Patent Application
20210020049
Various embodiments of the present disclosure relate generally to computing a flight path of an aircraft and, more particularly, to computing an alternate flight path around a zone to be avoided by the aircraft.
Aircraft traveling on a flight path may encounter hazards or airspace restrictions, such as hazardous weather, air traffic, temporary flight restrictions, no-fly zones, paid air corridors, unmanned aerial vehicles (UAVs) areas, and hot-air ballooning areas, and the like. Such hazards and airspace restrictions may be considered or represented as zones to be avoided by the aircraft, which are also referred to as “zones of avoidance” in this disclosure. If a zone of avoidance is ahead on the aircraft's current flight path, then the aircraft may need to find an alternate path around the zone.
Therefore, there is a need for automatic, real-time construction of such an alternate path. More particularly, there is a need for a computer-implemented method and a computer system that is configured for finding an alternate path that is both safe and economical, in real-time and in a deterministic manner. The present disclosure is directed to addressing one or more of these above-referenced challenges.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art, or suggestions of the prior art, by inclusion in this section.
According to certain aspects of the disclosure, systems and methods are disclosed for providing a flight path around a zone of avoidance located on a currently planned flight path of an aircraft.
For instance, the method may include: obtaining data of the zone of avoidance located on the currently planned flight path; determining a safe distance from the zone of avoidance based on a characteristic of the aircraft or a characteristic of the zone of avoidance; constructing a safety envelope outside of the zone of avoidance by defining the safety envelope based on the safe distance; constructing a plurality of alternate flight paths around the zone of avoidance such that each of the plurality of alternate flight paths deviates from the currently planned flight path before the zone of avoidance, avoids crossing into the zone of avoidance, avoids crossing in between the safety envelope and the zone of avoidance, and reconnects with the currently planned flight path after the zone of avoidance; and selecting an optimal flight path from among the plurality of alternate flight paths based on respective fuel expenditure or flight times of the plurality of alternate paths.
Furthermore, the system may include: one or more memory storing instructions; and one or more processors to execute the instructions to perform operations. The operations may include: obtaining data of the zone of avoidance located on the currently planned flight path; determining a safe distance from the zone of avoidance based on a characteristic of the aircraft or a characteristic of the zone of avoidance; constructing a safety envelope outside of the zone of avoidance by defining the safety envelope based on the safe distance; constructing a plurality of alternate flight paths around the zone of avoidance such that each of the plurality of alternate flight paths deviates from the currently planned flight path before the zone of avoidance, avoids crossing into the zone of avoidance, avoids crossing in between the safety envelope and the zone of avoidance, and reconnects with the currently planned flight path after the zone of avoidance; and selecting an optimal flight path from among the plurality of alternate flight paths based on respective fuel expenditure or flight times of the plurality of alternate paths.
Moreover, the non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform a method for providing a flight path around a zone of avoidance located on a currently planned flight path of an aircraft, the method including: obtaining data of the zone of avoidance located on the currently planned flight path; determining a safe distance from the zone of avoidance based on a characteristic of the aircraft or a characteristic of the zone of avoidance; constructing a safety envelope outside of the zone of avoidance by defining the safety envelope based on the safe distance; constructing a plurality of alternate flight paths around the zone of avoidance such that each of the plurality of alternate flight paths deviates from the currently planned flight path before the zone of avoidance, avoids crossing into the zone of avoidance, avoids crossing in between the safety envelope and the zone of avoidance, and reconnects with the currently planned flight path after the zone of avoidance; and selecting an optimal flight path from among the plurality of alternate flight paths based on respective fuel expenditure or flight times of the plurality of alternate paths
Additional objects and advantages of the disclosed embodiments will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the disclosed embodiments. The objects and advantages of the disclosed embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain principles of the disclosed embodiments.
Various embodiments of the present disclosure relate generally to computing a flight path of an aircraft and, more particularly, to computing an alternate flight path around a zone to be avoided by the aircraft. This zone is also referred to as a zone of avoidance.
In general, the present disclosure is directed to a method that finds an alternate flight path around a zone of avoidance, which may represent a weather hazard zone or a restricted part of airspace. The proposed method finds the alternate flight path such that the alternate flight path is both safe and economical. As discussed in more detail below, the method determines a safe distance that the aircraft should maintain from the zone of avoidance. This safe distance is then used to define a safety envelope around a cross section of the zone of avoidance. Then, candidate alternate flight paths are constructed around the cross section. These candidate alternate flight paths have the characteristics of not only avoiding the cross section of the zone of avoidance, but remaining on or outside of the safety envelope. The economically optimal one among the candidate alternate flight paths is chosen to be the alternate flight path to be implemented.
The terminology used in this disclosure may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed.
In this disclosure, the term “based on” means “based at least in part on.” The term “one or more of,” when preceding a list of items defined using the conjunction “and,” denotes an alternative expression that may be satisfied by a single item in the list or a combination of items in the list. The term “or” is meant to be inclusive and means either, any, several, or all of the listed items. Relative terms, such as, “substantially” and “generally,” are used to indicate a possible variation of ±10% of a stated or understood value. The singular forms “a,” “an,” and “the” include plural referents unless the context dictates otherwise. The term “exemplary” is used in the sense of “example” rather than “ideal.”
The airspace 100 may include one or more zones of avoidance. As examples of zones of avoidance,
In general, a “zone of avoidance” may be or represent any element that is to be avoided by an aircraft. Other examples of zones of avoidance include zones of air traffic, paid air corridors, and other areas of airspace in which operation is restricted. Whether or not a particular zone is a zone of avoidance may depend on the particular aircraft. For example, certain airspace restrictions may apply to some aircraft but not to others, and some aircraft may need to avoid other aircraft that have right-of-way.
The one or more ground facilities 120 may include a database 122 storing data of one or more zones of avoidance, such as data of no-fly zones, temporary flight restrictions, air traffic, pilot reports (PIREPs), weather forecasts, and real-time weather. The data may be usable by the one or more ground facilities 120 or by the aircraft 210 to compute an alternate flight path, and may be transmitted to the aircraft (as data 231). The database 122 may be part of a data center 121, which may also be referred to as a ground data center. The one or more ground facilities 120 may also include an air traffic controller 123, which, if separate from the data center 121, may be in communication with the data center 121 through a computer network. The one or more ground facilities 120 may include ground-based weather systems. Additionally, the one or more ground facilities 120 may include a computer system configured to perform alternate flight path computation.
At some time prior to the computation of the alternate flight path, the data center 121 or another component of the one or more ground facilities 120 may compute a flight path 230 and transmit the computed flight path 230 to the aircraft 210. This flight path 230 may serve as the planned flight path of the aircraft 210. In this disclosure, a planned flight path is sometimes referred to as a “currently planned flight path” to indicate that the planned flight path is the most current flight path of the aircraft at the time the alternate flight path is being computed.
As shown in
By using data of one or more zones of avoidance stored in the on-board database and obtained from any of the on-board or off-board sources mentioned above, the aircraft 210 may compute an alternate flight path 232. After computing the alternate flight path 232, the aircraft 210 may send the alternate flight path 232 to the air traffic controller 123. In response to receiving the alternate flight path 232, the air traffic controller 123 may return an approval 233 indicating that the alternate flight path 232 has been approved.
In other embodiments, the alternate flight path may be computed by an off-board computer system, such as a ground-based computer system of the one of more ground facilities 120. The ground-based computer system may have access to data of one or more zones of avoidance from any one or more of the above mentioned sources. For example, data gathered by or stored on aircraft 210 (or other aircraft 220) may be transmitted the ground-based computer system for use in computing the alternate flight path. The ground-based computer system may also have received data from the weather service 240. Once the alternate flight path is computed, the ground-based computer system may transmit the computed alternate flight path to the air traffic controller 123 for clearance (approval), before transmitting the computed alternate flight path to the aircraft 210. When the aircraft 210 receives the computed alternate flight path, the pilot or the computer system 211 of the aircraft 210 may then adopt the alternate flight path.
The method shown in
In operation 301 of
As an example of obtaining data of a zone of avoidance from an on-board system, the aircraft may use an on-board radar to detect thunderstorms and other weather or aerial hazards by continuously scanning the three-dimensional airspace in front of the aircraft to obtain reflectivity data. The reflectivity data may be adjusted to account for movement of the aircraft 210. The computer system 211 may store the reflectivity data obtained in a memory of the computer system 211. The memory may be continuously updated with data from the radar so that the data is up-to-date whenever computation of an alternate flight path around a zone of avoidance is performed.
A zone of avoidance may be constructed based on data received from one or more sources. The zone of avoidance may be constructed three-dimensionally and may be assumed to be a closed envelope. The size, position, and boundaries of the zone of avoidance may be determined based on an analysis of the data received from the one or more sources, which may include data on the intensities of weather phenomenon at different points in space. Therefore, the zone of avoidance may be a representative model of a physical element such as weather phenomenon. In other situations, such as a well-defined no-fly zone, the data from the one or more sources may already include coordinates defining the boundaries of the zone of avoidance.
The zone of avoidance may be constructed such that every point inside, outside, and on the boundary of the zone of avoidance can be correlated to corresponding coordinates of a two-dimensional or three-dimensional coordinate system used in navigation, so that the computer system is able to compute the coordinates of points of interest, such as points at which the aircraft would enter and exit the zone of avoidance under the current flight path. The zone of avoidance may be displayed on display 212 for viewing by a pilot.
The method shown in
The safe distance may be determined based on (e.g., a mathematical function of) one or a combination of factors, which may include characteristics of the airplane and characteristics of the zone of avoidance. Characteristics of the airplane may include the size, weight, and payload of the airplane. Characteristics of the zone of avoidance may include the type of weather phenomenon (e.g., hail, lighting or turbulence), and the intensity of the weather phenomenon as measured by the data of the zone of avoidance. The particular factors and relative importance of the factors may be configurable based on the objectives of the flight crew. For example, airplanes prioritizing passenger comfort may prefer a relatively larger safe distance when the zone of avoidance is hazardous weather.
Certain factors, such as certain characteristics of the airplane, may be manually specified prior to the determination of the safe distance. Other factors may be obtained from or computed based on data of the zone of avoidance obtained from any source. For example, the radar of the aircraft may measure the severity of a thunderstorm based on the intensity of the echo; the severity of the thunderstorm may thus serve as a characteristic of the zone of avoidance for purposes of determining the safe distance. When a zone of avoidance is hazardous weather, the safe distance may be inversely correlated with the severity of the weather phenomenon. For example, the lower the echo intensity of the thunderstorm, the lower the safe distance from the thunderstorm.
While
In operation 303 of
Since the cross sections are used for defining the zone of avoidance for purposes of computing the alternate flight path, the number of cross sections and their orientations may be manually set or automatically determined depending on factors such as the type, general shape, and complexity of the zone of avoidance. For example, if the characteristics of the zone of avoidance indicate that it can be adequately avoided by a lateral alternate path, then only horizontal cross sections may be sufficient. On the other hand, if, for example, the characteristics of the zone of avoidance indicate that it might be more efficiently avoided by a vertical alternate path, then cross sections of one or more other orientations may be obtained. In general, zones of avoidance other than bad weather and traffic need only lateral alternate paths; for these zones of avoidance, taking only horizontal cross sections is often sufficient. In certain scenarios, a single cross section is sufficient.
Therefore, in certain situations and embodiments, only a single cross section of the zone of avoidance is taken; in other situations and embodiments, a plurality of cross sections of the zone of avoidance are taken.
When a plurality of cross sections are taken, the cross sectional planes along which the cross sections are taken may be of a single orientation (e.g., only horizontal cross sections or only cross sections at an orientation) or of multiple orientations (e.g., a combination of horizontal, vertical, and/or oblique cross sections). Oblique cross sectional planes (and resulting cross sections) may all be parallel or substantially parallel with one another, or may include a mixture of different oblique orientations. Horizontal cross sectional planes (and resulting cross sections) may be parallel or substantially parallel to the planned flight path of the aircraft. Vertical cross sectional planes (and resulting cross sections) may be perpendicular or substantially perpendicular to the planned flight path of the aircraft.
A plurality of cross sectional planes may include planes of a same orientation that are spaced apart at regular intervals. In
The range of altitudes and distances covered by the cross sectional planes and their resulting cross sections may depend on aircraft performance parameters and other factors that may constrain the placement of an alternate flight path. For example, if the aircraft is only 500 feet below the ceiling altitude, and the interval between planes is 500 feet, as in the example given in the above paragraph, then the cross sections may include only one cross section above the flight path.
In embodiments in which a plurality of cross sections of the zone of avoidance are taken and only a single safety envelope is constructed, then the safety envelope may be constructed for a single cross section selected from among the plurality of cross sections. In this case, since the single cross section may serve as the basis for constructing the alternate flight path around the zone of avoidance, this single cross section may be selected as the cross section that will likely provide the shortest alternate flight path. Since the size of the cross section may correlate with the offset of the alternate flight path from the currently planned flight path, a small cross section may provide the shortest alternate flight path around the zone of avoidance.
Thus, according to certain embodiments, each of the plurality of cross sections may be evaluated to determine a smallest cross section among the plurality of cross sections. Then, the safety envelope is constructed for that smallest cross section. See operations 303b and 303c of
To estimate the size of a plurality of cross sections, one method is to compute a measure of cross sectional area by counting the number of pixels occupied by the cross section. By such a process, the actual area of the cross section may be computed using the pixels occupied by the cross section and a correspondence between the pixel representation and the distance represented by the pixels.
Another method for estimating the size of the plurality of cross sections is to construct a representative rectangle as shown in
To determine the other two boundaries of the rectangle, abeam lines 620 (shown as dotted lines) are drawn through the cross section 610 at regular intervals, such that the abeam lines 620 intersect with the outer periphery of the cross section 610 at various intersection points on each side of line 640. Among the intersection points, the points 611c and 611d furthest outward on each side of line 640 are noted. Then, the top and bottom boundaries of the rectangle are computed to be on lines 612c and 612d, which are defined as lines that intersect points 611c and 611d, respectively, and are parallel to line 640. Abeam lines 620 may be constructed using algorithms already available in an FMS (which may be an element of computer system 211). While points 611c and 611d are illustrated to be on the same abeam line in
The rectangle enclosed by lines 612a, 612b, 612c, and 612d is then used to represent the area of cross section 610. Similar rectangles may be constructed for other cross sections, and the smallest cross section is estimated by selecting the cross section whose representative rectangle is the smallest in area among all respective representative rectangles of the plurality of cross sections. It is noted that lines 612a, 612b, and 620 may be drawn at a degree that is not a right angle with respect to line 640, in which case the rectangle shown in
Having selected the smallest (or otherwise optimal) cross section among the plurality of cross sections, the safety envelope may then be constructed outside of this selected cross section. It is noted that if only a single cross section of the zone of avoidance was taken, then the process of finding the smallest cross section would not be necessary.
The safety envelope may be constructed by finding positions that are, on the respective cross sectional plane of the cross section, distanced by the safe distance from an outer periphery of the cross section in directions outward from the cross section (see operation 303c of
In
While
To construct the safety envelope 700b shown in
In
In general, every point on at least a portion of the safety envelope may be distanced (as measured along outward directions) from the outer periphery of the cross section by the safe distance. For example, the safety envelope may be constructed such that any two points respectively on the outer periphery of the cross section and on the at least the portion of the envelope are distanced from each other by at least the safe distance; in such a situation, the aforementioned “outward directions” may generally be directions normal to the outer periphery of the cross section. However, the “outward directions” may be defined as outer directions outward from the cross section. For example, in
In general, the safety envelope may be constructed on only one cross sectional plane, such as the cross sectional plane of the smallest cross section. However, the present disclosure is not limited thereto, and the safety envelope may exist beyond a single cross sectional plane.
When the safety envelope has been constructed, an alternate flight path around the zone of avoidance may then be constructed for the safety envelope. The alternate flight path is constructed so as to avoid crossing into the selected cross section and further avoid crossing in between the safety envelope and the selected cross section (or the zone of avoidance as a whole). That is, the alternate flight path avoids being in between any point on the safety envelope and any point of the cross section (or any point of the zone of avoidance as a whole). Here, the phrase “in between” as used in this context does not require the alternate flight path to avoid positions that are on the safety envelope itself. The alternate flight path may also be said to remain on or outside of the safety envelope. Two alternate flight paths may be constructed for the safety envelope, respectively traveling around two opposite sides of the zone of avoidance.
Referring to
While
Another alternate flight path (not shown) may be constructed on the other side of the cross section 710 in the same or similar manner, so as to obtain two alternate flight paths, one on each side of the cross section lateral to the currently planned flight path.
An optimal alternate flight path may be determined from among the plurality of alternate flight paths around the all safety envelope. The process of selecting the optimal alternate flight path may be performed by a cost-optimization process based on one or a plurality of factors, such as the (estimated) fuel expenditure and flight time required by each of the plurality of alternate flight paths. In certain embodiments, the cost-optimization process may consider either fuel expenditure or flight time as the main consideration, so as to typically select the alternate flight path that minimizes the fuel expenditure or flight time being added to the originally planned flight path. In other embodiments, the cost-optimization process may consider one of these two factors as the sole consideration, or as one among a plurality of factors weighed against with other. Factors that are considered in the cost-optimization process may be input variables of a function. The function may be a cost function that is minimized during the cost-optimization process to find the set of inputs, and the associated alternate flight paths, that results in the lowest cost.
Fuel expenditure and flight time may be estimated based on any or combination of suitable factors, such as the characteristics of the aircraft (e.g., weight), the altitude of the alternate flight path, the ratio of lateral distance covered and altitude climbed for a given time and fuel expenditure under computed conditions or assumed average conditions, etc. These estimations may be based on the length of the alternate flight path, which can be computed by adding all legs of the alternate flight path, accounting for any climb distance if the alternate flight path was computed for a cross section that is higher or lower than the current altitude of the aircraft.
Referring to
While the safety envelope may be constructed on only one cross sectional planes, such as the cross sectional plane of the smallest cross section, the safety envelope may alternatively be constructed so as to be extant on multiple cross sectional planes. For example, when a plurality of cross sections of the zone of avoidance are taken, the safety envelope may include a plurality of safety envelopes for the plurality of cross sections in a one-to-one correspondence between safety envelopes and cross section (i.e., for each of the plurality of cross sections, a respective safety envelope is constructed on the cross sectional plane of the respective cross section) or constructed for only a subset of the plurality of cross sections (i.e., on the cross sectional planes of the subset of the plurality of cross sections).
If a plurality of safety envelopes are constructed, a respective set of plural alternate flight paths may be constructed for each of the plurality of safety envelopes. Then, the selection of the optimal alternate flight path may be a selection from a candidate set that includes all alternate flight paths constructed. For example, if three cross sections were taken and two alternate flight paths are constructed for each of the three cross sections, then the total number of all alternate flight paths from which an optimal flight path is selected would be six.
According to embodiments discussed above, a safe and economical alternate flight path around an element to be avoided can be constructed. Additionally, the method of constructing the alternate flight path is deterministic and definitive. Additionally, the alternate flight path may be constructed automatically in real-time, thereby minimizing workload from the flight crew, especially when approval of the alternate flight path by the air traffic controller is automatic. Additionally, the embodiments discussed above may make use of a connected environment allowing data to be obtained from sources on-board and off-board an aircraft.
Furthermore, while selection of the optimal alternate flight path may be performed automatically, as discussed above, it is also possible for the selection to be performed manually. In this case, the candidate alternate flight paths that are constructed may be presented to the pilot (e.g., displayed on a display in the aircraft) for selection.
The method described herein may be performed by one or more processors that accept computer-readable (also called machine-readable) code containing a set of instructions that when executed by one or more of the processors carry out at least one of the methods described herein. The one or more processors may include any processor capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken are included.
In one or more embodiments, the one or more processors may be included in a processing system. Each processor may include one or more of a CPU, a graphics processing unit, and a programmable DSP unit. The processing system further may include a memory subsystem including main RAM and/or a static RAM, and/or ROM. A bus subsystem may be included for communicating between the components. The processing system further may be a distributed processing system with processors coupled by a network. If the processing system requires a display, such a display may be included, e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT) display. If manual data entry is required, the processing system also includes an input device such as one or more of an alphanumeric input unit such as a keyboard, a pointing control device such as a mouse, and so forth. The memory as used herein, if clear from the context and unless explicitly stated otherwise, also encompasses a storage system such as a disk drive. The processing system in some configurations may include a sound output device, and a network interface device. The memory subsystem thus includes a computer-readable carrier medium that carries computer-readable code (e.g., software) including a set of instructions to cause performing, when executed by one or more processors, one or more of the methods described herein. Note that when the method includes several elements, e.g., several steps, no ordering of such elements is implied, unless specifically stated. The software may reside in the hard disk, or may also reside, completely or at least partially, within the RAM and/or within the processor during execution thereof by the computer system. Thus, the memory and the processor also constitute computer-readable carrier medium carrying computer-readable code. Furthermore, a computer-readable storage medium may form, or be included in a computer program product.
The processing system discussed in the preceding paragraph may be computer system 211 shown in
In other embodiments, the one or more processors operate as a standalone device or may be connected, e.g., networked to other processor(s), in a networked deployment, the one or more processors may operate in the capacity of a server or a user machine in server-user network environment, or as a peer machine in a peer-to-peer or distributed network environment. The one or more processors may form a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine.
Thus, one embodiment of each of the methods described herein is in the form of a computer-readable carrier medium carrying a set of instructions, e.g., a computer program that is for execution on one or more processors, e.g., one or more processors that are part of web server arrangement. Thus, as will be appreciated by those skilled in the art, embodiments of the present invention may be embodied as a method, an apparatus such as a special purpose apparatus, an apparatus such as a data processing system, or a computer-readable carrier medium, e.g., a computer program product. The computer-readable carrier medium carries computer readable code including a set of instructions that when executed on one or more processors cause the processor or processors to implement a method. Accordingly, aspects of the present invention may take the form of a method, an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of carrier medium (e.g., a computer program product on a computer-readable storage medium) carrying computer-readable program code embodied in the medium.
The software may further be transmitted or received over a network via a network interface device. While the carrier medium may be a single medium, the term “carrier medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “carrier medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by one or more of the processors and that cause the one or more processors to perform any one or more of the methodologies of the present invention. A carrier medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical, magnetic disks, and magneto-optical disks. Volatile media includes dynamic memory, such as main memory. Transmission media includes coaxial cables, copper wire and fiber optics, including the wires that comprise a bus subsystem. Transmission media also may also take the form of acoustic or light waves, such as those generated during radio wave and infrared data communications. For example, the term “carrier medium” shall accordingly be taken to include, but not be limited to, solid-state memories, a computer product embodied in optical and magnetic media; a medium bearing a propagated signal detectable by at least one processor of one or more processors and representing a set of instructions that, when executed, implement a method; and a transmission medium in a network bearing a propagated signal detectable by at least one processor of the one or more processors and representing the set of instructions.
It will be understood that the steps of methods discussed are performed in one embodiment by an appropriate processor (or processors) of a processing (i.e., computer) system executing instructions (computer-readable code) stored in storage. It will also be understood that the invention is not limited to any particular implementation or programming technique and that the invention may be implemented using any appropriate techniques for implementing the functionality described herein. The invention is not limited to any particular programming language or operating system.
It should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.
Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.
Furthermore, some of the embodiments are described herein as a method or combination of elements of a method that can be implemented by a processor of a computer system or by other means of carrying out the function. Thus, a processor with the necessary instructions for carrying out such a method or element of a method forms a means for carrying out the method or element of a method. Furthermore, an element described herein of an apparatus embodiment is an example of a means for carrying out the function performed by the element for the purpose of carrying out the invention.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as falling within the scope of the invention. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.
