The analysis of the random vibrations that occur during the flight of the unmanned aerial vehicles is important, as these random vibrations have random characteristic properties and have the ability to decrease the endurance of such systems. The accuracy of data collected from sensors in the unmanned aerial vehicle system is important for the flight control system. The transferring of these data among different sensors such as inertial measurement unit, axis accelerometers, GPS or cameras is usually affected by many factors. One of the important factors is the random vibration, which is usually caused by aerodynamic excitation or air turbulence. The problem of random vibrations has been studied for a long time and explained in many text books. In this study, the author introduces a mathematical analysis for random vibrations that are independent of their sources by considering these vibrations as a random and non-stationary process and designs a control methodology based on expectations and probability theory to reduce the effect of these vibrations. The analysis used in this research is based on the assumptions of practical approximation techniques.
In the past decade, many approaches that attempted to solve the problem of optimal control and parameter estimation of an unmanned aerial vehicle with a priori uncertain parameters simply implied two ways to solve such problem. First, by the formation of optimal control based on a refined mathematical model of the unmanned aerial vehicle, and second, by using the estimation and identification methods of the model parameter of the unmanned aerial vehicle based on measured data from flight tests. However, the identification of the dynamic parameters of the unmanned aerial vehicle is a complicated task because of a number of factors such as random vibration noise, disturbance, and uncertainty of the sensor measurements. Due to the influence of random vibration noise, the problem of correlated vibration noises and uncertainty has encountered inevitably, and the accuracy of the state estimation for unmanned aerial vehicle is degraded. This study concentrates on the optimal control and state estimation for the unmanned aerial vehicle under the combination of both random vibration noise and uncertainty collected by the sensors. The effects of random vibrations at various stages of a large-scale flight that are a priori uncertain require the inclusion of identification algorithms in the optimal control loop. The results showed that the method used in the analysis had been able to provide accurate estimations.
Liquid sloshing in moving or stationary containers and flexible uncertainty caused by the slosh are considered to be the most probable causing unexpected coupling effects on the dynamics of many systems such as aerospace, ground vehicles, and high speed industries arms. The coupling of dynamic liquid slosh in a container system with the uncertainty caused by the sensors or dampers is rare documented and this coupling can be considered as a highly nonlinear system. In this paper, an investigation is presented to demonstrate a new approach for enabling the reduction of the liquid slosh and uncertainty by implementing adaptive robust wavelet control technique. Starting by creating the mathematical dynamic model for the nonlinear slosh coupled by uncertainty, adaptive robust control based wavelet transform is applied for calculating optimal motion that minimize residual slosh and uncertainty. Subsequently the adaptive robust control based wavelet network approximation and the appropriate parameter algorithms for the container system with slosh and uncertainty are derived to achieve the feedback linearization, adaptive control, and H∞ tracking performance. The simulation results show that the effects of slosh errors and external uncertainty can be successfully attenuated within a desired attenuation level.
Fifth-generation (5G) technologies enable a wide range of vertical applications by connecting heterogeneous equipment and machines, resulting in significantly improved service quality, increased network capacity, and improved system performance. As a result, the world is shifting to 5G wireless networks. Because 5G has the advantage of supporting various vertical applications, 5G systems must still overcome challenges such as transparency, data interoperability probabilities, decentralization, and network privacy. In this paper, we'll show how blockchain can be used to solve problems in 5G, as well as some of the idea’s researchers, have come up with to solve them, like resource sharing, security, and mobility.
The higher education sector has witnessed a drastic change due to new advanced technologies including computers and smartphones. As a result, higher education will need to establish a solid foundation aided by information communication technologies (ICT) where mobile applications can extend learning opportunities for students and graduates so they meet the requirements of the fast-changing jobs market. Many studies conducted in various contexts have revealed the drastic change of using mobile applications (henceforth apps) and advanced communication which help students develop their skills by means of using the digital environment. The study aims at identifying the general impression of Iraqi private universities students about the future role of ICT and the mobile learning in higher education. Al-Maarif University College is selected as a case study to measure the extent of students' reliance on the use of modern smartphones applications in research, study, and skills development in the field of specialization. The study also sheds light upon specifying the important variables and methods for enhancing the role of the mobile learning as a part of the electronic education for the private education sector in Iraq.
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