Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a radar high-resolution range profile target identification method based on width learning. The technical problem to be solved by the invention is realized by the following technical scheme:
the invention provides a radar high-resolution range profile target identification method based on width learning, which comprises the following steps:
s1: acquiring high-resolution range profile data and generating a training set;
s2: constructing a width learning model;
s3: training the width learning model by using the training set to obtain a trained width learning model;
s4: and identifying the original high-resolution range profile data to be identified by utilizing the trained width learning model to obtain an identification result.
In an embodiment of the present invention, the S1 includes:
s1 a: extracting high-resolution range profile data in a broadband radar echo signal and preprocessing the high-resolution range profile data to obtain high-resolution range profile time domain characteristic data;
s1 b: establishing a radar target database according to the high-resolution range profile time domain characteristic data subjected to the modulo two norm normalization processing, and setting a label value for each target category in the radar target database;
s1 c: and selecting a preset number of samples from the radar target database to form a training set.
In one embodiment of the invention, the pre-processing comprises:
performing modulo two norm normalization processing on the high-resolution range profile data:
wherein X represents the high-resolution range profile time domain feature data after modulo two-norm normalization, X represents the original high-resolution range profile data, | | · | | survival2Representing a modulo two-norm operation.
In an embodiment of the present invention, the S1 further includes:
and selecting a preset number of samples from the radar target database to form a test set, wherein the high-resolution range profile data in the test set and the high-resolution range profile data in the training set have any pitch angle.
In an embodiment of the present invention, the S2 includes:
s2 a: performing power transformation operation on the processed high-resolution range profile time domain feature data:
U=Xk
wherein U is data after power transformation, X is high-resolution range profile time domain characteristic data after modulo two norm normalization processing, and k is a power transformation coefficient;
s2 b: setting ith mapping characteristic node output Z of width learning modeli;
Wherein Z is
iOutput for ith mapping feature node, phi
iIn order to be a function of the mapping,
as a weight matrix, the weight matrix is,
is a bias matrix, and n is the number of characteristic nodes;
s2 c: splicing the mapping feature node outputs into a whole:
Zn=[Z1,Z2…,Zn]
wherein Z isnRepresenting a set of all mapped feature node outputs;
s2 d: set of mapping feature nodes ZnTransforming to obtain the jth enhanced node output E in the width learning modelj;
Wherein E is
jAnd for the jth enhancement node output, ζ is a nonlinear transformation function,
and
for random generationA weight matrix and a bias matrix, wherein m represents the number of enhanced nodes;
s2 e: splicing the enhanced node outputs into a whole:
Ej=[E1,E2…,Ej]
wherein E isjRepresenting a set of all enhanced node outputs;
s2 f: setting an output of the width learning model:
where W is the link weight value and H is the set of mapped feature node outputs and enhanced node outputs.
In an embodiment of the present invention, the S3 includes:
inputting all samples in the training set into the width learning model, and solving the connection weight value:
W=H+Y
H+calculated from the following formula:
where λ represents a regularization coefficient and I represents an identity matrix.
In an embodiment of the present invention, after the S3, the method further includes:
testing the trained width learning model using a test set.
Another aspect of the present invention provides a storage medium having a computer program stored therein, the computer program being configured to execute the steps of the radar high-resolution range profile target identification method according to any one of the above embodiments.
Yet another aspect of the present invention provides an electronic device, including a memory and a processor, where the memory stores a computer program, and the processor, when calling the computer program in the memory, implements the steps of the radar high-resolution range profile target identification method according to any one of the above embodiments.
Compared with the prior art, the invention has the beneficial effects that:
according to the radar high-resolution range profile target identification method based on width learning, due to the fact that the width learning model is used, the high-dimensional features of the radar high-resolution range profile data are extracted, and the radar target can be quickly identified on the premise that identification accuracy is guaranteed. Compared with a deep network, the method has obvious advantages in the aspects of prediction accuracy and recognition time.
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Detailed Description
In order to further explain the technical means and effects of the present invention adopted to achieve the predetermined invention, the following describes in detail a radar high-resolution range profile target identification method based on width learning according to the present invention with reference to the accompanying drawings and the detailed description.
The foregoing and other technical matters, features and effects of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings. The technical means and effects of the present invention adopted to achieve the predetermined purpose can be more deeply and specifically understood through the description of the specific embodiments, however, the attached drawings are provided for reference and description only and are not used for limiting the technical scheme of the present invention.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or device that comprises a list of elements does not include only those elements but may include other elements not expressly listed. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of additional like elements in the article or device comprising the element.
Example one
Referring to fig. 1, fig. 1 is a flowchart of a method for identifying a target in a radar high-resolution range profile based on width learning according to an embodiment of the present invention. The method comprises the following steps:
s1: high resolution range profile data is acquired and a training set is generated.
Specifically, step S1 includes:
s1 a: and extracting high-resolution range profile data in the broadband radar echo signal and preprocessing the high-resolution range profile data to obtain high-resolution range profile time domain characteristic data.
Specifically, the pretreatment comprises: the high-resolution range profile data is subjected to the following two-norm normalization processing:
wherein X represents the high-resolution range profile time domain feature data after modulo two-norm normalization, X represents the acquired original high-resolution range profile data, | | & | luminance2Representing a modulo two-norm operation.
S1 b: establishing a radar target database according to the high-resolution range profile time domain characteristic data subjected to the modulo two norm normalization processing, and setting a label value for each target category in the radar target database;
specifically, the object classes described herein may be different aircraft types to be identified, such as data for a B-737 aircraft, data for an A-330 aircraft, and so forth.
Further, setting a tag value for each target category within the radar target database includes:
label of the first category of data as d1,d1The value is 1;
label the second category of data as d2,d2The value is 2;
and so on … …
Label of data of M-th category as dM,dMThe value is M, where M is the total number of target classes.
Exemplarily, assuming that different airplane types in the high-resolution range profile data are to be identified, the target class is the airplane type, assuming that the B-737 airplane is the first class, all tags containing the time domain feature data of the high-resolution range profile of the B-737 airplane in the radar target database are all recorded as d1(ii) a Assuming that the A-330 plane is in the second category, all labels containing the high-resolution range profile time domain feature data of the A-330 plane in the radar target database are marked as d2And so on.
During data acquisition, a radar is generally aimed at a certain model of airplane (such as B-747) to acquire a large amount of data, and the data comprises various different pitch angles; the next model (e.g., A-330) is then collected, again including various pitch angles, and so on. These different models of aircraft target data together make up the radar target database.
It should be noted that the object category described herein may also be other objects, such as ships and the like.
S1 c: and selecting a preset number of samples from the radar target database to form a training set, and selecting a preset number of samples from the radar target database to form a testing set, wherein the high-resolution range profile data in the testing set and the high-resolution range profile data in the training set have different pitch angles.
The radar target database contains data of various target types, such as data of a B-737 airplane and data of an A-330 airplane. The data of each target category is usually obtained from different pitch angles, that is, different pitch angles are included, for example, the data of the B-737 airplane has the pitch angles of 3 degrees, 5 degrees, etc., and the data of the a-330 airplane also has the pitch angles of 3 degrees, 5 degrees, etc. In order to verify the popularization capability of the method, the pitch angles of different degrees are adopted when the training set and the test set are selected.
Specifically, samples with each target pitch angle of 3 degrees are selected from a radar target database to form a training sample set; and selecting samples with target pitch angles of 5 degrees from a radar target database to form a test sample set. However, in other embodiments, any pitch angle sample may be selected to form the training set, and similarly, any pitch angle sample may be selected to form the testing set.
It should be noted that each of the above-mentioned object types to be identified, such as different airplane types, is included in the training sample set and the test sample set.
S2: building a Width learning model
The width learning model generates characteristic nodes by carrying out characteristic mapping on input data, and then generates enhanced nodes by carrying out nonlinear transformation on the characteristic nodes. And splicing the characteristic nodes and the enhanced nodes to form a hidden layer. The input data passes through the hidden layer to obtain the final output. Referring to fig. 2, fig. 2 is a schematic diagram of a width learning model according to an embodiment of the present invention.
Specifically, step S2 includes:
s2 a: performing power transformation operation on the processed high-resolution range profile time domain feature data
U=Xk
U is data after power transformation, X is high-resolution range profile time domain feature data after modulo two norm normalization processing, k is a power transformation coefficient, and the value of k can be obtained according to practical experience and can be 0.1, 0.3, 0.5, 0.7 and 0.9, preferably 0.3.
S2 b: setting ith mapping characteristic node of width learning modelOutput Zi;
Wherein Z is
iOutput for ith mapping feature node, phi
iIn order to be a function of the mapping,
as a weight matrix, the weight matrix is,
for the bias matrix, n is the number of feature nodes. The weight matrix and the bias matrix are generated randomly, and the mapping function is a linear transformation function.
S2 c: splicing the mapping feature node outputs into a whole:
Zn=[Z1,Z2…,Zn]
wherein Z isnRepresenting the set of all mapped feature node outputs.
S2 d: mapping the feature node set Z bynTransforming to obtain the ith enhanced node output E in the width learning modelj;
Wherein E is
jAnd for the jth enhancement node output, ζ is a nonlinear transformation function,
and
m represents the number of enhanced nodes for randomly generated weight matrix and bias matrix.
S2 e: the enhanced nodes are aggregated and connected into a whole by the following formula:
Ej=[E1,E2…,Ej]
wherein E isjRepresenting the set of all enhanced node outputs.
S2 f: from the feature nodes and the enhanced nodes set forth above, the output of the width learning model is represented as:
wherein Y is the output of the width learning model, and W is a connection weight value, which is a set of mapping feature node output and enhancement node output. According to the above equation, the solution of the connection weight value is as follows:
W=H+Y,
wherein H+Can be calculated from the following formula:
where λ represents a regularization coefficient and I represents an identity matrix.
S3: and training the width learning model by using the training set to obtain a trained width learning model.
And (4) inputting the high-resolution range profile data in the training set obtained in the step (S1) into the width learning model, and obtaining and updating the connection weight value to obtain the trained width learning model.
Specifically, all samples in the training set are input into the width learning model, and the connection weight value is obtained:
W=H+Y
H+calculated from the following formula:
where λ represents a regularization coefficient and I represents an identity matrix.
Further, after the S3, the method further includes:
testing the trained width learning model using a test set.
Specifically, the test set is used as high-resolution range profile data to be recognized, the data in the test set is input into a trained width learning model for recognition, a classification label of a target to be recognized is obtained, and the recognition effect of the width learning model is tested. It should be noted that, in order to test the effect of the model, the test set of this embodiment selects high-resolution range profile data with a pitch angle of 5 °.
S4: and processing the original high-resolution range profile data to be recognized by utilizing the trained width learning model to obtain a recognition result.
Specifically, the high-resolution range profile data to be recognized is input into the trained width learning model, and the class label of the target in the high-resolution range profile data can be obtained. For example, the high-resolution range image of the airplane is input into the width learning model, so that the recognition result of the width learning model for the airplane type can be obtained.
It should be noted that, in practical applications, the trained width learning model can identify a target in the high-resolution range image data of any pitch angle.
The effects of the embodiments of the present invention will be described in further detail with reference to simulation experiments.
1. Simulation conditions are as follows:
the hardware platform of the simulation experiment is as follows: the processor is Intel (R) core (TM) i7-8700k CPU, the main frequency is 3.2GHz, and the memory is 16 GB.
The software platform of the simulation experiment is as follows: windows 10 operating system and python 3.6.
The data used in the simulation experiment is high-resolution range profile simulation data of 10 types of airplanes, the number of training samples of targets of all types of airplanes is 9000, and the total number of the training samples is 90000; the number of target test samples of each type of airplane is 1000, the total number of test samples is 10000, and the pitch angles of the training set and the test set of each type of airplane are respectively 3 degrees and 5 degrees.
2. Simulation content and result analysis thereof:
the method of the embodiment of the invention and the conventional convolutional neural network method are respectively used for identifying the high-resolution range profile, and the classification accuracy results under different bandwidths are shown in fig. 3, wherein the abscissa represents the bandwidth and respectively represents 400MHz, 500MHz, 600MHz, 700MHz, 800MHz, 900MHz, 1000MHz, 1100MHz, 1200MHz and 1300MHz, and the ordinate represents the accurate identification rate. In fig. 3, a solid square node line represents a relationship curve between the accurate recognition rate and different bandwidths obtained by the method of the present invention, and a solid circular node line represents a relationship curve between the accurate recognition rate and different bandwidths obtained by the conventional convolutional neural network.
As can be seen from FIG. 3, the accurate recognition rate of the method of the present invention is superior to that of the existing convolutional neural network method. When the bandwidth is 400MHz to 1000MHz, the recognition rate of the width learning model of the invention is higher than that of the existing convolutional neural network by about 3 percentage points on average, which shows that the feature extraction capability of the width learning model is better than that of the convolutional neural network. When the bandwidth is 1100MHz to 1300MHz, the identification rates of the two methods are similar, because the large bandwidth contains more information, and the two methods can better extract the characteristics of the high-resolution range profile, so the identification rates are similar.
FIG. 3 shows the recognition rate curves for the two methods, and Table 1 shows the comparison of the computation times for the breadth learning model method of the present invention and the prior convolutional neural network method.
TABLE 1 comparison of computation times for a breadth learning model and a convolutional neural network
As can be seen from Table 1, the training time average of the breadth learning model is about 9.5s, and the training time average of the convolutional neural network is about 420 s. The computation time of the convolutional neural network is about 45 times that of the width learning model. This is because iterative update of the convolutional neural network is time-consuming, which results in much higher computation time than width learning, which does not have the complex structure of the convolutional neural network, and thus computation time is greatly reduced.
In conclusion, the radar high-resolution range profile target identification method of the embodiment uses the width learning model to extract the high-dimensional features of the radar high-resolution range profile data, and can quickly identify the radar target on the premise of ensuring the identification precision. Compared with a neural network, the method has obvious advantages in the aspects of prediction accuracy and recognition time.
Another embodiment of the present invention provides a storage medium, in which a computer program is stored, the computer program being used for executing the steps of the radar high-resolution range profile object recognition method in the above-mentioned embodiment. Yet another aspect of the present invention provides an electronic device, including a memory and a processor, where the memory stores a computer program, and the processor implements the steps of the radar high-resolution range profile object recognition method according to the above embodiment when calling the computer program in the memory. Specifically, the integrated module implemented in the form of a software functional module may be stored in a computer readable storage medium. The software functional module is stored in a storage medium and includes several instructions to enable an electronic device (which may be a personal computer, a server, or a network device) or a processor (processor) to execute some steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.