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Theoretical and empirical improvement of a fast-switching electro-pneumatic valve by using different methods

Najjari Behrouz, Fotuhi Mohammad J., Vaezipour Mousa

Acta Mechanica et Automatica

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2022

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Vol. 16, no. 2

91--97

EN

In this paper, a non-linear model of a 2–2 way, on–off fast-switching valve is used. The model includes subsystems of electrical, magnetic, mechanical and fluid. Pulse width modulation (PWM) technique is adopted to energise the on–off solenoid valve and allow the air to flow towards the actuator. Since the non-linear behaviour of valve is of great importance, to reduce the delay in performance of switching valves, different approaches are proposed. Furthermore, hysteresis, proportional integrator (PI), optimal model predictive and fuzzy logic controller (FLC) are used and compared. Also, to improve the valve behaviour, an empirical setup based on AVR microcontrol-ler with FLC is implemented. Empirical and simulation results indicate that all proposed control methods have superior performance. How-ever, the fuzzy method is easy to implement in practice.

2

Rainfall-Induced Landslide Thresholds Development by Considering Different Rainfall Parameters: A Review

Mansor Maturidi Abdul Muaz Abu, Kasim Norhidayu, Abu Taib Kamaruddin, Wan Azahar Wan Nur Aifa

Journal of Ecological Engineering

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2021

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Vol. 22, nr 10

85--97

EN

This paper reviews the development of landslide thresholds from the perspective of rainfall and climate patterns. For certain, geology, morphology, lithology, etc., contribute to the initiation of the mass movement. However, the role of rainfall as the triggering mechanism of the landslide is vital as well. It has been proven by many researchers from various studies worldwide that have proposed the rainfall thresholds by utilising different rainfall parameters. The outcome of their studies is interesting, since different regions have diversified patterns of rainfall that produce a variety of threshold models. Therefore, from various published papers on rainfall thresholds, this paper studied the variety of rainfall parameters that have been utilised in establishing the rainfall threshold for landslide prediction. Instead of providing a better understanding regarding the application, this review aimed to cultivate the following study for deriving rigorous parameters for the purpose of sustainable findings.

3

Introducing of measurement uncertainty in empirical power models of physical phenomena during machining processes

Trajčevski N., Tomov M., Kuzinovski M., Cichosz P.

Mechanik

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2015

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R. 88, nr 8-9CD2

55--62

EN

This paper propose determining the measurement uncertainty of the coefficient and the exponents of an empirical predictive power model in the metal cutting machining processes. Uncertainty of the coefficient and exponents represent model’s capability and quality for further use. For empirical model ling it is used Design of experiments (DOE) method.

4

Studies on Empirical Approaches for Estimation of Detonation Velocity of High Explosives

Shekhar H.

Central European Journal of Energetic Materials

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2012

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Vol. 9, nr 1

39-48

EN

Despite many computer based codes like CHEETAH, TIGER, RUBY, BKW, etc. the velocity of detonation (VOD) for explosive molecules and explosive mixtures (formulations) is estimated by several empirical formulations. This article discusses various approaches for the estimation of the velocity of detonation by empirical mathematical equations. The formulation proposed by Kamlet in 1968 is the oldest one and it is confirmed to be more reliable by many subsequent researchers. The method proposed by Rothstein (1978), Xiong (1985), Stein (1990), Keshavarz (2006) are discussed and compared for conventional explosive molecules like RDX, HMX, TNT, PETN, and HNS. The values of the velocity of detonation for these molecules are found to be very close to each other. Further comparison of empirical mathematical formulations was carried out for four other explosive molecules of relatively recent origin (CL-20, FOX-7, TATB and NTO). These molecules were selected as they were unknown at the time of the proposed formulations except that by Keshavarz (2006). For CL-20, the velocity of detonation by different methods is 9345.1 m/s (Kamlet), 9378.8 m/s (Rothstein), 9116.0 m/s (Xiong), 9383.7 m/s (Stein) and 9887.9 m/s (Keshavarz) respectively. The method proposed by Keshavarz gives a higher value of the velocity of detonation than the others. For FOX-7, the values are 8636.6 m/s (Kamlet), 8733.3 m/s (Rothstein), 8766.1 m/s (Xiong), 8645.0 m/s (Stein) and 8245.3 m/s (Keshavarz) respectively. In this case the Keshavarz approach gives a lower value of the velocity of detonation. For these molecules, the results by the Xiong method is very close to that obtained by the Kamlet method. Deviation, as well as dispersion of the calculated values by other methods, is on the high side.

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Model-driven systems engineering: state-of-the-art and research challenges

Lauder M., Schlereth M., Rose S., Schurr A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2010

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Vol. 58, nr 3

409-421

EN

Model-driven software engineering is a well investigated and heavily used technique for software development. Within automation engineering we want to benefit from these ideas and concepts by adopting them to systems engineering. Parallel processes in systems engineering demand high synchronization effort between different disciplines, their engineers, and processes. Unfortunately, these processes are concurrently established, but do only support sequential engineering. With model-driven systems engineering we want to enable systems engineers to model their domain knowledge and tooling on a more abstract level. Thus, engineers may benefit in increasing efficiency and quality for the resulting products from existing integration approaches of engineering artifacts and tools. By means of an integration approach we are able to synchronize and check consistency of model data that evolved parallel in different tools. In this contribution, we present a new classification scheme for integration scenarios and explain our modeling and integration approach together with a proof-of-concept use case and prototype, located in automation engineering.