阅读说明：本技术 用于火炮跳角获取的弹丸坐标测试方法及装置 (Projectile coordinate testing method and device for acquiring cannon jump angle ) 是由 杜博军 王海峰 王亚林 王龙 姜志 姜军志 王志成 于 2020-11-20 设计创作，主要内容包括：本发明公开了一种用于火炮跳角获取的弹丸坐标测试方法及装置,包括：建立目标区域；对目标区域的空中靶标进行标定；根据标定数据,建立虚拟靶面；根据弹丸穿过虚拟靶面的位置,确定弹丸着虚拟靶弹道参数。所述装置包括：预处理模块,用于建立目标区域；标定模块,用于对目标区域的空中靶标进行标定；建靶模块,用于根据标定数据,建立虚拟靶面；数采模块,用于根据弹丸穿过虚拟靶面的位置,确定弹丸着虚拟靶弹道参数。通过实施本发明的技术方案,采用虚拟靶面构建技术,实现了非接触测量弹丸着靶坐标,弥补了实物靶无法进行大仰角射击的不足；通过动态标定技术,建立靶面坐标系,大幅提高数据精度。(The invention discloses a method and a device for testing shot coordinates for acquiring a gun jump angle, wherein the method comprises the following steps: establishing a target area; calibrating an aerial target of a target area; establishing a virtual target surface according to the calibration data; and determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface. The device comprises: the preprocessing module is used for establishing a target area; the calibration module is used for calibrating the aerial target in the target area; the target building module is used for building a virtual target surface according to the calibration data; and the data acquisition module is used for determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface. By implementing the technical scheme of the invention and adopting a virtual target surface construction technology, the pellet landing coordinates are measured in a non-contact manner, and the defect that a physical target cannot be shot at a large elevation angle is overcome; and a target surface coordinate system is established by a dynamic calibration technology, so that the data precision is greatly improved.)

1. A shot coordinate testing method for acquiring cannon jump angles is characterized by comprising the following steps:

establishing a target area;

calibrating an aerial target of a target area;

establishing a virtual target surface according to the calibration data;

and determining the virtual target coordinates of the projectile according to the position of the projectile passing through the virtual target surface.

2. The method for testing the coordinates of a projectile for acquiring the jump angle of a artillery according to claim 1, wherein the establishing of the target area specifically comprises:

according to given initial data of shootingCarrying out gun adjustment;

and hovering the aerial calibration target to a preset target area.

3. The method for testing the shot coordinates acquired by the gun jump angle according to claim 1, wherein the calibrating the aerial target of the target area specifically comprises:

continuously shooting an aerial target by adopting two high-frame-frequency photoelectric theodolites to form an external calibration image sequence;

and continuously shooting the aerial target by using a gun tail calibration camera placed in the barrel to form an internal calibration image sequence.

4. The method for testing the projectile coordinate testing system for acquiring the cannon jump angle according to claim 1, wherein the establishing a virtual target plane according to the calibration data specifically comprises:

selecting a clear internal calibration image as an internal calibration reference frame, and processing a muzzle circle center o' on the frame image;

selecting a corresponding external calibration image frame according to the absolute time of the internal calibration reference frame, and performing data intersection processing on the external calibration image frames of the two theodolites to obtain coordinates of each mark point on the aerial target;

obtaining the coordinates of the projection point o' of the center of the muzzle circle according to the relative relation between the center of the muzzle circle on the internal calibration reference frame and each mark point of the aerial target;

and establishing a virtual target surface vertical to the shot direction according to the coordinates of the central projection point of the muzzle circle and the shot direction, and establishing a target surface coordinate system which takes the central projection point of the muzzle circle as an original point, the horizontal direction as a horizontal axis and the vertical direction as a vertical axis.

5. The method for testing the coordinates of a projectile for acquiring the jump angle of a artillery according to claim 1, wherein the step of determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface specifically comprises the following steps:

according to the establishment of the virtual target surface, the distance from the target surface to the muzzle is determined to be x_t；

Starting at zero time, measuring initial speed V₀；

And obtaining the impact point c and the absolute time of the projectile according to the centroid position when the projectile passes through the virtual target surface.

6. The method for testing the coordinates of a projectile for cannon jump angle acquisition as recited in claim 1, further comprising:

the relative coordinates (Δ y, Δ z) of point c to point o 'are calculated, the on-target time t'.

7. A terminal device, comprising:

the preprocessing module is used for establishing a target area;

the calibration module is used for calibrating the aerial target in the target area;

the target building module is used for building a virtual target surface according to the calibration data;

and the data acquisition module is used for determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface.

8. The terminal apparatus according to claim 7, further comprising:

and the calculation module is used for calculating the relative coordinates (delta y, delta z) of the point c to the point o 'and the target time t'.

9. The terminal device according to claim 7, wherein the calibration module comprises:

the coordinate measuring device is used for continuously shooting an aerial target by at least two high-frame-frequency photoelectric theodolites;

the special calibration device is used for calibrating the camera at the tail of the gun and continuously shooting the aerial target through the barrel.

10. The terminal device according to claim 7, wherein the frame rate of the coordinate measuring device is greater than or equal to 500 frames/second.

Technical Field

The invention relates to the technical field of projectile coordinate systems, in particular to a projectile coordinate testing method and device for acquiring a gun jump angle.

Background

The angle between the initial velocity vector line when the projectile exits the muzzle and the theoretical axis of the barrel when the projectile is not launched (the line connecting the tail center and the muzzle center) is called the jump angle. The jump angle is caused by the vibration and angular displacement of the cannon barrel, the mass eccentricity of the shot, the bending of the barrel and the like in the launching process. The jump angle is the main component of the firing angle, and whether the jump angle is accurate directly determines the precision of trajectory calculation and a programmed firing table, thereby influencing the firing accuracy of the weapon.

At present, the jump angle of a barrel weapon in China is mainly obtained from a special horizontal shooting jump angle test, and a test mode that a section device is matched with a jump angle target is adopted in the open air. The jumping angle target is generally made of a wooden frame and horse dung paper and is used for measuring the three-dimensional coordinate of the flying projectile for about 0.1 s. The intercept device is matched with a timer to measure the time taken by the projectile to fly a certain distance, and the ballistic average velocity (actually the ballistic midpoint velocity) is calculated. During the test, the jump angle target is arranged 50-200 m away from the muzzle, and the section devices are arranged in pairs at equal intervals between the muzzle and the jump angle target. The artillery adopts a horizontal shooting mode, target paper is laid on a target frame before each shooting, a cross line is drawn to serve as a sighting center, a coordinate system is established, a target jumping angle cross line is aimed through a shooting hole and a muzzle cross line, a projectile penetrates through a section device during shooting, a timer on-off signal is triggered, a projectile hole is reserved on the target paper, and after the firing, the coordinates of the projectile hole of the target paper, the distance between each pair of section devices and the flight time of the projectile are measured and recorded. The target paper needs to be replaced and the aiming and calibration are needed for each shot. Under the vacuum ballistic theory, the ballistic descent amount is considered, and the ballistic value is calculated by using the average value of the jump angle target bullet hole coordinates and the ballistic average speed which are obtained by tests. The jump angle calculation formula is as follows:

in the formula:

Ω_z、Ω_y-vertical and horizontal test jump angles, rad;

averaging of shots from muzzle to jump-angle targetSpeed, m/s;

g-gravitational acceleration, taking the local value of the test site, m/s²；

x_tDelta y and delta z are the distance from the jump angle target to the muzzle, the vertical and horizontal coordinates of the bullet hole, and m.

When the jump angle of the artillery used in the range test project is determined, 3 groups are shot, and each group (5+1) is shot; when the fixed jump angle of the watch (the expected jump angle value of the gun matrix) is determined, 3 guns are needed, each gun shoots 3 groups, and each group (5+1) shoots.

The test method for obtaining the jump angle by adopting the cooperation test of the section device and the jump angle target has been used for more than 60 years, has defects in both theoretical support and engineering implementation, seriously lags behind the development of modern shooting chart planning and target range test technology, and is mainly shown in the following aspects.

1. The approximate application of the jump angle has large error

The trajectory calibration is a key link for firing table compiling, if the firing angle and the firing direction are inaccurate in the calibration, errors can be generated in the obtained basic parameters, the calibration effect is influenced, and the trajectory simulation or firing table compiling precision is reduced. Therefore, accurate acquisition of the firing angle and the firing direction is the basic requirement of the firing test and is a precondition for ensuring the simulation quality of firing test. However, the range test is usually an upward shooting trajectory, and cannot directly acquire a jump angle due to the limitation of an aerial projectile coordinate test means and precision, so that a gun for the range test must be used for carrying out a special horizontal shooting jump angle project. In general, the gun jump angle test shoots 3 groups, each group having 5 shots. Neglecting the difference of horizontal shooting and elevation shooting of the jump angle of the artillery at the door, and calculating the shooting angle and the shooting direction of the shooting range test by using the horizontal shooting jump angle. The jump angle formation is influenced by various factors, has both systematicness and strong random characteristics, and the jump angles caused by different artillery, the same artillery in different service life stages, different bullet weights, different initial speeds and different shooting conditions are different, so that the firing angles of all shooting states are corrected by special test jump angles under specific conditions, and errors of different degrees can be brought. In the firing chart simulation, a range test and a jump angle test are carried out separately, and the two types of tests have different launching states and different ammunition data are mixed and used without matching. In the use of troops, the flat shot fixed jump angle is used for replacing the full shot bound jump angle, and errors exist. The systematic deviation of the jump angle can reduce the trajectory simulation and firing table compiling precision, and can also obviously reduce the artillery shooting precision or the first firing hit probability. Particularly, the impact on the low-extension ballistic performance is remarkable, and the jump angle of 1mil (3.6') can generate a height error of 1m at a kilometer distance.

2. The ammunition consumption of the existing method is large

In the current external ballistic test, a special jump angle test is relied on to strike the change rule of the initial speed direction of the artillery ammunition, and then the elevation angle and the direction in the external ballistic test are corrected according to the change rule. Therefore, in the ballistic simulation, an additional jump angle test is required as long as the correspondence between the shooting angle and the range is concerned. As the jump angle has strong random characteristic, the jump angles of different artillery are different, the jump angles of different ammunitions shot by the same artillery are different, and the jump angles of the same ammunition of the same kind of artillery are different in different shooting states, the special jump angle test consumes a large amount of ammunition, 60 surplus ammunition is needed for a weapon, one ammunition and one charge number to carry out a watch setting jump angle test, 20 rounds are also consumed for the cannon jump angle test, more than 40 percent of the jump angle is consumed for single-charge shooting watch test, and the consumption of the jump angle ammunition basically accounts for 1/3 of the shooting watch test ammunition in the multi-charge shooting watch test.

3. Long test period and high risk

In the jump angle test, complicated operations such as target setting, target supplement, artillery calibration and the like are required, each group of shooting needs to be carried out again, artillery stabilization and 3 groups of shooting are required at most every day. Due to the fact that the trajectory is low in extension, the attack angle is small, the bullet jumps occur, impact points are not concentrated and are generally scattered within the range of 3-10km, difficulty in searching and destroying unexploded ammunition is large, even if a large amount of manpower, material resources and time are input, the unexploded ammunition cannot be cleaned up necessarily, and potential safety hazards exist.

The obvious deficiency exists when the special flat shooting jump angle test result is used for replacing the full shooting range jump angle of the artillery, the root cause of the backward practice is that the space coordinate of the projectile during the upward shooting cannot be accurately measured, and therefore, a technical scheme for solving the technical defects is urgently needed in the industry.

Disclosure of Invention

In order to solve the technical problem, the invention discloses a projectile coordinate testing method for acquiring the jump angle of an artillery, which comprises the following steps:

establishing a target area;

calibrating an aerial target of a target area;

establishing a virtual target surface according to the calibration data;

and determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface.

Further, the establishing of the target area specifically includes:

according to given firing initiation specification (λ₀) Carrying out gun adjustment;

and hovering the aerial calibration target to a preset target area.

Further, the calibrating the aerial target of the target area specifically includes:

continuously shooting an aerial target by adopting two high-frame-frequency photoelectric theodolites to form an external calibration image sequence;

and continuously shooting the aerial target by using a gun tail calibration camera placed in the barrel to form an internal calibration image sequence. Further, the establishing a virtual target surface according to the calibration data specifically includes:

selecting a clear internal calibration image as an internal calibration reference frame, and processing a muzzle circle center o' on the frame image;

selecting a corresponding external calibration image frame according to the absolute time of the internal calibration reference frame, and performing data intersection processing on the external calibration image frames of the two theodolites to obtain coordinates of each mark point on the aerial target;

obtaining the coordinates of the projection point o' of the center of the muzzle circle according to the relative relation between the center of the muzzle circle on the internal calibration reference frame and each mark point of the aerial target;

and establishing a virtual target surface perpendicular to the shot direction according to the coordinate of the central projection point of the gun muzzle circle and the shot direction, and establishing a target surface coordinate system on the target surface by taking the central projection point of the gun muzzle circle as an original point, taking the horizontal direction as a horizontal axis and taking the vertical direction as a vertical axis.

Further, the determining the virtual target trajectory parameters of the projectile according to the position of the projectile passing through the virtual target surface specifically includes:

according to the establishment of the virtual target surface, the distance from the target surface to the muzzle is determined to be x_t；

Starting at zero time, measuring initial speed V₀；

And obtaining the impact point c and the absolute time of the projectile according to the centroid position when the projectile passes through the virtual target surface.

Further, the method also comprises the following steps:

the relative coordinates (Δ y, Δ z) of point c to point o 'are calculated, the on-target time t'.

The invention also discloses a terminal device, comprising:

the preprocessing module is used for establishing a target area;

the calibration module is used for calibrating the aerial target in the target area;

the target building module is used for building a virtual target surface according to the calibration data;

and the data acquisition module is used for determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface.

Further, the method also comprises the following steps:

and the calculation module is used for calculating the relative coordinates (delta y, delta z) of the point c to the point o 'and the target time t'.

Further, the calibration module includes:

the coordinate measuring device is used for continuously shooting an aerial target by at least two high-frame-frequency photoelectric theodolites;

the special calibration device is used for calibrating the camera at the tail of the gun and continuously shooting the aerial target through the barrel.

Furthermore, the shooting frame frequency of the coordinate measuring equipment is more than or equal to 500 frames/second.

Has the advantages that:

by implementing the technical scheme of the invention and adopting a virtual target surface construction technology, the pellet landing coordinates are measured in a non-contact manner, and the defect that a physical target cannot be shot at a large elevation angle is overcome; by the dynamic calibration technology, the intersection point of the extension line of the gun barrel axis and the target surface is determined as the origin of a coordinate system, the target surface coordinate system is established, and the data precision is greatly improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic diagram of a standing target shooting of the projectile coordinate testing device for acquiring the jump angle of the artillery according to the application;

FIG. 2 is a schematic diagram of a coordinate measuring device of the projectile coordinate testing device for acquiring a gun jump angle according to the present application;

FIG. 3 is a schematic diagram of shooting by a shot tail calibration camera of the projectile coordinate testing device for acquiring the jump angle of the artillery according to the present application;

FIG. 4 is a schematic flow chart of the projectile coordinate testing method for acquiring the jump angle of the artillery according to the present application;

fig. 5 is a schematic structural diagram of the projectile coordinate testing device for acquiring the jump angle of the artillery.

Legend: 1. a coordinate measurement device; 2. calibrating a camera at the tail of the gun; 11. a preprocessing module; 12. a calibration module; 13. a target building module; 14. a data acquisition module; 100. provided is a device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The direct measurement of the gun muzzle coordinate (the gun position base point, the rotation center and the pitching center barrel length) and the initial section trajectory coordinate involves a plurality of error sources, and the precision is difficult to ensure. If the target is set up perpendicular to the shooting face, the target face coordinate system is established by taking the intersection point of the theoretical axis of the gun barrel and the target face as the center, and the shooting pellet landing coordinates are measured by the method of image identification, comparison and interpretation before and after the projectile, so that a plurality of error sources are eliminated, the data accuracy is greatly improved, and as shown in figure 1, o is a muzzle, o' is the intersection point of the extension line of the theoretical axis of the gun barrel and the target face, and c is an actual landing point. However, when shooting at a large elevation angle, the actual target standing is not practical, and a virtual target surface needs to be established.

As shown in fig. 4, the method for testing the shot coordinate for acquiring the gun jump angle of the invention specifically comprises the following steps:

s100: a target area is established.

Further, in a preferred embodiment provided in the present application, the establishing a target area specifically includes:

according to given firing initiation specification (λ₀) Adjusting the cannon by using a sighting telescope and an optical quadrant;

and hovering the aerial calibration target to a preset target area. It is required that the target be visible through the barrel from the breech.

The target zone is about 0.4s of projectile flight.

S200: and calibrating the aerial target of the target area.

Further, in a preferred embodiment provided in the present application, the calibrating the aerial target of the target area specifically includes:

continuously shooting an aerial calibration target by adopting two high-frame-frequency photoelectric theodolites to form an external calibration image sequence;

and continuously shooting the aerial calibration target by using a gun tail calibration camera placed in the barrel to form an internal calibration image sequence.

S300: and establishing a virtual target surface according to the calibration data.

Further, in a preferred embodiment provided by the present application, the establishing a virtual target plane according to the calibration data specifically includes:

selecting a clear internal calibration image as an internal calibration reference frame, and processing a muzzle circle center o' on the frame image;

selecting a corresponding external calibration image frame according to the absolute time of the internal calibration reference frame, and performing data intersection processing on the external calibration image frames of the two theodolites to obtain coordinates of each mark point on the aerial target;

obtaining the coordinates of the projection point o' of the center of the muzzle circle according to the relative relation between the center of the muzzle circle on the internal calibration reference frame and each mark point of the aerial target;

and establishing a virtual target surface perpendicular to the shot direction according to the coordinate of the central projection point of the gun muzzle circle and the shot direction, and establishing a target surface coordinate system on the target surface by taking the central projection point of the gun muzzle circle as an original point, taking the horizontal direction as a horizontal axis and taking the vertical direction as a vertical axis.

S400: and determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface.

Further, in a preferred embodiment provided by the present application, the determining the parameters of the virtual target trajectory of the projectile according to the position of the projectile passing through the virtual target surface specifically includes:

according to the establishment of the virtual target surface, the distance from the target surface to the muzzle is determined to be x_t；

Starting at zero time, measuring initial speed V₀；

And obtaining the impact point c and the absolute time of the projectile according to the centroid position when the projectile passes through the virtual target surface.

The invention also includes:

s500: the relative coordinates (Δ y, Δ z) of point c to point o 'are calculated, the on-target time t'.

Based on the same idea, the shot coordinate testing method for acquiring the gun jump angle provided in the embodiment of the present application further provides a terminal device 100, as shown in fig. 5.

A terminal device 100 comprising:

the preprocessing module 11 is used for establishing a target area;

the calibration module 12 is used for calibrating the aerial target in the target area;

the target building module 13 is used for building a virtual target surface according to the calibration data;

and the data acquisition module 14 is used for determining the virtual target coordinates of the projectile according to the position of the projectile passing through the virtual target surface.

Further, in an embodiment provided in the present application, the preprocessing module 11 is configured to establish a target area, and specifically configured to:

according to given firing initiation specification (λ₀) Adjusting the cannon by using a sighting telescope and an optical quadrant;

and hovering the aerial calibration target to a preset target area. It is required that the target be visible through the barrel from the breech.

Further, the calibration module 12 is configured to calibrate the aerial target in the target area, as shown in fig. 2 and 3, and includes:

coordinate measuring equipment 1, at least two coordinate measuring equipment carry out aerial target of shooing in succession, and in this embodiment, coordinate measuring equipment 1 symmetry sets up in artillery side rear. The coordinate measuring device 1 is a high frame frequency electro-optic theodolite. Two photoelectric theodolites are arranged at the back side of the artillery and continuously shoot the aerial target in a fixed waiting mode. Through the intersection of the two photoelectric theodolites, the coordinates of each mark point on the aerial target at the shooting moment of the gun tail calibration camera 2 can be obtained, and therefore the virtual target surface is established.

The special calibration device gun tail calibrates the camera 2, is used for shooting the aerial target continuously through the barrel.

The special calibration device comprises an aerial calibration target and a gun tail calibration camera 2, wherein the aerial calibration target uses a rotary wing type unmanned aerial vehicle as an aerial bearing platform, a calibration frame and a calibration lamp set are additionally arranged on the unmanned aerial vehicle, and the special calibration device is mainly used for providing an aerial reference point which is about 200-400 m away from a gun muzzle and providing a calibration reference for test equipment and the gun tail calibration camera. The artillery tail calibration camera shooting instrument comprises a CCD camera, an acquisition computer, a time system card, artillery calibration software, a clamp matched with an artillery barrel and the like. The endoscopic imaging structure is arranged at the tail part of the gun barrel, and shoots a gun muzzle and an aerial calibration target for calibrating an aerial aiming position.

Shooting the aerial target through a barrel by using a gun tail calibration camera to form an internal calibration image sequence, continuously shooting the aerial target by using two high-frame-frequency photoelectric theodolites to form an external calibration image sequence, wherein each device is required to have a time system card, the shooting is basically synchronous, and the frame frequency of the photoelectric theodolite is not lower than 500 frames/second.

Further, the targeting module 13 is configured to establish a virtual target surface according to the calibration data, and specifically configured to:

selecting a clear internal calibration image as an internal calibration reference frame, and processing the center o 'of a muzzle circle on the frame image, wherein the center o' is the intersection point of the extension line of the theoretical axis of the barrel and the virtual target surface;

selecting a corresponding external calibration image frame according to the absolute time of the internal calibration reference frame, and performing data intersection processing on the external calibration image frames of the two theodolites to obtain coordinates of each mark point on the aerial target;

obtaining coordinates of a projection point o' of the center of the muzzle circle by using an image interpretation system of a muzzle tail calibration camera according to the relative relation between the center of the muzzle circle on the internal calibration reference frame and each mark point of the aerial target;

and establishing a virtual target surface perpendicular to the shot direction according to the coordinate of the central projection point of the gun muzzle circle and the shot direction, and establishing a target surface coordinate system on the target surface by taking the central projection point of the gun muzzle circle as an original point, taking the horizontal direction as a horizontal axis and taking the vertical direction as a vertical axis.

Further, the data acquisition module 14 specifically includes:

filling ammunition, adjusting and launching;

starting the zero-time equipment at the muzzle simultaneously, and measuring the initial velocity V by using an initial velocity radar₀Shooting by a photoelectric theodolite;

accurately judging and reading the centroid position of the projectile when the projectile passes through the virtual target surface by a visual simulation imaging technology, an image identification technology and an image comparison and position matching technology to obtain a projectile impact point c;

calculating the distance from the target surface to the muzzle according to the virtual target surfaceIs separated as x_t。

A terminal device 100, further comprising:

and a calculation module 15 for calculating the relative coordinates (Δ y, Δ z) of the point c to the point o ', the target-on time t'.

By implementing the technical scheme of the invention and adopting a virtual target surface construction technology, the pellet landing coordinates are measured in a non-contact manner, and the defect that a physical target cannot be shot at a large elevation angle is overcome; by the dynamic calibration technology, the intersection point of the extension line of the gun barrel axis and the target surface is determined as the origin of a coordinate system, the target surface coordinate system is established, and the data precision is greatly improved.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.