Łukasz Warguła

Łukasz Warguła
Poznan University of Technology · Institute of Machine Design

About

102
Publications
36,664
Reads
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722
Citations
Citations since 2016
97 Research Items
718 Citations
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2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
Introduction
Łukasz Warguła currently works at the Institute of Machine Design, at the Faculty of Mechanical Engineering, at the Ponzan University of Technology.

Publications

Publications (102)
Article
Full-text available
Self-propelling a wheelchair up a hill requires intense muscular effort and introduces the risk of the wheelchair rolling down. The purpose of this paper was to assess the user's muscular activity during ramp climbing. Tests were carried out on a group of 10 subjects who had to propel a wheelchair up a standardized wheelchair ramp. Basic parameters...
Article
Operating conditions often fluctuate during processing of branches and sawmill offcuts using low-power wood size reduction machines (WSRMs), mainly due to changes in wood supply frequency. This results in relatively high proportions of idling time. Fuel consumption and associated exhaust emissions of WSRMs with combustion engines can be reduced by...
Article
Full-text available
This paper presents a review of mobile positive pressure ventilation fans for use in rescue operations available on the European market in correlation with the approval regulations of the drive units. The authors determined the approval limits for harmful compound emissions by their power units, as applicable within the European Union. The purpose...
Article
Full-text available
The size of wood is reduced by splitting or chipless cutting whilst logging trees, limbing, or preparing wood to be a fuel, for example, or in order to improve the efficiency of wood drying processes. Low costs of wood processing are desirable in each of these processes. The article presents experimental and simulation tests run in ABAQUS software,...
Article
Full-text available
The development and operation of road infrastructure require machines and equipment driven by low-powered internal combustion engines. In this study, we conducted emission tests on five small spark-ignition engines. We used the most popular commercial design on the market, the Lifan GX 390, with a carburettor power system, and another commercial po...
Article
Full-text available
The purpose of the study was to create a research methodology for testing the newly developed wheelchair drive, which allows the operator to choose the gear ratio and, thus, makes it possible to change the propulsion torque value. The aim was to choose such conditions in the experiment, that would result in great enough changes in the participant’s...
Article
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The continuous increase in the use of the transmissions with V-belt, the introduction of new materials for the production of belts and the development of new manufacturing techniques have become the reason for undertaking research works on the possibilities of increasing the load capacity and durability of belts as well as reducing their influence...
Article
Full-text available
Mobile overpressure fans are popular tools used in rescue and extinguishing operations carried out by Fire Protection Units. They are used for exhaust and venting buildings from harmful products of thermal decomposition occurs due to fire. Health and human life may depend on the proper operations of this type of equipment. The aim of the article is...
Article
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Wood choppers shredding branches equipped with low power drive units (up to 10 kW) are characterized by low technical sophistication. Their work translates into the consumption of non-renewable energy sources and the emission of toxic exhaust compounds into the environment. There are innovative technical solutions that allow you to increase the eff...
Article
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Experimental research on agricultural tractor movement, acquisition and archiving of kinematic features is an important issue in the analysis of braking and acceleration processes. The obtained traffic parameters depend on the environmental conditions, condition and type of pavement, load, tire pressure and the area of tire-pavement cooperation. Th...
Article
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Innovative wheelchair designs require new means of controlling the drive units or the propulsion transmission systems. The article proposes a signal to control the gear ratio or the amount of additional propulsion torque coming from an electric motor. The innovative control signal in this application is the signal generated by the maximum voluntary...
Article
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The aim of the research was to show that changes occur in floor surface parameters resulting from increased use in public utility buildings. The study included corridors and staircases that differ in terms of covering material in a public utility building in Poznań. Measurements were carried out with the use of the British Pendulum Test Value (PTV)...
Article
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The purpose of this article was to present an algorithm for creating an ellipse for any data set represented on a two-dimensional reference frame. The study objective was to verify the developed method on real results of experimental tests with different subject matter. This article contains a mathematical algorithm to describe a set of points with...
Article
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This study aimed at analysing the influence of the position of the centre of gravity variability and the movement velocity on the demand for a torque and work time coverage of a wheelchair with an electromechanical drive. The variable parameter in the study was the configuration of the wheelchair, namely changes in the position of the batteries whi...
Article
Full-text available
In order to improve the power selection of the drive unit for the shredding machines,theauthors determine the values of friction coefficients used in the cutting force models. These values consider the friction between steel and such wood-based materials as chipboard, MDF and OSB. The tests concern laminated and non-laminated external surfaces and...
Article
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Reducing the driving force when propelling a wheelchair, e.g. through mechanical gears, is beneficial for people using wheelchairs. This makes it possible to overcome terrain obstacles that would be otherwise impassable with a classic drive system. However, the disadvantage of additional mechanisms supporting the propulsion of the wheelchair is usu...
Article
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The article presents a conceptual design of a wood chipper with a cutting mechanism equipped with a mechanical overload system. The innovative design (subject to patent application at the Polish Patent Office P.431435) ensures continuous operation of the chopping machines, even if wood enters the feed channel, the characteristics of which exceed th...
Article
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In order to design effective shredding machines dedicated to shredding wood-based waste, information about the mechanical properties of materials subjected to shredding is necessary. A number of mechanical properties of particleboard, oriented strand boards, and medium-density fibreboards in the aspect of shredding process have been experimentally...
Article
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The article presents results of research on commercially used cutting mechanisms of low-power (about 10 kW) wood size reduction machines driven by small engines. The energy consumed was determined based on work demand, showing that two-cylinder cutting mechanism consumes less energy than disc cutting mechanism and drum cutting mechanism when wood s...
Preprint
Full-text available
The development and operation of road infrastructure requires machines and equipment driven by low-powered internal combustion engines. The authors of this paper examined five small spark-ignition engines. They used the most popular commercial design on the market, the Lifan GX 390, with a carburettor power system, and another commercial power unit...
Article
Full-text available
Machines and devices for the production, transport and segregation of products are placed in production and storage rooms. Flat conveyor and drive belts are very often used for their construction. Due to heavy loads and difficult operating conditions, these belts can catch fire and, as a result, become the main source of air contaminants harmful to...
Article
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The paper presents the procedure of generating geometrical features on the contours of non-circular pulleys through the selection of materials and technological parameters for easy and efficient production of these parts. Based on the models designed in the computer aided design (CAD) system, several prototype non-standard pulleys were made, which...
Article
Purpose - The aim of this research was to analyse the impact of the human body position changes caused by propelling a wheelchair with the pushrim propulsion on the value of motion resistance force. Material and methods - The research was carried out in the group of six persons propelling a wheelchair whose frame was inclined, in respect to the hor...
Article
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Beach cleaning and algae collection in the shoreline area are important for the tourism industry, mainly for aesthetic reasons, but also to protect human health. In addition, the collected material can be used in many industries such as energy, medicine, cosmetics or catering. The problem of cleaning the shoreline area concerns the need to clear la...
Article
Full-text available
Objective: The main objective of the tests conducted was to analyze the position variability of the human body's center of gravity during propelling the wheelchair, and to demonstrate the properties enabling the description of this variability by means of plane figures with a symmetry axis. A secondary objective was to show the impact of the used m...
Article
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Early detection of the causes of malfunction of toothed gears, cable gears, and various types of drives enables the prevention of breakdowns and related downtime. The work concerns the possibility of using terminography in order to assess the thermal state of the V-belt of the tension transmission used in the drive of a wood chipper. This device is...
Article
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The research aim was to analyse the influence of velocity and size of markers on the accuracy of motion capture measurement utilising image processing with the use of OpenCV. On the basis of the obtained results, the usefulness of the applied measurement method in studying the kinematics of the human body while driving operating a wheelchair was de...
Article
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This article presents the results of experimental research on the mechanical properties of pine wood (Pinus L. Sp. Pl. 1000. 1753). In the course of the research process, stress-strain curves were determined for cases of tensile, compression and shear of standardized shapes samples. The collected data set was used to determine several material cons...
Article
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The projected increase in the availability of gaseous fuels by growing popularity of household natural gas (NG) filling stations and the increase in the production of gaseous biogas-derived fuels is conducive to an increase in the use of NG fuel. Currently, natural gas in various forms (compressed natural gas (CNG), liquefied natural gas (LNG)) is...
Article
Full-text available
The effectiveness and precision of transporting wood chips on the transport trailer or hopper depends on an inclination angle, a conveyor belt speed, and length. In order to devise a methodology aiding designing and the selection of technical and performance parameters (aiding the settings of conveyor belt sub-assemblies), the authors carried out t...
Article
Full-text available
Purpose: The main purpose of the research conducted was the analysis of kinematic and biomechanical parameters measured during manual wheelchair ramp-climbing with the use of the anti-rollback system and the comparison of the values tested with the manual wheelchair climbing the same ramp but without any modifications. The paper presents a quantita...
Article
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The use of alternative fuels is a contemporary trend in science aimed at the protection of non-renewable resources, reducing the negative impact on people and reducing the negative impact on the natural environment. Liquefied petroleum gas (LPG) is an alternative fuel within the meaning of the European Union Directive (2014/94/UE), as it is an alte...
Article
Full-text available
In order to elaborate design guidelines for developing efficient and possibly most energy saving mills for comminuting carpentry, OSB and MDF waste, there have been performed some tests aimed at torque demand on the working unit of the machinery participating in that process. The tests were carried out on a cylindrical wood chipper. There were indi...
Article
Full-text available
Materials characterized by magnetorheological properties are non-classic engineering materials. A significant increase in the interest of the scientific community about this group of materials could be observed over the recent years. The results of research presented in this article are oriented on the examination of the said materials’ mechanical...
Preprint
Full-text available
Materials characterised by magnetorheological properties are non-classic engineering materials. A significant increase in the interest of scientific community in materials from this group can be observed over the recent several years. The results of research presented in this article are oriented on the examination of said materials’ mechanical pro...
Article
Full-text available
The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and comb...
Article
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This paper discusses the determination of fuel consumption and exhaust gas emissions when shredding branches in urban areas. It aimed to determine the hourly emission of exhaust gases to the atmosphere during such work and to identify the designs that can reduce it. The research was carried out with a cylinder woodchipper driven by a low-power (9.5...
Article
Full-text available
Alternative fuel within the meaning of Directive 2014/94/EU is, among others, LPG (liquefied petroleum gas), characterized by a lower purchase cost and lower emissions of toxic exhaust compounds in comparison to the combustion of classic gasoline. In wood chippers, intended for chopping branches, with low-power internal combustion engines that meet...
Article
Full-text available
Aim: The aim of the article is to identify innovative design solutions in chainsaws which are used in rescue and firefighting operations. The review concerns commercial solutions, scientific publications and patents. It enables to determine development trends of chainsaws utilised as mechanical rescue devices. Project and methods: Although chainsa...
Article
Full-text available
Branch chipping machines with low-power engines are distinguished with an intermittent operation due to a periodical supply of branches. A conventional drive speed control of these machines is not adapted to adjust the operating mode depending on frequency of material supply for shredding. This article discusses the issues related to the assessment...
Article
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Both energy consumption and the ecology of mobile wood-chipping machines are important issues in forest management. One way of improving the efficiency of wood-chippers is to use innovative design solutions in drive unit control systems. This can result in a reduction in fuel consumption and quantitative exhaust gas emissions. This article presente...
Article
Full-text available
The article presents the methods for measuring the position of the centre of gravity of an anthropotechnic human-wheelchair system in dynamic conditions. The methods were verified by the pilot studies using a pushrim-propelled wheelchair. Data processing methods were used to fit the ellipses to measured datasets including 4.463 to 3.434 points, whe...
Article
Full-text available
The development of belt transmissions with wedge belts and new materials used to produce belts inspire designers and people who deal with the exploitation of belt drives to carry research on the possibilities of increasing the load and durability of the belts. It is necessary to know the actual mechanical and rheological characteristics of the belt...
Article
Full-text available
Presently, we observe an increase in automation and mechanization of many areas of life and industry, which allow to increase work efficiency and reduce costs. However, many circumstances such as terrain shape, forestation or urban planning can prevent the deliver and operation of various types of machinery. Consequently, an important area of devel...
Article
Full-text available
The 21 st century is characterized by an increase in the obesity of society, including people with disabilities. The increase in the weight of people in wheelchairs requires them to have more power to drive these types of vehicles. Diseases and a varied level of disability or infirmity may lead to the inability to overcome the resistance of a vehic...
Article
Full-text available
Waste management in a selective manner requires the collection of waste, among others, also large-scale. In Poland, in January and February, the collection of biodegradable waste is carried out – Christmas trees. This process is carried out by collecting from the real estate the whole trees, and then transporting them to the utilization place, wher...
Article
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This article proposes thermography as a non-contact diagnostic tool for assessing drive reliability. The application of this technique during the operation of the belt transmission with a heat-welded thermoplastic polyurethane V-belt was presented. The V-belt temperature changes depending on the braking torque load at different values of the rotati...
Article
Full-text available
Overcoming terrain obstacles presents a major problem for people with disabilities or with limited mobility who are dependent on wheelchairs. An engineering solution designed to facilitate the use of wheelchairs are assisted-propulsion systems. The objective of the research described in this article is to analyze the impact of the hybrid manual–ele...
Preprint
Full-text available
Overcoming terrain obstacles presents a major problem for people with disabilities or with limited mobility who are dependent on wheelchairs. An engineering solution designed to facilitate the use of wheelchairs are assisted propulsion systems. The objective of the research described in this article is to analyse the impact of the hybrid manual-ele...
Book
Full-text available
The wheelchair is a basic device that provides mobility to disabled people. As indicated in "The Polish Population’s Health Status" survey by the Central Statistical Office, 16% of the population is affected by some form of disability of which 46% are people who suffer from motor disabilities (according to the National Census of 2002). The data onl...
Article
Full-text available
The effectiveness of agrocultural processes in wooded areas depends, inter alia, on the kind of machines used. Mobile machines chopping branches with low power engines are characterized by limited adaptation of the drive unit to the operating conditions. This results in increased fuel consumption and increased exhaust emissions. In order to develop...