METHODS FOR DETERMINING THE TAKE-OFF SPEED OF LAUNCHERS FOR UNMANNED AERIAL VEHICLES

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1 Jounal of KONES Powetain and Tanspot, Vol. 25, No METHODS FOR DETERMINING THE TAKE-OFF SPEED OF LAUNCHERS FOR UNMANNED AERIAL VEHICLES Gzegoz Jastzębski, Leszek Ułanowicz Ai Foce Institute of Technology Ksiecia Boleslawa Steet 6, Wasaw, Poland tel.: , fax: gzes.ofice@inteia.pl, leszek.ulanowicz@itwl.pl Abstact Unmanned aeial vehicles (UAV) ae cuently a vey apidly developing type of aviation. The poblem of suppot duing the take-off with the use of, i.e. take-off launches aose along with thei development, especially fo UAVs with weights and dimensions peventing manual take-off. One of the majo issues associated with UAV take-off launches is fo its UAV acceleating element to obtain its initial speed. The aticle pesents thee methods of detemining launche take-off speeds fo unmanned aeial vehicles, i.e. the concentated vey oblique pojection method, the highspeed camea methods, and the acceleation ecode method. The take-off launche caiage speed in the oblique pojection method is detemined fom a fomula. This method involves ejections of concentated masses fom the UAV mass ange and measuing the component values esulting fom the used fomula, which contains the ange of the oblique pojection, the elevation of the pojection and its angle. The method using the high-speed camea involves ecoding the couse of ejections of the concentated mass fom the launche. The aveage take-off speed is detemined on the sis of a take-off un length (section of the launche ace, whee the unit acceleates) and defining the stat and end fame of the caiage movement. The thid method fo the detemination of the take-off speed utilizes an acceleation ecode. The method with the ecode involves egisteing a change in the acceleations when the take-off caiage is being acceleated by a system fixed on the caiage o the acceleated object. The aticle pesents the methodology of dynamic tests of object acceleation on a launche, necessay fo the detemination of speed with the mentioned methods. Selected esults fom actual tests with the use of the 01/WS/2015 launche, which is an element of the ZOCP JET2 set, wee pesented. The test esults ae pesented in a tabula fom. The methods fo the detemination of the take-off speed wee compaed on the sis of pefomed tests. Based on the obtained esults, the factos impacting the accuacy of each of the methods wee identified. Keywods: aviation, unmanned aeial vehicle, take-off launche, take-off speed, acceleation ecode 1. Intoduction ISSN: e-issn: DOI: / The unmanned aeial vehicles (UAV) we encounte include vehicles of vaious types with the aicaft goup being the lagest [1]. Many of these aicaft, due to thei weight and dimensions peventing manual take-off, as well as high load of the caying suface and thust, equie take-off suppot, which is povided by, e.g. a take-off launche [2, 6]. A vey high ange of unmanned aicaft take-off weights esults in the use of vaious take-off launches; stating fom elatively simple, ubbe ones and ending with athe complex hydo pneumatic launches. Thee is no univesal type of a launche suitable fo the entie UAV family. Each launche is designed fo specific tasks and a defined UAV type. In the case of each newly constucted take-off launche, egadless of the used populsion, it is necessay to detemine the obtained take-off speeds within a stictly specified weight ange. As a esult, each launche is subject to expeimental tests, in ode to detemine the take-off speed and the speed envelope fo a given launche. An example of a speed envelope fo linea dive launches constucted at AFIT is shown in Fig. 1 [3]. In ode to detemine the ange of the speed and take-off weight fo a launche, a seies of ejections of concentated mass fom the UAV weight ange fo which the launche is dedicated need to be pefomed. Thee ae diffeent methods fo the detemination of the take-off speed sed on the pefomed ejections. Thee methods fo the detemination of the UAV launche take-off speed ae implemented at the Ai Foce Institute of Technology.

2 G. Jastzębski, L. Ułanowicz 110 Linea LinowaOCP OCPJET JET11 Linea ZSMCP Linowa ZSMCP Speed [km/h] PRĘDKOŚĆ [km/h] Weight MASA[kg] [kg] Fig. 1. Speed envelope fo the linea launche ZSMCP (black), OCP JET 1 (geen) [3] The sic method fo the detemination of the take-off launche caiage speed is the concentated vey oblique pojection method [4, 5]. The take-off launche caiage speed is detemined in the oblique pojection method fom a fomula, which includes the ange of the oblique pojection, elevation of the oblique pojection and the angle of the oblique pojection. Component values fo the fomula ae deived fom thei actual measuements. Anothe method fo the detemination of the take-off launche caiage speed is a method utilizing a high-speed camea. This method involves ecoding the tavel of the caiage with the concentated mass along the launche ace duing acceleation. The take-off launche caiage speed is detemined on the sis of inputting the length of the un path to the softwae and detemining the caiage movement stat and end fames. The thid of the take-off launche caiage speed detemination methods utilizes an acceleation ecode. The ecode is pemanently installed on the launche caiage and the data ae ead via a USB pot. The measuement in this method involves ecoding the launche caiage movement time and the acceleations, which the take-off launche caiage undegoes. 2. UAV design equiing take-off suppot Many of the UAVs equie suppot duing take-off [1, 2]. Giving the UAV its take-off speed is possible due to the use of a take-off launche. Take-off launches incease UAV opeational capabilities, due to the possibility of its take-off in any teain conditions with no unway. Below you can find the jet-popelled UAV family, as manoeuving ai tagets, designed and constucted at AFIT and opeated by the Polish Amed Foces, with take-off suppoted by a take-off launche. The jet ai taget JET-2B (Fig. 2) is used as a manoeuving imitato fo taining and ocket fiings by ai defence foces with the use of OSA and KUB sets. Automatically contolled, Basic data JET-2B : populsion system: maximum take-off weight: aispeed: span: length: opeating adius: pactical ceiling: flight time: stat: 2 jet engines with a 147 N thust each, 80 kg, m/s, 2.8 m, 3.5 m, 40 km m, 60 min, take-off launche. 170

3 Methods fo Detemining the Take-Off Speed of Launches fo Unmanned Aeial Vehicles Fig. 2. Jet ai taget JET 2B Fo each of the afoementioned jet ai tagets (JAT), it is necessay to detemine the minimum take-off paametes, which enable safe take-off and opeation of a JAT. The most impotant of the launche take-off paametes is the minimum take-off stat ensuing safe take-off of a JAT. Theefoe, pio to handing ove a take-off launche fo opeation with a specified JAT, it is necessay accuately to detemine the take-off speeds obtained on that launche. The tests of take-off launches, in this scope, ae sed on ejecting a concentated mass coesponding to a given UAV in tems of weight, and detemining the maximum ejection speed next. 3. Detemination of the maximum take-off launche caiage speed with the use of an oblique pojection method A diagam of a test ig in the oblique pojection method is pesented in Fig. 3 and 4. The oblique pojection method involves ejecting a defined concentated weight and measuing: the mass, the launche ace set angle (pojection angle) α (Fig. 3), the set elevation of the point at which the concentated mass is eleased fom the take-off caiage (vetical distance) y (Fig. 3), the vetical elevation of the efeence line of the levelle in a plane pependicula to the launche, passing the point at which the concentated mass is eleased fom the caiage (y1, Fig. 4), the vetical elevation of the efeence line of the levelle whee the concentated mass touches the gound (y2 in Fig. 4), the hoizontal distance between the levelle s position and the point at which the concentated mass is eleased fom the take-off caiage x1 (Fig. 3), the hoizontal distance between the levelle and the concentated mass s point of impact x2 (Fig. 3). The take-off launche caiage maximum speed is detemined fom a fomula (1), substituting the afoementioned components, deived fom actual measuements. Hoizontal distance of the oblique pojection x (Fig 3) is a sum of the hoizontal distance between the levelle and the point, at which the concentated mass sepaates fom the take-off launche caiage x1 (Fig. 3) and the hoizontal distance between the levelle and the concentated mass gound impact point x2 (Fig. 3) [4]. The take-off launche caiage maximum speed is detemined fom the elation [1, 2]: V= g x2. 2 cos 2 α ( x tgα + y p ) Fig. 3. Concentated mass flight path [4] 171 (1)

4 G. Jastzębski, L. Ułanowicz n α y1 y2 Fig. 4. Levelling of the concentated mass contact point with the gound; n levelle efeence line 4. Detemination of the maximum take-off launche caiage speed with the use of a high-speed camea This method involves using a high-speed camea to ecod the movement path of a caiage with concentated mass along the launche ace duing its acceleation. The launche caiage time and path ae measued in this method. Distance makes ae applied on the take-off ace of the launche, which enable accuate identification of the caiage s path. The film ecoded by the camea, showing the movement of the caiage along the ace, is then pocessed by softwae. The take-off launche caiage speed is detemined on the sis of inputting the length of the un path (eading taken fom the applied makes) to the softwae and detemining the caiage movement stat and end fames. The maximum speed of a take-off launche caiage is detemined on the sis of paametes ead fom the camea ecod (path and time), accoding to the elation: whee: dx path incement, dt time incement. V 0 dx =, (2) dt 5. Detemination of the take-off launche caiage maximum speed with the use of an acceleation ecode The measuement in this method involves ecoding the launche caiage movement time and the acceleations it undegoes. The ecode, with its block diagam pesented in Fig. 5, is fixed pemanently to the launche caiage. The ecode data ae ead via a USB pot. Recoding stats afte acceleation exceed 0.5 g. Recoding stops afte the acceleation sense changes to opposite. Afte the concentated mass is ejected, use a USB pot to ead the ecoded data and on thei sis, detemine the maximum speed of a take-off launche caiage. Acceleation ecode paametes: acceleomete ange: ±16 g, ecoding fequency: 1 khz, stat and end of ecoding sed on ead acceleations, system poweed with a built-in NiMH (x4) ttey, FLASH memoy ecoding, data ead via a USB pot. An exemplay ecod fom the acceleation ecode is shown in Fig Results of the pefomed tests Dynamic tests with the use of the afoementioned methods wee pefomed on AFIT pemises. A WS launche no. 01/WS/2015 constucted at the Ai Foce Institute of Technology (AFIT) in 2015, was used fo the ejections. Fig. 7 shows a WS launche no. 01/WS/2015 on a test ig, togethe with measuing instuments. 172

5 Methods fo Detemining the Take-Off Speed of Launches fo Unmanned Aeial Vehicles Batte + powe supply system Acceleomete ADXL 345 Mico compute STM 32 F 415 USB 128 MB Flash Memoy Fig. 5. Block diagam of the acceleation ecode Fig. 6. An exemplay ecod of acceleations fom the ecode Fig. 7. Launche WS no. 01/WS/2015 on a test ig in the daft vesions: 1 launche, 2 levelle, 3 UAV equivalent concentated mass The tests involved the detemination of the take-off caiage speed at the time of concentated mass elease fo diffeent loading pessues of the main tank. The following was measued diectly: weight of concentated mass, actual lift angle of the launche ace, concentated mass elease elevation, distance (ange). In the couse of the concentated mass ejections using the take-off launche, a high-speed camea ecoded the movement of the take-off caiage. A PHANTOM V4.0 camea with the below paametes was used fo the measuements: fequency 1 khz, esolution pixels. 173

6 G. Jastzębski, L. Ułanowicz Simultaneously, the take-off caiage had a fixed measuing system ecoding the acceleation. The tests wee pefomed in the following ode: weighing of the concentated mass, measuing of the elevation at the point, at which the concentated mass sepaates fom the take-off launche, measuement of the actual shot angle of the take-off launche, 3 test shots pio to the actual test of the take-off launche, the execution of thee ejections of concentated mass of 85.3 kg using a take-off launche with a supply pessue of 9, ecoding the movement of the launche caiage with concentated mass along the take-off ace with a PHANTOM V4.0 camea, the measuement, in each case, of the vetical distance between the take-off point and the point of mass hitting the gound, which detemines the actual ange of the oblique pojection, the execution of thee ejections of concentated mass of 85.3 kg using a take-off launche with a supply pessue of 10, ecoding the movement of the launche caiage with concentated mass along the take-off ace with a PHANTOM V4.0 camea, the measuement, in each case, of the vetical distance between the take-off point and the point of mass hitting the gound, calculating the speed of a take-off launche caiage. Results of the measuement with the oblique pojection method fo main tank loading pessues of 0.9 and 1.0 MPa and calculated maximum and aveage caiage speeds ae shown in Tab. 1. Results of the measuing the maximum speed with the PHANTOM V4.0 high-speed camea method fo main tank loading pessues of 0.9 and 1.0 MPa, the calculated maximum and aveage caiage speeds ae shown in Tab. 2. Results of the measuement with the acceleation ecode method fo main tank loading pessues of 0.9 and 1.0 MPa and detemined maximum and aveage caiage speeds ae shown in Tab. 3. Tab. 1. Results of the measuement with the oblique pojection method No. Shot angle, α, u(α) Weight, m, u(m) Hoizontal distance, x, u(x) Vetical distance, y, u(y) Maximum caiage speed, V 0 Aveage speed, V [ ] [kg] [m] [m] Tab. 2. Results of the measuement with the high-speed camea method No. Shot angle Weight Maximum caiage speed Aveage speed [ ] [kg]

7 Methods fo Detemining the Take-Off Speed of Launches fo Unmanned Aeial Vehicles Tab. 3. Results of the measuement with the acceleation ecode method No Shot angle [ ] Weight [kg] Maximum caiage speed Aveage speed Compaison of measuement methods The esults fo the maximum speed fo thee methods, with the main tank chage pessue of 0.9 and 1.0 MPa ae listed in Tab. 4, while the summay of aveage speeds fom these measuements ae pesented in Fig. 8. Maximum speeds obtained with thee methods (Tab. 4) fo equal weights and launche take-off paametes (take-off pessue) coincide. Tab. 4. The esults fo the maximum speed fo thee methods No Take-off launche caiage speed detemined fom fom fom the ange the high-speed the acceleation method camea ecoding ecoded Take-off launche caiage aveage speed detemined fom fom fom the the ange the high-speed acceleation method camea ecoding ecode Speed Pędkość Range 9 Camea 9 Recode 9 Range 10 Camea 10 R ej es tt o 10 Ka m e a 10 Za si ęg 10 9 to ta R ej es e a Ka m 29 Za si ęg Recode 10 Fig. 8. A summay of aveage speeds fo thee methods, fo the main tank pessue values of 9 and 10 The factos impacting the measuement accuacy in the ange method ae: accuacy of measuing equipment, positioning of the measuing station, human facto. 175

8 G. Jastzębski, L. Ułanowicz The facto impacting the measuement accuacy in the method utilizing the PHANTOM V4.0 high-speed camea is the accuacy of detemining the measuement stat and end fames. The factos impacting the measuement accuacy in the method utilizing the acceleation ecode ae sampling fequency and the data pocessing filte. 8. Conclusions The UAV take-off launche aveage speed detemination methods pesented in this aticle, in combination with the pesented examples of the study esults show diffeences between the methods, as well as a cetain dispesion of obtained esults. The launche take-off speed at the moment of the loading weight elease fo the same take-off paametes of the launche, obtained with the ange method, is compaable to the high-speed camea ecoding method and just slightly diffes fom the esults obtained fom the acceleation ecode. The pefomed tests show that despite slightly diffeent esults, the method using the acceleation ecode seems to be the most accuate one due to the actual acceleation measuement of the acceleated object. The two othe methods involve measuing indiect paametes. Summing up, the application of any of these methods, i.e., oblique pojection of concentated mass, with the use of a high-speed camea, an acceleation ecode, allows detemining the maximum take-off speed fo a defined UAV take-off weight. Detemining the take-off speed fo a given weight allows to match optimum launche take-off paametes and to define the speed envelope fo the launche, which is so impotant duing its opeation. In light of obtaining compaable esults, the choice between these methods is govened mainly by economic consideations. Refeences [1] Guszczyński, J., Unmanned aicaft in westen Euopean counties and the USA, New Militay Technique 10, pp /43 8, [2] Jastzębski, G., Impact of opening time of the take-off pneumatic launche main valve on take-off pessue losses, Jounal of KONES Powetain and Tanspot, Vol. 23, No. 4, pp , [3] Jastzębski, G., Jóźko, M., Szczepaniak, P., Ułanowicz, L., Pzegląd i kyteia dobou wyzutni BSP (UAV), ML-XVII Mechanics in Aviation, pp , Wasaw [4] Jastzębski, G., Detemination of the functional popeties of a WPA-1 pneumatic launche with a take-off pneumatic system, ML-XV Mechanics in Aviation, Wasaw [5] Jastzębski, G., Reseach pocedue PB-01/LBBSP. Detemination of an unmanned aeial vehicle take-off launche caiage speed, Ai Foce Institute of Technology, Wasaw [6] Pekowski, W., Pneumatic launche fo unmanned aeial vehicles, N27 Riga, Tanspot and Engineeing. Tanspot. Aviation Tanspot, RTU, pp , Riga Manuscipt eceived 22 Septembe 2017; appoved fo pinting 15 Januay