In this study, virtual global navigation satellite system data is created to be used when global navigation satellite system (GNSS) data of unmanned aerial vehicles (UAV) is jammed. Nowadays, when GNSS signals disappe...
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ISBN:
(数字)9781728172064
ISBN:
(纸本)9781728172071
In this study, virtual global navigation satellite system data is created to be used when global navigation satellite system (GNSS) data of unmanned aerial vehicles (UAV) is jammed. Nowadays, when GNSS signals disappear, the most common method used as aided navigation data is to obtain location information by using inertial measurement units based on MEMS (micro-electro-mechanical) system. However, the position error generated by inertial units increases in proportion to the square of time. In this study, the position information of the UAV is determined by calculating the slant range, elevation and azimuth angles between the electro optic ground station and the UAV. In this structure, 3 different sensors are used. The laser distance meter is used to measure the distance between the ground station and the UAV, the magnetic field meter is used to measure the angle of the azimuth and the accelerometer is used to measure the elevation angle. The sensor data obtained from the STEVAL-STLKT01V1 development board were processed and the effect of the measurement errors on the position error was analyzed. This study provides methods for aided navigation system developers and sheds light on the tradeoffs by giving effect to the position error of sensor measurement errors. It is thought that the study will help to establish an aided navigation system for UAVs that may work in harsh environmental and atmospheric conditions in the future.
This article deals with development of new type of onboard measurement system for carbon brush's length (wear) measurements. There are many applications where regular inspection is not feasible because of a number...
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ISBN:
(纸本)9781538656235;9781538656228
This article deals with development of new type of onboard measurement system for carbon brush's length (wear) measurements. There are many applications where regular inspection is not feasible because of a number of factors including, for example, time, labor, cost and disruptions due to down time. Thus, there is a need for an on-board system that can monitor the brush's length to calculate it's wear rate, while the component is in operation or without removing of the component from its operational position. We propose a novel method for characterization of carbon brush's length. This method based on the usage of advantages of the multiplicative response of FBGs and FBG arrays: spectral parameters depend on several aspects, such as grating's period, refractive index, it's physical length and so on. We are the first, in our point of view, who proposed to use third parameter for sensing application and prospectively all three parameters for complex measurement: the change of FBG's length is used to measure length of the brush and it's wear rate, grating's central wavelength shift for temperature (due to refractive index change) and mechanical stress (due to grating's period variations) measurements. The results of modelling and experiments are presented.
Network attacks are as diverse as the systems against which they are directed. Some attacks are very difficult, others are able to the usual operator, not even guessing what the consequences of his activities. To asse...
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The number of devices connected to the World Wide Web and the requirements of subscribers to the speed of mobile Internet access are increasing every year. Developers of telecom equipment and telecom operators, trying...
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ISBN:
(纸本)9781538656228
The number of devices connected to the World Wide Web and the requirements of subscribers to the speed of mobile Internet access are increasing every year. Developers of telecom equipment and telecom operators, trying to meet new challenges, are preparing to seriously change the architecture of networks and interaction regulations in radiofrequency applications. Availability of required radiofrequencies in radiofrequency applications is one of the main necessary factors for the development of such networks, along with the readiness of the network architecture and infrastructure, business models and subscriber devices [1]. In the development of fifth-generation technologies in radiofrequency applications, there is a certain set of 'input' characteristics that serve as a guide for a new standard. For example, compared to the best existing LTE networks, the data transfer speed in 5G networks should be 10-100 times higher, the response time is 5 times less, the network should support the number of devices 100 times more[2-4]. The modern telecommunication market is at a stage when operators have a favorable opportunity to bypass all the convergence difficulties inherent in the networks of the past, and go directly to the next-generation networks based on technology, which received the working name NGN - 'New Generation Network'. In order to make this breakthrough and join the number of high-tech operators, new solutions are needed to be constructed in the field of creating and providing high-performance services. NGN - technology of building a network - is designed to provide data transmission services and voice services in radiofrequency applications. It removes a number of restrictions and barriers that exist now, and this is its economic productivity[4]. DPI (Deep Packet Inspection) - technology for the classification and filtering of traffic by its content. DPI is able to define application protocols (HTTP, HTTPS, Skype, BitTorrent), the type of data transferred (web
At present, the problem of switching from traditional circuit-switched networks to packet-switched networks (NGN) is one of the most urgent for telecom operators in radiofrequency applications. Perspective development...
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ISBN:
(纸本)9781538656228
At present, the problem of switching from traditional circuit-switched networks to packet-switched networks (NGN) is one of the most urgent for telecom operators in radiofrequency applications. Perspective developments in the field of IP communications are connected with the creation of integrated solutions that allow the development of next-generation networks to maintain existing connections and ensure uninterrupted operation in any telephone access network: on the infrastructure of copper pairs, through optical channels, wireless (WiMAX, WiFi) and wired (ETTH, PLC and etc.) of the network. According to the concept of 'non-destructive' transition to NGN, such solutions should allow point-to-point transfer of certain segments to new technologies in radiofrequency applications without drastically changing the entire structure of the network. In particular, solutions for a 'nondestructive' transition to NGN must meet the following requirements: • Integration into the existing network of the operator, support not only for new transport technology, but also for the familiar management model;• Fully modular architecture with the capabilities of geographical distribution and redundancy;• The ability to flexibly increase productivity by purchasing licenses and adding servers to the system;• The possibility of introducing new types of services in the shortest possible time;• Compliance with the requirements of the legislation on network architecture [1-5]. Routing to date is determined not by formal rules and descriptions typical of networks of previous generations, but by customer requirements and economic considerations of the telecoms operator. To optimize the operation of networks in radiofrequency applications, various routing methods are being developed, ensuring a balanced load of all network resources. Among foreign scholars studying this problem, it is worthwhile to highlight D. Awduche, J. Malcolm, J. Agogbua, M. O'Dell, J. McManus, S. Hiroyuki, M. Yasuhiro, Y. M
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