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1

Any-angle Global Path Planning for Skid-Steered Mobile Robots on Heterogeneous Terrain

Jaroszek P.

Journal of Automation Mobile Robotics and Intelligent Systems

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2016

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Vol. 10, No. 2

50--56

EN

The paper is concerned with selection of the algorithm of path planning for a skid-steered mobile robot operating on heterogeneous terrain. Methods of path searching were reviewed and their applicability to particular kinematic structure of a robot was assessed. The Theta* graph search algorithm was selected, because of its property of returning any-angle paths. Because in this method variable terrain type is not considered, necessary changes in algorithm structure were proposed to check homogeneity of the terrain. In order to enable choice of arbitrary optimization criterion, the model of cost dependent on terrain properties was introduced, which includes both longitudinal motion and turning. Operation of the modified algorithm with the introduced cost model was verified by means of simulation against A* reference algorithm often used in path planning tasks.

2

Localization of the Wheeled Mobile Robot Based on Multi-Sensor Data Fusion

Jaroszek P., Trojnacki M.

Journal of Automation Mobile Robotics and Intelligent Systems

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2015

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Vol. 9, No. 3

73--84

EN

The paper presents a method of localization of a mobile robot which relies on aggregation of data from several sensors. A review of the state of the art regarding methods of localization of ground mobile robots is presented. An overview of design of the four-wheeled mobile robot used for the research is given. The way of representation of robot environment in the form of maps is described. The localization algorithm which uses the Monte Carlo localization method is described. The simulation environment and results of simulation investigations are discussed. The measurement and control equipment of the robot is described and the obtained results of experimental investigations are presented. The obtained results of simulation and experimental investigations confirm the validity of the developed robot localization method. They are the foundation of further research, where additional sensors supporting the localization process could be used.

3

Model–based energy efficient global path planning for a four–wheeled mobile robot

Jaroszek P., Trojnacki M.

Control and Cybernetics

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2014

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Vol. 43, no. 2

337--363

EN

This paper concerns an energy efficient global path planning algorithm for a four-wheeled mobile robot (4WMR). First, the appropriate graph search methods for robot path planning are described. The A* heuristic algorithm is chosen to find an optimal path on a 2D tile-decomposed map. Various criteria of optimization in path planning, like mobility, distance, or energy are reviewed. The adequate terrain representation is introduced. Each cell in the map includes information about ground height and type. Tire-ground interface for every terrain type is characterized by coefficients of friction and rolling resistance. The goal of the elaborated algorithm is to find an energy minimizing route for the given environment, based on the robot dynamics, its motor characteristics, and power supply constraints. The cost is introduced as a function of electrical energy consumption of each motor and other robot devices. A simulation study was performed in order to investigate the power consumption level for diverse terrain. Two 1600 m2 test maps, representing field and urban environments, were decomposed into 20x20 equal-sized square-shaped elements. Several simulation experiments have been carried out to highlight the differences between energy consumption of the classic shortest path approach, where cost function is represented as the path length, and the energy efficient planning method, where cost is related to electrical energy consumed during robot motion.

4

Mikrobiologiczny rozkład kwasu galusowego

Wojcieszyńska D., Guzik U., Jaroszek P.

Inżynieria i Ochrona Środowiska

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2009

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T. 12, nr 3

173-184

PL

Kwas galusowy należy do grupy roślinnych związków zwanych polifenolami. Związek ten występuje w roślinach w postaci wolnej i związanej w estrach. Rozkład GA zachodzi zarówno w tlenowych, jak i beztlenowych warunkach, a główną rolę w jego degradacji odgrywają mikroorganizmy. Kluczowymi enzymami tlenowej degradacji GA są, należące do oksygenaz, dioksygenazy rozszczepiające, katalizujące rozpad pierścienia aromatycznego z udziałem tlenu. Tlenowa degradacja kwasu galusowego u bakterii może zachodzić szlakiem meta, inicjowanym przez dioksygenazę galusanową i 4,5-dioksygenazę protokatechową, lub szlakiem orto, zapoczątkowanym aktywnością 3,4-dioksygenazy protokatechowej. Produktami rozkładu GA stwierdzonymi u Pseudomonas putida są pirogronian i szczawiooctan. Rozkład GA z udziałem tlenu powiązany jest również ze szlakiem ß-ketoadypinowym kwasu protokatechowego, którego końcowymi produktami są acetylo-CoA i bursztynylo-CoA. Stwierdzono także obecność tlenowej degradacji GA u grzybów. Głównymi związkami przejściowymi beztlenowej degradacji GA są floroglucyna oraz rezorcyna. Kluczowym produktem przejściowym w degradacji kwasu galusowego poprzez floroglucynę jest 3-hydroksy-5-ketoheksanian (HOHN). Rezorcyna, drugi produkt przejściowy beztlenowej degradacji GA, powstaje z floroglucyny i pirogalolu przez dehydroksylację. Związek ten może ulegać następnie redukcji z udziałem reduktazy rezorcynowej lub hydrolizie do kwasu 5-keto-2-heksenowego.

EN

Gallic acid (3,4,5-trihydroxybenzoic acid) is widely distributed throughout the plant kingdom. It is present in almost all plants. High gallic acid contents can be found in gallnuts, grapes, tea, hops and oak bark. According to its biochemical properties gallic acid is an industrially important chemical used as an antioxidant in food, cosmetics and pharmaceutical industries. It possesses a lot of potential therapeutic properties including anti-cancer and antimicrobial ones. The gallic acid is readily utilized by oxidative breakdown to simple aliphatic acids that are metabolized through the citric acid cycle. Although different aerobic pathways for the aromatic acids biodegradation are known they usually involve the formation of protocatechuate as a common intermediate. Protocatechuate may be cleaved by protocatechuate 3.4- dioxygenase [EC 1.13.11.3], which catalyzes the intradiol addition of molecular oxygen and forms 2-pyrone-4,6-dicarboxylic acid as well as protocatechuate 4.5-dioxygenase [1.13.11.8] that catalyzes extradiol addition of molecular oxygen result in 4-carboxy-2-hydroxy-cis,cis-muconic semialdehyde formation. Another mechanism of gallic acid degradation is observed in fungi. In Aspergillus niger gallic acid is oxidatively cleaved by an oxygenase to unstable tricarboxylic intermediate decarboxylated by an oxidative decarboxylase to cis-aconitic acid enter the citric acid cycle. Aspergillus flavus degrades gallic acid to oxaloacetic acid and finally pyruvic acid through the tricarboxylic acid intermediates. Different mechanisms of anaerobic breakdown of gallic acid are known. At the first step of its degradation gallate is decarboxylated to 1,2,3-trihydroxybenzene, which is isomerized to phloroglucinol by pyrogallol-phloroglucinol isomerase and then reduced to dihydrophloroglucinol by phloroglucinol reductase. In the next step dihydrophloroglucinol is converted to 3-hydroxy-5-oxohexanonic acid (HOHN) by dihydrophloroglucinol hydrolase. Then, HOHN may be degraded through different pathways. The first one is its conversion to 3,5-dioxohexanoate (triacetate) by HOHN dehydrogenase and ultimately to three molecules of acetyl-CoA via triacetyl-CoA by the sequential enzymatic reactions catalyzed by triacetyl-CoA transferase, triacetate-ketothiolase, acetoacetyl-CoA-ketothiolase, phosphotransacetylase and acetate kinase. In methanogenic conditions HONH-CoA is transformed to butyrate or acetate, which are finally degraded to methane and carbon dioxide.