Patent Publication Number: US-2021171216-A1

Title: METHODS AND APPARATUS TO RECOVER UNMANNED AERIAL VEHICLES (UAVs) WITH KITES

Description:
FIELD OF THE DISCLOSURE 
     This disclosure relates generally to aircraft and, more particularly, to methods and apparatus to recover unmanned aerial vehicles (UAVs) with kites. 
     BACKGROUND 
     In recent years, unmanned aerial vehicles (UAVs) or drones have been used to fly significant distances to transport payloads (e.g., packages, supplies, equipment, etc.) or gather information. Some UAVs land on runways while others are captured in flight by UAV recovery systems. Capturing UAVs without the use of a runway enables greater flexibility in recovery locations. In particular, a UAV can be recovered in an unprepared area or on relatively smaller ships or other vessels or vehicles. 
     SUMMARY 
     An example apparatus to recover an unmanned aerial vehicle (UAV) during flight includes a tether line, a tensioner operatively coupled to the tether line, and a kite operatively coupled to the tether line to support the tether line for recovery of the UAV. 
     An example method of recovering a UAV during flight includes suspending a tether line via a kite, contacting the UAV with the tether line to capture the UAV, and in response to contacting the UAV with the tether line, retrieving the UAV with a tensioner operatively coupled to the tether line. 
     An example non-transitory machine readable medium comprises instructions, which when executed, cause a processor to at least determine a position of a UAV to be captured by a tether line, determine a position of a kite suspending the tether line, and adjust movement of at least one of the UAV or the kite to capture the UAV by the tether line. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts an unmanned aerial vehicle (UAV) recovery system in accordance with teachings of this disclosure. 
         FIGS. 2A-2C  depict an example recovery sequence of examples disclosed herein. 
         FIG. 3  is a detailed view of an example kite that can be implemented in examples disclosed herein. 
         FIG. 4  depicts an example tether line spool implementation that can be implemented in examples disclosed herein. 
         FIG. 5  is a schematic overview of a UAV recovery analysis system that can be implemented in examples disclosed herein. 
         FIG. 6  is a flowchart representative of an example method to implement the example UAV recovery system of  FIG. 1  and/or the UAV recovery analysis system of  FIG. 5 . 
         FIG. 7  is a flowchart representative of an example subroutine of the example method of  FIG. 6 . 
         FIG. 8  is a block diagram of an example processing platform structured to execute the instructions of  FIGS. 6 and 7  to implement examples disclosed herein. 
     
    
    
     The figures are not to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part) is in any way on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Stating that any part is in “contact” with another part means that there is no intermediate part between the two parts. 
     Descriptors “first,” “second,” “third,” etc. are used herein when identifying multiple elements or components which may be referred to separately. Unless otherwise specified or understood based on their context of use, such descriptors are not intended to impute any meaning of priority, physical order or arrangement in a list, or ordering in time but are merely used as labels for referring to multiple elements or components separately for ease of understanding the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as “second” or “third.” In such instances, it should be understood that such descriptors are used merely for ease of referencing multiple elements or components. 
     DETAILED DESCRIPTION 
     Methods and apparatus to recover unmanned aerial vehicles (UAVs) with kites are disclosed. Some UAVs are recovered by recovery systems, which employ a recovery tether line that is suspended vertically. In particular, a UAV contacts and/or impacts the tether line and, as a result, the UAV is decelerated and/or stopped from flight, thereby enabling recovery of the UAV without need for a runway. In some known implementations, a parachute or support beam or movable boom is used to suspend the tether line for recovery of the UAV. 
     Examples disclosed herein enable an effective and relatively low cost recovery of an aircraft (e.g., a UAV) via a stationary platform or a moving vehicle and/or vessel, such as a ship or vessel, for example. In particular, a kite (e.g., a parafoil kite) extends from a boat or a stationary platform and generates lift to support and/or suspend a tether line carried by a vessel, for example, to enable controlled recovery of the aircraft. The tether line, in turn, is operatively coupled to a tension device (e.g., a tensioner, a winch, a motorized winch, etc.). The tension device is implemented to retrieve the tether line along with the kite and the aircraft. 
     In some examples, the kite is steerable to maneuver and/or direct movement of the kite for recovery of the aircraft. In some such examples, the kite is steerable via at least one steering line. In some examples, the tension device is utilized to maintain the tether line within a pre-defined tension range and/or value prior to the aircraft contacting the tether line. Further, movement of the kite and the aircraft can be coordinated to enable capture of the aircraft via the aforementioned tether line. In some examples, the kite is suspended from a vessel, such as a ship. In other examples, however, the kite is suspended from the ground. 
       FIG. 1  depicts a UAV recovery system  100  in accordance with teachings of this disclosure. The UAV recovery system  100  of the illustrated example includes a tether line control mount  102 , which includes a boom (e.g., a lower tether boom, a rotatable boom, a swivel boom, a pivoting boom, etc.)  104  and boom supports  106 . In the illustrated example, a tether line  108  extends from the tether line control mount  102  while a tensioner or tension device  110 , which is implemented as a winch in this example, is operatively coupled to the tether line  108 . Further, the tether line  108  is operatively coupled to a kite (e.g., a parafoil kite)  116  having support lines (e.g., kite lines, foil lines, etc.)  117  and a foil (e.g., a lift foil, a lift generation foil, a kite body)  118 . The UAV recovery system  100  of the illustrated example is implemented to capture an aircraft  120 , which is implemented as a UAV in this example. In other examples, the aircraft  120  may be implemented as another type of aircraft (e.g., a manned aircraft), spacecraft, etc. 
     The example UAV  120  includes a fuselage  121 , wings  122  each of which includes a distal capture portion  123 , and a propulsion system  124  with propellers  125 . In this example, the distal capture portion  123  extends from at least one of the corresponding wings  122  generally along a direction of movement of the UAV  120 . However, any appropriate type of capture or recovery mechanism can be, instead, implemented on any other portion and/or component (e.g., the fuselage  121 ) of the UAV  120 . Further any other appropriate type of propulsion of the UAV  120  can be implemented instead. 
     To recover and/or capture the UAV  120  as the UAV  120  moves along a flight path  126 , one of the distal capture portions  123  is brought into contact with the tether line  108  extending between the kite  116  and the tether line control mount  102 . As a result, the UAV  120  is brought to a rest and remains attached to the tether line  108 . In this example, the tether line  108  is suspended by the kite  116  as the kite  116  generates lift to support the tether line  108  in the air (e.g., substantially vertically in the air, within 5 degrees from vertical). 
     In some examples, the tensioner  110  maintains a tension of the tether line  108  extending between the tether line control mount  102  and the kite  116  within a threshold range and/or at a nominal tension value. In some examples, the kite  116  is steered to direct the tension line  108  within a requisite range of the aforementioned flight path  126 . Additionally or alternatively, the kite  116  is directed toward to the flight path  126  based on a desired impact force of the tether line  108  with the distal capture portion  123 . 
     In some examples, the UAV recovery system  100  includes a movement controller  130  which, in turn, includes at least one sensor  132 , a movement analyzer  134  and a transceiver  136 . In some examples, the UAV recovery system  100  includes a steering actuator  140 . In some such examples, movement of the kite  116  is coordinated with movement of the UAV  120  by the movement controller  130  and the steering actuator  140 . In some examples, the movement controller  130  directs movement of the steering actuator  140  and, thus, the kite  116  along with the UAV  120 . In such examples, the sensor(s)  132  can detect a position, range and/or movement of the kite  116 , the tether line  108  and/or the UAV  120  to enable the movement analyzer  134  to analyze the motion thereof. Based on the motion, the example movement analyzer  134  can transmit a signal to cause movement of the kite  116  and/or the UAV  120  to increase a probability that the distal capture portion  123  contacts the tether line  108 , thereby facilitating recovery of the UAV  120 . 
       FIGS. 2A-2C  depict an example recovery sequence of examples disclosed herein.  FIG. 2A  depicts the UAV  120  approaching the tether line  108 , which extends between a vessel  202  and the kite  116 . In this example, the UAV  120  is being navigated to cause the distal capture portion  123  (shown in  FIG. 1 ) of the UAV  120  to contact the tether line  108  and, thus, decelerate the UAV  120 . 
     Turning to  FIG. 2B , the UAV  120  is shown in contact with the tether line  108 . In this example, the distal portion  123  of  FIG. 1  is caught on the tether line  108 , thereby causing the tether line  108  along with the kite  116  to be displaced and/or moved as the UAV  120  is decelerated, thereby reducing an amount of force translated to the UAV  120 . Accordingly, in this example, movement of the kite  116  causes a deceleration of the UAV  120 . 
       FIG. 2C  depicts the UAV  120  captured on the tether line  108  and being winched toward the vessel  202 . In this particular example, the tension device  110  of  FIG. 1  causes a motion (e.g., a reeling motion) of the tether line  108  and the UAV  120  toward the vessel  202  while the kite  116  maintains a lift force (e.g., an upward lift force in the view of  FIG. 2C ) to support the tether line  108 . As a result, the UAV  120  is brought onto the vessel  202 . 
       FIG. 3  is a detailed view of the example kite  116  that can be implemented in examples disclosed herein. In the illustrated example, the kite  116  includes the aforementioned support lines  117 , as well as the foil  118 . Further, steering lines  302  are shown extending from a main cable portion (e.g., a cable bundle, a cable assembly, etc.)  312  of the tether line  108 . In particular, the steering lines  302  are housed and protected within the main cable portion  312 . In this example, the steering lines  302  are operatively coupled to the foil  118 . However, in some other examples, a first one of the steering lines  302  is coupled to a first set of the support lines  117  while a second one of steering lines  302  is coupled to a second set of the support lines  117 . In other words, the steering lines  302  can be coupled to different ones of the support lines  117  to enable controlled movement and/or steering of the kite  116 . In some examples, the support lines  117  are integral with the steering lines  302 . 
     To steer the kite  116  relative to the vessel  202  (shown in  FIGS. 2A-2C ) for recovery and/or capture of the UAV  120 , at least one of the steering lines  302  is displaced linearly, as generally indicated by arrows  320 , to re-orient the foil  118  and vary a direction of lift of the kite  116 . In particular, the steering lines  302  have movable portions (e.g., calipers, movable wires, etc.) that are enclosed within at least one cable that extends through the aforementioned main cable portion  312  of the tether line  108 . In other words, the steering lines  302  can be translated (e.g., linearly translated) relative to the main cable portion  312 . 
     While two of the steering lines  302  are shown in this example, any appropriate number of the steering lines  302  can be implemented instead (e.g., one, three, four, five, six, ten, twenty, fifty, etc.). Further, any other appropriate type of steering mechanism for the kite  116  can be implemented instead. 
       FIG. 4  depicts an example tether line spool implementation  400  that can be implemented in examples disclosed herein. In the illustrated example of  FIG. 4 , the tether line  108  is depicted coiled onto a spool  401  with a portion of the tether line  108  extending from the spool  401  toward the steering actuator  140  while another portion of the tether line  108  extends toward the kite  116  (not shown). 
     In operation, the spool  401  is caused to rotate by the tensioner  110 , which is implemented as a motorized winch in this example, about an axis (e.g., a rotational pivot axis)  402 , as generally indicated by a double arrow  404 . In this example, the steering actuator  140  causes movement of at least one of the steering lines  302  (e.g., a movement of a caliper of at least one of the steering lines  302 ) which, in turn, translates the steering lines  302  along the tether line  108  to steer the kite  116 . In other words, the kite  116  can be steered from the vessel  202 . 
       FIG. 5  is a schematic overview of a UAV recovery analysis system  500  that can be implemented in examples disclosed herein. The UAV recovery analysis system  500  of the illustrated example includes the movement analyzer  134 , which is operatively and/or communicatively coupled to the sensor(s)  132 , the transceiver  136 , a movement controller  502  and a kite steerer  503  which, in turn, is communicatively coupled to the steering actuator  140 . The example movement analyzer  134  includes a flight path analyzer  504 , a coordinator  506 , a kite analyzer  508  and a GPS/differential GPS analyzer  510 . Further, in this example, the movement analyzer  134  controls the transceiver  136 , which is communicatively coupled to a network (e.g., a communication network, a navigation network, a UAV flight system network, etc.)  520 . 
     In the illustrated example, the flight path analyzer  504  determines, estimates, interpolates and/or calculates a flight path of the UAV  120 . In particular, the flight path analyzer  504  can determine an estimated flight path, trajectory and/or potential flight travel zone (e.g., a parametric flight path cone based on known flight data of the UAV  120 , a potential trajectory zone or area, etc.). In some examples, the flight path analyzer  504  utilizes data from the network  520 . Additionally or alternatively, the example flight path analyzer utilizes data (e.g., positional data, image data, etc.) from the sensor(s)  132  and global positioning system (GPS) or differential GPS data from the GPS/differential GPS analyzer  510 . 
     The example coordinator  506  calculates a movement of the kite  116  and/or the UAV  120  based on the aforementioned flight path of the UAV  120  to facilitate recovery of the UAV  120  via the tether line  108 . In some examples, the coordinator  506  directs movement of both the UAV  120  and the kite  116  to increase a probability that an intended portion (e.g., the distal capture portion  123 ) of the UAV  120  contacts the tether line  108 . Additionally or alternatively, the movement coordinator  506  determines a desired contact velocity of the UAV  120  to contact the tether line  108 . The desired contact velocity may be determined based on desired contact/impact force, wind speed, wind resistance, movement of the tether line  108  and/or movement of the vessel  202  (e.g., movement of the vessel  202  caused by waves and/or current). 
     The kite analyzer  508  of the illustrated example analyzes movement of the kite  116  to determine and/or increase a probability of recovery of the UAV  120  by the tether line  108 . In this example, the kite analyzer  508  and/or the coordinator  506  directs the kite steerer  503  and, thus, the steering actuator  140  to control movement of the kite  116  based on the analyzed movement as the kite  116  generates lift to support the tether line  108 . 
     In some examples, the GPS/differential GPS data analyzer  510  determines, predicts, interpolates and/or analyzes GPS data associated with the UAV  120 . Additionally or alternatively, the GPS/differential GPS data analyzer  510  determines and/or analyzes GPS data associated with the kite  116 . In some such examples, the kite  116  can include a GPS sensor and/or transponder mounted thereto. 
     The example movement controller  502  directs movement of the control mount  102  (e.g., pivoting, translation and/or extension of the control mount  102 ), and/or the tensioner  110  based on instructions from the movement analyzer  134 . In this example, the movement controller  502  controls an amount of tension in the tether line  108  for recovery of the UAV  120 . In particular, the movement controller  502  controls the tensioner  110  so that the tether line  108  can be held within a desired threshold tension range and/or nominal tension value. 
     In the illustrated example, the kite steerer  503  controls the steering actuator  140  to direct movement of the steering lines  302  and, thus, the kite  116  based on instructions from the movement analyzer  134 . 
     While an example manner of implementing the UAV recovery analysis system  500  of  FIG. 5  is illustrated in  FIG. 5 , one or more of the elements, processes and/or devices illustrated in  FIG. 5  may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the example movement controller  502 , the example kite steerer  503 , the example flight path analyzer  504 , the example coordinator  506 , the example kite analyzer  508 , the example GPS/differential GPS analyzer  510  and/or, more generally, the example UAV recovery analysis system  500  of  FIG. 5  may be implemented by hardware, software, firmware and/or any combination of hardware, software and/or firmware. Thus, for example, any of the example movement controller  502 , the example kite steerer  503 , the example flight path analyzer  504 , the example coordinator  506 , the example kite analyzer  508 , the example GPS/differential GPS analyzer  510  and/or, more generally, the example UAV recovery analysis system  500  could be implemented by one or more analog or digital circuit(s), logic circuits, programmable processor(s), programmable controller(s), graphics processing unit(s) (GPU(s)), digital signal processor(s) (DSP(s)), application specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)) and/or field programmable logic device(s) (FPLD(s)). When reading any of the apparatus or system claims of this patent to cover a purely software and/or firmware implementation, at least one of the example, movement controller  502 , the example kite steerer  503 , the example flight path analyzer  504 , the example coordinator  506 , the example kite analyzer  508 , and/or the example GPS/differential GPS analyzer  510  is/are hereby expressly defined to include a non-transitory computer readable storage device or storage disk such as a memory, a digital versatile disk (DVD), a compact disk (CD), a Blu-ray disk, etc. including the software and/or firmware. Further still, the example UAV recovery analysis system  500  of  FIG. 5  may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated in  FIG. 5 , and/or may include more than one of any or all of the illustrated elements, processes and devices. As used herein, the phrase “in communication,” including variations thereof, encompasses direct communication and/or indirect communication through one or more intermediary components, and does not require direct physical (e.g., wired) communication and/or constant communication, but rather additionally includes selective communication at periodic intervals, scheduled intervals, aperiodic intervals, and/or one-time events. 
     Flowcharts representative of example hardware logic, machine readable instructions, hardware implemented state machines, and/or any combination thereof for implementing the UAV recovery analysis system  500  of  FIG. 5  are shown in  FIGS. 6 and 7 . The machine readable instructions may be one or more executable programs or portion(s) of an executable program for execution by a computer processor such as the processor  712  shown in the example processor platform  700  discussed below in connection with  FIG. 7 . The program may be embodied in software stored on a non-transitory computer readable storage medium such as a CD-ROM, a floppy disk, a hard drive, a DVD, a Blu-ray disk, or a memory associated with the processor  712 , but the entire program and/or parts thereof could alternatively be executed by a device other than the processor  712  and/or embodied in firmware or dedicated hardware. Further, although the example program is described with reference to the flowcharts illustrated in  FIGS. 6 and 7 , many other methods of implementing the example UAV recovery analysis system  500  may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined. Additionally or alternatively, any or all of the blocks may be implemented by one or more hardware circuits (e.g., discrete and/or integrated analog and/or digital circuitry, an FPGA, an ASIC, a comparator, an operational-amplifier (op-amp), a logic circuit, etc.) structured to perform the corresponding operation without executing software or firmware. 
     The machine readable instructions described herein may be stored in one or more of a compressed format, an encrypted format, a fragmented format, a compiled format, an executable format, a packaged format, etc. Machine readable instructions as described herein may be stored as data (e.g., portions of instructions, code, representations of code, etc.) that may be utilized to create, manufacture, and/or produce machine executable instructions. For example, the machine readable instructions may be fragmented and stored on one or more storage devices and/or computing devices (e.g., servers). The machine readable instructions may require one or more of installation, modification, adaptation, updating, combining, supplementing, configuring, decryption, decompression, unpacking, distribution, reassignment, compilation, etc. in order to make them directly readable, interpretable, and/or executable by a computing device and/or other machine. For example, the machine readable instructions may be stored in multiple parts, which are individually compressed, encrypted, and stored on separate computing devices, wherein the parts when decrypted, decompressed, and combined form a set of executable instructions that implement a program such as that described herein. 
     In another example, the machine readable instructions may be stored in a state in which they may be read by a computer, but require addition of a library (e.g., a dynamic link library (DLL)), a software development kit (SDK), an application programming interface (API), etc. in order to execute the instructions on a particular computing device or other device. In another example, the machine readable instructions may need to be configured (e.g., settings stored, data input, network addresses recorded, etc.) before the machine readable instructions and/or the corresponding program(s) can be executed in whole or in part. Thus, the disclosed machine readable instructions and/or corresponding program(s) are intended to encompass such machine readable instructions and/or program(s) regardless of the particular format or state of the machine readable instructions and/or program(s) when stored or otherwise at rest or in transit. 
     The machine readable instructions described herein can be represented by any past, present, or future instruction language, scripting language, programming language, etc. For example, the machine readable instructions may be represented using any of the following languages: C, C++, Java, C#, Perl, Python, JavaScript, HyperText Markup Language (HTML), Structured Query Language (SQL), Swift, etc. 
     As mentioned above, the example processes of  FIGS. 6 and 7  may be implemented using executable instructions (e.g., computer and/or machine readable instructions) stored on a non-transitory computer and/or machine readable medium such as a hard disk drive, a flash memory, a read-only memory, a compact disk, a digital versatile disk, a cache, a random-access memory and/or any other storage device or storage disk in which information is stored for any duration (e.g., for extended time periods, permanently, for brief instances, for temporarily buffering, and/or for caching of the information). As used herein, the term non-transitory computer readable medium is expressly defined to include any type of computer readable storage device and/or storage disk and to exclude propagating signals and to exclude transmission media. 
     “Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc. may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and/or” when used, for example, in a form such as A, B, and/or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, and (7) A with B and with C. As used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and/or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities and/or steps, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities and/or steps, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. 
     As used herein, singular references (e.g., “a”, “an”, “first”, “second”, etc.) do not exclude a plurality. The term “a” or “an” entity, as used herein, refers to one or more of that entity. The terms “a” (or “an”), “one or more”, and “at least one” can be used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements or method actions may be implemented by, e.g., a single unit or processor. Additionally, although individual features may be included in different examples or claims, these may possibly be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and/or advantageous. 
       FIG. 6  is a flowchart representative of an example method  600  to implement the example UAV recovery system  100  of  FIG. 1  and/or the UAV recovery analysis system  500  of  FIG. 5 . In this example, the method  600  is being performed to recover the example UAV  120  via the tether line  108 . 
     At block  602 , the kite  116  supporting the tether line  108  is deployed (e.g., deployed from the vessel  202 ). In this example, the coordinator  506  causes the kite  116  to be deployed and/or launched. 
     In some examples, at block  604 , the coordinator  506  coordinates movement of the UAV  120  and/or the kite  116  to facilitate recovery of the UAV  120 , as will be described in greater detail below in connection with  FIG. 7 . 
     At block  606 , the movement controller  502  and/or the kite analyzer  508  determines whether a measured tension value of the tether line  108  measured by the sensor(s)  132  is within a predefined range. The range may be defined to ensure that there is adequate tension for recovery of the UAV  120  while reducing potential damage to the UAV  120  (e.g., damage from an excessive impact force). If the tension is within the predefined range (block  606 ), control of the process proceeds to block  610 . Otherwise, the process proceeds to block  608 . In some examples, the tension is determined and/or measured by the tensioner  110 . 
     If the tension is not within the predefined range (block  606 ), at block  608 , the movement controller  502  controls the tensioner  110  to adjust the tension within the desired tension range and the process proceeds to block  610 . 
     At block  610 , the UAV  120  is brought into contact with the tether line  108 . In some examples, the coordinator  506  utilizes data from the flight path analyzer  504  to direct motion of the UAV  120  to contact the tether line  108 . 
     At block  612 , the movement controller  502  controls the tensioner  110  to pull the tether line  108  along with the UAV  120  toward the vessel  202 . As a result, the UAV  120  is recovered at the vessel  202 . 
     At block  614 , it is determined whether to repeat the process. If the process is to be repeated (block  614 ), control of the process returns to block  602 . Otherwise, the process ends. This determination may be based on whether additional ones of the UAV  120  are to be recovered. 
       FIG. 7  is a flowchart representative of the example subroutine  604  of the example method  600  of  FIG. 6 . The example subroutine  604  is implemented to enable the tether line  108  to be within a requisite distance (e.g., a proximate distance) of the UAV  120  for recovery thereof. 
     At block  702 , the GPS/differential GPS analyzer  510  of the illustrated example determines a position of the vessel  202 . In particular, the position of the vessel can be based on GPS data measured at a GPS receiver of the vessel  202 . 
     At block  704 , the coordinator  506  and/or the flight path analyzer  504  determines a relative position and/or an actual position of the UAV  120 . 
     At block  706 , additionally or alternatively, the example GPS/differential GPS analyzer  510  and/or the example kite analyzer  508  determines a position of the kite  116 . The position of the kite  116  may be the actual position (e.g., in GPS coordinates) or a relative position of the kite  116  to the vessel  202  (e.g., relative to a GPS position of the vessel  202 ). In some such examples, a GPS receiver can be placed onto or proximate the kite  116  to determine the position of the kite  116 . In some examples, a first position of the kite  116  relative to the vessel  202  and a second position of the vessel  202  (e.g., a measured GPS position of the vessel  202 ) are utilized (e.g., summed) to calculate a third position of the kite  116  (e.g., an actual position of the kite  116 ). 
     At block  708 , in some examples, a position of the tether line  108  is determined by the kite analyzer  508 . In some such examples, the kite analyzer  508  may determine a 3-D positional displacement and/or overall displacement of the tether line  108  (e.g., displacement curvature along different portions of the tether line  108 ) as the tether line  108  extends from the vessel  202 . 
     At block  710 , the example coordinator  506  directs movement of the UAV  120  toward the tether line  108 . For example, the coordinator  506  may transmit movement instructions and/or positional coordinates to the UAV  120  by signals transmitted from/to the transceiver  136  and/or the network  520 . In some examples, the coordinator  506  causes the transceiver  136  to transmit the position of the kite to the UAV  120 . 
     At block  712 , in some examples, the kite analyzer  508  directs the kite steerer  503  to move the steering actuator  140  to steer the kite  116 . In particular, the kite  116  can be moved along with the tether line  108  to increase a probability that the UAV  120  will contact the tether line  108 . 
     At block  714 , it is then determined whether to repeat the process. If the process is to be repeated, control of the process returns to block  702 . Otherwise, the process ends/returns. This determination may be based on whether the tether line  108  or the kite  116  is within a requisite range of a flight path (e.g., a projected flight path, an interpolated flight path, a projected light zone area, etc.) of the UAV  120  or a determined position of the UAV  120 . 
       FIG. 8  is a block diagram of an example processor platform  800  structured to execute the instructions of  FIGS. 6 and 7  to implement the UAV recovery analysis system  500  of  FIG. 5 . The processor platform  800  can be, for example, a server, a personal computer, a workstation, a self-learning machine (e.g., a neural network), a mobile device (e.g., a cell phone, a smart phone, a tablet such as an iPad), a personal digital assistant (PDA), an Internet appliance, a DVD player, a CD player, a digital video recorder, a Blu-ray player, a gaming console, a personal video recorder, a set top box, a headset or other wearable device, or any other type of computing device. 
     The processor platform  800  of the illustrated example includes a processor  812 . The processor  812  of the illustrated example is hardware. For example, the processor  812  can be implemented by one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. The hardware processor may be a semiconductor based (e.g., silicon based) device. In this example, the processor implements the example movement controller  502 , the example kite steerer  503 , the example flight path analyzer  504 , the example coordinator  506 , the example kite analyzer  508 , and the example GPS/differential GPS analyzer  510 . 
     The processor  812  of the illustrated example includes a local memory  813  (e.g., a cache). The processor  812  of the illustrated example is in communication with a main memory including a volatile memory  814  and a non-volatile memory  816  via a bus  818 . The volatile memory  814  may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS® Dynamic Random Access Memory (RDRAM®) and/or any other type of random access memory device. The non-volatile memory  816  may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory  814 ,  816  is controlled by a memory controller. 
     The processor platform  800  of the illustrated example also includes an interface circuit  820 . The interface circuit  820  may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), a Bluetooth® interface, a near field communication (NFC) interface, and/or a PCI express interface. 
     In the illustrated example, one or more input devices  822  are connected to the interface circuit  820 . The input device(s)  822  permit(s) a user to enter data and/or commands into the processor  812 . The input device(s) can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a track-pad, a trackball, isopoint and/or a voice recognition system. 
     One or more output devices  824  are also connected to the interface circuit  820  of the illustrated example. The output devices  1024  can be implemented, for example, by display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display (LCD), a cathode ray tube display (CRT), an in-place switching (IPS) display, a touchscreen, etc.), a tactile output device, a printer and/or speaker. The interface circuit  820  of the illustrated example, thus, typically includes a graphics driver card, a graphics driver chip and/or a graphics driver processor. 
     The interface circuit  820  of the illustrated example also includes a communication device such as a transmitter, a receiver, a transceiver, a modem, a residential gateway, a wireless access point, and/or a network interface to facilitate exchange of data with external machines (e.g., computing devices of any kind) via a network  826 . The communication can be via, for example, an Ethernet connection, a digital subscriber line (DSL) connection, a telephone line connection, a coaxial cable system, a satellite system, a line-of-site wireless system, a cellular telephone system, etc. 
     The processor platform  800  of the illustrated example also includes one or more mass storage devices  828  for storing software and/or data. Examples of such mass storage devices  828  include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, redundant array of independent disks (RAID) systems, and digital versatile disk (DVD) drives. 
     The machine executable instructions  832  of  FIGS. 6 and 7  may be stored in the mass storage device  828 , in the volatile memory  814 , in the non-volatile memory  816 , and/or on a removable non-transitory computer readable storage medium such as a CD or DVD. 
     Example 1 includes an apparatus to recover an unmanned aerial vehicle (UAV) during flight. The apparatus includes a tether line, a tensioner operatively coupled to the tether line, and a kite operatively coupled to the tether line to support the tether line for recovery of the UAV. 
     Example 2 includes the apparatus as defined in example 1, where the kite includes a parafoil kite. 
     Example 3 includes the apparatus as defined in examples 1 or 2, where the tether line includes a first steering line and a second steering line, the first and second steering lines operatively coupled to the kite to steer the kite. 
     Example 4 includes the apparatus as defined in any of examples 1 to 3, further including a sensor to measure a first position of the kite relative to a vessel from which the tether line extends. 
     Example 5 includes the apparatus as defined in example 4, further including a kite analyzer to calculate a second position of the kite based on the first position and a third position of the vessel. 
     Example 6 includes the apparatus as defined in example 5, further including a transceiver to transmit the calculated position of the kite to the UAV or a navigation network associated with the UAV. 
     Example 7 includes the apparatus as defined in any of examples 4-6, where the vessel includes a ship. 
     Example 8 includes the apparatus as defined in any of examples 1-7, where the tensioner is to maintain the tether line within a desired tension range prior to contact of the UAV with the tether line. 
     Example 9 includes a method of recovering a UAV during flight. The method includes suspending a tether line via a kite, contacting the UAV with the tether line to capture the UAV, and in response to contacting the UAV with the tether line, retrieving the UAV with a tensioner operatively coupled to the tether line. 
     Example 10 includes the method as defined in example 9, further including maintaining, via the tensioner, a tension of the tether line within a desired tension range prior to contact of the UAV with the tether line. 
     Example 11 includes the method as defined in examples 9 or 10, further including coordinating, via instructions executed by at least one processor, movement of the UAV for the UAV to contact the tether line. 
     Example 12 includes the method as defined in example 11, further including determining, via instructions executed by the at least one processor, a first position of the kite relative to a vessel carrying the tether line. 
     Example 13 includes the method as defined in example 12, further including calculating, via instructions executed by the at least one processor, a second position of the kite based on the determined first position and a third position of the vessel. 
     Example 14 includes the method as defined in example 13, further including steering the kite based on the determined position of the kite and a flight path of the UAV. 
     Example 15 includes the method as defined in example 14, where steering the kite includes controlling first and second steering lines extending through the tether line. 
     Example 16 includes the method as defined in any of examples 9-15, further including determining, via instructions executed by at least one processor, a position of the tether line. 
     Example 17 includes a non-transitory machine readable medium comprises instructions, which when executed, cause a processor to at least determine a position of a UAV to be captured by a tether line, determine a position of a kite suspending the tether line, and adjust movement of at least one of the UAV or the kite to capture the UAV by the tether line. 
     Example 18 includes the non-transitory machine readable medium as defined in example 17, where the instructions cause the processor to move the kite via at least one steering line to bring the tether line proximate a flight path of the UAV. 
     Example 19 includes the non-transitory machine readable medium as defined in examples 17 or 18, where the position of the kite is determined based on a position of the kite relative to a vessel from which the tether extends. 
     Example 20 includes the non-transitory machine readable medium as defined in example 19, where the instructions cause the processor to direct movement of the UAV based on the position of the kite. 
     From the foregoing, it will be appreciated that example methods, apparatus and articles of manufacture have been disclosed that provide an effective and relatively low cost manner of recovering a UAV. Examples disclosed herein can also be used to effectively adjust a position of a recovery tether line with a flight path of the UAV, thereby accounting for numerous variables (e.g., movement of a recovery vessel, winds, etc.) that can affect recovery of the UAV. 
     Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent. While examples disclosed herein are shown in the context of UAVs, examples disclosed herein can be implemented in any appropriate type of vehicle (e.g., spacecraft, watercraft, etc.) and/or other types of aircraft (e.g., manned aircraft). 
     The following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.