Disclosure of Invention
The invention provides a method, a system and equipment for classifying and controlling the warping of a corrugated board at a tile line outlet, which are used for collecting and analyzing the warping type of the produced corrugated board in real time and outputting corresponding production line control parameters according to the warping type.
The first aspect of the invention provides a tile line outlet paperboard warp classifying and process controlling method, which comprises the steps of acquiring a vertical plane curve outline image of a produced paperboard by using a linear light sensor, judging the paperboard type of the produced paperboard according to the vertical plane curve outline image, calculating warp convexity of the produced paperboard based on the vertical plane curve outline image when the type of the produced paperboard is a non-L-shaped paperboard, judging that the quality of the produced paperboard is qualified if the absolute value of the warp convexity is not larger than a warp preset threshold value, determining and outputting the type of the produced paperboard according to the warp convexity value and warp convexity preset range values corresponding to different warp types when the absolute value of the warp convexity is larger than the warp preset threshold value, inputting the type of the produced paperboard into a pre-trained neural network model to obtain production line control parameters output by the pre-trained neural network model, and outputting the production line control parameters to a production line control center for adjusting and controlling the quality of the paperboard.
The method comprises the steps of collecting vertical plane curve outline images of a produced paperboard by using a line structure light sensor, judging the paperboard type of the produced paperboard according to the vertical plane curve outline images, collecting vertical plane reflected light images of the produced paperboard for a plurality of times by using the line structure light sensor, preprocessing the collected vertical plane reflected light images to obtain a plurality of preprocessed images, extracting and integrating the vertical plane curve outline images of the produced paperboard from the preprocessed images, carrying out data fitting according to the extracted vertical plane curve outline images to obtain a unitary triple function of curve profile transverse pixel coordinates-curve profile longitudinal pixel coordinates, calculating the number of extreme points of the unitary triple function, judging that the produced paperboard is a normal paperboard when the number of the extreme points of the unitary triple function is 0, judging that the produced paperboard is a non-S type paperboard when the number of the extreme points of the unitary triple function is 1, judging that the produced paperboard is a S type paperboard when the number of the extreme points of the unitary triple function is 2, and sending an alarm reminding, calculating the difference value of derivatives on two sides of the produced paperboard based on the unitary triple function when the produced paperboard is the non-S type paperboard, calculating the preset derivative value, judging that the difference value exceeds the preset derivative value of the unitary value, and judging that the produced paperboard is L type, and the produced paperboard is not S type paperboard.
Preferably, the structural light sensor is used for collecting the vertical plane reflected light image of the produced paperboard for a plurality of times, and the collected vertical plane reflected light image is preprocessed to obtain a plurality of preprocessed images, wherein the preprocessing comprises the steps of projecting structural light to the vertical plane of the produced paperboard, collecting the vertical plane reflected light image of the produced paperboard for a plurality of times, and preprocessing the collected vertical plane reflected light image to obtain a plurality of preprocessed images.
Preferably, the vertical plane curve outline image of the produced paperboard is extracted from a plurality of preprocessed images and integrated, and the method comprises the steps of extracting light fringes in the preprocessed images to obtain a plurality of groups of light fringes, mapping the position of each group of light fringes to a space three-dimensional coordinate by using camera calibration parameters, converting and aligning the space three-dimensional coordinates of the plurality of groups of light fringes, fusing to obtain a vertical plane three-dimensional outline of the produced paperboard, and processing the vertical plane three-dimensional outline of the produced paperboard to obtain the vertical plane curve outline image of the produced paperboard.
Preferably, the unitary cubic function of the curve profile lateral pixel coordinates-the curve profile longitudinal pixel coordinates is expressed as:
f1(x)=a1x3+b1x2+c1x+d
Where x represents the transverse pixel coordinates of the vertical plane curve profile, f 1 (x) represents the longitudinal pixel coordinates of the vertical plane curve profile at the corresponding location, and a 1、b1、c1 and d represent the fitting constants.
Preferably, the difference δ in derivatives of both sides of the produced board is expressed as:
Where x i denotes the horizontal pixel coordinates of the profile of the vertical plane curve, x 1,x2,x3...xn...xm denotes the horizontal coordinates of all pixels, m denotes the number of coordinate points of all pixels, f '1 (x) denotes the function value of the derivative function corresponding to the position x i, and x n denotes the point where f' 1 (x) =0.
Preferably, when the type of the produced paperboard is non-L-shaped paperboard, calculating the warping convexity of the produced paperboard based on the vertical plane curve profile image comprises performing data fitting based on the vertical plane curve profile image to obtain a unitary quadratic function of the vertical plane curve profile longitudinal pixel coordinates and the vertical plane curve profile transverse pixel coordinates when the type of the produced paperboard is non-L-shaped paperboard, wherein the unitary quadratic function relation is:
f(x)=ax2+bx+c
Wherein x represents the transverse pixel coordinate of the profile of the vertical plane curve, f (x) represents the longitudinal pixel coordinate of the profile of the vertical plane curve corresponding to the x position, and a, b and c represent constants;
According to the unitary quadratic function, the warping convexity theta corresponding to the produced paperboard is calculated by adopting the following formula, wherein the warping convexity theta is expressed as:
Where K (x) is an average value of curvature at a position where three quarters are located, f '(x) represents a slope, f' (x) is a derivative of a profile of a vertical plane curve, f '(x) represents a rate of change of curvature, f' (x) is a second derivative of the profile of the vertical plane curve, x a and x b respectively represent pixel coordinates at positions where two end points of a lateral pixel coordinate of a unitary quadratic function are located, and x 1、x2、x3 respectively represent pixel coordinates at positions where three quarters of the lateral pixel coordinate of the unitary quadratic function are located, respectively:
The method comprises the steps of establishing an input and output data set through the paperboard warping type or warping degree recorded on a corrugated paperboard production line and the production line quality control parameters, training the input and output data set through the neural network model to obtain a pre-trained neural network model, establishing a corresponding relation between the production line paperboard warping type and the production line control parameters, inputting the warping type of the production paperboard into the pre-trained neural network model to obtain the production line control parameters output by the pre-trained neural network model, and outputting the production line control parameters to the production line control center to adjust and control the paperboard quality.
The invention provides a tile line outlet paperboard warping classification and process control system which comprises an acquisition module, a calculation module and a judgment module, wherein the acquisition module is used for acquiring a vertical plane curve outline image of a produced paperboard by using a linear light sensor and judging the paperboard type of the produced paperboard according to the vertical plane curve outline image, the calculation module is used for calculating the warping convexity of the produced paperboard based on the vertical plane curve outline image when the type of the produced paperboard is a non-L-shaped paperboard, the judgment module is used for judging that the quality of the produced paperboard is qualified when the absolute value of the warping convexity is not more than a warping preset threshold value, determining and outputting the type of the produced paperboard according to the value of the warping convexity and the warping convexity preset range value corresponding to different warping types when the absolute value of the warping convexity is more than the warping preset threshold value, and the control parameter output module is used for inputting the type of the produced paperboard into a pre-trained neural network model to obtain production line control parameters output by the pre-trained neural network model and outputting the production line control parameters to a production line control center for adjusting and controlling the quality.
A third aspect of the present invention provides a tile line outlet board warp classification and process control device comprising a memory and at least one processor, the memory having stored therein computer readable instructions, the memory and the at least one processor being interconnected by wires, the at least one processor invoking the computer readable instructions in the memory to cause the tile line outlet board warp classification and process control device to perform the steps of the tile line outlet board warp classification and process control method as described above.
According to the technical scheme provided by the invention, the type of the paperboard is intelligently judged and the warping convexity is calculated by accurately acquiring the profile image of the vertical plane curve of the paperboard, so that the quality of the paperboard is rapidly and accurately estimated, when the warping problem is found, the warping type can be automatically classified, and the targeted production line control parameters are output according to the pre-trained neural network model, so that the production is timely adjusted, the quality stability of the paperboard is ensured, and the overall production efficiency and the intelligent management level are improved.
Detailed Description
The terms "first," "second," "third," "fourth" and the like in the description and in the claims and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.
For ease of understanding, a specific flow of an embodiment of the present invention is described below, referring to fig. 1, a method for classifying and controlling warpage of a corrugated board in a corrugated board outlet according to an embodiment of the present invention includes:
s101, acquiring a vertical plane curve outline image of a produced paperboard by using a linear structure light sensor, and judging the paperboard type of the produced paperboard according to the vertical plane curve outline image;
S102, calculating the warping convexity of the produced paperboard based on the vertical plane curve outline image when the type of the produced paperboard is a non-L paperboard;
s103, if the absolute value of the warping convexity is not larger than a warping preset threshold, judging that the quality of the produced paperboard is qualified, and if the absolute value of the warping convexity is larger than the warping preset threshold, determining and outputting the warping type of the produced paperboard according to the value of the warping convexity and the warping convexity preset range value corresponding to different warping types;
S104, inputting the warping type of the production paper board into the pre-trained neural network model to obtain production line control parameters output by the pre-trained neural network model, and outputting the production line control parameters to a production line control center.
It will be appreciated that the subject of the present invention may be a tile line exit board warp classification and process control system, as well as a terminal or server, and is not limited in this regard. The embodiment of the invention is described by taking a server as an execution main body as an example.
In the embodiment, in step S101, a line structure light sensor is used for collecting a vertical plane curve outline image of a produced paperboard, and the paperboard type of the produced paperboard is judged according to the vertical plane curve outline image; the method comprises the steps of extracting and integrating vertical plane curve outline images of a produced paperboard from a plurality of preprocessing images, carrying out data fitting according to the extracted vertical plane curve outline images to obtain a unitary tertiary function of a curve outline transverse pixel coordinate and a curve outline longitudinal pixel coordinate, calculating the number of extreme points of the unitary tertiary function, judging that the produced paperboard is a normal paperboard when the number of the extreme points of the unitary tertiary function is 0, judging that the produced paperboard is a non-S-shaped paperboard when the number of the extreme points of the unitary tertiary function is 1, judging that the produced paperboard is an S-shaped paperboard when the number of the extreme points of the unitary tertiary function is 2, and sending out alarm reminding, calculating the difference value of derivatives on two sides of the produced paperboard based on the unitary tertiary function when the produced paperboard is a non-S-shaped paperboard, judging that the produced paperboard is L-shaped when the difference value exceeds a preset derivative range value, and sending out alarm reminding, and otherwise judging that the produced paperboard is non-L-shaped.
In the embodiment, the vertical plane reflected light image of the produced paperboard is collected for a plurality of times, and the collected vertical plane reflected light image is preprocessed to obtain a plurality of preprocessed images, wherein the preprocessing comprises the steps of projecting structural light to the vertical plane of the produced paperboard, collecting the vertical plane reflected light image of the produced paperboard for a plurality of times by using a structural light sensor, and preprocessing the collected vertical plane reflected light image to obtain a plurality of preprocessed images.
Alternatively, the structured light may be a light source emitted by a linear laser, and the structured light sensor is an image pickup device.
It will be appreciated that when capturing the vertical plane reflected light image of the produced board, there may be areas without pixels, and therefore, it is necessary to capture the vertical plane reflected light image of the produced board multiple times using the image capturing device, and then analyze the captured multiple times.
In the embodiment, the vertical plane curve outline image of the produced paperboard is extracted from a plurality of preprocessed images and integrated, and the method comprises the steps of extracting light fringes in the preprocessed images to obtain a plurality of groups of light fringes, mapping the position of each group of light fringes to a space three-dimensional coordinate by using camera calibration parameters, converting and aligning the space three-dimensional coordinates of the plurality of groups of light fringes, fusing to obtain the vertical plane three-dimensional outline of the produced paperboard, and processing the vertical plane three-dimensional outline of the produced paperboard to obtain the vertical plane curve outline image of the produced paperboard.
In this embodiment, the light fringes in the image are identified by an image processing algorithm (such as edge detection, threshold segmentation, etc.), the edges in the image are detected using a Canny edge detector or Sobel operator, and the light fringes are separated from the background by setting an appropriate threshold.
In this embodiment, before performing the three-dimensional reconstruction, the camera needs to be calibrated to obtain the internal parameters and external parameters of the camera. Then, the camera calibration parameters and the positions of the light fringes in the image are utilized to map the positions of the light fringes into space three-dimensional coordinates through a perspective projection principle.
In this embodiment, three-dimensional coordinates of space under different viewing angles are converted and aligned and then fused to obtain three-dimensional profiles of a vertical plane of the produced paperboard, and if overlapping areas are encountered, the overlapping areas are optimized through a point cloud fusion algorithm (such as an ICP algorithm), so that continuity and accuracy of the three-dimensional profiles are ensured.
In this embodiment, a slice plane is selected from the perpendicular three-dimensional profile of the board to be produced, perpendicular to the plane of the board, which plane should be located at the desired cross-sectional position of the board. Then, on the slice plane, a contour extraction algorithm (e.g., canny edge detection, hough transform, etc.) is used to extract the curve contour of the cardboard. This contour will reflect the shape and size of the cardboard at that location. Finally, smoothing the vertical plane three-dimensional contour of the produced paperboard by a filtering algorithm (such as Gaussian filtering, median filtering and the like) to generate a vertical plane curve contour image, and smoothing the contour extracted by the curve by the filtering algorithm (such as Gaussian filtering, median filtering and the like) to eliminate tiny fluctuation caused by noise or measurement errors.
In this embodiment, the unitary cubic function of the curve profile horizontal pixel coordinates-the curve profile vertical pixel coordinates is expressed as:
f1(x)=a1x3+b1x2+c1x+d
Where x represents the curve profile transverse pixel coordinates, f 1 (x) represents the vertical pixel coordinates of the vertical plane curve profile at the corresponding location, and a 1、b1、c1 and d represent the fitting constants.
The difference in derivative of both sides of the produced board, delta, is expressed as:
Where xi represents the horizontal pixel coordinates of the profile of the vertical plane curve, x 1,x2,x3...xn...xm represents the horizontal coordinates of all pixels, m represents the number of coordinate points of all pixels, f '1 (x) represents the function value of the derivative function corresponding to the position x i, and x n is the point where f' 1 (x) =0.
It will be appreciated that by calculating the difference in derivatives on both sides of the corrugated board and comparing the calculated difference with the preset range of derivative values, the reason for determining whether the board is an L-board or a non-L-board is that the L-board has a significant slope change at the bend (i.e., the corner of the L) but the non-L-board does not have such a feature.
The difference in derivatives on both sides of the corrugated board is calculated, i.e. the derivatives (slopes) are calculated on both sides of the suspected L-shaped region of the corrugated board, i.e. the region where corners may be present, respectively. The difference in the derivatives of these two sides is then calculated. This difference reflects the degree of change in slope in this region.
In this embodiment, before the actual production, the corrugated board is subjected to test production, and after the test production is completed, the difference values of the derivatives at the two sides of the non-L-shaped board are taken as the maximum value of the preset range values of the derivatives during the test production, and the difference values of the derivatives at the two sides of the L-shaped board are taken as the minimum value of the preset range values of the derivatives during the test production.
In the present embodiment, in step S102, when the type of the produced board is a non-L-shaped board, the warp convexity of the produced board is calculated based on the vertical plane curve profile image, including:
When the type of the produced paperboard is non-L-shaped paperboard, carrying out data fitting based on the profile image of the vertical plane curve to obtain a unitary quadratic function of the transverse pixel coordinate of the profile of the vertical plane curve and the longitudinal pixel coordinate of the profile of the vertical plane curve, wherein the unitary quadratic function relation is as follows:
f(x)=ax2+bx+c
Wherein x represents the transverse pixel coordinate of the profile of the vertical plane curve, f (x) represents the longitudinal pixel coordinate of the profile of the vertical plane curve corresponding to the x position, and a, b and c represent constants;
Where K (x) is an average value of curvature at a position where three quarters are located, f '(x) represents a slope, f' (x) is a derivative of a profile of a vertical plane curve, f '(x) represents a rate of change of curvature, f' (x) is a second derivative of the profile of the vertical plane curve, x a and x b respectively represent pixel coordinates at positions where two end points of a lateral pixel coordinate of a unitary quadratic function are located, and x 1、x2、x3 respectively represent pixel coordinates at positions where three quarters of the lateral pixel coordinate of the unitary quadratic function are located, respectively:
in the embodiment, in step S103, the method for determining the warp convexity preset range value specifically comprises the steps of collecting cross-sectional images of non-L-shaped paperboards with different warp directions and warp degrees as samples, identifying the warp directions and warp degrees of the samples, classifying the samples according to different warp types to obtain classification results, establishing sub-image libraries corresponding to different warp types and warp levels according to the classification results, calculating the warp convexity of each sample of each sub-image library one by one, and determining the warp convexity range value of the warp type and warp level corresponding to each sub-image library according to the minimum value and the maximum value of the warp convexity of each sub-image library sample.
It can be understood that the method for calculating the warp convexity of each sample of each sub-image library may be the method for calculating the warp convexity θ as described above, which is not described herein.
Illustratively, when identifying the warp direction and warp degree of a sample and classifying the sample according to different warp types and warp levels to obtain classification results, the classification results formed include up-type 1, up-type 2, up-type 3, down-type 1, down-type 2, down-type 3, and then six sub-image libraries are built according to the classification results, each image library corresponds to up-type 1, up-type 2, up-type 3, down-type 1, down-type 2, down-type 3, and then the warp convexity of each sample of the six sub-image libraries is calculated one by one, and then up-type 1, up-type 2, up-type 3, down-type 1, down-type 2, down-type 3 warp convexity range values are determined, including determining the warp convexity range values corresponding to up-type 1 according to the minimum and maximum values of the warp convexities of the samples of the image libraries corresponding to up-type 1Determining the warping convexity range value corresponding to the upwarp-type 2 according to the minimum value and the maximum value of the warping convexity of the sample of the upwarp-type 2 corresponding image libraryDetermining the warping convexity range value corresponding to the upwarp-type 3 according to the minimum value and the maximum value of the warping convexity of the sample of the upwarp-type 3 corresponding image libraryDetermining a warping convexity range value corresponding to the downward warping type 1 according to the minimum value and the maximum value of the warping convexity of the sample of the downward warping type 1 corresponding image libraryDetermining a warping convexity range value corresponding to the downward warping type 2 according to the minimum value and the maximum value of the warping convexity of the sample of the downward warping type 2 corresponding image libraryDetermining a warping convexity range value corresponding to the downward warping type 3 according to the minimum value and the maximum value of the warping convexity of the sample of the downward warping type 3 corresponding image library
In the present embodiment, the warp preset threshold isIf the absolute value of the warp convexity is not greater thanAnd judging that the quality of the produced paperboard is qualified.
9. In the embodiment, in step S104, the warp type of the production board is input into a pre-trained neural network model to obtain production line control parameters output by the pre-trained neural network model, the production line control parameters are output to a production line control center to adjust and control the quality of the board, specifically, an input-output data set is built through the warp type or warp degree of the board recorded on a corrugated board production line and the production line quality control parameters, the input-output data set is trained by adopting the neural network model to obtain the pre-trained neural network model, the pre-trained neural network model is built with a corresponding relation between the warp type of the production line board and the production line control parameters, the warp type of the production board is input into the pre-trained neural network model to obtain the production line control parameters output by the pre-trained neural network model, and the production line control parameters are output to the production line control center to adjust and control the quality of the board.
In this embodiment, different warp types correspond to different production line control parameters, and the correspondence between the warp types and the production line control parameters is learned through a pre-trained neural network model and fed back to a production line control center through prediction to control the product quality.
In this embodiment, the neural network model adopts a convolutional neural network model, and the neural network model includes an input layer, a hidden layer, and an output layer, where the input layer receives a warp type of the board as an input feature. The hidden layer contains multiple layers of neurons for extracting useful information in the input features and learning complex relationships between warp types and line control parameters. The output layer outputs the predicted line control parameters.
Before training the neural network model, an input and output data set is established through the paperboard warping type or warping degree recorded on the corrugated paperboard production line and quality control parameters (such as temperature, pressure, speed and the like) of the production line, and preprocessing operations such as cleaning, normalization and the like are performed on collected data so as to ensure the quality and consistency of the data.
In this embodiment, the neural network model is trained using the pre-processed paperboard production data to obtain a pre-trained neural network model. During the training process, the model learns the correspondence between different warp types and the line control parameters and adjusts its internal parameters (e.g., weights and offsets) to minimize the prediction error.
Alternatively, new data may be continuously collected and the neural network model continuously optimized and updated as the production process proceeds. The method can be realized by incremental learning, transfer learning and other methods so as to improve the prediction performance and adaptability of the model.
In this embodiment, the predicted line control parameters are fed back to the line control center in real time, and the line control center adjusts the operation of the line, such as temperature, pressure, speed, etc., according to these parameters, so as to achieve accurate control over the quality of the board.
The embodiment provides a warp classification and process control method for a tile line outlet paperboard, which is used for intelligently judging the type of the paperboard and calculating warp convexity by accurately collecting a contour image of a vertical plane curve of the paperboard, so that the quality of the paperboard is rapidly and accurately evaluated, when a warp problem is found, the warp type can be automatically classified, and targeted production line control parameters are output according to a pre-trained neural network model, so that the production is timely adjusted, the quality stability of the paperboard is ensured, and the overall production efficiency and the intelligent management level are improved.
The above describes a method for classifying and controlling the warpage of a corrugated board for export, and the following describes an apparatus for implementing the method for classifying and controlling the warpage of a corrugated board for export, referring to fig. 2, and an implementation of the system for classifying and controlling the warpage of a corrugated board for export, according to the embodiment of the present invention includes:
the acquisition module 201 is configured to acquire a profile image of a vertical plane curve of the produced paperboard by using the line structure light sensor, and determine a paperboard type of the produced paperboard according to the profile image of the vertical plane curve;
a calculation module 202 for calculating a warp convexity of the produced board based on the vertical plane curve profile image when the type of the produced board is a non-L-shaped board;
The judging module 203 is configured to judge that the quality of the produced paperboard is qualified when the absolute value of the warp convexity is not greater than a warp preset threshold, and determine and output a warp type of the produced paperboard according to the value of the warp convexity and the warp convexity preset range value corresponding to different warp types when the absolute value of the warp convexity is greater than the warp preset threshold;
the control parameter output module 204 is configured to input the warp type of the produced board into the pre-trained neural network model to obtain the production line control parameters output by the pre-trained neural network model, and output the production line control parameters to the production line control center for adjusting and controlling the quality of the board.
In the embodiment, through accurately collecting the vertical plane curve outline image of the paperboard, the paperboard type is intelligently judged and the warping convexity is calculated, so that the paperboard quality is rapidly and accurately evaluated, when the warping problem is found, the warping type can be automatically classified, and the targeted production line control parameters are output according to the pre-trained neural network model, so that the production is timely adjusted, the paperboard quality is ensured to be stable, and the overall production efficiency and the intelligent management level are improved. .
The construction of the tile line outlet board warp classification and process control system shown in fig. 2 is not limiting of the tile line outlet board warp classification and process control system, and the steps of the tile line outlet board warp classification and process control method provided by the above method embodiments may be implemented.
The above figure 2 describes the tile wire exit board warp classification and process control system of the embodiments of the present invention in detail from the point of view of the modular functional entity, and the below describes the tile wire exit board warp classification and process control device of the embodiments of the present invention in detail from the point of view of the hardware processing.
FIG. 3 is a schematic diagram of a construction of a tile line outlet board warp classification and process control device 300, which may vary widely in configuration or performance, and may include one or more processors (central processing units, CPU) 310 (e.g., one or more processors) and memory 320, one or more storage mediums 330 (e.g., one or more mass storage devices) storing applications 333 or data 332, according to an embodiment of the present invention. Wherein memory 320 and storage medium 330 may be transitory or persistent storage. The program stored on the storage medium 330 may include one or more modules (not shown), each of which may include a series of instruction operations in the device 300. Still further, the processor 310 may be configured to communicate with a storage medium 330 in which a series of instruction operations are performed on the device 300.
The device 300 may also include one or more power supplies 340, one or more wired or wireless network interfaces 350, one or more input/output interfaces 360, and/or one or more operating systems 331, such as Windows Serve, mac OS X, unix, linux, freeBSD, and the like.
It will be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working process of the system or apparatus and unit described above may refer to the corresponding process in the foregoing method embodiment, which is not repeated herein.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. The storage medium includes a U disk, a removable hard disk, a read-only memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.
While the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that the foregoing embodiments may be modified or equivalents may be substituted for some of the features thereof, and that the modifications or substitutions do not depart from the spirit and scope of the embodiments of the invention.