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EN
The paper discusses the application areas of UAVs and their regulations. Particular attention is paid to the inspection and maintenance of railway infrastructure. The use of UAVs in many railway networks around the world is reviewed. The implementation of autonomous solutions is highlighted. The safety of UAVs on railways is analysed and directions for their implementation at PKP PLK S.A. are indicated.
EN
Urbanization of stream ecosystems with the purpose of managing the flash-flood events is nowadays considered responsible for habitat loss and alteration of the natural flow regime with severe implications for the ecosystem functioning. Unsurprisingly, the river scientists have started seeking alternative options inspired from nature for mitigating the flood-risk and maintaining the stream at its natural state. With this article the authors demonstrate the effects of a nature-based solution (NBS) for managing an urban stream based on the use of bioengineering materials (e.g. plants) and the implementation of the actions that restore the stream to its natural form (e.g channel widening). The HEC-RAS software was employed to simulate the flow and hydraulic components of an approximately 800m long reach of an urban stream under three different scenarios of flood risk management with a design flow set to 400 m3/s. The first scenario was based on the current situation of the stream, the second scenario concerned the stream restoration by following the nature-based solutions, while the third scenario was based on the classical “grey” engineering approach of concrete channelization. Unmanned Aerial Vehicle (UAV) photogrammetry methods and the Pix4Dmapper software were used in order to develop a detailed 3D model of the studied reach that accurately captured the current geomorphology. The obtained results showed that with concrete channelization, the average and maximum flow of the stream increases significantly in relation to the current situation, from 2.48 and 4.88m/s to 9.82 and 11.22 m/s, respectively, while the average Froude number raises from 0.36 to 1.69 implying super-critical flows. In contrast, the NBS scenario retained lower flow velocities and average Froude number similar to those under the current conditions. In addition, a cost estimation analysis for both stream management techniques revealed that the NBS is much cheaper than the traditional channelization (1.1 mil € vs 5.6 mil €). In conclusion, our findings suggest that the future restoration of urban streams should consider the nature-based solutions since i) they can be effective with regard to the reduction of flood-risk, ii) are cheaper than the traditional “grey” techniques and, most importantly, iii) maintain the natural state of the ecosystem which improves not only the ecosystem functioning but also the aesthetic value within the urban context.
EN
The problem of delivering goods in a distribution network is considered in which a fleet of Unmanned Aerial Vehicles (UAV) carries out transport operations. The changing weather conditions in which the transport operations take place and the UAVs energy capacity levels influenced by the weather conditions are taken into account as factors that affect the determination of a collision-free route. The goods must be delivered to the customers in a given time window. Establishing the routes are the focus of this study. Solutions maximizing the level of customer satisfaction are focused and the computational experiments presented in the study show the impact of weather conditions on route determination.
EN
The main focus of this paper is the capabilities of Unmanned Aerial Vehicles as a military logistic support in conflicts areas. The conducted research addresses the problems of traditional military delivery methods. Next, the problem of using UAVs only for civilian purposes is considered. The paper begins with short elucidation of logistic support and further provides the classification of logistic materials and discusses five categories of military equipment from the logistics point of view. Next, the paper discusses the characteristics of the parameters and properties of the chosen existing UAVs that are used for the delivery of materials. Consequently, a comparison of the UAVs is carried out, and new technologies for logistic transport are presented. This paper is concluded with the claim that it is necessary to modernize the process of logistic support in the military.
5
Content available remote Towards implementation of a formation flying for efficient UAV operations
EN
A flight of a UAV formation is an efficient way to implement surveillance and reconnaissance operations. The usage of a few UAVs as a formation instead of a single vehicle allows creating a distributed network of sensors, which decreases the duration of flight missions and enlarges a total field of view. From a practical point of view, implementations of formation flights require taking into account several separate aspects of flight of UAV such as a quick take-off of several aircraft, aggregating all UAVs in the same space to create swarm and collective flight of the formation towards the area of a surveillance mission. The paper presents the results of researches and experiments carried out towards practical solutions to those aspects. A magnetic launcher is an excellent appliance to put UAV in the air, and its operation could be repeated quickly. Hence, it is ideal to be used in a formation flight. The leader-follower approach based on two-stage switching control is an effective method to aggregate UAVs in the same space while they are flying over large areas. Whereas, the decentralized control of aerial flocking can be used to achieve a coherent flight of UAV formation, which is able to self-organize. Results from simulations and experiments show the effectiveness of each presented aspect and prove their usability in the implementation of formation flights.
EN
We describe an experimental study, based on several million video scenes, of seven keypoint detection algorithms: BRISK, FAST, GFTT, HARRIS, MSER, ORB and STAR. It was observed that the probability distributions of selected keypoints are drastically different between indoor and outdoor environments for all algorithms analyzed. This paper presents a simple method for distinguishing between indoor and outdoor environments in a video sequence. The proposed method is based on the central location of keypoints in video frames. This has lead to a universally effective indoor/outdoor environment recognition method, and may prove to be a crucial step in the design of robotic control algorithms based on computer vision, especially for autonomous mobile robots.
7
Content available remote Battery discharge forecast applied in Unmanned Aerial Vehicle
EN
This paper proposes a comparative study methodology for the prediction of Li-Po (Lithium Ion Polymer) batteries discharge in UAVs (Unmanned Aerial Vehicles) using four approaches based on Artificial Neural Networks (ANNs) using Multilayer Perceptron (MLP) and Extreme Learning Machine (ELM) techniques, Polynomial Regression, and Kalman Filter (KF). The information estimates are important to assist in making decisions on which missions can be addressed to UAVs when supplied by such batteries. The data series for the experiments are obtained from tests carried out on a test bench.
PL
W artykule przedstawiono stadium porównawcze metodologii przewidywania procesu rozładowania baterii litowych wykorzystujących sieci neuronowe. Baterie te były stosowane w pojazdach typu dron.
EN
The problem of fault detection and isolation in a class of nonlinear systems having a Hamiltonian representation is considered. In particular, a model of a planar vertical take-off and landing aircraft with sensor and actuator faults is studied. A Hamiltonian representation is derived from an Euler–Lagrange representation of the system model considered. In this form, nonlinear decoupling is applied in order to obtain subsystems with (as much as possible) specific fault sensitivity properties. The resulting decoupled subsystem is represented as a Hamiltonian system and observer-based residual generators are designed. The results are presented through simulations to show the effectiveness of the proposed approach.
EN
The article presents assumptions that were the basis to develop maritime versions of Unmanned Aerial Vehicles (UAVs) and the experiences of using UAVs in naval operations so far. In the further part of the article there have been presented the tasks to be performed by unmanned sea vessels, co-operating with surface vessels and submarines and also the future of the UAVs to operate over seas has been defined. Conclusions concerning the influence of UAVs in naval operations are described in the final part of the article.
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