scholarly journals Calculation of geometric dimensions of the levitation track

2020 ◽  
Vol 6 (2) ◽  
pp. 47-60
Author(s):  
Konstantin K. Kim ◽  
Vadim V. Veshkin ◽  
Igor R. Kron

Background: The problemto reduce the metal content of the levitation track is important when we create the transport systems with magnetic suspension. Aim is develop the reasonable recommendations to choose the geometric dimensions of the levitation track. Methods: we usedthe main provisions of the electromagnetic field theory and the aspects of the Fourier theory. Results: the optimal values of the width and thickness of the levitation track are justified. Conclusion: when we choose the width of the track we should be guided by considerations related to material consumption and the appearance of the side electromagnetic forces. The values of these forces are bigger the greater the ratio of the transverse displacement of the excitation solenoid to the track width. From the point of view of electrodynamics the value of the order of several centimeters we can consider as the upper limit of the track thickness.

2021 ◽  
Vol 13 (5) ◽  
pp. 2935
Author(s):  
Natalia Drop ◽  
Daria Garlińska

Using intelligent transport systems in cities is gaining popularity. The fundamental aim of their existence is to improve safety and traffic flow and prevent congestion in city centres. All people moving around the city, such as public transport passengers, as well as truck and emergency vehicle drivers and drivers of passenger vehicles, are users of intelligent transport systems. Research which was carried out for the article entirely concerns functioning and utility of intelligent transport systems from truck drivers’ experience. The main aim of the research was to evaluate services and tools within intelligent transport systems in European cities which are visited by Polish truck drivers. Our research indicates that most drivers (almost 98%) stated that they find intelligent transport systems useful and 92.5% of interviewed pointed that intelligent transport systems help with their everyday work duties. Of all the tools in the survey drivers agreed that variable content signs, accommodative traffic lights, and extra road illumination have most influence in road safety. Identifying the most useful and helpful tools of intelligent transport systems will allow to define their preferred development directions from truck drivers’ point of view.


2011 ◽  
Vol 199-200 ◽  
pp. 251-256
Author(s):  
Kai An Yu ◽  
Ke Yu Chen

Based on requirements of pipe transport systems on deepwater pipelaying vessel, a new pipe lifting mechanism was designed. It was composed of crank-rocker and rocker-slider mechanism with good lifting capacity and high efficiency. When the slider went to the upper limit position, the mechanism could approximatively dwell, meeting the requirement for transverse conveyor operation. According to the theory of dynamics, numerical analysis method was used to the dynamic analysis of the mechanism. The results showed the maximum counterforce was at the joint between the rocker and ground, and this calculation could be a guideline for the kinematic pair structure designing.


2021 ◽  
pp. 56-66
Author(s):  
Nikolay N. Vasilyuk ◽  
Alexander P. Chervonkin

The problem of the synchronization of onboard clocks of navigation satellites has considered from a relativistic point of view using the concept of “coordinate simultaneity”. This concept allows an unambiguous interpretation of the synchronization results within the framework of general relativity. The algorithm of intersatellite measurements processing has formulated in terms of a proper time of a space vehicle and the coordinate time of a reference frame. Rules of transformation between coordinate and proper time scales have indicated. An analytical expression has obtained for the periodic relativistic correction to the estimated value of the relative clock drift. This correction has expressed in terms of the coordinate time of a ground observer. The value of this correction exceeds the acceptable synchronization error and should be taken into account for the inter-satellite measurements processing. The error of the relativistic correction determination has calculated. This error provides an upper limit for the period of uploading of ephemeris data on the board of the space vehicle.


2019 ◽  
Vol 123 (1268) ◽  
pp. 1545-1560 ◽  
Author(s):  
I. Staack ◽  
K. Amadori ◽  
C. Jouannet

ABSTRACTProduct development, especially in aerospace, has become more and more interconnected with its operational environment. In a constant changing world, the operational environment will be subjected to changes during the life cycle of the product. The operational environment will be affected by not only technical and non-technical perturbations, but also economical, managerial and regulatory decisions, thus requiring a more global product development approach. One way to try tackling such complex and intertwined problem advocates studying the envisioned product or system in the context of system of systems (SoS) engineering. SoSs are all around us, probably in any field of engineering, ranging from integrated transport systems, public infrastructure systems to modern homes equipped with sensors and smart appliances; from cities filling with autonomous vehicle to defence systems.Since also aerospace systems are certainly affected, this work will present a holistic approach to aerospace product development that tries spanning from needs to technology assessment. The proposed approach will be presented and analysed and key enablers and future research directions will be highlighted from an interdisciplinary point of view. Consideration of the surrounding world will require to look beyond classical engineering disciplines.


Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 934
Author(s):  
Jorge Gálvez ◽  
Erik Cuevas ◽  
Krishna Gopal Dhal

Evolutionary Computation Methods (ECMs) are proposed as stochastic search methods to solve complex optimization problems where classical optimization methods are not suitable. Most of the proposed ECMs aim to find the global optimum for a given function. However, from a practical point of view, in engineering, finding the global optimum may not always be useful, since it may represent solutions that are not physically, mechanically or even structurally realizable. Commonly, the evolutionary operators of ECMs are not designed to efficiently register multiple optima by executing them a single run. Under such circumstances, there is a need to incorporate certain mechanisms to allow ECMs to maintain and register multiple optima at each generation executed in a single run. On the other hand, the concept of dominance found in animal behavior indicates the level of social interaction among two animals in terms of aggressiveness. Such aggressiveness keeps two or more individuals as distant as possible from one another, where the most dominant individual prevails as the other withdraws. In this paper, the concept of dominance is computationally abstracted in terms of a data structure called “competitive memory” to incorporate multimodal capabilities into the evolutionary operators of the recently proposed Cluster-Chaotic-Optimization (CCO). Under CCO, the competitive memory is implemented as a memory mechanism to efficiently register and maintain all possible optimal values within a single execution of the algorithm. The performance of the proposed method is numerically compared against several multimodal schemes over a set of benchmark functions. The experimental study suggests that the proposed approach outperforms its competitors in terms of robustness, quality, and precision.


2012 ◽  
Vol 49 (No. 3) ◽  
pp. 119-123
Author(s):  
A. Janeček ◽  
M. Mikleš

In this paper is evaluated an optimal constructional and operating performance of the mobil terrain system, that works in forest ecosystems from point of view of volume of processed biomass and total amount of logging transport erosion. A monitored terrain system, working in forestry, is considered as a production system, with its material and energy flow. The determination value, that optimizes the production system, is the operating and constructional performance. In this paper is evaluated the amount erosion in dependence of cutting mass, by means of mathematics and from system point of view. The conditions for the mobile terrain system work, that insure optimal, i.e. minimal value of erosion will be determined. The theoretical results are verified. The optimal values of soil erosion are determined by experimental measurements. The principles of the paper are based on theses of ecological synthesis that determine coupling between dissipative energy of a production system and its ecological cleanliness of work.


2020 ◽  
Vol 5 (10) ◽  
pp. 88
Author(s):  
Salvatore Trubia ◽  
Alessandro Severino ◽  
Salvatore Curto ◽  
Fabio Arena ◽  
Giovanni Pau

The goal of civil engineering has always been the research and implementation of methods, technologies, and infrastructures to improve the community’s quality of life. One of the branches of civil engineering that has the strongest effect on progress is transport. The quality of transport has a profound economic and social impact on our communities regarding trade (freight transport) and city livability (public transport systems). However, innovation is not the only way to improve the features above-mentioned, especially public transport, considering that it is usually beneficial to enhance and repurpose vehicles with appropriate adjustments to offer more efficient services. Other perspectives that influence public transport systems are the costs and times of design and construction, maintenance, operating costs, and environmental impact, especially concerning CO2 emissions. Considering these issues, among the various types of existing public transport systems, those of the so-called Bus Rapid Transit (BRT) offer worthwhile results. The BRT system is a type of public road transport operated by bus on reserved lanes, and it is significantly profitable, especially from an economic point of view, in areas where there are existing bus routes. Nonetheless, for the construction of works minimization, it is closely linked to other features that improve its usefulness, depending on the vehicles’ quality such as capacity, but above all, the propulsion or driving autonomy that would guarantee high efficiency. This paper introduces an analysis of some BRT systems operating worldwide, presenting the background, general technical features, and the correlation with autonomous vehicles.


2019 ◽  
Vol 124 ◽  
pp. 65-78
Author(s):  
Krzysztof Krawiec ◽  
Marcin Jacek Kłos ◽  
Sylwester Markusik ◽  
Aleksander Bułkowski

The article presents threats related to broadly understood cybersecurity, encountered in modern public transport, especially in cases of increasingly introduced Intelligent Transport Systems (ITS). Experience to date has shown strong links between the technical sphere and IT system of public transport, ensuring its protection against unwanted externa l interference from people (or organizations) trying to disrupt its functioning. The following - inter alia - are of a key importance: the system of existing bus network as well as organization of bus work on routes (schedule) and its IT links, monitoring and system protection against external interference. The main goal of cybersecurity in public transport is to increase the level of cybersecurity in city agglomeration by increasing the availability of hardware and IT tools, included in intelligent transport systems, protecting safety and reliability of operation of public transport.


2020 ◽  
Vol 130 ◽  
pp. 43-52
Author(s):  
Anna Kobaszyńska-Twardowska ◽  
Monika Wantuła

The transport system from the safety point of view consists of: technical objects, operators and human resources, operation safety subsystems, and system management center. In the area of these subsystems, there may be hazardous sources of external or internal character. Based on the analysis of transport systems, it is concluded that man causes numerous mistakes. The baggage control system and the persons responsible for the functioning of this system have a significant impact on airports' safety level. Dia-grams of multi-stage processes for checking hand luggage and checked baggage has been developed. Eighty-two flights departing from the airport, in which over 1500 passengers were checked-in, were observed to indicate gaps in procedures during baggage processing. They sent over 7500 luggage items in total. During the observation, passengers were asked whether they carried objects defined as hazardous in their hand luggage or checked baggage, and then the affirmative answers obtained were counted. During the check-in, passengers of all analyzed flights, while answering the "safety questions", declared 281 items, which we defined as hazardous. The study confirmed the hypothesis that the transport of dangerous objects in the wrong luggage type has not yet been eliminated and is a hazard source in air transport. Groups of travelers were indicated by a constant lack of awareness about the materials not permitted for air transport.


1978 ◽  
Vol 100 (4) ◽  
pp. 333-342 ◽  
Author(s):  
P. K. Sinha

Several forms of novel suspension systems for passenger-carrying vehicles are currently being investigated throughout the world. Most of these, however, are aimed at high-speed, intercity transport systems, and comparatively less development work has been undertaken to provide a new form of low-speed system for urban-transportation. The possibility of using controlled direct-current electromagnets for low-speed (up to 70 kph) vehicle suspension has been explored in this paper. This system, also known as ferromagnetic or attraction suspension system, offers a very attractive combination of design simplicity, low operating and maintenance costs, high reliability and virtually silent operation. This system is also considered to have capital costs comparable with alternative forms of urban-transport systems and could be designed to fit into the existing fabric of cities and towns. The feasibility of the d-c system is illustrated here through analytical and experimental results of the ride and track-clearance characteristics for a single-degree of freedom suspension system. These results are used to formulate a procedure for designing a multimagnet vehicle suspension system. Main design and performance criteria for maglev vehicles are discussed in the context of experimental results obtained from test vehicles. Engineering aspects of some of the system components have been presented with a view to evaluating their suitability for low-speed systems.


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