Patent Publication Number: US-11043133-B2

Title: Method and system to improve safety concerning drones

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. Parent application Ser. No. 15/927,923 filed Mar. 21, 2018 and entitled “Method and System to Improve Safety Concerning Drones,” now U.S. Pat. No. 10,217,369, issued Feb. 26, 2019, which in turn is a continuation of U.S. patent application Ser. No. 15/207,874 filed Jul. 12, 2016 and entitled “Method and System to Improve Safety Concerning Drones,” now U.S. Pat. No. 9,947,233, issued Apr. 17, 2018, all of which applications are hereby incorporated by reference in their respective entireties. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present application relate to methods and systems for controlling unmanned vehicles (UVs), and more particularly to methods and systems that provide maps and flight controls of an Unmanned Aerial Vehicle (“UAV”) to enforce no-fly or restricted fly zones. 
     BACKGROUND 
     Today a large number of companies are greatly expanding their use of UAVs. UAVs have been used for military applications, search-and-rescue missions, scientific research, delivering goods, and other uses. UAVs can include a plurality of airborne platforms or air vehicles, each carrying a plurality of sensors that may be used to collect information about an area under surveillance or to deliver a payload to a certain location. The airborne platforms may communicate with users, which may include persons or equipment, that desire access to data collected by the sensors or desire to control the UAV. More sophisticated UAVs have built-in control and/or guidance systems to perform low-level human pilot duties, such as speed and flight path surveillance, and simple pre-scripted navigation functions. 
     While UAVs are becoming increasingly valuable with commercial, government and recreational uses, having multiple UAVs flying in an area of the sky may also increase potential risk. For example, commercial UAVs flying over an area designated as an emergency zone may pose a risk for first responders or other UAVs being used by first responders. A UAV flying over a military or government installation may pose a security risk. A UAV entering into an area saturated with other UAVs may pose a flight risk for itself or other UAVs. For this reason, a mechanism is needed to warn or move a drone if it causes a safety concern, which may for example result from the UAV flying into an RF fencing safety buffer or near a no-fly or restricted flight zone. 
     SUMMARY 
     In an embodiment, a method for providing safety and security for UAVs by establishing no-fly and restricted flight sectors and buffer sectors surrounding those sectors. The method includes creating a multi-dimensional map of airspace, overlaying a sector having boundaries onto the map, wherein the sector contains a restricted flight zone and a buffer zone, monitoring the flight of an unmanned aerial vehicle (UAV), sending a command to the UAV if the UAV enters the buffer zone and generating a response if the UAV does not leave the sector based on the command. The response may include sending a second command to the UAV to override a current flight plan of the UAV or generating an alarm. Access to the sector may be restricted to one of time of day, authorization levels, and number of UAVs in the sector. The boundaries may be generated based on events and then transmitted to the UAV or the boundaries may be received from a second UAV and transmitted to the UAV. The boundaries may move as a function of time or the boundaries may move based on the movement of events on the ground. The method may further include receiving a request from the UAV to enter the sector and transmitting a response to the UAV. 
     The disclosure may also include a system having a UAV and a command and control center in which a processor in the command and control center is connected to a memory, the memory including instructions which when executed by the processor, performs the functions set forth above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following detailed description of preferred embodiments is better understood when read in conjunction with the appended drawings. For the purposes of illustration, there is shown in the drawings exemplary embodiments; however, the subject matter is not limited to the specific elements and instrumentalities disclosed. In the drawings: 
         FIG. 1  is a schematic representation of an exemplary system environment in which the methods and systems to dynamically manage flight paths of UAVs near areas of concern may be implemented. 
         FIG. 2  is a system diagram of an exemplary UAV control system. 
         FIG. 3  is a system diagram of an exemplary embodiment of a UAV command and control center. 
         FIG. 4  is a system diagram of an exemplary embodiment of a mission policy management system. 
         FIG. 5  is an exemplary diagram implementing the concept of no-fly zones and buffer zones. 
         FIG. 6  is a flow diagram of an embodiment of a method for dynamically controlling the flight path of a UAV near areas of concern. 
         FIG. 7  is a flow diagram of an embodiment of a method for an unexpected event. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     System Environment. 
     Illustrated in  FIG. 1  is a schematic representation of a exemplary system environment  1  in which embodiments of the present disclosure may operate. The system environment  1  includes UAV  2  and UAV  3 , each carrying sensors (sensor  4  and sensor  5 ) for collecting information or payloads (payload  6  and payload  7 ) for delivery. Although only two UAVs are illustrated in  FIG. 1 , it is contemplated that the system environment  1  would encompass a plurality of UAVs. UAV  2  and UAV  3  may communicate with a command and control center  8  and a plurality of user devices (user device  9 , user device  10 , and user device  11 ). Command and control center  8  may communicate with UAV  2  through a network  12  or an RF transmitter  13 . Similarly user device  11  may communicate with UAV  3  through the network  12  or an RF transmitter  14 . Network  12  may be a distributed network such as the Internet or a wireless cellular network, which may, for example, be a 3G, 4G LTE network, or any number of wireless networks that are capable of providing a communication interface to the plurality of UAVs. User device  9 , user device  10  and user device  11  may comprise any wireless device such as a cell phone, a smart phone, personal data assistants (PDA) or a personal computer such as a desktop, a laptop computer or a tablet computer. Command and control center  8  may be part of a larger command and control center (not shown) which controls not only UAV flights, but which may also include other military, commercial or private flights. The command and control center is typically a facility that operates as the operating entity&#39;s dispatch center, surveillance monitoring center, coordination office and alarm monitoring center all in one. Command and control centers may be operated by the operating entity. 
     UAV Control System. 
       FIG. 2  is an exemplary block diagram illustrating the main hardware and system components of one embodiment of a UAV control system  51 . The UAV control system  51  includes a central processing unit (CPU  53 ), which is responsible for processing data and executing commands and instructions. The CPU  53  may be responsible for processing sensor data, handling I/O to a GPS receiver  55 , a UAV transmitter/receiver  57 , and bypass circuit  59 , thereby enabling communications with the ground station. The UAV control system  51  is provided with sufficient memory to store the autopilot source code and effect runtime execution. The CPU  53  is in electronic communication with various sensors and may, for example, be responsible for processing raw data from the various sensors such as sensor  60  and storing and transmitting the data. Data is stored in memory  61 , which is in electronic communication with the CPU  53 . The memory  61  may include random access memory (RAM), flash memory or any other type of memory technology currently available. To control a UAV such as UAV  2  in  FIG. 1 , the UAV control system  51  may have access to the location coordinates of UAV  2 . These coordinates are measured using the GPS receiver  55  that is in electronic communication with the CPU  53 . The GPS receiver  55  receives its data through a GPS antenna  65 . The fixed rotational rates of UAV  2  may be measured by rate gyros  67   a ,  67   b , and  67   c  which are in electronic communication with the CPU  53 . The rate gyros  67   a ,  67   b  and  67   c  are disposed to enable sensing of the rotational rates about the body axes of the UAV  2 . The altitude of the UAV may be measured using an absolute pressure sensor  69  or other altitude measuring device that is in electronic communication with the CPU  53 . Acceleration in the x, y, and z axes may be measured by accelerometers  26   a ,  26   b , and  26   c  which are in electronic communication with the CPU  53 . The velocity of UAV  2  may be measured using a differential pressure sensor  73  in electronic communication with the CPU  53 . The differential pressure sensor  73  outputs a voltage based on the difference in pressure between its two external ports. A pitot tube may be connected to one of the ports and the other is left open to the ambient air. The flow of air against the pitot tube causes a pressure difference proportional to the speed of the air. The corresponding voltage produced by the differential pressure sensor  73  is used to calculate the airspeed of the UAV  2 . The CPU  53  may be also in electronic communication with payload inputs  75  which may include data from a video processing unit or any other data that involves a payload (such as payload  6 ) on the UAV. The UAV is controlled using flight actuators  77  which include servos in electronic communication with the CPU  53  that control the flight of the UAV  2 . The bypass circuit  59  may be provided to allow a user to take control of the UAV  2 . The UAV control system  51  is electrically connected to a power source  81 . In one embodiment the power source  81  may include a plurality of batteries. The power source  81  may be used to power the UAV control system  51  and connected accessories. The power source  81  may also be used to power an actuator  83  that propels the UAV  2 . The UAV control system  51  may be provided with an RC control system  85  that allows a user to take control of a UAV (such as UAV  3 ) using an RF transmitter such as RF transmitter  14  or RF transmitter  13  shown in  FIG. 1 . 
     The UAV control system  51  may interact with a mission policy management system  89 , which are described in more detail below, and that control access to the UAV control system  51  by user devices such as user device  11  (shown in  FIG. 1 ). An access management system and the mission policy management system  89  may be implemented in the UAV  2  or in the network  12 . 
     Command and Control Station. 
       FIG. 3  is a block diagram illustrating the main hardware components of a command and control center  8 . The command and control center  8  includes a ground station computer  100 . The ground station computer  100  may be a laptop computer, a desktop computer, a personal digital assistant, a tablet PC, a wireless device such as a smart phone or similar devices. The ground station computer  100  runs ground station system software  101  as well as user interface software  102 . The ground station computer  100  may also run policy management software  103  that provides mission management parameters to the UAV during operations. The ground station computer  100  is in electronic communication with a ground unit  104 . Electronic communication between the ground station computer  100  and the ground unit  104  may be accomplished via a serial or USB port. Ground unit  104  may include CPU  105 , memory  106 , a payload processing system  107 , a ground transmitter/receiver  108 , and a ground antenna  109 . CPU  105  processes data from the ground station computer  100  and the UAV such as UAV  2  in  FIG. 1 . The payload processing system  107  processes any payload data received from the UAV control system  51 , (shown in  FIG. 2 ), or payload commands from the ground station computer  100 . The payload processing system  107  may also be connected directly to CPU  105  or the ground station computer  100 . Data from the payload processing system  107 , CPU  105 , or the ground station computer  100  is sent through the ground transmitter/receiver  108 . The ground transmitter/receiver  108  also receives data from the UAV control system  51  (shown in  FIG. 2 ). In an embodiment an RC controller  110  in electronic communication with the command and control center  8  (shown in  FIG. 1 ) may be provided. The CPU  105  may also be connected to an RC unit  110  with RC antenna  111  that can be used to control the UAV  3  (shown in  FIG. 1 ) using RC signals. 
     The ground station computer  100  may also include a mapping function  113 . The mapping function  113  may, for example, include a three-dimensional (“3D”) map of a volume of space through which a UAV may fly. The mapping function  113  may also include two-dimensional (“2D”) mapping function. The mapping function  113  may include the ability to partition the space volume into either 3-dimensional volume-based sectors or two-dimensional area-based sectors encompassing and defining space in two dimensions from the ground to a relatively high altitude above the ground. For the purpose of this disclosure and claims, the use of the term “sector” will include both 3D volume sectors as well as 2-dimensional area sectors. The use of such sectors will be described in greater detail with reference to  FIG. 5  below. The mapping function  113  may create sectors off-line and share those sectors with UAVs  2 ,  3  prior to or during flight. The mapping function  113  may also receive inputs from a user through user interface software  102  which could create additional or alter existing sectors based on real-time or near-real time inputs. Those inputs may, for example, include the location of a presidential motorcade on a particular freeway, thereby creating the need to define a sector dynamically such that a no-fly zone or restricted fly zone may be implemented and updated periodically as the motorcade progresses through its route. Static and dynamically generated maps may be communicated to UAVs  2 ,  3  through the RF interface  111 . 
     In accordance with an alternative embodiment, sectors may be generated by a UAV, for example, UAV  2  or UAV  3 , and communicated wirelessly from the UAV to the command and control center  8 . Such functionality may prove useful, for example, in an emergency situation such as a traffic accident or an industrial incident in which a sector has to be mapped from the air by a UAV in order to create the boundaries of sector that will ultimately be set up as a no-fly or restricted flight zone and then communicated to other UAVs in real time or near real time to provide a no fly zone or restricted fly zone for all other UAVs until the emergency situation is resolved. The foregoing use case is exemplary only and is not intended to limit the scope of the present disclosure. 
     Mission Management System. 
     Illustrated in  FIG. 4  is an exemplary embodiment of the mission policy management system  89 . The mission policy management system  89  may include a mission information subsystem  125  and an environment subsystem  126 . The mission information subsystem  125  and the environment subsystem  126  may be coupled to a mission decision engine  127 . Mission decision engine  127  may optionally be coupled to an artificial intelligence module  128  if the UAV is intended to have a self-learning capability. 
     The mission information subsystem  125  may include a mission profile module  129  that stores and processes mission profile information relating to the type of mission such as reconnaissance, attack, payload delivery, and the like. Associated with each mission profile will be a set of mission parameters such as regions that must be visited or avoided, time constraints, time of year, flight altitude, flight latitude, and payload mass and power, initial position of the target, direction of a target, and flight path, among others. 
     The mission information subsystem  125  may include a checklist module  130  that stores and processes checklists to ensure that the UAV is performing correctly during flight. Prior to and during operation, the unmanned vehicle may undergo one or more verification procedures that are performed according to one or more corresponding checklists. The checklists in the checklist module  130  generally include a sequence of various operating parameters to be verified for proper functionality and/or control actions to be taken once required operational parameters have been achieved. For example, a particular checklist implemented prior to take off may include verification of the unmanned vehicle&#39;s fuel supply and other suitable operating parameters. In addition to a checklist implemented for use with takeoff, other checklists may be implemented for other tasks performed by unmanned vehicles, such as a change in flight plan, or in response to specific events or situations that may arise during any particular mission. 
     The mission information subsystem  125  may also include a policies module  131 . Policies module  131  may include a set of policies related to the level of control to be exercised by the command and control center  8  during flight. For example, a commercial UAV may have policies that permit flight to and from commercial distribution centers to target destinations, but restricted from airspace over military installations. A military UAV carrying weapons may have policies that permit flight in certain areas but may restrict flight over certain population centers. Other parameters for policies may include UAV and target location, customer and operator preferences, UAV status (e.g. power, type, etc.), next mission on the list, available resources and the like. The policies may, for example, contain levels of authorization which will dictate, based on defined or dynamic sectors, where a UAV may fly and where a UAV may not fly. The policies may also include authorization levels for modifying such policies during flight operations. 
     The environment subsystem  126  may include a UAV state module  132  which may include information about the state of the UAV such as power, payload capacity, distance to user, location and the like. 
     The environment subsystem  126  may also include a UAV environment module which may include information about the environment in which the UAV is operating such as weather, threat level and the like. The environment subsystem  126  may also include a user environment module which may include information about the environment in which the ground-based user is operating, such as weather, location, terrain, threat level and the like. 
     The mission information subsystem  125  and the environment subsystem  126  may be coupled to the mission decision engine  127  configured to receive mission parameters from the mission information subsystem  125 , fetch a plurality of mission plans from the mission profile module  129 , and select one of the plurality of mission profiles based upon the current requirements and the environmental parameters. The mission decision engine  127  may access a rules database  135  that provides rules to the mission decision engine  127 . The mission decision engine  127  may also receive updated mission parameters during flight that alerts the mission information subsystem of updated sectors that may include no-fly or restricted flight zones based on the level of authorization of the UAV. 
     The artificial intelligence module  128  may include an inference engine, a memory (not shown) for storing data from the mission decision engine  127 , heuristic rules, and a knowledge base memory (not shown) which stores network information upon which the inference engine draws. The artificial intelligence module  128  is configured to apply a layer of artificial intelligence to the mission profiles stored in the mission profile module  129  to develop relationships between mission parameters to perform and improve the assessments, diagnoses, simulations, forecasts, and predictions that form the mission profile. The artificial intelligence module  128  recognizes if a certain action (implementation of mission parameters) achieved a desired result (successfully accomplishing the mission). The artificial intelligence module  128  may store this information and attempt the successful action the next time it encounters the same situation. Likewise, the artificial intelligence module  128  may be trained to look for certain conditions or events that would necessitate the need or desire to define sectors to be used as no-fly zones or restricted fly zones. Such defined sectors may then be transmitted to the command and control system  8 . The mission policy management system  89  may be incorporated in the UAV or may be a component of the network  12 . It will be understood that the mission policy management system  89  described above may include all or a subset of the functions set forth above, or may include additional functions. Such a description is exemplary only and is not intended to limit the scope of the disclosure. 
       FIG. 5  shows an example of the mapping of sectors and how those sectors may define no-fly zones, restricted flight zones, and buffer zones. There is shown a plurality of sectors  156   a - 156   h . While those sectors are shown as similarly-sized, intersecting circles, it will be understood that the sectors may be defined to be any size and/or shape, intersecting or non-intersecting, and 2-dimensional or 3-dimensional. 
     By way of example only, shown within the sectors are three landmarks, a government building  158 , a sports stadium  160  and a residential house  162 . Each of those landmarks may include the definition of a buffer zone, shown as  159 ,  161 , and  163 . A buffer zone  159 ,  161 ,  163  may be a 2D or 3D sector of any size or shape and may, for example, be used as a warning area for a UAV about to enter into a no-fly or restricted zone surrounding the landmarks  158 ,  160 , and  162 . 
     By way of example, UAV  152  may or may not be authorized to fly over landmark  158  or buffer zone  159 . UAV  153  may or may not be authorized to fly over landmark  160  or buffer zone  161 . UAV  154  may or may not be authorized to fly over landmark  162  or buffer zone  163 . Such authorization may be programmed in advance and off-line and stored in the mission policy management system  89  or updated in real-time or near real time during flight and communicated to the UAV  152 ,  153 ,  154  during flight from the command and control system  8 . Updates to the respective authorizations may be provided by a UAV in flight and communicated to other UAVs through the command and control system  8 . Alternatively, updates to the respective authorizations may be made off-line and communicated to the UAVs through the command and control system  8 . Such authorizations may be further limited by time-of-day, weather, payloads, or any number of other filters. 
     In operation, there may, for example, be a presidential event or other event at stadium  160 . If a presidential event, it may be that only secret service UAVs and a limited number of authorized news oriented UAVs are allowed in or near the stadium  160  during the event. The no-fly zone above stadium  160  and its associated buffer zone  161  related to the stadium  160  may be pre-programmed into the UAVs flying in this area along with a permitted flying path. When a UAV flies into the buffer zone  161 , a request is triggered to send to the command and control unit  8   a  request for permission to enter. If allowed, the permission is granted with a tag indicating the ATS in the zone. If the UAV is not allowed, the permission to enter is denied, e.g. with the ATS=0, and the UAV has to leave immediately. A command is triggered to ask it to leave the No-fly zones/RF buffer zone immediately. In addition, if the UAV does not leave within a programmable interval an alarm can be triggered or countermeasures taken. The restricted sector above the stadium  160  and the buffer zone  161  may be restricted as a function of time. 
     By way of another example, a UAV may be used with respect to the sale of a home. A home  162  may be for sale. Her agent had made a few appointments with several potential buyers&#39; real estate agents to survey the property prior to an onsite visit. In order to control UAV traffic in and around the home  162  and the buffer zone  163 , a temporary permit is given to an approved list of UAVs for a given period of the time during which only UAVs on that list are permitted to fly over the property while and other UAVs are not permitted. For the permitted UAVs a tag is assigned with ATS=x as well as the areas allowed/not-allowed to enter, e.g. all the areas except the pool area to prevent taking pictures of kids swimming. For other UAVs the permission to enter is denied, e.g. with the ATS=0, and the UAV must leave the protected sector. A command is triggered to request that the UAV leave the No-fly sector/RF buffer zone sector. In addition, if the UAV does not leave within a programmable interval an alarm can be triggered or countermeasures taken. It will be understood that certain limitations on permitted sector entry may be made, for example, never allow UAVs to fly over a swimming pool area, and such limitations are within the scope of the present disclosure. 
     Another use case may include the package delivery to a military campus. In general, it may be the case that a government building  158  or military campus (not shown) not allow any non-government or non-military related UAVs to fly over or near the government building  158  or inside or near the campus. But when packages are scheduled and permitted to be delivered to the government building  158  or military campus, a temporary permission may be provided to the UAV. The restricted sector and its associated RF buffer zone  159  related to the government building  158  or the military campus may be pre-programmed into this carrier UAV. When a UAV flies into the buffer zone  159 , a request is triggered to send to the command and control center  8  managed by the government or military management or via a command and control center  8  service provider to request permission-to-enter. The permission is granted to the carrier UAV on a temporary basis with a tag indicating the ATS in the sector, as well as the sectors permitted or not permitted to enter, for example, no areas are permitted to enter except the non-sensitive areas, like the front entrance. If the UAV is not permitted, the permission to enter is denied, e.g. setting the ATS=0, and the UAV must leave immediately. A command is triggered to request that the UAV leave the no-fly sector above the government building  158  or the RF buffer sector  159 . In addition, if the UAV does not leave within a programmable interval an alarm can be triggered or countermeasures taken. It will be understood that certain limitations relating to a permitted sector entry may be made, for example, never allow UAVs to fly over military barracks or weapons training areas, and such limitations are within the scope of the present disclosure. 
     It will be understood that there are other use cases not illustrated. For example, a UAV may be deployed over an accident or a disaster area and develop a prohibited or restricted sector during flight and communicate that sector to other UAVs directly or through the command and control center  8 . 
     Illustrated in  FIG. 6  is an embodiment of a method  200  for controlling the flight path of a UAV. 
     In step  202 , a determination is made whether there are restricted zones. If not the process ends. If so, then the process continues at  203  in which the restricted sectors are overlaid onto the RF maps. The updated maps are then sent to the UAV at  204 . The command and control system  8  continues to track the flight status of the UAV at  205  with the updated maps programmed into the UAV. 
     At  206 , the command and control center receives a request for permission to enter. If permission is denied, the denial is sent at  211 . At  212 , the determination is made as to whether the UAV has complied with the denial of entry. If not, then a flight program override or an alarm or other countermeasure is effectuated at  213 . If so, then the flight status is tracked at  208  and the information on the flight path and requests is logged at  209 . 
     If permission to enter is granted at  206 , then an authorization is sent at  207 . The flight status is tracked at  208  and the information on the flight path and requests is logged at  209 . control system  51  receives a request from a user for access to the UAV control system  51 . 
     With reference to  FIG. 7 , there is shown an exemplary method  300  in which a UAV maps a restricted sector in flight. At  301 , an unexpected event occurs, which may, for example, be a traffic accident, a fire or a natural disaster such as a flood or tornado. At  302 , the UAV determines, itself or in conjunction with a command and control center  8 , whether certain sectors should be restricted. If not, then no further action is taken. If so, then the UAV generates a restricted sector map at  303  and sends that map to the command and control center  8  at  304 . The command and control center updates maps with the newly developed restricted sector at  305 . At  306 , a determination is made whether other UAVs are in the area. If so, a map with the new restricted sector is sent at  311 . Note that such updated maps may be sent from the command and control center  8  or directly from the UAV that generated the updated maps. At  312 , a determination is made whether the UAVs are in compliance with the restrictions in the updated maps. If not, then a flight program override may be sent or an alarm sounded at  313 . If there are no other UAVs in the area or if the new UAVs are sent the updated maps, then the flight status is tracked at  308  and activity logged at  309 . 
     In accordance with the present disclosure, there is provided the ability to improve the public safety in no-fly or restricted sectors or in or around other locations with safety or security concerns. There is provided the ability to provide the UAV with the instructions regarding when and where it is allowed to fly within the no-fly or restricted flight sectors. There is also provided the ability to trigger a command to the UAV to move if a UAV enters into the RF buffer sectors or no-fly sectors. 
     Although not every conceivable combination of components and methodologies for the purposes describing the present disclosure have been set out above, the examples provided will be sufficient to enable one of ordinary skill in the art to recognize the many combinations and permutations possible in respect of the present disclosure. Accordingly, this disclosure is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. For example, numerous methodologies for defining, restricting and enforcing restricted flight zones and corresponding buffer zones may be encompassed within the concepts of the present disclosure. 
     In particular and in regard to the various functions performed by the above described components, devices, circuits, systems and the like, the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., a functional equivalent), even though not structurally equivalent to the disclosed structure, which performs the function in the herein illustrated exemplary aspects of the embodiments. In this regard, it will also be recognized that the embodiments includes a system as well as a computer-readable medium having computer-executable instructions for performing the acts and/or events of the various methods. 
     In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “includes,” and “including” and variants thereof are used in either the detailed description or the claims, these terms are intended to be inclusive in a manner similar to the term “comprising.”