scholarly journals THE STUDY OF THE “CETUS” UNMANNED AERIAL VEHICLE FOR TOPOGRAPHIC AERIAL SURVEYING

2021 ◽  
Vol 47 (2) ◽  
pp. 96-103
Author(s):  
Volodymyr Hlotov ◽  
Alla Hunina ◽  
Ihor Kolb ◽  
Vadim Kolesnichenko ◽  
Ihor Trevoho
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Aerial Photography ◽  
Large Scale ◽  
Aerial Survey ◽  
Control Points ◽  
Gps Survey ◽  
Aerial Surveys ◽  
Spatial Coordinates ◽  
Aerial Vehicle ◽  
And Control

The work aims to analyze and study the possibilities of using “Cetus” unmanned aerial vehicle (UAV) for performing topographic aerial surveys. The authors developed and tested aircraft-type UAV for topographic aerial photography. The studies were conducted on a specialized landfill, at which there is an appropriate number of situational points whose coordinates are determined with high accuracy. These points were used as both reference and control points. The obtained UAV aerial survey materials were subjected to a phototriangulation process to determine the orientation elements and to analyze, first and foremost, the angular orientation elements. The surveying was carried out on a mountainous territory, where the spatial coordinates of 37 situational points were determined by the method of ground-based GPS survey with an average accuracy of up to 0.05 m. These points were used as reference and control points. Aerial photography was performed in such a way that the scale of the images was as uniform as possible. The design solutions implemented in the Cetus UAV provide all the possibilities to perform aerial surveys of territories in strict compliance with the projected flight parameters. UAV equipment provides the necessary real-time correction of the position of the aerial camera. At the same time the optimum straightness of routes, stability of scales and mutual overlapping of pictures is reached. Regarding the accuracy of obtaining the spatial coordinates of the points of terrain objects, using “Cetus” UAV surveys, plans can even be made on a scale of even 1: 1000. As a result of the creation of the UAV “Cetus”, it became possible to perform the topographic aerial survey of the territories and to create large-scale orthophotos that fully meet the instructions. As a result of testing the “Cetus” UAV, it can be used in production processes when drawing up topographic plans for a large-scale series: 1: 1000 – 1: 5000, which will significantly save the cost of performing topographic work.

scholarly journals Influence of the shape and size of the ground targets on the accuracy of photogrammetric processing

2020 ◽  
Vol 28 (3) ◽  
pp. 293-304
Author(s):  
Amr Elsheshtawy ◽  
Larisa A. Gavrilova ◽  
Anatoly N. Limonov ◽  
Mohamed Elshewy
Keyword(s):  
Large Scale ◽  
Soil Layer ◽  
Aerial Survey ◽  
Control Points ◽  
Aerial Photos ◽  
Emergency Situations ◽  
Ground Control Points ◽  
First Case ◽  
Aerial Vehicle ◽  
Mosaic Generation

The materials obtained from the unmanned aerial vehicle (UAV) are used to solve many problems, including large-scale mapping and monitoring of linear objects, as well as the ecological situation and monitoring of emergency situations. The promptly obtained photographic materials make it possible to reveal the consequences of man-made human impact associated with degradation of the soil cover, flooding of lands, salinization and pollution of the soil layer, and changes in the vegetation cover. Control points are used for absolute orientation of the generated models in the most projects of photogrammetric processing of aerial photos and images obtained from UAVs. In areas with low contour, before aerial survey, targeting is carried out in the required zones. The research is devoted to the study of the influence of the shape of ground targets on the accuracy of photogrammetric processing. It involved three different types of ground targets located on the land cover along the survey path at a distance not exceeding 1 m from each other. The targets were used as ground control points in the photogrammetric processing of the materials from the UAV. Two three-stripe photographic surveys of the 900 m long track were carried out: with UAV DJI PHANTOM 4 PRO camera FC6310 at a scale of 1:3400 and ground resolution of 1 cm and with the DJI Mavic PRO UAV camera FC220 at a scale of 1:12 700 and ground resolution of 2 cm. In both cases, the direction of flight is north - south, 36 targets were included in the photogrammetric processing. In the first case, 502 images were processed, in the second - 152. The photogrammetric processing for the orthophoto mosaic generation was carried out using the Agisoft Photo Scan Professional software. Four different contrasting sites in the study area were selected for the study: green grass, dry grass, clay, sand. Accuracy was assessed according to two criteria: 1) the degree of visualization of the target on the images; 2) the accuracy of the orthophoto mosaic, generated using various targets.

scholarly journals GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY

2020 ◽  
Vol 92,2020 (92) ◽  
pp. 45-54
Author(s):  
V. Hlotov ◽  
◽  
М. Fys ◽  
О. Pashchetnyk ◽  
◽  
...  
Keyword(s):  
Aerial Photography ◽  
Large Scale ◽  
Digital Images ◽  
Optimal Algorithm ◽  
Reference Points ◽  
Practical Significance ◽  
System Of Equations ◽  
First Case ◽  
Spatial Coordinates ◽  
Aerial Vehicle

Purpose. Develop an optimal algorithm that will increase the accuracy of determining the coordinates of the terrain when using the aerial process applying an unmanned aerial vehicle (UAV). Method. The minimization of function based on the condition of collinearity is performed, which clarifies the elements of external orientation (EZO) of digital images and leads to an increase in the accuracy of the spatial coordinates of the points of objects. The proposed function is the sum of the squares of the differences between the calculated and measured reference points on the corresponding digital images. The sequence of implementation of the proposed algorithm is that taking into account the condition of the minimum of this function makes it possible to obtain a system of six nonlinear equations for EZO. The process of determining EZO is performed in two ways: in the first case, the function G is minimized directly by one of the numerical methods, and in the second - obtained as a solution of a system of equations, which gives refined EZO values based on initial approximations obtained directly from UAV telemetry. Modified conditions of the minimum of the function G in which there are no differentiation operations are used to control the accuracy of EZO determination. As a result, we obtain the final values of the EZO at the time of shooting. Results. An algorithm has been developed and tested on mock-ups on real examples, which allows to increase the accuracy of calculating the coordinates of terrain points when using UAVs for the aerial photography process. Scientific novelty. Formulas are obtained, which increase the accuracy of creating topographic materials by digital stereophotogrammetric method. Practical significance. The implementation of the developed algorithm will significantly increase the accuracy of processing large-scale orthophotos and topographic plans created on the basis of aerial photography from UAVs.

scholarly journals Improving the Accuracy of Aerial Photography Using Ground Control Points

2021 ◽  
Vol 15 (4) ◽  
pp. 42-47
Author(s):  
R. K. Kurbanov ◽  
N. I. Zakharova ◽  
D. M. Gorshkov
Keyword(s):  
Data Processing ◽  
Unmanned Aerial Vehicle ◽  
High Precision ◽  
Aerial Photography ◽  
Ground Control ◽  
Control Points ◽  
Post Processing ◽  
Standard Data ◽  
Ground Control Points ◽  
Aerial Vehicle

The authors showed that it is possible to quickly collect up-to-date information on the agricultural land condition using an unmanned aerial vehicle. It was noted that the use of ground control points increases the accuracy of project measurements, helps to compare the project post-processing results with the real measurements. (Research purpose) To compare the results of standard and high-precision post-processing of aerial survey data using ground control points. (Materials and methods) Aerial photography was carried out on a 1.1- hectare breeding field. The authors used DJI Matrice 200 v2 unmanned aerial vehicle with a GNSS L1/L2 receiver and a modified DJI X4S camera, five control points sized 50 × 50 centimeters and an EMLID Reach RS2 multi-frequency GNSS receiver. The results of scientific research into the use of ground control points during aerial photography were studied. (Results and discussion) It was found out that the error of georeferencing images obtained by an unmanned aerial vehicle without control points is significantly higher during the standard data processing compared to the high-precision one. The project error when using five control points is 3.9 times higher during the standard data processing. (Conclusions) It was shown that using ground control points it is possible to improve the project measurement accuracy, as well as compare the project post-processing results with the measurements on the ground. It was detected that the high-precision monitoring enables the use of fewer ground control points. It was found out that in order to obtain data with the accuracy of 2-4 centimeters in plan and height, at least 3 ground control points need to be used during the high-precision post-processing.

scholarly journals Influence of flight altitude and control points in the georeferencing of images obtained by unmanned aerial vehicle

2021 ◽  
Vol 54 (1) ◽  
pp. 59-71
Author(s):  
Lucas Santos Santana ◽  
Gabriel Araújo E Silva Ferraz ◽  
Diego Bedin Marin ◽  
Brenon Dienevam Souza Barbosa ◽  
Luana Mendes Dos Santos ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Control Points ◽  
Flight Altitude ◽  
Aerial Vehicle ◽  
And Control

scholarly journals The features of application of different systems of orientation angles at the processing of aerospace images

2021 ◽  
Vol 310 ◽  
pp. 04004
Author(s):  
Vladimir Bezmenov
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Aerial Photography ◽  
Numerical Experiments ◽  
Mean Square ◽  
The Earth ◽  
Spatial Coordinates ◽  
Aerial Vehicle ◽  
Camera Orientation ◽  
Mean Square Errors ◽  
Aerospace Images

The angular elements of external orientation characterize the position of a shooting camera relative to the coordinate system in which the spatial coordinates of the points of the object under study are determined from the processing of its images. In many cases of aerial photography, e.g. shooting from an unmanned aerial vehicle, as well as in the case of space survey, the values of the orientation angles could be very significant. This paper presents the results of numerical experiments for five different systems of external orientation angles (Euler angles). The studies were performed using the condition of complanarity, which is the basis of space forward intersection. For a space forward intersection, a model of errors in determining spatial coordinates for five systems of shooting camera orientation angles has been developed. In the numerical experiments, the general case of aerial photography from an unmanned aerial vehicle and of space survey of the Earth were simulated. By comparing the root-mean-square errors (RMSE) in determining the spatial coordinates obtained using the studied systems of external orientation angles, the features of the use of these systems of orientation angles were revealed. The results of the research will allow to determine the spatial coordinates of the points of the studied objects with a greater degree of reliability by photogrammetry methods.

scholarly journals Recent Advances in Unmanned Aerial Vehicles Forest Remote Sensing—A Systematic Review. Part II: Research Applications

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 397
Author(s):  
Riccardo Dainelli ◽  
Piero Toscano ◽  
Salvatore Filippo Di Gennaro ◽  
Alessandro Matese
Keyword(s):  
Remote Sensing ◽  
Unmanned Aerial Vehicle ◽  
Sustainable Management ◽  
Large Scale ◽  
Spectral Signature ◽  
Accurate Information ◽  
Data Interoperability ◽  
Critical Issues ◽  
Management Context ◽  
Aerial Vehicle

Forest sustainable management aims to maintain the income of woody goods for companies, together with preserving non-productive functions as a benefit for the community. Due to the progress in platforms and sensors and the opening of the dedicated market, unmanned aerial vehicle–remote sensing (UAV–RS) is improving its key role in the forestry sector as a tool for sustainable management. The use of UAV (Unmanned Aerial Vehicle) in precision forestry has exponentially increased in recent years, as demonstrated by more than 600 references published from 2018 until mid-2020 that were found in the Web of Science database by searching for “UAV”+“forest”. This result is even more surprising when compared with similar research for “UAV”+“agriculture”, from which emerge about 470 references. This shows how UAV–RS research forestry is gaining increasing popularity. In Part II of this review, analyzing the main findings of the reviewed papers (227), numerous strengths emerge concerning research technical issues. UAV–RS is fully applicated for obtaining accurate information from practical parameters (height, diameter at breast height (DBH), and biomass). Research effectiveness and soundness demonstrate that UAV–RS is now ready to be applied in a real management context. Some critical issues and barriers in transferring research products are also evident, namely,(1) hyperspectral sensors are poorly used, and their novel applications should be based on the capability of acquiring tree spectral signature especially for pest and diseases detection, (2) automatic processes for image analysis are poorly flexible or based on proprietary software at the expense of flexible and open-source tools that can foster researcher activities and support technology transfer among all forestry stakeholders, and (3) a clear lack exist in sensors and platforms interoperability for large-scale applications and for enabling data interoperability.

Modeling and control of a quadrotor tail-sitter unmanned aerial vehicles

2021 ◽  
pp. 095965182110504
Author(s):  
Hongbo Xin ◽  
Yujie Wang ◽  
Xianzhong Gao ◽  
Qingyang Chen ◽  
Bingjie Zhu ◽  
...  
Keyword(s):  
Control System ◽  
Unmanned Aerial Vehicles ◽  
Unmanned Aerial Vehicle ◽  
Euler Angle ◽  
Level Flight ◽  
Aerial Vehicles ◽  
Flight Mode ◽  
Aerial Vehicle ◽  
Hover Flight ◽  
And Control

The tail-sitter unmanned aerial vehicles have the advantages of multi-rotors and fixed-wing aircrafts, such as vertical takeoff and landing, long endurance and high-speed cruise. These make the tail-sitter unmanned aerial vehicle capable for special tasks in complex environments. In this article, we present the modeling and the control system design for a quadrotor tail-sitter unmanned aerial vehicle whose main structure consists of a traditional quadrotor with four wings fixed on the four rotor arms. The key point of the control system is the transition process between hover flight mode and level flight mode. However, the normal Euler angle representation cannot tackle both of the hover and level flight modes because of the singularity when pitch angle tends to [Formula: see text]. The dual-Euler method using two Euler-angle representations in two body-fixed coordinate frames is presented to couple with this problem, which gives continuous attitude representation throughout the whole flight envelope. The control system is divided into hover and level controllers to adapt to the two different flight modes. The nonlinear dynamic inverse method is employed to realize fuselage rotation and attitude stabilization. In guidance control, the vector field method is used in level flight guidance logic, and the quadrotor guidance method is used in hover flight mode. The framework of the whole system is established by MATLAB and Simulink, and the effectiveness of the guidance and control algorithms are verified by simulation. Finally, the flight test of the prototype shows the feasibility of the whole system.

scholarly journals Dynamic Stability and Control of a Manipulating Unmanned Aerial Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yunping Liu ◽  
Xijie Huang ◽  
Yonghong Zhang ◽  
Yukang Zhou
Keyword(s):  
Stability Analysis ◽  
Lyapunov Exponent ◽  
Dynamic Stability ◽  
Unmanned Aerial Vehicle ◽  
Impedance Control ◽  
System Stability ◽  
Constructive Method ◽  
Aerial Vehicle ◽  
And Control ◽  
The Impact

This paper focuses on the dynamic stability analysis of a manipulator mounted on a quadrotor unmanned aerial vehicle, namely, a manipulating unmanned aerial vehicle (MUAV). Manipulator movements and environments interaction will extremely affect the dynamic stability of the MUAV system. So the dynamic stability analysis of the MUAV system is of paramount importance for safety and satisfactory performance. However, the applications of Lyapunov’s stability theory to the MUAV system have been extremely limited, due to the lack of a constructive method available for deriving a Lyapunov function. Thus, Lyapunov exponent method and impedance control are introduced, and the Lyapunov exponent method can establish the quantitative relationships between the manipulator movements and the dynamics stability, while impedance control can reduce the impact of environmental interaction on system stability. Numerical simulation results have demonstrated the effectiveness of the proposed method.

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