Patent Publication Number: US-2023140387-A1

Title: Landing systems and methods for unmanned aerial vehicles

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/273,126 filed Oct. 28, 2021 and entitled “LANDING SYSTEMS AND METHODS FOR UNMANNED AERIAL VEHICLES,” which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to unmanned aerial vehicles and, more particularly, to landing systems and methods for unmanned aerial vehicles. 
     BACKGROUND 
     Modern unmanned sensor platforms, such as unmanned aerial vehicles (UAVs), are able to operate over long distances and in various environments (e.g., rural, urban, undeveloped). In particular, UAVs are used to support a wide range of real-world applications including surveillance, reconnaissance, exploration, item transportation, disaster relief, aerial photography, large-scale agriculture monitoring, and other untethered or tethered applications. In many cases, a UAV may be equipped with a variety of different elements, such as different types of sensors and navigation devices, and may be configured to address a broad variety of operational needs. In conducting various missions, a UAV may have to land and take-off. Landing and take-off for UAVs, especially autonomous UAVs, require accurate positioning between the UAV and the landing location. Even more accurate positioning may be required when the UAV needs to be aligned with a target location to be docked for battery charging or replacement, data exchange and processing, picking up or loading cargo, or movement into storage. Further complications in landing UAVs arise when considering stresses that a UAV must endure to safely land. Thus, there exists a need for highly accurate and robust landing systems and methods capable of precise positioning and safe fixation of the UAV at landing locations. 
     SUMMARY 
     In one or more embodiments, a method includes receiving a UAV on a surface of a landing platform. The method may further include operating a positioning device disposed under the surface to locate the UAV. The method may further include operating the positioning device to move the UAV to a location and/or an orientation on the surface. The UAV may comprise landing gear having a plurality of legs, where each leg comprises a shock absorption system, and the method may further include operating the shock absorption system during the receiving operation to reduce force received at stress areas of the UAV, and after the receiving operation to dampen movement by the UAV. 
     In one or more embodiments, a system includes a landing platform having a surface, a positioning device disposed under the surface and communicatively coupled to a logic device. The logic device may be configured to receive the UAV on the surface of the landing platform. The logic device may further be configured to operate the positioning device to locate the UAV. The logic device may further be configured to operate the positioning device to move the UAV to a location and/or orientation on the surface. 
     The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the present invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a block diagram of a system in accordance with one or more embodiments of the present disclosure. 
         FIG.  2    illustrates a diagram of a system in accordance with one or more embodiments of the present disclosure. 
         FIG.  3    illustrates a flow diagram of a process for positioning a UAV on a landing platform in accordance with one or more embodiments of the present disclosure. 
         FIG.  4    illustrates a diagram of a UAV approaching a landing platform for landing in accordance with one or more embodiments of the present disclosure. 
         FIG.  5    illustrates a diagram of a UAV that has landed on a landing platform in accordance with one or more embodiments of the present disclosure. 
         FIG.  6    illustrates a diagram of a positioning device that has located a UAV that has landed on a landing platform in accordance with one or more embodiments of the present disclosure. 
         FIG.  7    illustrates a diagram of a UAV that has been moved to a target location and orientation on a landing platform in accordance with one or more embodiments of the present disclosure. 
         FIG.  8    illustrates diagrams showing a top view of a UAV (transparent) that has landed on a landing platform, is located using a positioning device, and is moved to a target location and orientation on the landing platform in accordance with one or more embodiments of the present disclosure. 
         FIGS.  9 A and  9 B  illustrate example implementations of landing platforms and UAVs in accordance with one or more embodiments of the present disclosure. 
         FIG.  10    illustrates example implementations of a UAV in accordance with one or more embodiments of the present disclosure. 
         FIG.  11    illustrates an example implementation of a UAV in accordance with one or more embodiments of the present disclosure. 
     
    
    
     Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It is noted that sizes of various components and distances between these components are not drawn to scale in the figures. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures. 
     DETAILED DESCRIPTION 
     The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced using one or more embodiments. In one or more instances, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. One or more embodiments of the subject disclosure are illustrated by and/or described in connection with one or more figures and are set forth in the claims. 
     Various systems and methods related to landing operations for a UAV are provided by the present disclosure. One issue related to landing operations is UAV positioning. Positioning a UAV on a landing surface or platform after landing is desirable for a number of reasons including aligning to dock for battery charging or replacement and data exchange and processing, picking up or loading cargo, movement into a structure for storage, or proper positioning to await a next mission. Other issues related to landing operations include impact on landing and descent velocity, which are challenging to address due to changing environments in which a UAV operates. Oftentimes, an unmanaged landing impact and descent velocity may cause a UAV to experience conditions where landing stresses exceed what the UAV can tolerate, which may lead to permanent deformation of components or failures. 
     In some embodiments, a UAV is received on a surface of a landing platform. The landing platform may have a positioning device disposed under the surface and implemented with a magnetic mechanism. The positioning device may be operable to locate the UAV from under the surface and move the UAV to a target location and/or orientation on the landing platform surface using the magnetic mechanism. For example, the positioning device may have an electromagnet that may be selectively activated to attract the UAV (e.g., metal disposed on the UAV landing gear/feet/skid/ring) and moved below the surface to slide the UAV above the surface to the target location and/or orientation and may also fixedly secure the UAV once properly positioned (or the UAV may be secured through various other mechanisms as would be understood by one skilled in the art). In one embodiment, the positioning device may have a Hall effect sensor that is operable to detect the location of the UAV on the landing platform. In another embodiment, the landing platform surface may have a conical shape to passively guide the UAV to the target location where the positioning device can then orient the UAV to the target orientation. 
     In further embodiments, the UAV may have landing gear implemented with a shock absorption system. The shock absorption system may include a spring and/or other visco-elastic material configured to reduce the force received at stress areas of the UAV during a landing operation. The shock absorption system may include a shock absorber configured to dampen the movement by the UAV after the landing operation that may partially be due to the spring. In an embodiment, the shock absorption system may be implemented as a magnetorheological shock absorber. The positioning device of the landing platform may be able to attract the magnetorheological shock absorber to locate and/or move the UAV after it has landed on the landing platform and may also fixedly secure the UAV once properly positioned (or secured via other techniques as would be understood by one skilled in the art). 
     While reference is primarily made to UAVs herein, it will be appreciated that the systems and methods described in the present disclosure may generally be applied for other types of vehicles such as automobiles, bikes, boats, etc. Additional details and embodiments are described by reference to the accompanying figures below. 
       FIG.  1    illustrates a block diagram of a system  100  including a UAV  110  in accordance with one or more embodiments of the present disclosure. In various embodiments, the system  100  and/or elements of the system  100  may be configured to fly over a scene or survey area, to fly through a structure, or to approach a target and image or sense the scene, structure, or target, or portions thereof, using a gimbal system  122  to aim an imaging system/sensor payload  140  at the scene, structure, or target, or portions thereof, for example. Resulting imagery and/or other sensor data may be processed (e.g., by the sensor payload  140 , UAV  110 , and/or base station  130 ) and displayed to a user through use of a user interface  132  (e.g., one or more displays such as a multi-function display (MFD), a portable electronic device such as a tablet, laptop, or smart phone, or other appropriate interface) and/or stored in memory for later viewing and/or analysis. In some embodiments, the system  100  may be configured to use such imagery and/or sensor data to control operation of the UAV  110  and/or the sensor payload  140 , as described herein, such as controlling the gimbal system  122  to aim the sensor payload  140  towards a particular direction, and/or controlling a propulsion system  124  to move the UAV  110  to a desired position in a scene or structure or relative to a target. In some cases, the imagery and/or sensor data may be used to detect light emitting devices or fiducial markers, such as AprilTag markers, associated with a target location and, in turn, land the UAV  110  at the target location or align the UAV  110  to interact with the target location, which may be on a landing platform  131 . 
     In the embodiment shown in  FIG.  1   , the system  100  includes the UAV  110 , a base station  130 , at least one imaging system/sensor payload  140 , and a landing platform  402 . The UAV  110  may be implemented as a mobile platform configured to move or fly and position and/or aim the sensor payload  140  (e.g., relative to a designated or detected target). As shown in  FIG.  1   , the UAV  110  may include one or more of a logic device  112 , an orientation sensor  114 , a gyroscope/accelerometer  116 , a global navigation satellite system (GNSS)  118 , a communication system  120 , a gimbal system  122 , a propulsion system  124 , and other modules  126 . Operation of the UAV  110  may be substantially autonomous and/or partially or completely controlled by the base station  130 , which may include one or more of the following: a user interface  132 , a communications module  134 , a logic device  138 , and other modules  136 . In other embodiments, the UAV  110  may include one or more of the elements of the base station  130 , such as with various types of manned aircraft, terrestrial vehicles, and/or surface or subsurface watercraft. The sensor payload  140  may be physically coupled to the UAV  110  and be configured to capture sensor data (e.g., visible spectrum images, infrared images, narrow aperture radar data, and/or other sensor data) of a target position, area, and/or object(s) as selected and/or framed by operation of the UAV  110  and/or the base station  130 . In some embodiments, one or more of the elements of the system  100  may be implemented in a combined housing or structure that can be coupled to or within the UAV  110  and/or held or carried by a user of the system  100 . 
     The logic device  112  may be implemented as any appropriate logic device (e.g., processing device, microcontroller, processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), memory storage device, memory reader, or other device or combinations of devices) that may be adapted to execute, store, and/or receive appropriate instructions, such as software instructions implementing a control loop for controlling various operations of the UAV  110  and/or other elements of the system  100 , such as the gimbal system  122 , for example. Such software instructions may also implement methods for processing infrared images and/or other sensor signals, determining sensor information, providing user feedback (e.g., through the user interface  132 ), querying devices for operational parameters, selecting operational parameters for devices, or performing any of the various operations described herein (e.g., operations performed by logic devices of various elements of the system  100 ). 
     In addition, a non-transitory medium may be provided for storing machine readable instructions for loading into and execution by the logic device  112 . In these and other embodiments, the logic device  112  may be implemented with other components where appropriate, such as volatile memory, non-volatile memory, one or more interfaces, and/or various analog and/or digital components for interfacing with devices of the system  100 . For example, the logic device  112  may be adapted to store sensor signals, sensor information, parameters for coordinate frame transformations, calibration parameters, sets of calibration points, and/or other operational parameters, over time, for example, and provide such stored data to a user using the user interface  132 . In some embodiments, the logic device  112  may be integrated with one or more other elements of the UAV  110 , for example, or distributed as multiple logic devices within the UAV  110 , base station  130 , and/or sensor payload  140 . 
     In some embodiments, the logic device  112  may be configured to substantially continuously monitor and/or store the status of and/or sensor data provided by one or more elements of the UAV  110 , sensor payload  140 , and/or base station  130 , such as the position and/or orientation of the UAV  110 , sensor payload  140 , and/or base station  130 , for example. In various embodiments, sensor data may be monitored and/or stored by the logic device  112  and/or processed or transmitted between elements of the system  100  substantially continuously throughout operation of the system  100 , where such data includes various types of sensor data (e.g., for blinking pattern detection), control parameters, and/or other data. 
     The orientation sensor  114  may be implemented as one or more of a compass, float, accelerometer, and/or other device capable of measuring an orientation of the UAV  110  (e.g., magnitude and direction of roll, pitch, and/or yaw, relative to one or more reference orientations such as gravity and/or Magnetic North), gimbal system  122 , imaging system/sensor payload  140 , and/or other elements of system  100 , and providing such measurements as sensor signals and/or data that may be communicated to various devices of the system  100 . In some cases, a yaw and/or position of the UAV  110  may be adjusted to better position/orient the UAV  110  to align with a target location based on a fiduciary marker associated with the target location. The gyroscope/accelerometer  116  may be implemented as one or more electronic sextants, semiconductor devices, integrated chips, accelerometer sensors, accelerometer sensor systems, or other devices capable of measuring angular velocities/accelerations and/or linear accelerations (e.g., direction and magnitude) of the UAV  110  and/or other elements of the system  100  and providing such measurements as sensor signals and/or data that may be communicated to other devices of the system  100  (e.g., user interface  132 , logic device  112 , logic device  138 ). The GNSS  118  may be implemented according to any global navigation satellite system, including a GPS, GLONASS, and/or Galileo based receiver and/or other device capable of determining absolute and/or relative position of the UAV  110  (e.g., or an element of the UAV  110 ) based on wireless signals received from space-born and/or terrestrial sources (e.g., eLoran, and/or other at least partially terrestrial systems), for example, and capable of providing such measurements as sensor signals and/or data (e.g., coordinates) that may be communicated to various devices of the system  100 . In some embodiments, the GNSS  118  may include an altimeter, for example, or may be used to provide an absolute altitude. 
     The communication system  120  may be implemented as any wired and/or wireless communications module configured to transmit and receive analog and/or digital signals between elements of the system  100 . For example, the communication system  120  may be configured to receive flight control signals and/or data from the base station  130  and provide them to the logic device  112  and/or propulsion system  124 . In other embodiments, the communication system  120  may be configured to receive images and/or other sensor information (e.g., visible spectrum and/or infrared still images or video images) from the sensor payload  140  and relay the sensor data to the logic device  112  and/or base station  130 . In some embodiments, the communication system  120  may be configured to support spread spectrum transmissions, for example, and/or multiple simultaneous communications channels between elements of the system  100 . Wireless communication links may include one or more analog and/or digital radio communication links, such as WiFi and others, as described herein, and may be direct communication links established between elements of the system  100 , for example, or may be relayed through one or more wireless relay stations configured to receive and retransmit wireless communications. Communication links established by the communication system  120  may be configured to transmit data between elements of the system  100  substantially continuously throughout operation of the system  100 , where such data includes various types of sensor data, control parameters, and/or other data. 
     The gimbal system  122  may be implemented as an actuated gimbal mount, for example, that may be controlled by the logic device  112  to stabilize the sensor payload  140  relative to a target (e.g., a target location) or to aim the sensor payload  140  or components coupled thereto according to a desired direction and/or relative orientation or position. As such, the gimbal system  122  may be configured to provide a relative orientation of the sensor payload  140  (e.g., relative to an orientation of the UAV  110 ) to the logic device  112  and/or communication system  120  (e.g., gimbal system  122  may include its own orientation sensor  114 ). In other embodiments, the gimbal system  122  may be implemented as a gravity driven mount (e.g., non-actuated). In various embodiments, the gimbal system  122  may be configured to provide power, support wired communications, and/or otherwise facilitate operation of articulated the sensor/sensor payload  140 . In further embodiments, the gimbal system  122  may be configured to couple to a laser pointer, range finder, and/or other device, for example, to support, stabilize, power, and/or aim multiple devices (e.g., the sensor payload  140  and one or more other devices) substantially simultaneously. 
     In some embodiments, the gimbal system  122  may be adapted to rotate the sensor payload  140 ±90 degrees, or up to 360 degrees, in a vertical plane relative to an orientation and/or position of the UAV  110 . In further embodiments, the gimbal system  122  may rotate the sensor payload  140  to be parallel to a longitudinal axis or a lateral axis of the UAV  110  as the UAV  110  yaws, which may provide 360 degree ranging and/or imaging in a horizontal plane relative to UAV  110 . In various embodiments, logic device  112  may be configured to monitor an orientation of gimbal system  122  and/or sensor payload  140  relative to UAV  110 , for example, or an absolute or relative orientation of an element of sensor payload  140 . Such orientation data may be transmitted to other elements of system  100  for monitoring, storage, or further processing, as described herein. 
     The propulsion system  124  may be implemented as one or more propellers, rotors, turbines, or other thrust-based propulsion systems, and/or other types of propulsion systems that can be used to provide motive force and/or lift to the UAV  110  and/or to steer the UAV  110 . In some embodiments, the propulsion system  124  may include multiple propellers (e.g., a tri, quad, hex, oct, or other type “copter”) that can be controlled (e.g., by the logic device  112  and/or the logic device  138 ) to provide lift and motion for the UAV  110  and to provide an orientation for UAV  110 . In other embodiments, the propulsion system  124  may be configured primarily to provide thrust while other structures of the UAV  110  provide lift, such as in a fixed wing embodiment (e.g., where wings provide the lift) and/or an aerostat embodiment (e.g., balloons, airships, hybrid aerostats). In various embodiments, the propulsion system  124  may be implemented with a portable power supply, such as a battery and/or a combustion engine/generator and fuel supply. 
     Other modules  126  may include other and/or additional sensors, actuators, communications modules/nodes, and/or user interface devices, for example, and may be used to provide additional environmental information related to operation of the UAV  110 , for example. In some embodiments, other modules  126  may include a humidity sensor, a wind and/or water temperature sensor, a barometer, an altimeter, a radar system, a proximity sensor, a visible spectrum camera or infrared camera (with an additional mount), an irradiance detector, and/or other environmental sensors providing measurements and/or other sensor signals that can be displayed to a user and/or used by other devices of the system  100  (e.g., logic device  112 ) to provide operational control of the UAV  110  and/or the system  100 . 
     In some embodiments, other modules  126  may include one or more actuated and/or articulated devices (e.g., light emitting devices (e.g., light emitting diodes), multi-spectrum active illuminators, visible and/or IR cameras, radars, sonars, and/or other actuated devices) coupled to the UAV  110 , where each actuated device includes one or more actuators adapted to adjust an orientation of the device, relative to the UAV  110 , in response to one or more control signals (e.g., provided by the logic device  112 ). In particular, other modules  126  may include a stereo vision system configured to provide image data that may be used to calculate or estimate a position of the UAV  110 , for example, or to calculate or estimate a relative position of a navigational hazard in proximity to the UAV  110 . In various embodiments, the logic device  112  may be configured to use such proximity and/or position information to help safely pilot the UAV  110  and/or monitor communication link quality, as described herein. 
     The landing gear  128  may be implemented according to various embodiments. The landing gear  128  may provide the principal support of the UAV  110  during landing, enable the UAV  110  to land on a landing platform or ground/terrain and keep other areas of the UAV above a landing surface, and absorb the landing impact energy so as to minimize the loads transmitted to a frame/body of the UAV  110  including any of the sensor components of the UAV  110 . In some embodiments, the landing gear  128  may be located at ends of propulsion system extension arms or under the center of rest of the UAV  110  (e.g., the body). The landing gear  128  may include various components including a shock absorber system (e.g., spring, shock absorber), legs, wheels, a brake system, a turning system, an undercarriage retractile system, etc. In some embodiments, the landing gear  128  may include a magnet (e.g., an electromagnet) or metal that may be used as described herein in conjunction with the landing platform  131  to locate and/or move the UAV  110  about the landing platform  131  to a target position and/or orientation and may further secure the UAV to the landing platform (or the UAV may be secured by various other techniques as would be known by one skilled in the art). In some cases, the landing gear  128  may include a plurality of legs, where each leg has a corresponding shock absorber system that can be operated during and after a landing of the UAV  110  to reduce force received at stress areas of the UAV  110 . The shock absorption system may further dampen movement by the UAV  110  after the landing. The shock absorption system may include a spring and/or other visco-elastic material to reduce the force at the stress areas and a shock absorber configured to dampen the movement caused by the spring and/or other visco-elastic material. The spring may be configured to bias two portions of a corresponding leg according to some implementations. In some embodiments, the shock absorber may include a magnetorheological shock absorber, where the magnetorheological shock absorber may be attracted by a positioning device of the landing platform  131  to locate and/or move the UAV  110 . 
     The landing platform  131  of the system  100  may be configured to receive the UAV  110  on a surface of the landing platform  131 . The landing platform  131  may include a positioning device disposed under the surface of the landing platform  131 , where the positioning device may be operated to locate the UAV  110  and move the UAV  110  to a location and/or orientation of the surface. For example, the positioning device may be operated to translate the UAV  110  to the location on the surface and/or rotate the UAV  110  to the orientation on the surface. The landing platform  131  may further include at least one Hall effect sensor, which may be implemented in the positioning device. The Hall effect sensor may be used to detect a magnet or other component disposed on the UAV  110  (e.g., the landing gear  128  or components thereof). 
     The user interface  132  of the base station  130  may be implemented as one or more of a display, a touch screen, a keyboard, a mouse, a joystick, a knob, a steering wheel, a yoke, and/or any other device capable of accepting user input and/or providing feedback to a user. In various embodiments, the user interface  132  may be adapted to provide user input (e.g., as a type of signal and/or sensor information transmitted by the communication system  134  of the base station  130 ) to other devices of the system  100 , such as the logic device  112 . The user interface  132  may also be implemented with logic device  138  (e.g., similar to logic device  112 ), which may be adapted to store and/or execute instructions, such as software instructions, implementing any of the various processes and/or methods described herein. For example, the user interface  132  may be adapted to form communication links and transmit and/or receive communications (e.g., infrared images and/or other sensor signals, control signals, sensor information, user input, and/or other information), for example, or to perform various other processes and/or methods described herein (e.g., via logic device  138 ). 
     In one embodiment, the user interface  132  may be adapted to display a time series of various sensor information and/or other parameters as part of or overlaid on a graph or map, which may be referenced to a position and/or orientation of the UAV  110  and/or other elements of the system  100 . For example, the user interface  132  may be adapted to display a time series of positions, headings, and/or orientations of the UAV  110  and/or other elements of the system  100  overlaid on a geographical map, which may include one or more graphs indicating a corresponding time series of actuator control signals, sensor information, and/or other sensor and/or control signals. 
     In some embodiments, the user interface  132  may be adapted to accept user input including a user-defined target heading, waypoint, route, and/or orientation for an element of the system  100 , for example, and to generate control signals to cause the UAV  110  to move according to the target heading, route, and/or orientation, or to aim the sensor payload  140  accordingly. In other embodiments, the user interface  132  may be adapted to accept user input modifying a control loop parameter of the logic device  112 , for example. In further embodiments, the user interface  132  may be adapted to accept user input including a user-defined target attitude, orientation, and/or position for an actuated or articulated device (e.g., the sensor payload  140 ) associated with the UAV  110 , for example, and to generate control signals for adjusting an orientation and/or position of the actuated device according to the target altitude, orientation, and/or position. Such control signals may be transmitted to the logic device  112  (e.g., using the communication system  134  and  120 ), which may then control the UAV  110  accordingly. 
     The communication system  134  may be implemented as any wired and/or wireless communications module configured to transmit and receive analog and/or digital signals between elements of the system  100 . For example, the communication system  134  may be configured to transmit flight control signals from the user interface  132  to communication system  120  or  144 . In other embodiments, the communication system  134  may be configured to receive sensor data (e.g., visible spectrum and/or infrared still images or video images, or other sensor data) from the sensor payload  140 . In some embodiments, the communication system  134  may be configured to support spread spectrum transmissions, for example, and/or multiple simultaneous communications channels between elements of the system  100 . In various embodiments, the communication system  134  may be configured to monitor the status of a communication link established between the base station  130 , the sensor payload  140 , and/or the UAV  110  (e.g., including packet loss of transmitted and received data between elements of the system  100 , such as with digital communication links), as described herein. Such status information may be provided to the user interface  132 , for example, or transmitted to other elements of the system  100  for monitoring, storage, or further processing. 
     Other modules  136  of the base station  130  may include other and/or additional sensors, actuators, communications modules/nodes, and/or user interface devices used to provide additional environmental information associated with the base station  130 , for example. In some embodiments, other modules  136  may include a humidity sensor, a wind and/or water temperature sensor, a barometer, a radar system, a visible spectrum camera, an infrared camera, a GNSS, and/or other environmental sensors providing measurements and/or other sensor signals that can be displayed to a user and/or used by other devices of the system  100  (e.g., logic device  112 ) to provide operational control of the UAV  110  and/or system  100  or to process sensor data to compensate for environmental conditions, such as an water content in the atmosphere approximately at the same altitude and/or within the same area as the UAV  110  and/or base station  130 , for example. In some embodiments, other modules  136  may include one or more actuated and/or articulated devices (e.g., multi-spectrum active illuminators, visible and/or IR cameras, radars, sonars, and/or other actuated devices), where each actuated device includes one or more actuators adapted to adjust an orientation of the device in response to one or more control signals (e.g., provided by the user interface  132 ). 
     In embodiments where the imaging system/sensor payload  140  is implemented as an imaging device, the imaging system/sensor payload  140  may include an imaging module  142 , which may be implemented as a cooled and/or uncooled array of detector elements, such as visible spectrum and/or infrared sensitive detector elements, including quantum well infrared photodetector elements, bolometer or microbolometer based detector elements, type II superlattice based detector elements, and/or other infrared spectrum detector elements that can be arranged in a focal plane array. In various embodiments, the imaging module  142  may include one or more logic devices (e.g., similar to the logic device  112 ) that can be configured to process imagery captured by detector elements of the imaging module  142  before providing the imagery to memory  146  or the communication system  144 . More generally, the imaging module  142  may be configured to perform any of the operations or methods described herein, at least in part, or in combination with the logic device  112  and/or user interface  132 . 
     In some embodiments, the sensor payload  140  may be implemented with a second or additional imaging modules similar to the imaging module  142 , for example, that may include detector elements configured to detect other electromagnetic spectrums, such as visible light, ultraviolet, and/or other electromagnetic spectrums or subsets of such spectrums. In various embodiments, such additional imaging modules may be calibrated or registered to the imaging module  142  such that images captured by each imaging module occupy a known and at least partially overlapping field of view of the other imaging modules, thereby allowing different spectrum images to be geometrically registered to each other (e.g., by scaling and/or positioning). In some embodiments, different spectrum images may be registered to each other using pattern recognition processing in addition or as an alternative to reliance on a known overlapping field of view. 
     The communication system  144  of the sensor payload  140  may be implemented as any wired and/or wireless communications module configured to transmit and receive analog and/or digital signals between elements of the system  100 . For example, the communication system  144  may be configured to transmit infrared images from the imaging module  142  to communication system  120  or  134 . In other embodiments, the communication system  144  may be configured to receive control signals (e.g., control signals directing capture, focus, selective filtering, and/or other operation of sensor payload  140 ) from the logic device  112  and/or user interface  132 . In some embodiments, communication system  144  may be configured to support spread spectrum transmissions, for example, and/or multiple simultaneous communications channels between elements of the system  100 . In various embodiments, the communication system  144  may be configured to monitor and communicate the status of an orientation of the sensor payload  140  as described herein. Such status information may be provided or transmitted to other elements of the system  100  for monitoring, storage, or further processing. 
     The memory  146  may be implemented as one or more machine readable mediums and/or logic devices configured to store software instructions, sensor signals, control signals, operational parameters, calibration parameters, infrared images, and/or other data facilitating operation of the system  100 , for example, and provide it to various elements of the system  100 . The memory  146  may also be implemented, at least in part, as removable memory, such as a secure digital memory card for example including an interface for such memory. 
     An orientation sensor  148  of the sensor payload  140  may be implemented similar to the orientation sensor  114  or gyroscope/accelerometer  116 , and/or any other device capable of measuring an orientation of the sensor payload  140 , the imaging module  142 , and/or other elements of the sensor payload  140  (e.g., magnitude and direction of roll, pitch, and/or yaw, relative to one or more reference orientations such as gravity, Magnetic North, and/or an orientation of the UAV  110 ) and providing such measurements as sensor signals that may be communicated to various devices of the system  100 . A gyroscope/accelerometer (e.g., angular motion sensor)  150  of the sensor payload  140  may be implemented as one or more electronic sextants, semiconductor devices, integrated chips, accelerometer sensors, accelerometer sensor systems, or other devices capable of measuring angular velocities/accelerations (e.g., angular motion) and/or linear accelerations (e.g., direction and magnitude) of the sensor payload  140  and/or various elements of the sensor payload  140  and providing such measurements as sensor signals that may be communicated to various devices of the system  100 . 
     Other modules  152  of the sensor payload  140  may include other and/or additional sensors, actuators, communications modules/nodes, cooled or uncooled optical filters, and/or user interface devices used to provide additional environmental information associated with the sensor payload  140 , for example. In some embodiments, other modules  152  may include a humidity sensor, a wind and/or water temperature sensor, a barometer, a radar system, a visible spectrum camera, an infrared camera, a GNSS, and/or other environmental sensors providing measurements and/or other sensor signals that can be displayed to a user and/or used by the imaging module  142  or other devices of the system  100  (e.g., logic device  112 ) to provide operational control of the UAV  110  and/or system  100  or to process imagery to compensate for environmental conditions. 
     In general, each of the elements of the system  100  may be implemented with any appropriate logic device (e.g., processing device, microcontroller, processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), memory storage device, memory reader, or other device or combinations of devices) that may be adapted to execute, store, and/or receive appropriate instructions, such as software instructions implementing a method for providing sensor data and/or imagery, for example, or for transmitting and/or receiving communications, such as sensor signals, sensor information, and/or control signals, between one or more devices of the system  100 . In addition, one or more non-transitory mediums may be provided for storing machine readable instructions for loading into and execution by any logic device implemented with one or more of the devices of the system  100 . In these and other embodiments, the logic devices may be implemented with other components where appropriate, such as volatile memory, non-volatile memory, and/or one or more interfaces (e.g., inter-integrated circuit (I2C) interfaces, mobile industry processor interfaces (MIPI), joint test action group (JTAG) interfaces (e.g., IEEE 1149.1 standard test access port and boundary-scan architecture), and/or other interfaces, such as an interface for one or more antennas, or an interface for a particular type of sensor). 
     Sensor signals, control signals, and other signals may be communicated among elements of the system  100  using a variety of wired and/or wireless communication techniques, including voltage signaling, Ethernet, WiFi, Bluetooth, Zigbee, Xbee, Micronet, or other medium and/or short range wired and/or wireless networking protocols and/or implementations, for example. In such embodiments, each element of the system  100  may include one or more modules supporting wired, wireless, and/or a combination of wired and wireless communication techniques. In some embodiments, various elements or portions of elements of the system  100  may be integrated with each other, for example, or may be integrated onto a single printed circuit board (PCB) to reduce system complexity, manufacturing costs, power requirements, coordinate frame errors, and/or timing errors between the various sensor measurements. Each element of the system  100  may include one or more batteries, capacitors, or other electrical power storage devices, for example, and may include one or more solar cell modules or other electrical power generating devices. In some embodiments, one or more of the devices may be powered by a power source for the UAV  110 , using one or more power leads. Such power leads may also be used to support one or more communication techniques between elements of the system  100 . 
       FIG.  2    illustrates a diagram of a system  200  in accordance with one or more embodiments of the present disclosure. In the embodiment shown in  FIG.  2   , the system  200  includes a base station  130 , a UAV  110 , and a landing platform  131 . In some embodiments, the base station  130  may be configured to control motion, position, and/or orientation of the UAV  110  and/or sensor payloads  140 . Further, the base station  130  may be configured to control operation of the landing platform  131  in some embodiments. In various embodiments, the UAV  110  may be configured to control an operation of the landing platform  131  such that the UAV  110  may automate a landing procedure as discussed herein. Generally, the system  200  may include any number of UAVs, landing platforms, and base stations. 
       FIG.  3    illustrates a flow diagram of an example process  300  for positioning a UAV on a landing platform in accordance with one or more embodiments of the present disclosure. For explanatory purposes, the process  300  is described with reference to  FIGS.  4 - 9   . Note that one or more operations in  FIG.  3    may be combined, omitted, and/or performed in a different order as desired. According to various embodiments, the process  300  may be performed by a logic device, such as the logic device  112  of the UAV  110 , a logic device for a landing platform  131 , the logic device  138  for the base station  130 , or a combination of the aforementioned logic devices, which may be communicatively coupled to execute the operations of process  300 . 
     At block  302  of process  300 , and in reference to an environment  400  of  FIG.  4   , a logic device may operate the UAV  110  to land the UAV  110  on a surface  402  of the landing platform  131 . In some embodiments, the imaging system  140  may capture images of a target location on the surface  402  to land the UAV  110  on the landing platform  131 . For example, the imaging system  140  may capture images of the surface  402  from certain distances away as the UAV  110  approaches the landing platform  131 , where the images may be used to guide the UAV  110  to the target location on the surface  402  of the landing platform  131 . In some embodiments, the surface  402  may include fiduciary markers such as AprilTags or light emitting device patterns, which may be used to guide the UAV  110  toward a target location on the surface  402 . The logic device may communicate with imaging system  140  to capture and process said images according to some embodiments. 
     In various embodiments, the landing platform  131  may be where the UAV  110  is parked for movement into storage or docked for power (e.g., battery charging) or data exchange. In cases where the UAV  110  needs to be aligned, such as for battery charging or data exchange, the UAV  110  may need to be precisely aligned on the landing platform  131  in a target location and/or orientation such that a wired or wireless interface may connect the UAV  110  to an electronic system associated with the landing platform  131 . The electronic system associated with the landing platform  131  may be configured to provide power to the UAV  110  and/or exchange data with the UAV  110 . 
     At block  304  of process  300 , the landing platform  131  may receive the UAV  110  on the surface  402  of the landing platform  131 . However, the UAV  110  may not have landed on the surface  402  at the target location and/or in the target orientation. For example, in reference to diagram  802  of  FIG.  8   , a UAV&#39;s landing position, as denoted by the solid-line ABCD pattern, may be offset from the target location and target orientation denoted by the dashed-line ABCD pattern. 
     In some embodiments, the logic device may detect that the UAV  110  did not land in the target location or orientation. For example, the UAV  110  may communicate to the landing platform  131  that the UAV  110  has landed, but a positioning device  404  located under the surface  402  of the landing platform  131  may be used to determine that the UAV  110  is not at the target location and orientation denoted by the dash-line ABCD pattern. In some embodiments, the UAV  110  may be able to determine that it has not precisely landed on the surface  402 , such as through imagery of fiduciary markers on the landing platform  131 , and may request the landing platform  131  to make any needed corrections to move the UAV  110  to the target location and/or orientation. In this regard, in some embodiments, the UAV  110  may make a rough landing while the landing platform  131  may be used to make fine adjustments to the location and orientation of the UAV  110  to place the UAV  110  in a target location and/or orientation and may further secure the UAV  110  to the landing platform  131  once properly positioned. 
     At block  306  of process  300 , the logic device may operate the positioning device  404  to locate the UAV  110 . In various embodiment, the positioning device  404  may be disposed under the surface  402  of the landing platform  131  such that the positioning device  404  is able to make detections through the surface  402 . Thus, the positioning device  404  may be disposed sufficiently near or touching an underside of the surface  402  opposite of the UAV  110 , such that the positioning device  404  may move about the underside of the surface  402  to locate the UAV  110 . 
     In some embodiments, the positioning device  404  may include one or more Hall effect sensors configured to interact with components (e.g., magnet, electromagnet) disposed in the landing gear  128  of the UAV  110 . The logic device may locate the UAV  110  by moving the positioning device  404 , such as in a predefined pattern under the surface  402  and detecting an interaction between the Hall effect sensor(s) and the component(s) of the landing gear  128 . For example, in reference to  FIG.  5   , the positioning device  404  may locate the UAV  110  by detecting a magnet  502  disposed on the landing gear  128  of the UAV  110 . The positioning device  404  may be operated to continue locating each magnet of the remaining legs of the landing gear  128  until each leg has been found and the positioning device  404  is in a position under the surface  402  suitable to move the UAV  110  (e.g., underneath the UAV  110 ) as shown in  FIG.  6    and may further for an embodiment be used to secure the UAV  110  in a fixed position once properly positioned. 
     As another example, referring to diagram  804  shown in  FIG.  8   , the positioning device  404  may have located at a magnet disposed on the UAV  110 , depicted as solid-line A. As shown in diagrams  806  and  808  of  FIG.  8   , once the positioning device  404  has located one magnet disposed on the UAV  110 , the positioning device  404  may be operated to locate the other magnets of the UAV  110 , which may correspond to legs of the landing gear  128  and depicted as solid-lines BCD. It is noted that the positioning device  404  may be configured to have translational and rotational motion to locate and move the UAV  110 . 
     At block  308  of process  300 , the logic device may operate the positioning device  404  to move the UAV  110  to a location and/or orientation on the surface  404  of the landing platform  131 . For example, the positioning device  404  may move the UAV  110  from the initial landing location on the surface  404  shown in  FIG.  6    to the target location shown in  FIG.  7   . As another example, and in reference to diagrams  808 - 812  of  FIG.  8   , the positioning device  404  may move the UAV  110  from an initial landing location on the surface  404  to the target location and orientation, which is depicted as the solid-line ABCD pattern for the UAV  110  aligning with the dashed-line ABCD pattern for the target location and orientation. 
     According to various embodiments, once the UAV  110  has been moved to the target location and/or orientation, the logic device may operate one or more other electromechanical systems associated with the landing platform  131  to perform actions. For example, the logic device may dock (e.g., connect by wire or wirelessly) the UAV  110  for battery charging or replacement and/or data exchange and processing. As another example, the logic device may cause a pick-up or loading of cargo. As another example, the logic device may cause the UAV  110  to be moved and/or packaged for storage or safely secured to the landing platform  131 . In cases where the UAV  110  is moved and/or packaged for storage, moving the UAV  110  to a correct location and orientation may be required, such as to prevent damage to the UAV  110  for example. 
     Referring now to  FIGS.  9 A and  9 B , illustrated are example implementations of a landing platform and a UAV (e.g., similar to landing platform  404  and UAV  110 ) in accordance with various embodiments of the present disclosure. In example  900   a , a landing platform  131   a  may include positioning device  404   a  disposed under the surface  402   a  of the landing platform  131   a , where the surface  402   a  has a flat configuration suitable to receive the UAV  110 . A logic device  902  may be communicatively coupled to the positioning device  404   a  to operate the positioning device  404   a  as generally described herein. In some embodiments, the logic device  902  may be the logic device  112  of the UAV  110 , the logic device  138  of the base station  130 , and/or a logic device of the positioning device  404   a , which may be communicatively coupled to the logic device  112  and/or the logic device  138 . 
     The positioning device  404   a  may further include components  904 . In some embodiments, the components  904  may be magnets, such as permanent magnets or temporary magnets. In some cases, the components  904  may be implemented as electromagnets, which may be a type of magnet in which a magnetic field is produced by selectively passing an electric current through a wire wound into a coil. Further, when the components  904  are implemented as electromagnets, the logic device  902  may selectively activate the electromagnets for certain operations in process  300  of  FIG.  3   , such as when locating the UAV  110  and moving the UAV  110 . The logic device  902  may deactivate the electromagnets when they are not needed or to control the electromagnets to fixedly secure the UAV  110  to the landing platform  131 . In some embodiments, the components  904  of the positioning device  404   a  may include a metal substance configured to interact with components  906  disposed on the landing gear  128   a  of the UAV  110 . For example, the components  906  of the UAV  110  may be implemented as permanent magnets or temporary magnets, including electromagnets, which may be selectively activated by the UAV  110  or the positioning device  404   a  to interact with the components  904  of the positioning device  404   a . In other embodiments, the components  906  may be implemented to include a metal substance that is configured to interact with the components  904  of the positioning device  404 . 
     According to one embodiment, the positioning device  404   a  may be configured to move away (e.g., in a negative-Z direction depicted in example  900   a ) from the underside of the surface  402   a  to reduce a magnetic force on the UAV  110  (e.g., the landing gear  128   a ). For example, in embodiments where components  904  are implemented as permanent magnets and components  906  are implemented to include a metal substance, the positioning device  404   a  may be moved away from the underside of the surface  402   a  so that the UAV  110  may take-off or otherwise move about the landing platform  131   a  without or with minimal interference. 
     Example  900   b  may be similar to example  900   a . However, in example  900   b , the surface  402   b  of the landing platform  131   b  may be implemented to have a raised perimeter  908  adjacent to the surface  402   b , which may be configured to guide landing gear  128   b  of the UAV  110 , and thus the UAV  110 , to a target location on the surface  402   b . For example, the landing gear  128   b  may have a ring configuration or other configuration that complements the raised perimeter  908  of the surface  402   b  such that the UAV  110  passively sinks into the target location on the surface  402   b  through gravity. For example, the raised perimeter  908  may be substantially conical to guide the UAV  110  to a centered target location on the surface  402   b . In such cases, the UAV  110  lands in the target location and the positioning device  404   b  may rotate the UAV  110  about the surface  402   b  to arrive at the target orientation. 
     In some embodiments, the logic device  902  may determine an orientation of the UAV  110  so that the positioning device  404   b  can correctly rotate the UAV  110  to the target orientation. In various embodiments, the components  904  may be synced with the components  906  such that the logic device  902  will know the orientation of the UAV  110  when each component  906  of the UAV  110  is located using the components  904  of the positioning device  404   b . In some cases, each component  906  may have a passive or active identifier that may be used to identify the orientation of the UAV  110 . In other embodiments, the UAV  110  may determine an orientation for itself (e.g., using orientation sensor  114 ), which may be passed to the logic device  902  so that the logic device  902  knows how to rotate the UAV  110  to the correct target orientation. 
     Referring now to  FIG.  10   , illustrated are example implementations of the UAV  110  in accordance with various embodiments of the present disclosure. During landing of the UAV  110 , areas that are joined and/or furthest away from a center of gravity of the UAV  110  typically exhibit most of the stresses of landing and are more prone to extensive deflection/stresses, fractures, and/or failures due to increased and/or concentrated stresses. Typically, when a UAV system&#39;s overall size and mass increases, so do landing stresses. To reduce stresses during landing, a shock absorption system  1002  may be implemented to reduce overall impact energy/force(s) on areas that are more prone to higher deflection/stresses (e.g., stress areas). In example  1000   a , the UAV  110  may include shock absorption system  1002  implemented on each leg of the landing gear  128  that extends from a body of the UAV  110 . More or less legs of the landing gear  128  may be implemented according to various configurations. In example  1000   b , the UAV  110  may include shock absorption system  1002  implemented on landing gear  128  located at the ends of propulsion system extension arms  1004 . 
     In some embodiments, the shock absorption system  1002  may be operated to reduce force received at stress areas of the UAV  110  when the landing platform  131  receives the UAV  110  during landing. For example, referring now to  FIG.  11   , the shock absorption system  1002  may include a spring  1102  or other elastic and/or other visco-elastic material configured to reduce the impact force at landing. In some embodiments, the spring  1102  may connect two portions of a leg of the landing gear  128  (e.g., portion  1106   a  and  1106   b ), where the two portions of the leg may telescope (e.g., one leg barrel is insertable into the second leg barrel) and be biased relative to each other by the spring or other elastic and/or other visco-elastic material. 
     The shock absorption system  1002  may further include a shock absorber  1104  configured to dampen movement by the UAV  110  at landing, such as vibrations caused by the spring  1102 . The shock absorber  1104  may be implemented with gas, liquid, or other material(s) with rebounding characteristics. In some embodiments, the shock absorber  1104  may be a magnetorheological shock absorber, which may be filled with magnetorheological fluid that can be controlled by a magnetic field produced by an electromagnet. In some embodiments, the UAV  110  may be configured to continuously control the damping characteristics of the magnetorheological shock absorber during landing by varying the power of the electromagnet, which may cause a fluid viscosity in the magnetorheological shock absorber to increase or decrease based on the electromagnet intensity. In some embodiments, the positioning device  404  of the landing platform  131  may be configured to attract the magnetorheological shock absorber to locate and/or move the UAV  110  as described herein. 
     Where applicable, various embodiments provided by the present disclosure can be implemented using hardware, software, or combinations of hardware and software. Also, where applicable, the various hardware components and/or software components set forth herein can be combined into composite components comprising software, hardware, and/or both without departing from the spirit of the present disclosure. Where applicable, the various hardware components and/or software components set forth herein can be separated into sub-components comprising software, hardware, or both without departing from the spirit of the present disclosure. In addition, where applicable, it is contemplated that software components can be implemented as hardware components, and vice-versa. 
     Software in accordance with the present disclosure, such as non-transitory instructions, program code, and/or data, can be stored on one or more non-transitory machine-readable mediums. It is also contemplated that software identified herein can be implemented using one or more general purpose or specific purpose computers and/or computer systems, networked and/or otherwise. Where applicable, the ordering of various steps described herein can be changed, combined into composite steps, and/or separated into sub-steps to provide features described herein. 
     Embodiments described above illustrate but do not limit the invention. It should also be understood that numerous modifications and variations are possible in accordance with the principles of the present invention. Accordingly, the scope of the invention is defined only by the following claims.