1. A three-dimensional side scan sonar array forming method is characterized by comprising the following steps: dividing the signals of the receiving array into a plurality of range snapshots according to the receiving time difference, and performing conventional beam forming on each range snapshot to generate a gray level image based on signal intensity; setting the range of each distance snapshot according to the signal intensity, and setting a two-dimensional convolution kernel according to the array element number and the array element interval in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle; and setting iteration times, entering a distance snapshot, performing Richardson-Lucy inverse convolution algorithm iterative operation, and taking the result of Richardson-Lucy inverse convolution algorithm iterative operation as the output of the distance snapshot if the maximum iteration times is reached.

2. The three-dimensional side-scan sonar imaging method according to claim 1, wherein the generating a gray scale image based on signal intensity by performing conventional beamforming for each range snapshot includes:

wherein S (x, y) is the intensity value of the conventional beamformed output image; x, y are respectively the abscissa and ordinate of the beamformed output image, i.e., the number of pre-formed beams; f (m, n) is the original signal of the array element with specific coordinates, and is a complex number; m and N are the number of the sonar receiving array elements in the transverse direction and the longitudinal direction respectively; j is an imaginary unit; m is the horizontal mth sonar receiving array element; n is the nth sonar receiving array element in the vertical direction.

3. The three-dimensional side scan sonar array-forming method according to claim 2, wherein the two-dimensional convolution kernel is set according to array element number and array element spacing in the yaw and pitch directions of the sonar receiving array, and the yaw angle and pitch angle, and comprises:

wherein the content of the first and second substances,a convolution kernel two-dimensional array;the number of array elements in the yaw and pitch directions;array element spacing in yaw and pitch directions;is a pitch angle;is a yaw angle;the wavelength of the underwater acoustic signal.

4. The three-dimensional side-scan sonar array-forming method according to claim 3, wherein the performing Richardson-Lucy deconvolution algorithm iterative operations include:

wherein the content of the first and second substances,the output of the last iteration;is the output of the iteration; is a two-dimensional convolution operation.

5. The three-dimensional side-scan sonar array-forming method according to claim 4, further comprising, after the performing Richardson-Lucy deconvolution algorithm iterative operations: and if the maximum iteration number is not reached, continuing to perform Richardson-Lucy deconvolution algorithm iterative operation.

6. The three-dimensional side-scan sonar array-forming method according to claim 5, further comprising, after the outputting the one-distance snapshot with results of Richardson-Lucy deconvolution algorithm iterative operations: and if the calculation of all the distance snapshots is finished, finishing the Richardson-Lucy deconvolution algorithm iterative operation.

7. A three-dimensional side scan sonar array-forming system, comprising: the transmitting array module is used for transmitting spherical wave or cylindrical wave ultrasonic signals; the receiving array module is used for converting the change of the sound pressure intensity of the ultrasonic echo into an electric signal and extracting the amplitude and the phase of the signal through an orthogonal demodulation circuit; a beam forming and deconvolution module for implementing a three-dimensional side-scan sonar array method according to any one of claims 1 to 6; and the display control module is used for carrying out user interaction and displaying the three-dimensional imaging data.

8. A three-dimensional side scan sonar array-forming device is characterized by comprising: the first main module is used for dividing the signals of the receiving array into a plurality of distance snapshots according to the receiving duration difference, performing conventional beam forming on each distance snapshot and generating a gray image based on signal intensity; the second main module is used for setting the range of each distance snapshot according to the signal intensity, and setting a two-dimensional convolution kernel according to the array element number and the array element interval in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle; and the third main module is used for setting iteration times, entering a distance snapshot and carrying out Richardson-Lucy inverse convolution algorithm iterative operation, and if the maximum iteration times are reached, taking the result of the Richardson-Lucy inverse convolution algorithm iterative operation as the output of the distance snapshot.

9. An electronic device, comprising:

at least one processor, at least one memory, and a communication interface; wherein the content of the first and second substances,

the processor, the memory and the communication interface are communicated with each other;

the memory stores program instructions executable by the processor, the processor invoking the program instructions to perform the method of any of claims 1 to 6.

10. A non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the method of any one of claims 1 to 6.

Background

The three-dimensional side scan sonar has very wide application in the underwater topography measurement field. Because the sonar system has the advantage of stereo imaging, an accurate three-dimensional model of an underwater object can be obtained, and the resolution of the geometric shape is realized. For the existing three-dimensional side-scan sonar, the angular resolution and the distance resolution restrict the accuracy of three-dimensional imaging, and because the three-dimensional side-scan sonar may need to be installed or used in various narrow and small environments, the limitation of the number of array elements and the spacing of the array elements of the sonar receiving array is obvious, and the spatial angular resolution is further limited. It is difficult to install a plurality of receiving arrays in a narrow space, so that the number of array elements of the existing three-dimensional side-scan sonar receiving array is small, and the improvement of resolution ratio is limited. Meanwhile, the data of each distance slice needs to be respectively processed by beam forming, so that the calculation is complicated, and the accuracy and the real-time performance of three-dimensional imaging are restricted. Therefore, it is an urgent technical problem to be solved in the art to develop a three-dimensional side scan sonar array method and apparatus, which can effectively overcome the above-mentioned drawbacks in the related art.

Disclosure of Invention

Aiming at the problems in the prior art, the embodiment of the invention provides a three-dimensional side-scan sonar array forming method and equipment.

In a first aspect, an embodiment of the present invention provides a three-dimensional side-scan sonar array method, including: dividing the signals of the receiving array into a plurality of range snapshots according to the receiving time difference, and performing conventional beam forming on each range snapshot to generate a gray level image based on signal intensity; setting the range of each distance snapshot according to the signal intensity, and setting a two-dimensional convolution kernel according to the array element number and the array element interval in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle; and setting iteration times, entering a distance snapshot, performing Richardson-Lucy inverse convolution algorithm iterative operation, and taking the result of Richardson-Lucy inverse convolution algorithm iterative operation as the output of the distance snapshot if the maximum iteration times is reached.

On the basis of the content of the above method embodiment, the three-dimensional side-scan sonar array forming method provided in the embodiment of the present invention, which performs conventional beam forming on each range snapshot to generate a gray level image based on signal intensity, includes:

wherein S (x, y) is the intensity value of the conventional beamformed output image; x, y are respectively the abscissa and ordinate of the beamformed output image, i.e., the number of pre-formed beams; f (m, n) is the original signal of the array element with specific coordinates, and is a complex number; m and N are the number of the sonar receiving array elements in the transverse direction and the longitudinal direction respectively; j is an imaginary unit; m is the horizontal mth sonar receiving array element; n is the nth sonar receiving array element in the vertical direction.

Based on the content of the above method embodiment, the three-dimensional side scan sonar array forming method provided in the embodiment of the present invention, wherein two-dimensional convolution kernels are set according to the number of array elements and the array element pitch in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle, and the method includes:

wherein the content of the first and second substances,a convolution kernel two-dimensional array;the number of array elements in the yaw and pitch directions;array element spacing in yaw and pitch directions;is a pitch angle;is a yaw angle;the wavelength of the underwater acoustic signal.

Based on the content of the embodiment of the method, the three-dimensional side scan sonar array forming method provided by the embodiment of the invention performs Richardson-Lucy deconvolution algorithm iterative operation, and comprises the following steps:

wherein the content of the first and second substances,the output of the last iteration;is the output of the iteration; is a two-dimensional convolution operation.

Based on the content of the above method embodiment, the three-dimensional side scan sonar array forming method provided in the embodiment of the present invention further includes, after the Richardson-Lucy deconvolution algorithm is performed with iterative operation: and if the maximum iteration number is not reached, continuing to perform Richardson-Lucy deconvolution algorithm iterative operation.

Based on the content of the above method embodiment, the three-dimensional side scan sonar array forming method provided in the embodiment of the present invention further includes, after taking the result of iterative operation of Richardson-Lucy deconvolution algorithm as the output of the one-distance snapshot: and if the calculation of all the distance snapshots is finished, finishing the Richardson-Lucy deconvolution algorithm iterative operation.

In a second aspect, embodiments of the present invention provide a three-dimensional side-scan sonar array-forming system, comprising: the transmitting array module is used for transmitting spherical wave or cylindrical wave ultrasonic signals; the receiving array module is used for converting the change of the sound pressure intensity of the ultrasonic echo into an electric signal and extracting the amplitude and the phase of the signal through an orthogonal demodulation circuit; a beam forming and deconvolution module for implementing a three-dimensional side-scan sonar array-forming method as described in any one of the method embodiments of the first aspect; and the display control module is used for carrying out user interaction and displaying the three-dimensional imaging data.

In a third aspect, an embodiment of the present invention provides a three-dimensional side-scan sonar array apparatus, including: the first main module is used for dividing the signals of the receiving array into a plurality of distance snapshots according to the receiving duration difference, performing conventional beam forming on each distance snapshot and generating a gray image based on signal intensity; the second main module is used for setting the range of each distance snapshot according to the signal intensity, and setting a two-dimensional convolution kernel according to the array element number and the array element interval in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle; and the third main module is used for setting iteration times, entering a distance snapshot and carrying out Richardson-Lucy inverse convolution algorithm iterative operation, and if the maximum iteration times are reached, taking the result of the Richardson-Lucy inverse convolution algorithm iterative operation as the output of the distance snapshot.

In a fourth aspect, an embodiment of the present invention provides an electronic device, including:

at least one processor; and

at least one memory communicatively coupled to the processor, wherein:

the memory stores program instructions executable by the processor, which are capable of performing the three-dimensional side-scan sonar array method provided by any of the various implementations of the first aspect.

In a fifth aspect, embodiments of the invention provide a non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform a three-dimensional side-scan sonar array method provided by any of the various implementations of the first aspect.

According to the three-dimensional side scan sonar array forming method and the equipment, a gray level image based on signal intensity is generated through each distance snapshot, the range of each distance snapshot is set according to the signal intensity, a two-dimensional convolution kernel is set, the iteration times are set, Richardson-Lucy deconvolution algorithm iterative operation is carried out on the distance snapshots, the result is used as the output of the distance snapshots, real-time processing of the three-dimensional image can be achieved, super-resolution imaging is carried out on the underwater sound image, and high-precision surveying and mapping of underwater objects are completed on the premise that the number of array elements and the spacing of the array elements of the sonar are limited.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description will be given below to the drawings required for the description of the embodiments or the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a flowchart of a three-dimensional side-scan sonar array-forming method according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a three-dimensional side-scan sonar array-forming device according to an embodiment of the present invention;

fig. 3 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a three-dimensional side-scan sonar array system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. 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 invention. In addition, technical features of various embodiments or individual embodiments provided by the present invention may be arbitrarily combined with each other to form a feasible technical solution, and such combination is not limited by the sequence of steps and/or the structural composition mode, but must be realized by a person skilled in the art, and when the technical solution combination is contradictory or cannot be realized, such a technical solution combination should not be considered to exist and is not within the protection scope of the present invention.

The embodiment of the invention provides a three-dimensional side-scan sonar array forming method, which comprises the following steps of: dividing the signals of the receiving array into a plurality of range snapshots according to the receiving time difference, and performing conventional beam forming on each range snapshot to generate a gray level image based on signal intensity; setting the range of each distance snapshot according to the signal intensity, and setting a two-dimensional convolution kernel according to the array element number and the array element interval in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle; and setting iteration times, entering a distance snapshot, performing Richardson-Lucy inverse convolution algorithm iterative operation, and taking the result of Richardson-Lucy inverse convolution algorithm iterative operation as the output of the distance snapshot if the maximum iteration times is reached.

Based on the content of the foregoing method embodiment, as an optional embodiment, the three-dimensional side-scan sonar array method provided in the embodiment of the present invention, where performing conventional beam forming on each range snapshot to generate a grayscale image based on signal intensity includes:

（1）

wherein S (x, y) is the intensity value of the conventional beamformed output image; x, y are respectively the abscissa and ordinate of the beamformed output image, i.e., the number of pre-formed beams; f (m, n) is the original signal of the array element with specific coordinates, and is a complex number; m and N are the number of the sonar receiving array elements in the transverse direction and the longitudinal direction respectively; j is an imaginary unit; m is the horizontal mth sonar receiving array element; n is the nth sonar receiving array element in the vertical direction.

Specifically, each original signal of the range snapshot is firstly processed by a conventional beam forming algorithm to generate a gray image based on intensity. The invention completes the processing of conventional beam forming by running an FFT algorithm on a GPU platform, which is specifically shown as a formula (1).

Based on the content of the foregoing method embodiment, as an optional embodiment, the three-dimensional side-scan sonar array forming method provided in the embodiment of the present invention, wherein a two-dimensional convolution kernel is set according to the number of array elements and the array element pitch in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle, includes:

（2）

wherein the content of the first and second substances,a convolution kernel two-dimensional array;the number of array elements in the yaw and pitch directions;array element spacing in yaw and pitch directions;is a pitch angle;is a yaw angle;the wavelength of the underwater acoustic signal.

Specifically, after the conventional beamforming operation is completed, the range of the distance snapshot for performing the deconvolution algorithm is set by a user or automatically according to the signal strength. The size of the two-dimensional convolution kernel is set according to the horizontal and vertical spacing of the sonar receiving array elements and the number of pre-formed beams in the yaw and pitch directions. The convolution kernel is a function of pitch angle and yaw angle, and the calculation formula is shown as formula (2).

Based on the content of the above method embodiment, as an optional embodiment, the three-dimensional side-scan sonar array forming method provided in the embodiment of the present invention performs Richardson-Lucy deconvolution algorithm iterative operations, including:

（3）

wherein the content of the first and second substances,the output of the last iteration;is the output of the iteration; is a two-dimensional convolution operation. It should be noted that, in the Richardson-Lucy deconvolution algorithm, the formula for each iteration is shown as formula (3).

Based on the content of the above method embodiment, as an optional embodiment, the three-dimensional side-scan sonar array forming method provided in the embodiment of the present invention further includes, after performing Richardson-Lucy deconvolution algorithm iterative operation: and if the maximum iteration number is not reached, continuing to perform Richardson-Lucy deconvolution algorithm iterative operation.

Based on the content of the foregoing method embodiment, as an optional embodiment, the three-dimensional side-scan sonar array forming method provided in the embodiment of the present invention further includes, after taking a result of iterative operation of the Richardson-Lucy deconvolution algorithm as an output of the one-distance snapshot: and if the calculation of all the distance snapshots is finished, finishing the Richardson-Lucy deconvolution algorithm iterative operation.

According to the three-dimensional side scan sonar array forming method provided by the embodiment of the invention, a gray image based on signal intensity is generated through each distance snapshot, the range of each distance snapshot is set according to the signal intensity, a two-dimensional convolution kernel is set, the iteration times are set, Richardson-Lucy deconvolution algorithm iteration operation is carried out on the distance snapshots, the result is used as the output of the distance snapshots, the real-time processing of the three-dimensional image can be realized, the super-resolution imaging is carried out on the underwater sound image, and the high-precision surveying and mapping of underwater objects are completed on the premise that the number of array elements and the spacing of the array elements of a sonar are limited.

According to the three-dimensional side-scan sonar array forming method provided by the embodiment of the invention, the operation time of the algorithm is effectively shortened by operating the core signal processing algorithm on the NVIDIA GPU platform, the key algorithm can finish operation in the time interval of two times of sonar signal emission, the real-time processing of the three-dimensional image is realized, and the super-resolution imaging of the underwater sound image is realized through the deconvolution algorithm. Under the condition that array element quantity and array element interval of sonar are limited, the high-precision underwater surveying and mapping function is well realized, three-dimensional data measured for many times can be automatically spliced under the condition of integrating angle and position sensors, and three-dimensional underwater topography in the full track direction is generated.

The embodiment of the invention provides a three-dimensional side scan sonar array system, which comprises the following components in part by weight according to the figure 4: the transmitting array module is used for transmitting spherical wave or cylindrical wave ultrasonic signals; the receiving array module is used for converting the change of the sound pressure intensity of the ultrasonic echo into an electric signal and extracting the amplitude and the phase of the signal through an orthogonal demodulation circuit; a beam forming and deconvolution module for implementing a three-dimensional side-scan sonar array-forming method as described in any of the preceding method embodiments; and the display control module is used for carrying out user interaction and displaying the three-dimensional imaging data.

Specifically, the transmitting array module is used for transmitting spherical wave or cylindrical wave ultrasonic signals. Since the average distance between the sonar and the target is much larger than the wavelength at which the sonar operates, the received array processed signals are approximated to be far-field signals, i.e. the echoes of the target are assumed to be parallel. And the receiving array module is a phased array system consisting of a plurality of underwater acoustic transducers, and all array elements are arranged on one plane. The transducer can convert the change of the sound pressure intensity of the ultrasonic wave echo into an electric signal, and extract the amplitude and the phase of the signal through a quadrature demodulation circuit. Each transducer array element outputs a complex number at a certain moment, including amplitude and phase information of the signal. And the beam forming and deconvolution module is used for realizing the operation of the algorithm on the NVIDIA GPU by calling the CUDA API. And the display control module is responsible for carrying out user interaction and displaying the three-dimensional imaging data. When the sonar is installed on a mobile platform, the display control software can automatically perform offset of the sonar position and generation of a corresponding three-dimensional model according to data of a gyroscope and a GPS receiver connected with the sonar.

The implementation basis of the various embodiments of the present invention is realized by programmed processing performed by a device having a processor function. Therefore, in engineering practice, the technical solutions and functions thereof of the embodiments of the present invention can be packaged into various modules. Based on this actual situation, in addition to the above embodiments, the embodiments of the present invention provide a three-dimensional side-scan sonar array apparatus for performing the three-dimensional side-scan sonar array method in the above method embodiments. Referring to fig. 2, the apparatus includes: the first main module is used for dividing the signals of the receiving array into a plurality of distance snapshots according to the receiving duration difference, performing conventional beam forming on each distance snapshot and generating a gray image based on signal intensity; the second main module is used for setting the range of each distance snapshot according to the signal intensity, and setting a two-dimensional convolution kernel according to the array element number and the array element interval in the yaw and pitch directions of the sonar receiving array, as well as the yaw angle and the pitch angle; and the third main module is used for setting iteration times, entering a distance snapshot and carrying out Richardson-Lucy inverse convolution algorithm iterative operation, and if the maximum iteration times are reached, taking the result of the Richardson-Lucy inverse convolution algorithm iterative operation as the output of the distance snapshot.

The three-dimensional side scan sonar array forming device provided by the embodiment of the invention adopts a plurality of modules in the figure 2, generates a gray image based on signal intensity through each range snapshot, sets the range of each range snapshot according to the signal intensity, sets a two-dimensional convolution kernel, sets the iteration times, performs Richardson-Lucy deconvolution algorithm iterative operation on the range snapshots, and takes the result as the output of the range snapshot, so that the real-time processing of the three-dimensional image can be realized, the super-resolution imaging of the underwater sound image is performed, and the high-precision surveying and mapping of underwater objects are completed on the premise that the number of array elements and the spacing of the array elements of a sonar are limited.

It should be noted that, the apparatus in the apparatus embodiment provided by the present invention may be used for implementing methods in other method embodiments provided by the present invention, except that corresponding function modules are provided, and the principle of the apparatus embodiment provided by the present invention is basically the same as that of the apparatus embodiment provided by the present invention, so long as a person skilled in the art obtains corresponding technical means by combining technical features on the basis of the apparatus embodiment described above, and obtains a technical solution formed by these technical means, on the premise of ensuring that the technical solution has practicability, the apparatus in the apparatus embodiment described above may be modified, so as to obtain a corresponding apparatus class embodiment, which is used for implementing methods in other method class embodiments. For example:

based on the content of the above device embodiment, as an optional embodiment, the three-dimensional side-scan sonar array device provided in the embodiment of the present invention further includes: the first sub-module is used for realizing the conventional beam forming of each range snapshot and generating a gray level image based on signal intensity, and comprises:

wherein S (x, y) is the intensity value of the conventional beamformed output image; x, y are respectively the abscissa and ordinate of the beamformed output image, i.e., the number of pre-formed beams; f (m, n) is the original signal of the array element with specific coordinates, and is a complex number; m and N are the number of the sonar receiving array elements in the transverse direction and the longitudinal direction respectively; j is an imaginary unit; m is the horizontal mth sonar receiving array element; n is the nth sonar receiving array element in the vertical direction.

Based on the content of the above device embodiment, as an optional embodiment, the three-dimensional side-scan sonar array device provided in the embodiment of the present invention further includes: the second submodule piece is used for realizing and receiving array element quantity and array element interval of array driftage and pitch direction according to the sonar and sets up two-dimensional convolution kernel including:

wherein the content of the first and second substances,a convolution kernel two-dimensional array;the number of array elements in the yaw and pitch directions;array element spacing in yaw and pitch directions;is a pitch angle;is a yaw angle;the wavelength of the underwater acoustic signal.

Based on the content of the above device embodiment, as an optional embodiment, the three-dimensional side-scan sonar array device provided in the embodiment of the present invention further includes: the third submodule is used for realizing the Richardson-Lucy deconvolution algorithm iterative operation, and comprises:

wherein the content of the first and second substances,the output of the last iteration;is the output of the iteration; is a two-dimensional convolution operation.

Based on the content of the above device embodiment, as an optional embodiment, the three-dimensional side-scan sonar array device provided in the embodiment of the present invention further includes: the fourth sub-module is configured to implement that after the Richardson-Lucy deconvolution algorithm iterative operation is performed, the fourth sub-module further includes: and if the maximum iteration number is not reached, continuing to perform Richardson-Lucy deconvolution algorithm iterative operation.

Based on the content of the above device embodiment, as an optional embodiment, the three-dimensional side-scan sonar array device provided in the embodiment of the present invention further includes: a fifth sub-module, configured to implement that after the result of iterative operation of the Richardson-Lucy deconvolution algorithm is used as the output of the one-distance snapshot, the method further includes: and if the calculation of all the distance snapshots is finished, finishing the Richardson-Lucy deconvolution algorithm iterative operation.

The method of the embodiment of the invention is realized by depending on the electronic equipment, so that the related electronic equipment is necessarily introduced. To this end, an embodiment of the present invention provides an electronic apparatus, as shown in fig. 3, including: the system comprises at least one processor (processor), a communication Interface (communication Interface), at least one memory (memory) and a communication bus, wherein the at least one processor, the communication Interface and the at least one memory are communicated with each other through the communication bus. The at least one processor may invoke logic instructions in the at least one memory to perform all or a portion of the steps of the methods provided by the various method embodiments described above.

In addition, the logic instructions in the at least one memory may be implemented in software functional units and stored in a computer readable storage medium when sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the method embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. Based on this recognition, each block in the flowchart or block diagrams may represent a module, a program segment, or a portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In this patent, 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 … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.