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1

Suitable sites identifcation for potential rainwater harvesting (PRWH) using a multi criteria decision support system (MCDSS)

Radwan Farid, Alazba Abdulrahman Ali

Acta Geophysica

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2023

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Vol. 71, no. 1

449--468

EN

The world today faces water scarcity issues, especially in developing countries. This situation is further aggravated under arid and semiarid climates with the water demand increasing and limited rainfall events. The study was conducted in the Riyadh metropolitan area of Saudi Arabia. The study area has a hot arid desert climate. Therefore, there is an urgent need for harvesting rainwater to confront the increasing water demand. This research aims to identify the potential rainwater harvesting (PRWH) suitable sites based on the multi-criteria decision support system by the spatial analytic hierarchy process, with the aid of the integration of geographic information systems and remote sensing techniques. Mapping PRWH was carried out using the thematic layers of the slope, soil texture, land use and land cover (LULC), precipitation, and potential runoff coefficient (PRC). The study findings revealed that Riyadh has four hydrologic soil groups (HSGs), namely A, B, C, and D groups, and the percentage area is 2%, 26%, 3%, and 71%, respectively. The slope classes are fat (8–15%), moderately steep (>15–30%), and mountainous (>30%). The LULC layers are barren lands, agricultural lands, urban, and roads. The precipitation has been distributed into five classes namely very low (5.9%), low (10.1%), medium (13.2%), high (13.5%), and very high (57.3%) of the total investigated area. The PRC values were distributed in five levels namely very low (0.3–0.5), high (>0.5–0.7), and very high (>0.7–1), where about 83% of the capital faces high and very high PRC values. The percentage area of PRWH suitability sites is unsuitable (0.4%), poor (0.8%), moderate (13.3%), good (47.5%), and excellent (38%) of the total entire area. More than 85% of Riyadh has good and excellent suitability for PRWH. This study is tantamount to a powerful tool for identifying the PRWH suitability sites in arid and semiarid regions to confront the water demand increase.

2

Flood risk assessment and mapping using AHP in arid and semiarid Regions

Radwan Farid, Alazba A. A., Mossad Amr

Acta Geophysica

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2019

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Vol. 67, no. 1

215--229

EN

Identifying flood risk-prone areas in the regions of extreme aridity conditions is essential for mitigating flood risk and rainwater harvesting. Accordingly, the present work is addressed to the assessment of the flood risk depending on spatial analytic hierarchy process of the integration between both Remote Sensing Techniques (RST) and Geographic Information Systems (GIS). This integration results in enhancing the analysis with the savings of time and efforts. There are several remote sensing-based data used in conducting this research, including a digital elevation model with an accuracy of 30 m, spatial soil and geologic maps, historical daily rainfall records, and data on rainwater drainage systems. Five return periods (REPs) (2, 5, 10, 25, 50, 100, and 200 years) corresponding to flood hazards and vulnerability developments maps were applied via the weighted overlay technique. Although the results indicate lower rates of annual rainfall (53–71 mm from the southeast to the northwest), the city has been exposed to destructive flash floods. The flood risk categories for a 100-year REP were very high, high, medium, low, and very low with 17%, 41%, 33%, 8%, and 1% of total area, respectively. These classes correspond to residential zones and principal roads, which lead to catastrophic flash floods. These floods have caused socioeconomic losses, soil erosion, infrastructure damage, land degradation, vegetation loss, and submergence of cities, as well life loss. The results prove the GIS and RST effectiveness in mitigating flood risks and in helping decision makers in flood risk mitigation and rainwater harvesting.

3

High performances of polynomial and nonlinear backstepping control strategies of an induction motor fed by matrix converter

Boumediene H., Hassaine S., Mazari B.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 11

133--139

EN

The main objective of this paper is to present the performance analysis of the oriented flux control of an induction motor associated with a matrix converter. A polynomial technique of RST type is used for speed control. As for the control of internal current loops, the technique used is based on the nonlinear approach. Overall, the proposed feedback law is asymptotically stable, which is shown in the context of the Lyapunov theory. The design of the control laws by the backstepping technique has been detailed while taking account of the non-linearities in the design phase of the control system. The objective is to obtain a good transient response and a good capacity of rejection of charge disturbance. The induction motor incorporating the proposed control techniques (RST-Backstepping) has been successfully implemented in numerical simulation using Matlab/Simulink under different operating conditions where the static and dynamic responses of the system are evaluated. It can be seen that the proposed control technique provides good speed monitoring performance. For internal loops, overall stability is ensured and the proposed approach presents good robustness to the uncertainties of the system parameters.

PL

W artykule zaprezentowano analizę właściwości sterowania silnikiem indukcyjnym za pośrednictwem przetwornika macierzowego. Zastosowano wielomianową technikę RST do sterowania prędkością. Do sterowania pętlą prądową zastosowano metodę nieliniową. Zaproponowane sprzężenie zwrotne jest asymtotycznie stabilne w konteksście teorii Lapunova. Numeryczne symulacje wykazały skuteczność zaproponowanej metody.

4

Sterowanie mikrosilników o bardzo wysokich prędkościach obrotowych sprzężonych z wielostopniowymi przekładniami planetarnymi

Leniowski R., Leniowska L.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2012

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z. 182, t. 1

160--175

PL

W pracy przedstawiono analizę problem sterowania miniaturowymi silnikami typu BLDC, pracującymi w bardzo szerokim zakresie prędkości obrotowych: 0-65 000 [obr/min] i sprężonych z wielostopniowymi przekładami planetarnymi. Cztery takie silniki stanowią napęd wieloczłonowego robota chirurgicznego ROCH-1, przeznaczonego do wykonywania małoinwazyjnych operacji, którego prototyp powstaje w ramach projektu badawczego MNiSzW 237/B/T02/2010/38. Cechą miniaturowych silników BLDC jest niskie napięcie zasilania (od 3 do 5 V), które może komplikować precyzyjne sterowanie robotem w zakresie wolnych ruchów. Na pracę całego układu napędowego silny wpływ mają oddziaływania wielostopniowych przekładni planetarnych z powodu występowania tarcie i deformacji sprężystych ich części składowych. Aby poprawić jakość sterowania, zaproponowano zastosowanie w układzie regulatora prądu dodatkowej pętli, kompensującej spadki napięć na kluczach tranzystorowych oraz zastosowano układy PWM o wysokiej rozdzielczości, tzw. HRPWM. Testowano działanie zmodyfikowanego serwomechanizmu z regulatorem typu RST, który będzie implementowany na sterownik zbudowany w oparciu o specjalizowany układ Stellaris LM3S8971. Przeprowadzone badania potwierdziły poprawę precyzji sterowania w pełnym pasmie pracy, a zwłaszcza w zakresie niskich prędkości obrotowych.

EN

The paper presents an analysis of the problem of controlling the BLDC micro-motors, working in a very wide speed range: 0-65 000 [rpm], and coupled with multi-stage planetary gears. Four such motors constitute a drive of multilink robot ROCH-1, designed to perform minimally invasive surgery, whose prototype is being developed though a research project MNiSzW 2376/B/T02/2010/38. The feature of BLDC micro-motors is low voltage (from 3 to 5 V), which can complicate the precise control of the robot in the range of slow movements. The work of the entire propulsion system strongly affected the impact of multi-stage planetary gears because of the presence of friction and elastic deformation of its components. To improve the quality control system, the additional current controller loop to compensate voltage drops of transistor keys is proposed and also PWM circuits with high resolution, so called HRPWM are used. We tested the modified servo operation of a RST controller, which will be implemented on the controller built on a dedicated system Stellaris LM3S8971. The study confirmed the improvement in the precision control of a full working band, and especially at low speeds.

5

Własności konfigurowalnej sieci radiowej w radiotelefonicznym systemie telemechaniki - RST

Mielcarek R., Nawrocki W.

Studia Informatica

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2002

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Vol. 23, nr 3

155-172

PL

W referacie przedstawiono zadania i strukturę Radiotelefonicznego Systemu Telemechaniki RST, a także zastosowany w nim protokół transmisji radiowej PTR. Podano strukturę ramek protokółu i ich funkcje. Przedstawiono transmisyjną sieć nadrzędną, bazującą na PTR. Modyfikując ramki protokółu PTR, uzyskano nowy protokół transmisji radiowej z możliwością retransmisji - PTRR. Podano warunki pracy sieci radiowej w RST z retransmisją i wynikającą z PTRR możliwość programowania trasy przesyłu danych w RST. Na zakończenie referatu przedstawiono sposób zabezpieczenia nadmiarowego typu CRC danych protokółu.

EN

In the paper tasks and structure of Radiotelephonic Remote Control System RST furnished with the wireless transmission protocol PTR are presented. The structure and functions of protocol frames are given and supervisory network based on PTR is described as well. By modifying frames of PTR protocol a new radio transmission protocol PTRR has been created with the retransmission option. Working conditions for radio network in RST with the retransmission function are given and a possibility of transmission route programming resulting from PTRR is described. In the final part of the paper the method of protocol data protection using CRC type redundancy code is provided.