scholarly journals MATHEMATICAL MODELLING OF THE UNMANNED AERIAL VEHICLE DYNAMICS

Author(s):  
V. Y. Stepanov

The article gives a classification of the main components of unmanned aerial vehicle (UAV) systems, gives the areas in which the application of UAVs is actual in practice today. Further, the UAV is considered in more detail from the point of view of its flight dynamics analysis, the equation necessary for creating a mathematical model, as well as the model of an ordinary dynamic system as a non-stationary nonlinear controlled object, is given. Next, a description of the developed software for modeling and a description of program algorithm are given. Finally, a conclusion describes the necessary directions for further scientific researches.

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Haruka Tsunetaka ◽  
Slim Mtibaa ◽  
Shiho Asano ◽  
Takashi Okamoto ◽  
Ushio Kurokawa

AbstractAs wood pieces supplied by landslides and debris flows are one of the main components of ecological and geomorphic systems, the importance of quantifying the dimensions of the wood pieces is evident. However, the low accessibility of disturbed channels after debris flows generally impedes accurate and quick wood-piece investigations. Thus, remote-sensing measurements for wood pieces are necessitated. Focusing on sub-watersheds in coniferous and broadleaf forests in Japan (the CF and BF sites, respectively), we measured the lengths of wood pieces supplied by landslides (> 0.2 m length and > 0.03 m diameter) from orthophotos acquired using a small unmanned aerial vehicle (UAV). The measurement accuracy was analyzed by comparing the lengths derived from the UAV method with direct measurements. The landslides at the CF and BF sites were triggered by extremely heavy rainfalls in 2017 and 2018, respectively. UAV flights were operated during February and September 2019 at the CF site and during November 2018 and December 2019 at the BF site. Direct measurements of wood pieces were carried out on the date of the respective second flight date in each site. When both ends of a wood piece are satisfactorily extracted from an orthophoto acquired by the UAV, the wood-piece lengths at the CF site can be measured with an accuracy of approximately ±0.5 m. At the BF site, most of the extracted lengths were shorter than the directly measured lengths, probably because the complex structures of the root wad and tree crown reduced the visibility. Most wood pieces were discharged from landslide scars at the BF site, but at the CF site, approximately 750 wood pieces remained in the landslide scars approximately 19 months after the landslide occurrence. The number of wood pieces in the landslide scars of the CF site increased with increasing landslide area, suggesting that some wood pieces can be left even if large landslides occur. The lengths and locations of the entrapped wood pieces at both sites were not significantly changed between the two UAV flight dates. However, during this period, the rainfall intensities around the CF site measured by the closest rain-gauge of the Japan Meteorological Agency reached their second highest values from 1976 to 2019, which exceeded the 30-year return period. This suggests that most of the entrapped wood pieces rarely migrated even under intense rainfall.


Author(s):  
Inon Wiratsin ◽  
Veerapong Suchaiporn ◽  
Pojchara Trainorapong ◽  
Jirachaipat Chaichinvara ◽  
Sakwaroon Rattanajitdamrong ◽  
...  

Author(s):  
A. A. Lobaty ◽  
Y. F. Yatsyna ◽  
V. Y. Stepanov ◽  
A. Y. Bumai

The probabilistic analysis of crossing by an unmanned aerial vehicle (UAV) of the boundary of the no-fly area is solved. Condition of stating of the fact of the violation of the boundary of the restricted area is to stand of UAV within the area during a specified time. The substantiation of the mathematical model to research through linearized vector stochastic equation is carried out. The problem is solved by applying the theory of Markov processes of random structure with absorption of realizations at the boundary of a given area. Particularity of the approach is the contemporaneously consideration of two probability densities of the distribution of phase coordinates that describe the boundary conditions. In this case, two equations systems are solved for probabilistic moments: taking into account the absorption of realizations and without taking into account the absorption. The probability of an object gets into specified area and do not leave one during the time that necessary to notice the unmanned aerial vehicle at the restricted area.


Author(s):  
Luís Pádua ◽  
Nathalie Guimarães ◽  
Telmo Adão ◽  
Pedro Marques ◽  
Emanuel Peres ◽  
...  

Author(s):  
A. A. Lobaty ◽  
Y. F. Yatsyna ◽  
S. S. Prohorovith ◽  
Y. A. Hvitko

The problem of determining the shape and parameters of a mathematical model in the form of a transfer function for the movement of an unmanned aerial vehicle (UAV) in the vertical plane of space is solved. The angle of deviation of the Elevator is considered as the input signal, and the pitch angle of the UAV is considered as the output signal. We use the results of experimental studies of UAV flight, which are considered as known values of input and output signals under specified flight conditions. The measured discrete values of the experimental results are approximated by a fourth-order polynomial based on regression analysis for ease of use in identification. The analytical substantiation of the need to apply the methods of linearization of the mathematical model of UAV movement and the accepted assumptions for obtaining differential equations of UAV movement relative to the center of mass, allowing to synthesize the required transfer function of the corresponding element of the UAV control system. The results of computer modeling confirmed the validity of the synthesized mathematical model obtained on the basis of structural and parametric identification. This approach can be used to obtain simplified mathematical models that are used to solve problems of synthesis and optimization of control systems not only for UAVS, but also for other dynamic objects.


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