Poland
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Abstract

Irrigation and hydropower are among the most important sectors in the construction industry that propel the economic needs of a developing country like Vietnam. The construction of these projects often suffers from severe delays, leading to financial losses and other negative impacts on the economy. This paper aims to determine delay factors in the construction of these projects. Among many, 39 most important candidates of delay causes were identified from the literature review. Further surveys on project participants were conducted for the severity of these causes. An exploratory factor analysis was utilized to identify latent factors that cause delays in construction projects. The analysis result categorized a few groups of factors such as abnormal factors on the construction site (e.g., labor accidents, hydrology, water flow, extreme weather) and technical factors related to the construction contractor (e.g., unsuitable schedule, outdated construction technology, unprofessional workers) that have the greatest impact on the delay in construction of irrigation and hydropower projects in Vietnam. These findings contribute to the body of knowledge of project management and risk management, hence an improvement in the efficiency of the project sectors’ performance.
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Authors and Affiliations

Van Son Nguyen
1
ORCID: ORCID
Huu-Hue Nguyen
1
ORCID: ORCID
Duc Anh Nguyen
2
ORCID: ORCID
Dinh Tuan Hai
3
ORCID: ORCID

  1. ThuyLoi University, Faculty of Civil Engineering, No. 175 Tay Son Road, Dong Da District, Hanoi City, Vietnam
  2. Hanoi University of Civil Engineering, Faculty of Department of Building and Industrial Construction, No. 55 Giai Phong Street, Hai Ba Trung District, Hanoi City, Vietnam
  3. Hanoi Architectural University, Faculty of Civil Engineering, Km 10, Nguyen Trai Street, Thanh Xuan District, Hanoi City, Vietnam
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Abstract

The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.

Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.

Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.

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Authors and Affiliations

Nadhem Echi
Boulbaba Ghanmi
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Abstract

This paper presents an enhanced internal model control (EIMC) scheme for a time-delayed second order unstable process, which is subjected to exogenous disturbance and model variations. Even though the conventional internal model control (IMC) can provide an asymptotic tracking response with desired stability margins, the major limitation of conventional IMC is that it cannot be applied for an unstable system because a small exogenous disturbance can trigger the control signal to grow unbounded. Hence, modify- ing the conventional IMC structure to guarantee the internal stability, we present an EIMC scheme which can offer better trade-off between setpoint tracking and disturbance rejec- tion characteristics. To improve the load disturbance rejection characteristics and attenuate the effect of sensor noise, we solve the selection of controller gains as an H¥ optimization problem. One of the key aspects of the EIMC scheme is that the robustness of the closed loop system can be tuned via a single tuning parameter. The performance of the EIMC scheme is experimentally assessed on a magnetic levitation plant for reference tracking application. Experimental results substantiate that the EIMC scheme can effectively coun- teract the inherent time delay in the model and offer precise tracking, even in the presence of exogenous disturbance. Moreover, by comparing the trajectory tracking performance of EIMC with that of the proportional integral velocity (PIV) controller through cumulative power spectral density (CPSD) of the tracking error, we show that the EIMC can offer better low frequency servo response with minimal vibrations.
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Authors and Affiliations

Vinodh Kumar Elumalai
Raaja Ganapathy Subramanian
Joshua Sunder David Reddipogu
Soundarya Srinivasan
Shantanu Agrawal
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Abstract

This paper presents an innovative method for measuring the time delay of ultrasonic waves. Pulse methods used in the previous studies was characterized by latency. The method of phase correlation, presented in this article is free from this disadvantages. Due to the phase encoding with the use of Walsh functions the presented method allows to obtain better precision than previous methods. The algorithm to measure delay of the reflected wave with the use of microprocessor ARM Cortex M4 linked to a PC has been worked out and tested. This method uses the signal from the ultrasonic probe to precisely determine the time delay, caused by the propagation in medium, possible. In order to verify the effectiveness of the method a part of the measuring system was implemented in LabVIEW. The presented method proved to be effective, as it is shown in presented simulation results.
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Authors and Affiliations

K. Gądek
M. Jaraczewski
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Abstract

The paper deals with the issue of constructing delay lines on the basis of surface acoustic waves and their application to single-mode oscillators. As a result of a theoretical analysis concrete delay lines are proposed.

In the contribution, there is presented a theory of designing a symmetrical mismatched and matched delay line for a single-mode oscillator of electrical signals on the basis of which there were designed and fabricated acoustic-electronic components for sensors of non-electrical quantities.

From the experimental results it can be stated that all of six designed and fabricated delay lines can be effectively used in the construction of single-mode oscillators.

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Authors and Affiliations

Milan Šimko
Miroslav Gutten
Milan Chupáč
Daniel Korenčiak
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Abstract

This paper presents the results of the theoretical and practical analysis of selected features of the function of conditional average value of the absolute value of delayed signal (CAAV). The results obtained with the CAAV method have been compared with the results obtained by method of cross correlation (CCF), which is often used at the measurements of random signal time delay. The paper is divided into five sections. The first is devoted to a short introduction to the subject of the paper. The model of measured stochastic signals is described in Section 2. The fundamentals of time delay estimation using CCF and CAAV are presented in Section 3. The standard deviations of both functions in their extreme points are evaluated and compared. The results of experimental investigations are discussed in Section 4. Computer simulations were used to evaluate the performance of the CAAV and CCF methods. The signal and the noise were Gaussian random variables, produced by a pseudorandom noise generator. The experimental standard deviations of both functions for the chosen signal to noise ratio (SNR) were obtained and compared. All simulation results were averaged for 1000 independent runs. It should be noted that the experimental results were close to the theoretical values. The conclusions and final remarks were included in Section 5. The authors conclude that the CAAV method described in this paper has less standard deviation in the extreme point than CCF and can be applied to time delay measurement of random signals.

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Authors and Affiliations

Adam Kowalczyk
Robert Hanus
Anna Szlachta
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Abstract

Touch-trigger probes for CNC milling machines usually use wireless communication in the radio or IR band. Additionally they enable triggering signal filtering in order to avoid false triggers of the probe. These solutions cause a delay in trigger signal transmission from the probe to the machine tool controller. This delay creates an additional pre-travel component, which is directly proportional to the measurement speed and which is the cause of a previously observed but not explained increase of the pre-travel with the increase of the measurement speed. In the paper, a method of testing the delay time of triggering signal is described, an example of delay time testing results is presented and the previous, unexplained results of other researchers are analysed in terms of signal transmission delay.
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Authors and Affiliations

Michał Jankowski
Adam Woźniak
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Abstract

The designing process of high resolution time interval measurement systems creates many problems that need to be eliminated. The problems are: the latch error, the nonlinearity conversion, the different duty cycle coefficient of the clock signal, and the clock signal jitter. Factors listed above affect the result of measurement. The FPGA (Field Programmable Gate Array) structure also imposes some restrictions, especially when a tapped delay line is constructed. The article describes the high resolution time-to-digital converter, implemented in a FPGA structure, and the types of errors that appear there. The method of minimization and processing of data to reduce the influence of errors on the measurement is also described.

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Authors and Affiliations

Stanisław Grzelak
Marcin Kowalski
Jarosław Czoków
Marek Zieliński
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Abstract

In the paper the parallel compensator considered in [1] is applied to control of the plants with delay and compared with Smith predictor. It is noted that Smith predictor removes only the delay, while the parallel compensator also changes the dynamics of the replacement plant; the latter may be in some degree of freedom shaped by the designer. Owing to this the transients of the system with parallel compensator are significantly faster. Accounting implementability, the control saturations are introduced in control algorithms. Additionally it is shown that using parallel compensator we may apply a relay control to the plants with delay and nonminimum phase zeros, which is impossible by using Smith predictor. Several results of simulations are described which confirm these observations.

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Authors and Affiliations

R. Gessing

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