Possible solutions for the flight of several unmanned aircraft systems in urban areas

Scientific Journal of Silesian University of Technology. Series Transport Zeszyty Naukowe Politechniki Śląskiej. Seria Transport Volume 103 2019 p-ISSN: 0209-3324 e-ISSN: 2450-1549 DOI: https://doi.org/10.20858/sjsutst.2019.103.9 Journal homepage: http://sjsutst.polsl.pl Article citation information: Martinec, F., Koblen, I., Krajčík, V., Lazar, V. Possible solutions for the flight of several unmanned aircraft systems in urban areas. Scientific Journal of Silesian University of Technology. Series Transport. 2019, 103, 105-116. ISSN: 0209-3324. DOI: https://doi.org/10.20858/sjsutst.2019.103.9. František MARTINEC 1 , Ivan KOBLEN 2 , Vladimír KRAJČÍK 3 , Václav LAZAR 4 POSSIBLE SOLUTIONS FOR THE FLIGHT OF SEVERAL UNMANNED AIRCRAFT SYSTEMS IN URBAN AREAS Summary. The development and use of unmanned airborne systems are currently undergoing a huge transformation. This allows the development of computer technology, new materials for their construction. Reducing airborne funds would enable them to be widely used. This applies to not only military use but also mainly civil use, industrial and commercial use as well. This new use brings new challenges, including security, legislative, technical, social, and so forth. This paper focused on the possibility of having several Unmanned Aircraft Systems movement in urban areas. It contains the description of a philosophical proposal of flight corridors and flight trajectories in urban areas with the example of a small town. Keywords: Unmanned Aircraft System, urban area, pilot-operator, flight corridor, flight trajectory 1 VŠO in Prague, o.p.s. Czech Republic. Email: [email protected] 2 Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Slovak Republic. Email: [email protected] 3 VŠO in Prague, o.p.s. Czech Republic. Email: [email protected] 4 Technical University of Ostrava, Faculty of Mechanical Engineering, Institute of Transport, Czech Republic. Email: vaclav.lazar.s[email protected] 106 F. Martinec, I. Koblen, V. Krajčík, V. Lazar 1. INTRODUCTION The use of several Unmanned Aircraft Systems (UAS) in urban areas has proven to be one possible solution for parcel delivery to customers in the future, however, it is forbidden according to the current European and worldwide legislation. Quick delivery of goods to the customer is the current trend in business and this is what new devices like Unmanned Aircraft Systems seek. Presently used as one way of delivery for individual goods, it is being explored for mass delivery of goods in the future. It is concerned mainly with light package weighing up to 20 kg, delivered to customers through Unmanned Aircraft Systems with maximal take-off weight up to 27 kg. The aim of this paper is to analyse possible conditions and propose possibilities under which several Unmanned Aircraft Systems would fly in urban areas in the future. 2. PRINCIPAL CONDITIONS FOR FLIGHT OF SEVERAL UAS The philosophy of movement of several UAS (n UAS) requests to introduce into the system of such conditions, which assure: a) Flight safety – not only safe mission fulfilment; b) The solving of a psychological problem – the introduction of such operations into the lives of people without any apprehension resulting from potential risk. Until now, no survey of peoples’ reaction on the flight of one or several UAS in the town was conducted. The simple survey focused on the use of auto aircraft in the Czech Republic turned out in the negative (40% of people voted in favour of, while 60% of people counter voted against); c) UAS technical solution; d) Flights in solid legislative conditions. The above-mentioned conditions are linked together. Safety is interconnected with technical and legislative problems. We will deal more with the technical and partially with safety and psychological problems. These conditions are as follows (Figure 1): - exact and reliable UAS control, also without direct visibility, - necessity of autonomous control, - necessity of coordination with other UAS, - solution of safety – collisions, - automatic landing at take-off place, - automatic emergency landing, - requirements on safety design and meeting of all requirements resulting from legislation, etc. Possible solutions for the flight of several unmanned aircraft systems in urban areas 107. Ambient effects Satelite navigation, ATC instructions Wind speed, VFR, IFR Input requirements for FT target, trajectory definition, trajectory Flight trajectory (FT) profile, flight speed, safety criteria Coordination with other UAS control (manual, automatic) Collisions solving Fig. 1. Model philosophy of more - n UAS movement Above conditions must be meet by all UAS with strict compliance. 3. INITIAL AMBIENT CONDITIONS FOR FLIGHT OF SEVERAL UAS An ambient condition is another important determining factor for flight movement of several UAS, especially in urban areas. The most important ambient conditions are: a) day time, b) Weather, c) Environment, d) building obstacles, e) energy obstacles, f) emergency landing possibility. a) Day time is an important parameter because during the day it is easy to make a visual sighting of the controlled UAS, as such normal people can react to its presence, accordingly. However, it is difficult to sight a UAS at night owing to the ensued darkness. b) Weather: 1) Under visibility – in wind speed (WS) up to 20 km/h - IFR 2) During the night and in reduced visibility in the course of automatic control assurance in meeting landing safety in wind speed of up to 20km/h - VFR Therefore, functional dependency for flight trajectory (FT) can be formulated thus: FT = f (IFR, VFR, WS) (1) c) Environment: These are the towns and villages divided according to habitation structure from the security point of view. Different requirements are observed in different sections of these localities, that is, populated area, park, square or field, meadows and forest. Presently, some enthusiasts have been observed flying UAS around the residential houses without observing safety standards. From a safety viewpoint, it might be impossible to avoid collision with humans and UAS in the future. UAS 108 F. Martinec, I. Koblen, V. Krajčík, V. Lazar d) Building and other obstacles: The building landscape is relatively fast changing. Due to this fact, the flight paths actualisation must be frequently reviewed on a periodic basis based on the speed of changes in the relevant location. e) Energy obstacles: In the proposed flight trajectories, we almost collided with energy routes (for example, high voltage distribution that can reach our flight trajectory). Due to this fact, energy routes significantly appear at altitudes and visibility points of view, this was demonstrated several times during flights of manned aircraft and helicopters in low altitude. f) Emergency landing possibility. This problem needs to be solved in case of UAS failure, deficiency of power energy, etc. The places selection for emergency landing must be done in advance and take into account the UAS emergency systems for emergency landing. 4. PHILOSOPHY OF SEVERAL UAS MOVEMENT Philosophy of several UAS movement is possible, based on the Line staff system with the support of:  multi-satellite navigation for accurate and particularly reliable definition of trajectory points with accuracy of maximum 2 m,  updated maps with aircraft view, with panorama and 3D execution (road and water routes),  access to internet and phone (mobile phone network) connection,  equipping with a video system for evaluation of position and movement in real time,  equipping with a transponder,  other important orientation devices. Example: A,B,C, D, … - fundamental orientation control and safety points Cn1 - Cnn…… - target points a, b, c, d,… - movement trajectories – flight paths The larger village is divided to individual main settled parts, where it may threaten the risk for the population and, hence, propose the main flight trajectory with branch lines – orientation and control points meeting the safety criteria and then, side trajectories for meeting the purpose of the mission Figure 2. Possible solutions for the flight of several unmanned aircraft systems in urban areas 109. Side target trajectories Cn1 - Cnn Main trajectory Fig. 2. Principal village divided into individual parts For a smaller town, it is possible to come out from its principal structure and propose closed settled agglomerations and among these introduce and select suitable safe flight trajectories as shown in Figure 3 and Figure 4, respectively. 5. PHILOSOPHY OF FLIGHT CORRIDORS AND FLIGHT TRAJECTORIES It is necessary to define the needed data for a flight in the flight space (flight corridor) – “tunnel” with the exact defined and approved flight trajectory (defined course, flight altitude and speed range), with the defined control points and potential crossing of flight corridors and flight trajectories. Division of corridors can be according to local organisation and operation intensity in several flight trajectories. The flight corridor illustrated in Figure 5; it is divided into four flight trajectories in Figure 5a and six flight trajectories in Figure 5b. Flight in the flight corridor “tunnel” must be well defined and must have defined space for entrance and exit of UAS from the flight corridor. Regarding the current division of flight corridors, it turns out to be a suitable corridor up to altitude maximum 300 m. It is valid without the definition of safety separation. The developed legislative documents accept maximum UAS flight altitude of up to 150 m. Due to this fact, the flight corridor begins from the minimum UAS flight altitude, that is, 10 m and maximum altitude up to 150 m. Highaltitude distance of flight corridor will be 50 m. Width distance would arise from the safety condition defined in the given locality. Practical experience demonstrates that this distance would be in the range 5-20 m. Cn1 - Cnn Settled C part of village 3 c M a i n r o a d i n v i l l a g e o b c i Cn1 - Cnn A a Settled part of village 1 Cn1 - Cnn Settled B part of village 2 b Cn1 - Cnn Settled part of village 4 110 F. Martinec, I. Koblen, V. Krajčík, V. Lazar Fig. 3. Philosophy of town divided into individual parts Fig. 4. Philosophy of selected and exactly defined town flight trajectories in individual parts Take-off place                   Takeoff place                   Possible solutions for the flight of several unmanned aircraft systems in urban areas 111. Exit Enter Exit Enter a) b) Fig. 5. Philosophy of flight corridors and flight trajectories, a) corridor with four flight trajectories, b) corridor with six flight trajectories 6. FLIGHT CORRIDORS ELABORATION PROCEDURE FOR UAS OPERATION Flight corridors (FC) are designated only for UAS operation. In the framework of our considerations, we assume the UAS is used, for example, by the distribution companies, for the realisation of the delivery of parcels from the company warehouse to the target destination. The target destination is subsequently the place selected in advance by the customer (buyer). Selection of target destinations corresponds with the FC network outside the town. Customer selects parcel delivery place during order. The idea of FC in the selection of spaces should be assured the following conditions: 1) Adequate safety. 2) Adequate place service. 3) Possible connection of published sectors. These general conditions are subsequently applied to the concrete decision-making process for FC selection. FC is first selected in a horizontal plane with the help of an internet map. Herein, the selection is controlled by undermentioned requirements for the fulfilment of initial conditions. Subsequently, the vertical plane was proposed. It contents describe the accrued FC only. Operation of FC depends on equipping of unmanned aircraft only. It assumes mostly autonomous flights (over advance planned routes outsider FC) without visual control of pilots-operators, which is in discrepancy with the actual formulation of regulations almost all around the world. FC eventually consists of three more aviation routes (depending on the width of the road, water surface and railway) within them in a UAS operation. FC placed above the earlier selected spaces in that manner pose no safety risk. Exit Enter Exit Enter 112 F. Martinec, I. Koblen, V. Krajčík, V. Lazar 6.1. Horizontal selection of flight corridors Suitable spaces (trajectories) for flight corridors (FC) creation were selected through the use of internet maps. These spaces are: 1) Existing transport lines - roads, railways, cycle paths. 2) Watercourseslakes. 3) Energy routes – electric, oil, gas 4) Free surfaces – meadows, forests, mountain ranges. Due to the selection of these spaces, the safety of the flight trajectories is increased. Possible incidents on roads, watercourses or railways would not have fatal results. In addition, they ensure the possibility of satisfactory UAS separation from persons, because increased movement of persons in these areas is not expected. These usable trajectories were marked on the map. The main and additional routes were selected by the valuation of the company domicile location and selected trajectories. These routes are also marked and differentiated. 6.2. Vertical segmentation of flight corridors The inspiration for the vertical division of flight corridors was gotten from the dividing of air space for transport aircraft operation. A lone corridor is situated 100 m above ground level and it is up to altitude an of 150 m above ground level. This ensures the impossibility of likely collision with ambient traffic because minimal flight altitude above densely built-up areas according to VFR rule is 300 m. Taking into account the different sizes of possible operating UAS, it is suitable to divide this space vertically as well. Dividing ensures sufficient spaces for the operation of any UAS. During denser traffic, however, there would be need for this segment to be further divided horizontally in order to increase route capacity. Flight in “tunnel” with space dividing according to altitude and speed is introduced in Figure 6. Fig. 6. Philosophy of flight corridors and flight trajectories “Tunnel” 150 125 100 Altitude 75 [m] 50 25 Width 10-15m Possible solutions for the flight of several unmanned aircraft systems in urban areas 113. 6.3. Functional dependence on movement proposal Flight trajectory is an important parameter from all points of view on which probably depends also the overall mass deployment of UAS into urban agglomerations. The basic definition of flight trajectory (FT) is designated as follow: - ZLT – engaged flight trajectory, - SNS – satellite navigation system, - Hb – altitude barometric, - HSNS – altitude, - Hra – radio altitude, - v – flying speed against the ground, - OP – orientation points, - OI – operation intensity. FT = f (SNS, Hb, HSNS, Hra ,v, OP, OI) (2) Achievement of this functional dependence will fundamentally determine the use of UAS in urban agglomerations in the future. 7. AN EXAMPLE OF FLIGHT CORRIDORS AND FLIGHT TRAJECTORIES SELECTION An example of flight corridors and flight trajectories selection with labelling of applicable trajectories for flight routes creation is illustrated in Frýdlant nad Ostravicí town in the Moravian-Silesian Region. Fig. 7. Labelling of applicable trajectories for flight routes creation in the framework of Frýdlant nad Ostravicí town