Patent Publication Number: US-2022212789-A1

Title: Method Of Flight Plan Optimization Of A High Altitude Long Endurance Aircraft

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/838,783, filed Apr. 25, 2019, U.S. Provisional Patent Application No. 62/838,833, filed Apr. 25, 2019, and U.S. Provisional Patent Application No. 62/854,738, filed May 30, 2019, the contents of all of which are hereby incorporated by reference herein for all purposes. 
    
    
     FIELD OF ENDEAVOR 
     The invention relates generally to Unmanned Aerial Vehicles (UAVs), and more particularly to flight patterns for UAVs. 
     BACKGROUND 
     Unmanned aerial vehicles (UAVs), such as a High Altitude Long Endurance aircraft, are lightweight planes that are capable of controlled, sustained flight. UAVs may be associated with ground-based operators for two-way communications. Generally speaking, a UAV may fly in large, sweeping pattern over a ground station, taking advantage of wind patterns. 
     SUMMARY 
     A system embodiment may include: at least one unmanned aerial vehicle (UAV); at least one flight control computer (FCC) associated with each UAV of the at least one UAV, where the FCC controls movement of each UAV of the at least one UAV; at least one computing device associated with a ground control station, where the at least one computing device may be in communication with the at least one FCC; where the at least one FCC maintains a first flight pattern of a respective UAV of the at least one UAV above the ground control station; where the at least one computing device may be configured to transmit a transition signal to the at least one FCC to transition the respective UAV of the at least one UAV from the first flight pattern to a second flight pattern in response to a wind speed exceeding a set threshold relative to a flight speed of the respective UAV of the at least one UAV. 
     In additional system embodiments, the FCC may be further configured to transition the respective UAV of the at least one UAV from the first flight pattern to the second flight pattern by generating a connecting flight path between the first flight pattern and the second flight pattern. In additional system embodiments, the connecting flight path allows for a constant turn rate over most of the connecting flight path. In additional system embodiments, the connecting flight path allows for gradual banking maneuvers over most of the connecting flight path. 
     In additional system embodiments, the first flight pattern and the second flight pattern may be station keeping patterns over the ground control station. In additional system embodiments, where the first flight pattern may be a D-loop flight pattern. In additional system embodiments, the second flight pattern may be a figure-eight flight pattern. In additional system embodiments, the transition signal comprises a set of spatial coordinates for the FCC of the respective UAV of the at least one UAV to follow. 
     In additional system embodiments, the at least one computing device may be configured to transmit an exit command signal to the at least one FCC to transition the respective UAV of the at least one UAV from the second flight pattern to the first flight pattern in response to a wind speed falling below the set threshold relative to the flight speed of the respective UAV of the at least one UAV. In additional system embodiments, the exit command signal comprises a set of spatial coordinates for the FCC of the respective UAV of the at least one UAV to follow. 
     A method embodiment may include: maintaining, by at least one flight control computer (FCC) associated with each unmanned aerial vehicle (UAV) of one or more UAVs, a first flight pattern above a ground control station, where the FCC controls movement of each UAV of the at least one UAV; determining a wind speed relative to a set threshold, where the set threshold may be relative to a flight speed of the respective UAV of the at least one UAV; transmitting, by at least one computing device associated with the ground control station, a transition signal to the at least one FCC in response to the determined wind speed exceeding the set threshold; and transitioning, by the at least one FCC associated with the respective UAV of the one or more UAVs, the respective UAV from the first flight pattern to a second flight pattern. 
     In additional method embodiments, transitioning the respective UAV from the first flight pattern to the second flight pattern further comprises: generating, by the at least one FCC associated with the respective UAV of the one or more UAVs, a connecting flight path between the first flight pattern and the second flight pattern. In additional method embodiments, the connecting flight path allows for a constant turn rate over most of the connecting flight path. In additional method embodiments, the connecting flight path allows for gradual banking maneuvers over most of the connecting flight path. 
     In additional method embodiments, the first flight pattern and the second flight pattern may be station keeping patterns over the ground control station. In additional method embodiments, the first flight pattern may be a D-loop flight pattern. In additional method embodiments, the second flight pattern may be a figure-eight flight pattern. In additional method embodiments, the transition signal comprises a set of spatial coordinates for the FCC of the respective UAV of the at least one UAV to follow. 
     Additional method embodiments may further include: transmitting, by the at least one computing device associated with the ground control station, an exit command signal to the at least one FCC in response to the determined wind speed falling below the set threshold; and transitioning, by the at least one FCC associated with the respective UAV of the one or more UAVs, the respective UAV from the second flight pattern to the first flight pattern. In additional method embodiments, the exit command signal comprises a set of spatial coordinates for the FCC of the respective UAV of the at least one UAV to follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principals of the invention. Like reference numerals designate corresponding parts throughout the different views. Embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which: 
         FIG. 1  depicts a system for an unmanned aerial vehicle flying in a D-loop flight pattern, according to one embodiment; 
         FIG. 2  illustrates a top-level functional block diagram of a computing device associated with an operator at a ground station, according to one embodiment; 
         FIG. 3  illustrates a top-level functional block diagram of a computing device of the unmanned aerial vehicle of  FIG. 1 , according to one embodiment; 
         FIG. 4  depicts a process for the unmanned aerial vehicle of  FIG. 1  to transition from a D-loop flight pattern to a figure-eight flight pattern, according to one embodiment; 
         FIG. 5  depicts an alternative process for the unmanned aerial vehicle of  FIG. 1  to transition from a D-loop flight pattern to a figure-eight flight pattern, according to one embodiment; 
         FIG. 6  depicts a process for the unmanned aerial vehicle of  FIG. 1  to transition from a figure-eight flight pattern to a D-loop flight pattern, according to one embodiment; 
         FIG. 7  depicts an alternative process for the unmanned aerial vehicle of  FIG. 1  to transition from a figure-eight flight pattern to a D-loop flight pattern, according to one embodiment; 
         FIG. 8  depicts a flow diagram of a method for flight plan optimization of an unmanned aerial vehicle, according to one embodiment; 
         FIG. 9  shows a high-level block diagram and process of a computing system for implementing an embodiment of the system and process; 
         FIG. 10  shows a block diagram and process of an exemplary system in which an embodiment may be implemented; and 
         FIG. 11  depicts a cloud computing environment for implementing an embodiment of the system and process disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is made for the purpose of illustrating the general principles of the embodiments discloses herein and is not meant to limit the concepts disclosed herein. Further, particular features described herein can be used in combination with other described features in each of the various possible combinations and permutations. Unless otherwise specifically defined herein, all terms are to be given their broadest possible interpretation including meanings implied from the description as well as meanings understood by those skilled in the art and/or as defined in dictionaries, treatises, etc. 
     A flight pattern for an unmanned aerial vehicle (UAV), such as a high altitude long endurance solar-powered aircraft, may be a D-loop. In one example, the aircraft traces a circular- or oblong-shaped pattern, referred to as a “D-loop” pattern. A D-loop flight pattern is advantageous in lower wind speeds. As wind speeds increase, the size of the D-loop must also increase, making it a challenge for the UAV to stay close to a ground station while minimizing its turn rate and bank angle. In the D-loop, the UAV is flown into the wind until is necessary to turn around. The pattern approximately forms a “D” shape, though other shapes, such as circles or ovals are possible and described below. For example, in zero winds the D-loop is a circular shape. The D-loop flight pattern is advantageous in lower wind speeds; however, as the wind speeds increase, the size of the D-loop has to increase as well. If the wind speed continues to increase, it may be desired to transition to a tighter flight pattern formation in order to station keep. 
     In one embodiment, as the wind speed approaches approximately 40% of flight speed, the aircraft may transition to a figure-eight loop. The figure-eight loop allows the aircraft to stay in a compact flight pattern over the ground station, with the intersect point of the figure-eight positioned approximately above the ground control station. 
     As wind speeds increase it is a challenge to transition from a D-loop to a figure-eight loop. More specifically, every time the UAV approaches or passes through the intersect point a decision may be made as to what type of loop to fly. When transitioning, it may be desired to minimize the bank angle because the payload may not be on gimbals. Thus, when the plane tilts, the antenna beams tilt, and the aircraft beams may need to be redirected. Alternatively, the antenna beams may be designed to have a wider angle, which may reduce signal strength at ground control stations. 
     In one embodiment, as the UAV travels in low winds and traces out a D-loop flight pattern, a portion of the D-loop flight pattern passes through what would be the intersect point of the figure-eight pattern. If the winds are at or above approximately 40% of flight speed, the aircraft may bank out of the D-loop at the intersect point, and transition into the figure-eight loop pattern. In another embodiment, the aircraft D-loop flight pattern does not pass directly through the intersect point of the figure-eight flight pattern. Rather, if the winds are at or above 40% of flight speed, the aircraft may veer from its D-shape trajectory towards what will be the point of the figure-eight where the aircraft is flying directly into the wind. A potential benefit of this method is the ability for gradual banking maneuvers of the UAV as the UAV transitions between flight patterns. In both embodiments, it is possible that as the winds die down, the aircraft may exit the figure-eight loop and transition back to the D-loop. 
     With reference to  FIG. 1 , a system  100  flight plan optimization of an unmanned aerial vehicle (UAV)  101  is illustrated. UAVs are aircraft with no onboard pilot and may fly autonomously or remotely. In one embodiment, the UAV  101  is a High Altitude Long Endurance aircraft. The UAV  101  may have between one and forty motors, and a wingspan between 100 feet and 400 feet. In one embodiment, the UAV  101  may have a wingspan of approximately 260 feet and may be propelled by ten electric motors powered by a solar array covering at least a portion of the surface of the wing, resulting in zero emissions. Flying at an altitude of approximately 65,000 feet above sea level and above the clouds, the UAV  101  is designed for continuous, extended missions of up to months without landing. In another embodiment, the UAV  101  may fly at 60,000 feet above sea level. 
     The UAV  101  functions optimally at high altitude due at least in part to the lightweight payload of the UAV. The UAV  101  is capable of considerable periods of sustained flight without recourse to land. In one embodiment, the UAV  101  may weigh approximately 3,000 lbs and may include wing panel sections and a center panel, providing for efficient assembly and disassembly of the UAV  101  due to the attachability and detachability of the wing panel sections to each other and/or to the center panel. 
     The UAV  101  may fly in a large, sweeping geostationary pattern within the stratospheric layer over at least one ground control station  104 , taking advantage of wind patterns at high altitude. In one embodiment, a D-loop flight pattern approximately forms a “D” shape. The D-loop will trace out the shape of a “D” by flying directly into the wind, then performing a constant-rate 360 degree turn until the UAV  101  again points into the wind. In one embodiment, the flight pattern is a circular flight pattern when zero winds are present. In one embodiment, there may be more than one ground control station  104 . 
     The ground control station  104  may be the central hub for aircraft control. The UAV  101  may be within a beam width of a terrestrial GPS receiver  134  associated with the ground control station  104 . The GPS receiver  134  may be configured to provide the position of the ground control station  104  and a landing site to operators  106  at the ground control station  104  and to the UAV  101 . Each UAV may include a dedicated GPS receiver for calculating the position of the UAV and may communicate an associated position data to the ground control station  104  over a terrestrial RF receiver  132  in communication with the ground control station  104 . 
     A terrestrial RF emitter  124  may emit signals to the UAV  101  so the UAV  101  will know the location of the ground control station  104  and/or a landing site. Other emitters configured for terrestrial communication with the UAV  101  may be included, such as a visual band emitter  122 . In one embodiment, the terrestrial RF emitter  124  may emit signals to the UAV  101  to generally communicate commands to the UAV  101 . In some embodiments, the ground control station  104  may include the terrestrial GPS receiver  134 , terrestrial RF emitter  124 , terrestrial RF receiver  132 , and/or visual band emitter  122 . In other embodiments, the ground control station  104  may be in communication with the terrestrial GPS receiver  134 , terrestrial RF emitter  124 , terrestrial RF receiver  132 , and/or visual band emitter  122 . 
     In one embodiment, one or more operators  106  may be located at the ground control station  104  for optimization of the UAV  101  flight pattern. More than one operator is possible for optimization of the UAV  101  flight pattern. The operator  106  may control the transition of the UAV  101  from one flight pattern to another flight pattern via at least one processor of the ground control station  104  and/or at least one processor of the UAV  101 . The transition between flight patterns may be based primarily on the wind speed. In some embodiments, the transition between flight patterns may be automatic based on one or more criteria, such as wind speed, UAV location, and the like. 
     At low wind speeds, for example zero to thirty knots, the UAV  101  may trace the “D-loop” shape flight pattern  103 . The D-loop flight pattern  103  is advantageous in lower wind speeds. As the wind speeds increase, the size of the D-loop has to increase as well, making it a challenge for the UAV  101  to station keep. If the wind speed continues to increase, the operator  106  may cause the UAV  101  to transition to a tighter flight pattern in order to station keep, as will be described in detail below. Still further, the operator  106  may cause the UAV  101  to transition back to the D-loop  103  as the ambient wind speed lowers or dies down. 
     While the operator  106  is depicted as a person, the operator  106  may be a processor having addressable memory, such as shown in  FIG. 2 . The control of the UAV  101  and/or change of flight pattern of the UAV  101  may be via the operator  106  in some embodiments. In other embodiments, control of the UAV  101  and/or change of flight pattern of the UAV  101  may be via the ground control  104 , an autonomous system, a semi-autonomous system, or the like. 
       FIG. 2  illustrates an example of a top-level functional block diagram of a computing device  108  operated by the operator  106 . The computing device  108  comprises a processor  138 , such as a central processing unit (CPU), addressable memory  140 , an external device interface  142 , e.g., an optional universal serial bus port and related processing, and/or an Ethernet port and related processing, and an optional user interface  144 , e.g., an array of status lights and one or more toggle switches, and/or a display, and/or a keyboard and/or a pointer-mouse system and/or a touch screen. Optionally, the addressable memory may, for example, be: flash memory, eprom, and/or a disk drive or other hard drive. These elements may be in communication with one another via a data bus  146 . In some embodiments, via an operating system  148  such as one supporting a web browser  150  and applications  152 , the processor  138  may be configured to execute steps of a process establishing a communication channel. For example, the processor  138  may be in communication with the RF receiver  132  to process the received position data of the UAV  101 . 
     Since a UAV does not have an onboard pilot, a flight control computer (FCC)  110  onboard the UAV is the central intelligence of the aircraft. The FCC  110  may partially or completely control much of the functionality of the UAV, such as changing direction (e.g., flight pattern) based on commands received from the operator  106 . The functionality of the UAV may also be completely or partially controlled by a ground control station. 
       FIG. 3  illustrates an example of a top-level functional block diagram of the FCC  110  of the UAV  101 . The FCC  110  comprises at least a processor  114 , such as a central processing unit (CPU), addressable memory  154 , an external device interface  156 , e.g., an optional universal serial bus port and related processing, and/or an Ethernet port and related processing, and an optional user interface, e.g., an array of status lights, sensors and one or more toggle switches. Optionally, the addressable memory may, for example, be: flash memory, eprom, and/or a disk drive or other hard drive. These elements may be in communication with one another via a data bus  160 . In one embodiment, the FCC  110  may have a suite of sensors for measuring the current flight status and health status of the aircraft. 
     In some embodiments, via an operating system  162  such as one supporting applications  164 , the processor  114  may be configured to execute steps of a process establishing a communication channel. For example, the processor  114  may be in communication with a receiver  112  configured to receive a command signal from the computing device  108 . In one embodiment, the command signal is a transition command signal received by the receiver  112 , and the processor executes steps to cause the UAV  101  to transition from a current flight pattern to a different flight pattern. In another embodiment, the command signal is an exit command signal received by the receiver  112 , and the processor  114  executes steps to cause the UAV  101  to exit out of the new flight pattern and transition back to the original flight pattern, such as the original flight pattern  103 . 
     The FCC  110  may further be connected to or in communication with a global positioning system (GPS) configured for receiving position data from a constellation of satellites. Still further, the FCC  110  may include a transmitter  116  for transmitting to the ground GPS correction information and/or transmitting to the ground translated GPS position in an auxiliary frequency band to a terrestrial RF receiver  132 . 
     With respect to  FIG. 4 , two flight patterns are illustrated. In one embodiment, the UAV  101  may fly in a first flight pattern  103 . In one embodiment, the first flight pattern  103  may be a D-loop. More specifically, the UAV  101  will trace out the shape of a “D” by flying directly into the wind and then performing a constant-rate 360 degree turn until the UAV  101  again points into the wind. The UAV  101  may fly the first flight pattern  103  when wind speeds are low. In another embodiment, the UAV  101  may fly the first flight pattern  103  in the opposite, counter-clockwise direction. The UAV  101  may generally station keep with the ground control station  104 , flying at high altitude, e.g., approximately 65,000 ft above sea level, above the ground control station  104  as denoted by the z vector. The center point of the D-loop  103  may be directly above the ground control station  104 . The UAV  101  may also trace a second flight pattern  105 , such as a figure-eight flight pattern, when winds speeds are at or above approximately 40% of flight speed. When winds increase to at or above approximately 40% of flight speed, the size of the D-loop flight pattern  103  increases. Specifically, the portion of the D-loop flight pattern  103  that points approximately into the wind and the portion the D-loop flight pattern  103  that points approximately downwind will increase; however, the portions of the D-loop flight pattern  103  that are approximately perpendicular to the wind direction do not increase. Thus, the D-loop flight pattern  103  may not get wider; the D-loop flight pattern  103  may get longer. The total distance that the UAV  101  travels away from the defined center point, such as intersect point  165  described below, of the ground control station  104  above 40% wind speed is minimized by using the figure eight flight pattern  105 . The figure-eight flight pattern  105  provides for a tighter flight path of the UAV  101 , allowing the UAV  101  to generally be closer to the ground control station  104  than the D-loop pattern  103 . 
     The figure-eight flight pattern  105  may have an intersect point  165  that the UAV  101  passes through each time the UAV  101  traces the full second flight pattern  105 . The second or figure-eight flight pattern  105  further allows the UAV  101  to travel in high wind speeds while minimizing the distance the UAV  101  travels from the intersect point  165 . In one embodiment, the intersect point  165  is located approximately directly above the ground control station  104 . 
     Arrows indicate the direction of the UAV  101  as the UAV  101  travels through each flight pattern  103 ,  105 . The first flight pattern  103  may pass through the intersect point  165  as the UAV  101  traces the first flight pattern  103 . If the wind speed  101  increases to at or above approximately 40% of flight speed, the UAV  101  may bank out of the first flight pattern  103  at the intersect point  165 , and transition into the figure-eight loop pattern  105 , as shown by reference element  180 . In one embodiment, a transition command signal  166  may be sent from the operator  106 , or a computing device of the ground control station  104 , to an FCC of the UAV  101  to change the trajectory of the UAV  101  and transition from the first flight pattern  103  to the second flight pattern or figure-eight loop  105 . In one embodiment, the transition command signal  166  may be a set of spatial coordinates for the FCC of the UAV  101  to follow. 
     The wind speed may be measured at the UAV  101  in some embodiments. In other embodiments, external sensors may be used to measure the wind speed. In other embodiments, multiple UAVs may be used and the wind speed measurements at the one or more UAVs may be recorded and transmitted to at least one other UAV of the multiple UAVs. The threshold for wind speed may be based on an average wind speed, such as an average wind speed throughout a flight path of the UAV  101 . The point of transition between the different patterns  103 ,  105  may depend on several factors, as disclosed herein. The transition between the different patterns  103 ,  105  may be commanded by a computer on the ground in the ground control station in some embodiments. In other embodiments, the transition between the different patterns  103 ,  105  may be could be determined autonomously by the flight control computer of the UAV. The shape of the D-loop first flight pattern  103  may be based on the point of reference of the aircraft and the wind. The D-loop first flight pattern  103  is only shown for reference and is not drawn to scale or shape. In one embodiment, a downwind straight section of the D-loop first flight pattern  103  may be much shorter, or non-existent, than the leg as shown in the figures. In embodiments where the D-loop first flight pattern  103  comprises a constant rate 360 degree turn there may not be any straight downwind leg as the flight path may be a continuous elongated turn. In some embodiments, the D-loop first flight pattern  103  comprises a straight leg, such as the leg into the wind and a turning leg where the UAV  101  makes a long turn before transitioning back into the straight leg. 
     In some embodiments, the transition between patterns  103 ,  105  may be based on a desired proximity to the desired loiter point. For example, a transition may be selected that does not cause the UAV  101  to go outside of a set threshold distance from the loiter point or ground control station. In some embodiments, the transition between patterns  103 ,  105  may be based on other aircraft or UAVs in the constellation. For example, the transition may depend on the position, battery level, and the like of other UAV so as to prioritize transitions for aircraft with lower battery levels, maintain a desired distance between aircraft, and the like. In some embodiments, the transition between patterns  103 ,  105  may be based on a time of day. For example, the transition may be based on a location of the Sun relative to the wind, especially closer to sunrise and sunset when certain flight patterns may limit absorption of solar energy. In some embodiments, the transition between patterns  103 ,  105  may be based on a time of year. For example, in winter there may be less time between sunrise and sunset for each UAV  101  to recharge and the transition may consider a sun angle relative to a desired pattern and/or transition so that the UAV  101  may continue to receive solar energy if needed. In some embodiments, the transition and/or selected pattern  103 , 105  may consider the solar energy that can be used to charge the UAV in each flight pattern  103 ,  105  as compared to an extra energy needed to fly a non-optimal flight pattern  103 ,  105 . 
     The transition command signal  166  may be communicated to the RF emitter  124  from the processor of the ground control station  104 . The RF emitter  124  transmits the signal  166  to be received at the UAV  101 . The signal  166  may be a wireless radio frequency signal. Furthermore, the receiver  112  of the FCC  110 , as shown in  FIG. 3 , may be tuned to the same frequency as the RF emitter  124 . In one embodiment, the transition command signal  166  has a unique identifier code for the particular UAV that the transition command signal  166  is in communication with, such as UAV  101 , to make sure the signal is not sent to other UAV if there are other UAVs in the vicinity. Upon receiving the transition command signal  166  at the FCC  110  of the UAV  101 , the FCC  110  causes the UAV  101  to turn into the figure-eight flight pattern  105  as the UAV  101  passes through the intersection point  165 . 
     With respect to  FIG. 5 , the first flight pattern  103  and the figure-eight or second flight pattern  105  of  FIG. 4  are shown, wherein the intersect point  165  of the figure-eight loop  105  is approximately located at the center of the D-loop  103 . If the wind speed increases to at or above approximately 40% of flight speed, the operator  106  or a processor of the ground control station  104  transmits the transition command signal  166  to cause the UAV  101  to gradually veer out of the D-loop  103 , and follow a flight path denoted by connecting flight path  182 . The UAV  101  passes through the intersect point  165  and follows the new figure-eight path  105 . The gradual transition of the connecting flight path  182  allows for a constant turn rate over much of the D-loop  103 , and more gradual banking maneuvers as the UAV  101  transitions between flight patterns. 
     As described above, and with respect to  FIG. 6 , the figure-eight flight pattern  105  allows the UAV  101  to travel in high wind speeds while station keeping above the ground control station  104 . The figure-eight or second flight pattern  105  further allows the UAV  101  to minimize the distance travelled from the intersect point  165 . If the wind speed  101  decreases to below approximately 40% of flight speed, the UAV  101  may bank out of the figure-eight loop  103  at the intersect point  165 , and transition into the D-loop pattern  105  via connecting flight path  184 . In one embodiment, an exit command signal  168  is sent from the operator  106  or a processor of the ground control station  104  to the FCC of the UAV  101  to change the trajectory of the UAV  101  to exit from the figure-eight loop  105  back to the D-loop  103 . The exit command signal  168  may be a new set of spatial coordinates for the UAV  101  to follow. 
     The exit command signal  168  is communicated to the RF emitter  124 , and the RF emitter emits the signal  168  to be received at the UAV  101 . The exit command signal  168  may be a wireless radio frequency signal. Furthermore, the receiver  112  of the FCC  110  may be tuned to the same frequency as the RF emitter  124 . In one embodiment, the exit command signal  168  has a unique identifier code for the particular aircraft it is in communication with, such as UAV  101 , to make sure the signal is not sent to other aircraft if there are other UAVs in the vicinity. Upon receiving the exit command signal  168  at the FCC  110  of the UAV  101 , the FCC  110  causes the UAV  101  to turn into the figure-eight flight pattern  105  as the UAV  101  passes through the intersection point  165 . 
     With respect to  FIG. 7 , the D-loop or first flight pattern  103  and the figure-eight or second flight pattern  105  of  FIG. 5  are shown. In one embodiment, if the wind speed  101  decreases to below approximately 40% of flight speed, the operator  106  or a processor  104  of the ground control station  104  transmits the exit command signal  168  to cause the UAV  101  to pass through the intersect point  165  and follow a flight path denoted by a gradual transition of the connecting flight path  186  to follow the D-loop flight pattern  103 . The gradual transition of the connecting flight path  186  allows for a constant turn rate over much of the D-loop  103 , and more gradual banking maneuvers as the UAV  101  transitions between flight patterns. 
     With respect to  FIG. 8 , a flowchart for a method  200  for flight plan optimization of an unmanned aerial vehicle (UAV) is illustrated. The UAV may trace a first flight pattern when winds speeds are below approximately 40% of the UAV flight speed (step  202 ). In one embodiment, the UAV will trace out the shape of a “D” by flying directly into the wind, then performing a constant-rate 360 degree turn until the UAV again points into the wind. The UAV may fly this D-loop flight pattern when wind speeds are low. An operator or processor of a ground control station may transmit a transition command signal to change the trajectory of the UAV when the wind speed is at or above approximately 40% of the UAV flight speed (step  204 ). While 40% of the UAV flight speed is used as an example, other set thresholds are possible and contemplated relative to the UAV flight speed. The set threshold amount may be based on the UAV dimensions, available battery power, weather conditions, or the like. A flight control computer (FCC) of the UAV may receive the transition command signal (step  206 ). The FCC may execute steps to transition the UAV out of the first flight pattern (e.g., at an intersect point), and into a second flight pattern (step  208 ). In one embodiment, the second flight pattern is a figure-eight loop pattern. In one embodiment, the transition command signal may be a set of spatial coordinates for the UAV to follow. The figure-eight flight pattern allows the UAV to travel in high wind speeds and still station keep above a ground station. 
     The operator or processor may transmit an exit command signal to change the trajectory of the UAV when the wind speed is below approximately 40% of the UAV flight speed (step  210 ). The FCC receives the exit command signal (step  212 ). The FCC may execute steps to transition the UAV out of the second flight pattern, and back into the first flight pattern based on the received exit command signal (step  214 ). In one embodiment, the exit command signal may be a new set of spatial coordinates for the UAV to follow. In one embodiment, the exit command signal is communicated to a radio frequency (RF) emitter by the operator, and the RF emitter emits the signal to be received at the UAV FCC. 
     In one embodiment, if the wind speed decreases to below approximately 40% of flight speed, the UAV may bank out of the figure-eight loop at the intersect point, and gradually transition into the D-loop pattern via a connecting flight path. The gradual transition allows for a constant turn rate over much of the D-loop, and more gradual banking maneuvers as the UAV transitions between the first and second flight patterns. 
       FIG. 9  is a high-level block diagram  500  showing a computing system comprising a computer system useful for implementing an embodiment of the system and process, disclosed herein. Embodiments of the system may be implemented in different computing environments. The computer system includes one or more processors  502 , and can further include an electronic display device  504  (e.g., for displaying graphics, text, and other data), a main memory  506  (e.g., random access memory (RAM)), storage device  508 , a removable storage device  510  (e.g., removable storage drive, a removable memory module, a magnetic tape drive, an optical disk drive, a computer readable medium having stored therein computer software and/or data), user interface device  511  (e.g., keyboard, touch screen, keypad, pointing device), and a communication interface  512  (e.g., modem, a network interface (such as an Ethernet card), a communications port, or a PCMCIA slot and card). The communication interface  512  allows software and data to be transferred between the computer system and external devices. The system further includes a communications infrastructure  514  (e.g., a communications bus, cross-over bar, or network) to which the aforementioned devices/modules are connected as shown. 
     Information transferred via communications interface  514  may be in the form of signals such as electronic, electromagnetic, optical, or other signals capable of being received by communications interface  514 , via a communication link  516  that carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular/mobile phone link, an radio frequency (RF) link, and/or other communication channels. Computer program instructions representing the block diagram and/or flowcharts herein may be loaded onto a computer, programmable data processing apparatus, or processing devices to cause a series of operations performed thereon to produce a computer implemented process. 
     Embodiments have been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments. Each block of such illustrations/diagrams, or combinations thereof, can be implemented by computer program instructions. The computer program instructions when provided to a processor produce a machine, such that the instructions, which execute via the processor, create means for implementing the functions/operations specified in the flowchart and/or block diagram. Each block in the flowchart/block diagrams may represent a hardware and/or software module or logic, implementing embodiments. In alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures, concurrently, etc. 
     Computer programs (i.e., computer control logic) are stored in main memory and/or secondary memory. Computer programs may also be received via a communications interface  512 . Such computer programs, when executed, enable the computer system to perform the features of the embodiments as discussed herein. In particular, the computer programs, when executed, enable the processor and/or multi-core processor to perform the features of the computer system. Such computer programs represent controllers of the computer system. 
       FIG. 10  shows a block diagram of an example system  600  in which an embodiment may be implemented. The system  600  includes one or more client devices  601  such as consumer electronics devices, connected to one or more server computing systems  630 . A server  630  includes a bus  602  or other communication mechanism for communicating information, and a processor (CPU)  604  coupled with the bus  602  for processing information. The server  630  also includes a main memory  606 , such as a random access memory (RAM) or other dynamic storage device, coupled to the bus  602  for storing information and instructions to be executed by the processor  604 . The main memory  606  also may be used for storing temporary variables or other intermediate information during execution or instructions to be executed by the processor  604 . The server computer system  630  further includes a read only memory (ROM)  608  or other static storage device coupled to the bus  602  for storing static information and instructions for the processor  604 . A storage device  610 , such as a magnetic disk or optical disk, is provided and coupled to the bus  602  for storing information and instructions. The bus  602  may contain, for example, thirty-two address lines for addressing video memory or main memory  606 . The bus  602  can also include, for example, a 32-bit data bus for transferring data between and among the components, such as the CPU  604 , the main memory  606 , video memory and the storage  610 . Alternatively, multiplex data/address lines may be used instead of separate data and address lines. 
     The server  630  may be coupled via the bus  602  to a display  612  for displaying information to a computer user. An input device  614 , including alphanumeric and other keys, is coupled to the bus  602  for communicating information and command selections to the processor  604 . Another type or user input device comprises cursor control  616 , such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to the processor  604  and for controlling cursor movement on the display  612 . 
     According to one embodiment, the functions are performed by the processor  604  executing one or more sequences of one or more instructions contained in the main memory  606 . Such instructions may be read into the main memory  606  from another computer-readable medium, such as the storage device  610 . Execution of the sequences of instructions contained in the main memory  606  causes the processor  604  to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in the main memory  606 . In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the embodiments. Thus, embodiments are not limited to any specific combination of hardware circuitry and software. 
     The terms “computer program medium,” “computer usable medium,” “computer readable medium”, and “computer program product,” are used to generally refer to media such as main memory, secondary memory, removable storage drive, a hard disk installed in hard disk drive, and signals. These computer program products are means for providing software to the computer system. The computer readable medium allows the computer system to read data, instructions, messages or message packets, and other computer readable information from the computer readable medium. The computer readable medium, for example, may include non-volatile memory, such as a floppy disk, ROM, flash memory, disk drive memory, a CD-ROM, and other permanent storage. It is useful, for example, for transporting information, such as data and computer instructions, between computer systems. Furthermore, the computer readable medium may comprise computer readable information in a transitory state medium such as a network link and/or a network interface, including a wired network or a wireless network that allow a computer to read such computer readable information. Computer programs (also called computer control logic) are stored in main memory and/or secondary memory. Computer programs may also be received via a communications interface. Such computer programs, when executed, enable the computer system to perform the features of the embodiments as discussed herein. In particular, the computer programs, when executed, enable the processor multi-core processor to perform the features of the computer system. Accordingly, such computer programs represent controllers of the computer system. 
     Generally, the term “computer-readable medium” as used herein refers to any medium that participated in providing instructions to the processor  604  for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical or magnetic disks, such as the storage device  610 . Volatile media includes dynamic memory, such as the main memory  606 . Transmission media includes coaxial cables, copper wire and fiber optics, including the wires that comprise the bus  602 . Transmission media can also take the form of acoustic or light waves, such as those generated during radio wave and infrared data communications. 
     Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read. 
     Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to the processor  604  for execution. For example, the instructions may initially be carried on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to the server  630  can receive the data on the telephone line and use an infrared transmitter to convert the data to an infrared signal. An infrared detector coupled to the bus  602  can receive the data carried in the infrared signal and place the data on the bus  602 . The bus  602  carries the data to the main memory  606 , from which the processor  604  retrieves and executes the instructions. The instructions received from the main memory  606  may optionally be stored on the storage device  610  either before or after execution by the processor  604 . 
     The server  630  also includes a communication interface  618  coupled to the bus  602 . The communication interface  618  provides a two-way data communication coupling to a network link  620  that is connected to the world wide packet data communication network now commonly referred to as the Internet  628 . The Internet  628  uses electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on the network link  620  and through the communication interface  618 , which carry the digital data to and from the server  630 , are exemplary forms or carrier waves transporting the information. 
     In another embodiment of the server  630 , interface  618  is connected to a network  622  via a communication link  620 . For example, the communication interface  618  may be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line, which can comprise part of the network link  620 . As another example, the communication interface  618  may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, the communication interface  618  sends and receives electrical electromagnetic or optical signals that carry digital data streams representing various types of information. 
     The network link  620  typically provides data communication through one or more networks to other data devices. For example, the network link  620  may provide a connection through the local network  622  to a host computer  624  or to data equipment operated by an Internet Service Provider (ISP). The ISP in turn provides data communication services through the Internet  628 . The local network  622  and the Internet  628  both use electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on the network link  620  and through the communication interface  618 , which carry the digital data to and from the server  630 , are exemplary forms or carrier waves transporting the information. 
     The server  630  can send/receive messages and data, including e-mail, program code, through the network, the network link  620  and the communication interface  618 . Further, the communication interface  618  can comprise a USB/Tuner and the network link  620  may be an antenna or cable for connecting the server  630  to a cable provider, satellite provider or other terrestrial transmission system for receiving messages, data and program code from another source. 
     The example versions of the embodiments described herein may be implemented as logical operations in a distributed processing system such as the system  600  including the servers  630 . The logical operations of the embodiments may be implemented as a sequence of steps executing in the server  630 , and as interconnected machine modules within the system  600 . The implementation is a matter of choice and can depend on performance of the system  600  implementing the embodiments. As such, the logical operations constituting said example versions of the embodiments are referred to for e.g., as operations, steps or modules. 
     Similar to a server  630  described above, a client device  601  can include a processor, memory, storage device, display, input device and communication interface (e.g., e-mail interface) for connecting the client device to the Internet  628 , the ISP, or LAN  622 , for communication with the servers  630 . 
     The system  600  can further include computers (e.g., personal computers, computing nodes)  605  operating in the same manner as client devices  601 , where a user can utilize one or more computers  605  to manage data in the server  630 . 
     Referring now to  FIG. 11 , illustrative cloud computing environment  50  is depicted. As shown, cloud computing environment  50  comprises one or more cloud computing nodes  10  with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA), smartphone, smart watch, set-top box, video game system, tablet, mobile computing device, or cellular telephone  54 A, desktop computer  54 B, laptop computer  54 C, and/or automobile computer system  54 N may communicate. Nodes  10  may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment  50  to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices  54 A-N shown in  FIG. 11  are intended to be illustrative only and that computing nodes  10  and cloud computing environment  50  can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser). 
     It is contemplated that various combinations and/or sub-combinations of the specific features and aspects of the above embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments may be combined with or substituted for one another in order to form varying modes of the disclosed invention. Further, it is intended that the scope of the present invention herein disclosed by way of examples should not be limited by the particular disclosed embodiments described above.