Features of slopes overcoming by walking devices

2021 ◽  
Vol 9 (3) ◽  
pp. 234-240
Author(s):  
Vadim Chernyshev ◽  
Vladimir Arykantsev ◽  
Anton Goncharov ◽  
Nikolay Sharonov
Keyword(s):  
Mobile Robots ◽  
Experimental Studies ◽  
Field Tests ◽  
Soil Conditions ◽  
Adhesion Properties ◽  
Walking Machines ◽  
Volgograd Region ◽  
Propulsion Unit ◽  
Force Characteristics ◽  
Robot Body

For mobile robots designed to work in extreme conditions, an important characteristic is the value of the overcoming slope. For wheeled and tracked vehicles, the angle of the overcoming slope is limited by the adhesion properties of the soil. The walking device can provide overcoming of higher slopes, since the analogue of the adhesion coefficient for walking machines, with a large footprint track depth, can be significantly greater than 1. The paper discusses the results of experimental studies of the features of overcoming slopes by a walking device in weak soil conditions. When mobile robots overcoming inclines, they may overturn or slide downhill. It is shown that on soft soils the sliding of walking machines downhill is unlikely because of significant deformations of the soil under the support elements. On the other hand, the deformation of the soil worsens the resistance of the walking vehicle to overturning. A method of increasing resistance to overturning by controlling the position of the robot body by separately regulating the conditional clearance of walking mechanisms is considered. The possibility of adjusting the clearance in the propulsion unit on the basis of Umnov-Chebyshev cyclic walking mechanisms is shown. Climbing slopes requires a certain amount of traction. The values of the additional power and the force characteristics of the walking device’s drive necessary for successful overcoming of slopes have been determined. The results of the work can be demand in the development of walking machines and mobile robots. Key words Mobile robots, walking machines, interaction with the ground, traction and coupling properties, overcoming slopes, tipping resistance, mathematical modeling, field tests. Acknowledgements Research was partially supported by RFBR and the Administration of the Volgograd region, research projects no. 19-08-01180 a, 19-48-340007 p_a.

The Effect of Blade Geometry on Blade Stall Characteristics

2005 ◽  
Vol 127 (4) ◽  
pp. 496-502 ◽  
Author(s):  
R. P. J. O. M. van Rooij ◽  
J. G. Schepers
Keyword(s):  
Correction Term ◽  
Field Tests ◽  
Test Results ◽  
Wind Tunnel Experiments ◽  
Twisted Blade ◽  
The Impact ◽  
2D Airfoil ◽  
Twist Pitch ◽  
Force Characteristics ◽  
Blade Geometry

The effect of rotation has been investigated with emphasis on the impact of blade geometry on the “correction factor” in stall models. The data used came from field tests and wind tunnel experiments performed by the National Renewable Energy Laboratory and were restricted to the steady-state nonyawed conditions. Three blade layouts were available; a blade with constant chord without twist (phase II), a blade with constant chord and twist (phases III and IV), and a tapered blade with twist (phase VI). Effects due to twist and taper were determined from comparison of c n between the different blade layouts. The formulation of the stall model was rewritten so that the measured c n values could be used without reference to 2D airfoil performance. This enabled a direct comparison of the normal force characteristics between the four blade stations of the selected blade configurations. In particular, the correction term f used in stall models for rotational effects was analyzed. The comparison between the test results with a straight and a twisted blade showed that a relation for twist + pitch is required in f . In addition, a dependency offon the angle-of-attack was identified in the measurements and it is recommended that this dependency be incorporated in the stall models.

scholarly journals MODIFICATION OF ELASTOMER FOR RESTORATION OF CASE PARTS OF AUTOTRACTOR ENGINEERING

2018 ◽  
Vol 13 (3) ◽  
pp. 90-95
Author(s):  
Роман Ли ◽  
Roman Li ◽  
Дмитрий Псарев ◽  
Dmitriy Psarev ◽  
Мария Киба ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Experimental Studies ◽  
Polymeric Materials ◽  
Body Part ◽  
Body Parts ◽  
Filled Polymers ◽  
Adhesion Properties ◽  
Energy Inputs ◽  
Tractor Equipment ◽  
Comparative Results

Body parts are typical, most material-intensive and expensive parts. When repairing worn out hull details, the costs for repairing equipment are significantly reduced, in comparison with the manufacture of new ones, the consumption of metal, electricity, and environmental pollution is reduced. Unlike many other methods, the methods of restoring body parts with polymeric materials are technologically simple, do not require large energy inputs and high qualification of the personnel. Due to the polymer layer, the stresses in the contact zone of loaded bodies with the bearing raceways decrease and its durability increases, there is no fretting corrosion and the service life of the bearing and body part increases manyfold. The use of polymeric composites can significantly improve the efficiency of restoring body parts. This is due to increased thermal conductivity, thermal and heat resistance, lower cost of composites in comparison with non-filled polymers. A promising direction in improving the consumer properties of the material is the filling of the polymer matrix with nanoscale particles. The nanocomposite based on elastomer F-40 filled with aluminum and copper nanoparticles has been developed and thoroughly studied at the LSTU. The material is designed to restore the landing holes in the hull parts of the tractor equipment. The article presents the results of experimental studies and analysis of deformation-strength and adhesion properties of a nanocomposite, its optimal composition is justified. Comparative results of the study of heat resistance and thermal stability of the F-40 elastomer and a nanocomposite based on are presented. It is shown that the nanocomposite has higher consumer properties than the F-40 elastomer: the strength and endurance are increased to 1.3 times, the heat resistance is up to 123C, the aging coefficients are 1.8 times higher in strength, 1.4 times in deformation.

scholarly journals METHODS FOR IMPROVING THE ADHESION PROPERTIES OF BITUMENS TO MINERAL MATERIALS

2020 ◽  
pp. 29-35
Author(s):  
Н. А. Страхова ◽  
П. С. Цамаева ◽  
А. А. Эльмурзаев
Keyword(s):  
Atmospheric Oxygen ◽  
Experimental Studies ◽  
Effect Of Temperature ◽  
Volatile Components ◽  
Processing Plant ◽  
Adhesion Properties ◽  
Gas Phases ◽  
Gas Processing ◽  
Petroleum Bitumen

Статья посвящена анализу и изучению различных способов получения нефтяных битумов и улучшения адгезионных свойств в различных минеральных материалах. На примере Астраханского газоперерабатывающего завода показана эффективность добавления присадок - азот-, серосодержащих веществ, элементной серы и др. для улучшения адгезионных свойств битумов к минеральным материалам. Проведен анализ воздействия перепада температур в летнее и зимнее время на вяжущие свойства битумов. Рассмотрен способ предварительной отгонки летучих компонентов из нефтей, что приводит к уменьшению содержания парафинонафтеновых углеводородов и улучшению качества получаемых битумов. В статье также приведены результаты экспериментальных исследований влияния окисления кислородом воздуха, повышения температуры процесса на пластичность битумов. Эффективность окисления битумов зависит от величины поверхности контакта между жидкой и газовой фазой. Ускорение процесса окисления достигается в 6-7 раз при хорошем перемешивании реагирующих фаз. The article also presents the results of experimental studies of the effect of oxidation with atmospheric oxygen, an increase in the process temperature on the plasticity of bitumen. The efficiency of bitumen oxidation depends on the size of the contact surface between the liquid and gas phases. Acceleration of the oxidation process is achieved 6-7 times with good mixing of the reacting phases.The article is devoted to the analysis and study of various methods of obtaining petroleum bitumen and improving the adhesion properties in various mineral materials. Using the example of the Astrakhan gas processing plant, the effectiveness of the addition of additives - nitrogen-, sulfur-containing substances, elemental sulfur, etc. - to improve the adhesion properties of bitumen to mineral materials is shown. The analysis of the effect of temperature differences in summer and winter on the binding properties of bitumen is carried out. A method for preliminary stripping of volatile components from oils is considered, which leads to a decrease in the content of paraffin-naphthenic hydrocarbons and an improvement in the quality of the obtained bitumen.

CREATING A WORKING MODEL OF A DRIVERLESS AIRFIELD TOW TRUCK

2021 ◽  
Vol 2021 (10) ◽  
pp. 45-52
Author(s):  
Denis D'yakov ◽  
Iskander Valiulin ◽  
Dmitriy Lihovidov ◽  
Aleksey Velikanov
Keyword(s):  
Research Methods ◽  
Economic Efficiency ◽  
Experimental Studies ◽  
Field Tests ◽  
Climatic Conditions ◽  
Full Scale ◽  
Support Surface ◽  
Reliable Operation ◽  
Working Model ◽  
Full Scale Tests

The purpose of the research in this paper is to develop a promising airfield driverless tow truck to increase the economic efficiency of aircraft towing facilities, including unmanned aircrafts as well as to ensure reliable operation in various climatic conditions. The research methods include the analysis of the experience of using such driverless airfield tow trucks abroad, the theory of calculating traction and speed indicators and experimental studies conducted during the creation and study of field tests of devices used to load the driving wheels of a tractor. To achieve the goal, the configuration of the structure being designed and its intended composition are determined analytically. The operation of the designed device in the traction mode is considered, and the characteristic of calculating its indicators when moving along the support surface is presented. The presented material briefly illustrates the process from creating a model of a driverless airfield tow truck to the created design of an existing sample, which will later be used to conduct its full-scale tests and a comprehensive assessment of its strength traction and speed characteristics.

Mobile Worm-Like Robots for Pipe Inspection

2015 ◽  
pp. 168-218 ◽  
Author(s):  
Sergey Fedorovich Jatsun ◽  
Andrei Vasilevich Malchikov
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mobile Robots ◽  
Experimental Studies ◽  
Design Parameters ◽  
Robot Motion ◽  
Robot Dynamics ◽  
Confined Space ◽  
Pipe Inspection ◽  
The Mathematical Model

This chapter describes various designs of multilink mobile robots intended to move inside the confined space of pipelines. The mathematical model that describes robot dynamics and controlled motion, which allows simulating different regimes of robot motion and determining design parameters of the device and its control system, is presented. The chapter contains the results of numerical simulations for different types of worm-like mobile robots. The experimental studies of the in-pipe robots prototypes and their analyses are presented in this chapter.

Tension distribution shaping via reconfigurable attachment in planar mobile cable robots

Robotica ◽  
2013 ◽  
Vol 32 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Xiaobo Zhou ◽  
Seung-kook Jun ◽  
Venkat Krovi
Keyword(s):  
Mobile Robots ◽  
Configuration Space ◽  
Optimization Problem ◽  
Null Space ◽  
Experimental Studies ◽  
Analysis Framework ◽  
Tension Distribution ◽  
Fixed Base ◽  
Tension Direction ◽  
Cable Robots

SUMMARYTraditional cable robots derive their manipulation capabilities using spooling winches at fixed base locations. In our previous work, we examined enhancing manipulation capabilities of cable robots by the addition of base mobility to spooling winches (allowing a group of mobile robots to cooperatively manipulate a payload using cables). Base mobility facilitated the regulation of the tension-direction (via active coordination of mobile bases) and allowed for better conditioning of the wrench-feasible workspace. In this paper we explore putting idler pulleys on the payload attachment as alternate means to simplify the design and enable practical deployment. We examine analysis of the system using ellipse geometry and develop a virtual cable-subsystem formulation (which also facilitates subsumption into the previously developed mobile cable robot analysis framework). We also seek improvement of the tension distribution by utilizing configuration space redundancy to shape the tension null space. This tension distribution shaping is implemented in the form of a tension factor optimization problem over the workspace and explored via both simulation and experimental studies.

Evaluation of Dynamic Behavior of Pile Foundations for Interim Storage Facilities Through Geotechnical Centrifuge Tests

2002 ◽  
Author(s):  
Shizuo Tsurumaki ◽  
Hiroyuki Watanabe ◽  
Akira Tateishi ◽  
Kenichi Horikoshi ◽  
Shunichi Suzuki
Keyword(s):  
Dynamic Behavior ◽  
Experimental Studies ◽  
Centrifuge Modeling ◽  
Pile Foundations ◽  
Soil Conditions ◽  
Confining Stress ◽  
Geotechnical Centrifuge ◽  
Centrifuge Tests ◽  
Interim Storage ◽  
Storage Facilities

In Japan, there is a possibility that interim storage facilities for recycled nuclear fuel resources may be constructed on quaternary layers, rather than on hard rock. In such a case, the storage facilities need to be supported by pile foundations or spread foundations to meet the required safety level. The authors have conducted a series of experimental studies on the dynamic behavior of storage facilities supported by pile foundations. A centrifuge modeling technique was used to satisfy the required similitude between the reduced size model and the prototype. The centrifuge allows a high confining stress level equivalent to prototype deep soils to be generated (which is considered necessary for examining complex pile-soil interactions) as the soil strength and the deformation are highly dependent on the confining stress. The soil conditions were set at as experimental variables, and the results are compared. Since 2000, the Nuclear Power Engineering Corporation (NUPEC) has been conducting these research tests under the auspices on the Ministry of Economy, Trade and Industry of Japan.

Process-Integrated Manufacturing and Embedding of Novel Piezoelectric Sensor Modules into Glass Fibre-Reinforced Polyurethane Composite Structures

2015 ◽  
Vol 825-826 ◽  
pp. 563-570 ◽  
Author(s):  
Sirko Geller ◽  
Maik Gude
Keyword(s):  
Composite Structures ◽  
Experimental Studies ◽  
Piezoelectric Sensor ◽  
Research Centre ◽  
Adhesion Properties ◽  
Integrated Manufacturing ◽  
Polyurethane Composite ◽  
Research Activities ◽  
Significant Step ◽  
Component Manufacturing

Due to an increasing use of composite materials in various applications and related open questions concerning structural health monitoring and damage detection, the realisation of function integrating lightweight structures with sensory properties is subject of numerous research activities. Main objective is the transfer of already in laboratory and prototype scale established methods for the integration of sensory elements on serial applications. Here, combining the previously separated processing steps sensor manufacturing, component manufacturing and sensor integration can help to make a significant step forwards. Therefore, as part of the activities in the Collaborative Research Centre/Transregio (CRC/TR) 39, a highly productive spray coat method based on the long fibre injection (LFI) process is developed, which allows the process-integrated manufacturing and embedding of novel piezoelectric sensor modules into fibre-reinforced polyurethane composite structures.Based on studies on the technological implementation of the newly developed process, theoretical and experimental studies for contacting and polarisation of the novel sensor elements are presented. In addition, the characterisation of the adhesion properties of thermoplastic films on the used fibre-reinforced polyurethane composites is part of the presented research to evaluate the possibility of integrating thermoplastic-compatible piezo modules for actuator applications.

BIOSYSTEMATICS OF THE GENUS EUXOA (LEPIDOPTERA: NOCTUIDAE): XVI. COMPARATIVE BIOLOGY AND EXPERIMENTAL TAXONOMY OF FOUR SUBSPECIES OF EUXOA COMOSA

1982 ◽  
Vol 114 (7) ◽  
pp. 551-565 ◽  
Author(s):  
J. R. Byers ◽  
J. D. Lafontaine
Keyword(s):  
Sex Pheromone ◽  
Larval Growth ◽  
Experimental Studies ◽  
Field Tests ◽  
Taxonomic Status ◽  
Companion Paper ◽  
Genetic Incompatibility ◽  
Preoviposition Period ◽  
Preimaginal Development ◽  
Wide Range

AbstractLaboratory and experimental studies of four of the five subspecies of Euxoa comosa (Morr.), i.e. annir, altera, lutulenta and Ontario, each formerly considered of specific rank, were undertaken to assess their taxonomic status. Morphologically the immature stages of the subspecies are similar although lutulenta has a 40–50% larger egg and the larvae of lutulenta and Ontario are darker than those of annir and altera. The subspecies show differentiation in larval growth rate, number of larval instars, duration of preimaginal development and length of the preoviposition period. The possible adaptive significance of these differences are discussed. Hybrid F1 were obtained from 11 of the 12 possible pairwise combinations. Eight of the F1 hybrids were inbred and six produced fertile eggs. Some of the F2 progenies exhibited a wide range of phenotypes encompassing all subspecies including those of the 5th subspecies, E. c. comosa. Although hybridization success was high there was some evidence of genetic incompatibility including dyssynchronous emergence of the sexes and the absence, shortage, or inviability of female moths in some crosses. Mating discrimination tests show a moderate level of mating bias between subspecies. Calling periods of females of the subspecies largely overlap although differences in the time at which calling begins might be responsible for some of the mating bias. Both laboratory and field tests of sex pheromone attraction indicate considerable sex pheromone specificity among the subspecies. The results are discussed with reference to a companion paper which on the basis of conventional taxonomic characters and biogeographic considerations concludes that Euxoa comosa is best regarded as a polytypic species encompassing five subspecies.

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