Dynamic roll angle measurement method based on the trend of antenna intensity change

Abstract

This application relates to the technical field of roll angle measurement, and specifically relates to a dynamic roll angle measurement method based on the change trend of antenna intensity. The method includes: designing a phased array radar beam to track the target of the projectile, obtaining the desired signal in real time, and obtaining the received signal reflected by the antenna on the projectile for each array element after the signal is transmitted; calculating the disorder coefficient of each modal component; determining the interference coefficient of each array element at the current moment; determining the step size parameter of the least mean square algorithm at the current moment; based on the desired signal and the step size parameter, combining the least mean square algorithm, adjusting the beam direction of the transmitted signal of each array element in real time; each array element transmits a signal with the adjusted transmitted signal, and when the signal intensity received by the antenna on the projectile shows a minimum value, the roll angle of the projectile is measured. This application dynamically adjusts the step size parameter in the least mean square algorithm to improve the accurate measurement of the roll angle of the projectile.

Description

Technical Field

[0001] This application relates to the technical field of roll angle measurement, and particularly to a dynamic roll angle measurement method based on the change trend of antenna intensity. Background Art

[0002] Inertial navigation can calculate the attitude angle, speed, and position of a carrier in real time through accelerometers and gyroscopes. However, the solution of inertial navigation needs to obtain initial values to be completed. The high overload during the launch of a shell will cause serious damage to the gyroscope and accelerometer. Moreover, due to the high rotation accompanying the high overload impact, it is almost impossible for the gyroscope to ensure the measurement accuracy of the angular velocity, resulting in the inability to accurately measure the roll angle.

[0003] When the traditional method measures the roll angle through the earth's magnetic field dynamically, it is necessary to align the initial value of the geomagnetic sensor, which is easily affected by the accuracy of the measuring device itself. And when the angle between the shell firing direction and the local earth's magnetic field direction is small, it will cause a large error in the determination of the initial value of the roll angle, resulting in a low measurement accuracy of the roll angle of the projectile body. Summary of the Invention

[0004] To solve the above technical problems, a dynamic roll angle measurement method based on the change trend of antenna intensity is provided to solve the existing problems.

[0005] The solution of this application to solve the technical problem is to provide a dynamic roll angle measurement method based on the change trend of antenna intensity, including the following steps:

[0006] Design a phased array radar beam to track the target of the projectile body, obtain the desired signal in real time, and obtain the received signal reflected by the antenna on the projectile body for each array element after the signal is transmitted;

[0007] Perform modal decomposition on the received signal of each array element at the current moment, analyze the degree of dispersion of the amplitude in each modal component, and the difference in the degree of dispersion of the amplitude in different modal components, and calculate the disorder coefficient of each modal component; analyze the correlation degree of the received signals between each array element and the remaining array elements at the current moment, and the difference degree of the disorder coefficients of all modal components between each array element and the remaining array elements, and determine the interference coefficient of each array element at the current moment;

[0008] Based on the interference coefficients of all array elements at the current moment, determine the step size parameter of the least mean square algorithm at the current moment; based on the desired signal and the step size parameter, combine the least mean square algorithm to adjust the beam direction of the transmitted signal of each array element in real time;

[0009] Each array element emits a signal with the adjusted transmitted signal, and when the signal intensity received through the antenna on the projectile body shows a minimum value, measure the roll angle of the projectile body.

[0010] Preferably, the degree of dispersion is the coefficient of variation of all amplitudes of each modal component.

[0011] Preferably, calculating the disorder coefficient of each modal component includes:

[0012] Calculating the sum of the differences in the degree of dispersion between all any two modal components corresponding to each array element at the current moment, denoted as the relative difference degree;

[0013] Performing positive fusion on the degree of dispersion and the relative difference degree to obtain the disorder coefficient of each modal component.

[0014] Preferably, the further determination process of the positive fusion is: calculating the product of the degree of dispersion and the relative difference degree.

[0015] Preferably, the further measurement process of the correlation degree is: calculating the Pearson correlation coefficient of the received signals between each array element and the remaining array elements at the current moment.

[0016] Preferably, the further measurement process of the degree of difference is: calculating the metric distance of the disorder coefficients of all modal components between each array element and the remaining array elements at the current moment.

[0017] Preferably, determining the interference coefficient of each array element at the current moment includes:

[0018] Calculating the ratio between the metric distance and the absolute value of the Pearson correlation coefficient;

[0019] Taking the fusion result of the ratios between each array element and all the remaining array elements at the current moment as the interference coefficient of each array element at the current moment.

[0020] Preferably, the further measurement method of the fusion result is: calculating the sum of the accumulations of the ratios between each array element and all the remaining array elements at the current moment.

[0021] Preferably, determining the step size parameter of the least mean square algorithm at the current moment includes:

[0022] Normalizing the interference coefficients of all array elements at the current moment and calculating the average value of all the normalization results;

[0023] The step size parameter of the least mean square algorithm at the current moment The calculation formula is: , where is the preset minimum step size parameter, is the difference between the preset maximum step size parameter and the preset minimum step size parameter, is the average value.

[0024] Preferably, measuring the roll angle of the measurement projectile includes: when the signal intensity received by the antenna is at the minimum point, establishing a polar coordinate system with the center of the radar beam as the origin to obtain the position coordinates of the center of the projectile; calculating the antenna angle according to the position coordinates and the radius of the projectile; and obtaining the roll angle of the projectile based on the antenna angle corresponding to the minimum signal intensity received by the antenna.

[0025] The present application has at least the following beneficial effects:

[0026] In the present application, the disorder coefficient of each modal component is calculated based on the change of the amplitude of the received signals of each element in the phased array radar within different frequency ranges. The beneficial effect is that it considers the fluctuation of the received signals within different frequency ranges, thereby indicating the degree of interference of the received signals at this frequency. Secondly, the interference coefficient of each element at the current moment is calculated through the difference change of the disorder coefficients between different elements. The beneficial effect is that it considers the interference situation of the signal of this element in the beam directivity. By the degree of interference received by different elements, the step size parameter of the least mean square algorithm at the current moment is determined. Combining with the least mean square algorithm, the beam direction of the transmitted signal of each element is adjusted in real time, so that the beam direction of the transmitted signal of each element points to the beam direction of the desired signal. The beneficial effect is that the step size parameter is determined through the interference of the signals of all elements, and the amplitude and phase of the received signals of all elements are continuously adjusted, so that the beam direction of the received signal of each element is consistent with the beam direction of the desired signal; each element transmits with the adjusted signal, and when the signal intensity received by the antenna on the projectile appears at the minimum value, the roll angle of the projectile is measured. The beneficial effect is that the measurement of the roll angle does not depend on the earth's magnetic field environment, but only depends on the measurement of the signal reception of the ground phased array radar, and has strong anti-interference ability. Compared with the traditional beam adjustment based on the filtering adjustment technology, it can dynamically adjust the step size parameter in the least mean square algorithm according to the influence characteristics of the transmitted signal of each element in the phased array radar on the beam directivity, improve the control stability and accuracy of the beam direction, and through real-time adjustment of the amplitude and phase of the transmitted signals of different elements, there is no need to measure the initial value of the roll angle, and the accurate measurement of the roll angle of the projectile is improved. Description of the Drawings

[0027] The following further elaborates in detail on the dynamic roll angle measurement method based on the antenna intensity change trend of the present application with reference to the drawings.

[0028] Figure 1 It is a flowchart of the steps of the dynamic roll angle measurement method based on the antenna intensity change trend provided by the embodiment of the present application;

[0029] Figure 2 It is a schematic diagram of the phased array radar beam provided by the embodiment of the present application;

[0030] Figure 3 It is a flight schematic diagram of the projectile provided by the embodiment of the present application;

[0031] Figure 4 It is a schematic diagram of the projectile roll provided by the embodiment of the present application;

[0032] Figure 5 It is a flowchart of the steps of the method for obtaining the interference coefficient of each array element provided by the embodiment of the present application. Detailed implementation manners

[0033] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the dynamic roll angle measurement method based on the antenna intensity change trend proposed in the present application will be further described in detail below with reference to the accompanying drawings and implementation examples. It should be understood that the specific implementation examples described herein are only used to explain the present application and are not used to limit the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs.

[0035] Please refer to Figure 1 , which shows a flowchart of the steps of the dynamic roll angle measurement method based on the antenna intensity change trend provided by an embodiment of the present application. The method includes the following steps:

[0036] Step 1: Design a phased array radar beam to track the target of the projectile, obtain the desired signal in real time, and obtain the received signal reflected by the antenna on the projectile for each array element after the signal is transmitted.

[0037] Inertial navigation calculates the position and attitude of the projectile through integral operation. However, the initial reference needs to be determined before the inertial navigation solution process can calculate the position and attitude of the projectile, and the initial reference is easily affected by the geomagnetic field error. Therefore, after the projectile is launched, in order to avoid the error influence caused by inaccurate calibration of the initial reference, the phased array radar signal is adjusted through beamforming technology to measure the roll angle of the projectile.

[0038] First, design a phased array radar beam. Specifically: by controlling the shape and the number of arrays of the phased array radar, the beam shape is designed to be an axisymmetric shape, generate a beam width that meets the requirements, and ensure that the final generated beam cross-sectional shape is an axisymmetric figure.

[0039] In this embodiment, the radar beam is designed as an ellipse with a short axis as the horizontal axis and a long axis as the vertical axis. Among them, the radar beam is designed as an ellipse with a long axis of 2 and a short axis of 1.5. The radius of the circular cross-section of the projectile is 1. Antennas are installed in pairs on the circular edge of the circular cross-section of the projectile and numbered.

[0040] It should be noted that the schematic diagram of the phased array radar beam provided in this embodiment is as follows Figure 2 shown. Among them, it rotates with the rotation of the projectile body. When the antenna rotates to the minimum point of the antenna intensity as shown in Figure 2 , the signal intensity of the antenna is at a minimum value;

[0041] Secondly, plan the flight path of the projectile body, specifically: make the irradiation direction of the phased array radar consistent with the flight direction of the projectile body. At the same time, when the projectile body is flying forward, there is a certain offset between the center of its circular cross-section and the center of the radar beam. Such a design can make the radar signal intensity received by the antenna on the projectile body show regular changes during the rotation process.

[0042] The flight schematic diagram of the projectile body provided in this embodiment is as follows Figure 3 shown. Move the ellipse representing the beam upward so that the center of the ellipse corresponding to the beam does not overlap with the center of the projectile body. Figure 3 The solution distance in represents the radar signal intensity received by the antenna.

[0043] Finally, install the receiving antenna of the projectile body. Install the receiving antennas of the phased array radar in pairs on the circular edge of the circular cross-section of the projectile body and number them. Ensure that there is a clear mathematical relationship between the installation position of the antenna and the roll angle of the projectile body. For example, taking a specific antenna position as a reference, a corresponding relationship between the roll angle and the antenna position can be established to facilitate subsequent calculation of the roll angle according to the change of the signal intensity received by the antenna.

[0044] The roll schematic diagram of the projectile body provided in this embodiment is as follows Figure 4 shown. Taking the rotation process of Figure 4 as an example, taking antenna 1 as a reference, the angle value of rotation around the center of the circular cross-section of the projectile body is the same as the roll angle value of the projectile body. When the projectile body rotates clockwise, when the roll angle is near -90°, the order of the minimum values of the signal intensity of the antenna is antenna 1, antenna 2, that is, antenna 1 reaches the minimum value before antenna 2. When the roll angle is near 90°, the order of the minimum values of the signal intensity of the antenna is antenna 2, antenna 1, that is, antenna 2 reaches the minimum value before antenna 1. When the projectile body rotates counterclockwise or the beam moves downward, the order of the minimum values of the signal intensity of the antenna is opposite. Therefore, when the roll angle rotates from -180° to 180°, the minimum values of the radar signal intensity received by the antenna have obvious order characteristics.

[0045] Based on the above analysis, during the flight of the projectile body, the electronic control device inside the projectile body continuously obtains the phased array radar signal intensity received by the antenna. As the projectile body rotates, the relative position between the antenna and the radar beam changes continuously, resulting in a corresponding change in the received signal intensity. The electronic control device records the signal intensity at different moments received by the antenna in real time;

[0046] Secondly, during the flight of the projectile, different array elements in the phased array radar transmit radar signals, which are received by the antenna of the projectile. Then, the electronic control device in the projectile continuously obtains the intensity of the phased array radar signals received by the antenna. Each array element will receive the received signals reflected by the antenna. According to the received signals of different array elements in the phased array radar, the amplitudes and phases of the received signals corresponding to the array elements of different phased array radars are analyzed, and the beam width of the phased array radar during the dynamic roll angle measurement is adjusted in real time according to the analysis results.

[0047] By tracking the target of the projectile in real time, the expected signals of the phased array radar are obtained in real time;

[0048] It should be noted that the expected signal is the ideal received signal obtained by reflecting the transmitted signal of the radar by the target.

[0049] Thus, the received signals of different array elements of the phased array radar are obtained.

[0050] Step 2: Perform modal decomposition on the received signals of each array element at the current moment, analyze the dispersion degree of the amplitudes in each modal component, and the difference in the dispersion degree of the amplitudes in different modal components, and calculate the disorder coefficient of each modal component; analyze the correlation degree of the received signals between each array element and the remaining array elements at the current moment, and the difference degree of the disorder coefficients of all modal components between each array element and the remaining array elements, and determine the interference coefficient of each array element at the current moment.

[0051] During the flight of the projectile, the pointing mismatch between its antenna and the radar beam may occur due to maneuvers, rotations, or environmental interferences. Adaptive beam control can adjust the beam direction in real time to keep the radar signal always aligned with the projectile antenna; secondly, the beam width of the phased array radar depends on the spatial superposition of the signals transmitted by each array element. The wider the in-phase superposition angle range, the wider the beam; otherwise, it is narrower. The change in the flight position of the projectile and environmental interferences will increase the difference in the received signals of different array elements, affecting the stability of beam adjustment. Secondly, the positions of different array elements of the phased array radar relative to the interference source are different, resulting in a disordered change in the amplitude of the received signals in different frequency ranges. If only the overall difference in the received signals is used to adjust the weights of the amplitudes and phases of the array element signals, the stability of weight determination will have a large deviation, affecting the stability and accuracy of beam adjustment.

[0052] Furthermore, the step flowchart of the method for obtaining the interference coefficient of each array element provided in the embodiment of the present application is as Figure 5 shown.

[0053] Based on the above analysis, by analyzing the disordered change of the amplitudes of the received signals of each array element at the current moment in different frequency ranges, the disorder coefficient is calculated to evaluate the interference effect on the received signals of each array element. Specifically:

[0054] Perform modal decomposition on the received signals of each array element at the current moment to obtain multiple modal components;

[0055] In this embodiment, the variational mode decomposition algorithm is used for modal decomposition. Among them, the variational mode decomposition algorithm is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of existing technologies, for example, the empirical mode decomposition algorithm, etc. This embodiment does not make special restrictions on this.

[0056] Calculate the coefficient of variation of all amplitudes of each modal component;

[0057] In this embodiment, the degree of dispersion is measured by calculating the coefficient of variation of all amplitudes of each modal component. The calculation method of the coefficient of variation is a well-known technology and will not be elaborated here.

[0058] It should be noted that due to the differences in the positions of the interference sources in the projectile relative to the phased array radar array elements, the received signals of each array element are affected by interference differently in different frequency ranges. Therefore, the greater the degree of dispersion, the greater the amplitude fluctuation degree in the corresponding frequency range.

[0059] Calculate the sum of the differences in the degree of dispersion between all any two modal components corresponding to each array element at the current moment, which is denoted as the relative difference degree;

[0060] In this embodiment, calculate the sum of the absolute values of the differences in the degree of dispersion between all any two modal components corresponding to each array element at the current moment, which is denoted as the relative difference degree;

[0061] Take the product of the degree of dispersion of each modal component and the relative difference degree as the disorder coefficient of each modal component;

[0062] It should be noted that the greater the relative difference degree, the greater the amplitude fluctuation difference between the frequency ranges corresponding to different modal components, and the greater the obtained disorder coefficient, the greater the amplitude disorder change difference caused by the interference effect on this modal component.

[0063] Furthermore, when considering the received signals reflected by the same target received by different array elements, their received signals have a high correlation. Therefore, by analyzing the interference effects on the received signals of different array elements of the phased array radar, the influence of this interference on the beam directivity during the signal transmission process is evaluated. Therefore, calculate the interference coefficient of each array element during signal transmission, specifically:

[0064] Calculate the metric distance of the disorder coefficients of all modal components between each array element and the remaining array elements at the current moment;

[0065] In this embodiment, all modal components of each array element are arranged in ascending order according to the frequency range corresponding to the modal components. Then, the metric distance is measured by calculating the DTW distance of the disorder coefficients of all modal components between each array element and the remaining array elements. The calculation of the DTW distance is a well-known technique and will not be elaborated here.

[0066] Calculate the Pearson correlation coefficient of the received signals between each array element and the remaining array elements at the current moment;

[0067] Calculate the ratio between the metric distance and the absolute value of the Pearson correlation coefficient. The sum of the ratios between each array element and all the remaining array elements at the current moment is used as the interference coefficient of each array element at the current moment;

[0068] It should be noted that the larger the metric distance, the greater the interference effect on the received signal, resulting in a larger difference in the amplitude disorder change between the received signals of different array elements in different frequency ranges. The smaller the absolute value of the Pearson correlation coefficient, the lower the correlation between different array elements with respect to the same target due to the influence of the interference signal; the larger the obtained interference coefficient, the more serious the interference situation of the signal of this array element in the beam directivity.

[0069] Thus, the interference coefficient of each array element at the current moment is obtained.

[0070] Step 3: Based on the interference coefficients of all array elements at the current moment, determine the step size parameter of the least mean square algorithm; based on the desired signal and the step size parameter, in combination with the least mean square algorithm, adjust the beam direction of the transmitted signal of each array element in real time.

[0071] Furthermore, based on the interference coefficient, in combination with the least mean square algorithm, determine the weight vector during the beam width adjustment, and then adjust the amplitude and phase of the transmitted signals of different array elements.

[0072] First of all, the magnitude of the step size parameter of the least mean square algorithm affects the algorithm convergence speed and stability. If the influence characteristics of the transmitted signals of each array element in the phased array radar on the beam directivity are more significant, a smaller step size parameter is set to ensure the beam control stability; if the influence characteristics of the transmitted signals of each array element in the phased array radar on the beam directivity are less significant, a larger step size parameter is set to improve the algorithm convergence speed and thus improve the beam control efficiency. Therefore, based on the interference coefficient, determine the step size parameter of the least mean square algorithm, specifically:

[0073] Normalize the interference coefficients of all array elements in the phased array radar at the current moment, and calculate the average value of all the normalized results;

[0074] In this embodiment, the maximum-minimum normalization method is used for normalization processing. Among them, the maximum-minimum normalization method is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the existing technology. For example, the Z-Score method, etc. This embodiment does not make special restrictions on this.

[0075] The calculation formula for the step size parameter of the least mean square algorithm at the current moment is:

[0076]

[0077] Wherein, is the step size parameter of the least mean square algorithm at the current moment, is the preset minimum step size parameter, is the difference between the preset maximum step size parameter and the preset minimum step size parameter, is the said average value.

[0078] In this embodiment, the value of the preset minimum step size parameter is 0.001, and the preset maximum step size parameter is 0.1. As other implementation manners, implementers can set them according to actual situations.

[0079] Based on the step size parameter, through the least mean square algorithm, iterative operations are performed on the received signals of all array elements to obtain the weight vector in real time;

[0080] It should be noted that the least mean square algorithm is a well-known technology and will not be elaborated here; secondly, the step process of the least mean square algorithm is as follows:

[0081] Construct an initial weight vector, denoted as ;

[0082] It should be noted that the initial weight vector is constructed by randomly assigning values to the elements in the initial weight vector, where the number of elements in the initial weight vector is equal to the number of all array elements.

[0083] The signals received by all array elements of the phased array radar at the nth moment are formed into an input vector , after the signals received by all array elements are weighted and added, the output signal of the array can be expressed as: , wherein, is the output signal of the array, represents the conjugate transpose of the initial weight vector ;

[0084] The desired signal at the nth moment is denoted as , and the error signal is calculated, that is , then ;

[0085] It should be noted that the error signal reflects the difference between the output signal and the desired signal.

[0086] By continuously iterating and updating the weight vector, the iteration formula for the weight vector is:

[0087]

[0088] where, is the weight vector at the (n + 1)-th moment, is the weight vector at the n-th moment, is the step size parameter of the least mean square algorithm, is the input vector at the n-th moment, is the error signal at the n-th moment is the conjugate transpose;

[0089] Furthermore, according to the weight vectors at each moment, the beam direction of the transmission signal of each array element is adjusted in real time so that the beam direction of the transmission signal of each array element points to the beam direction of the desired signal. Specifically:

[0090] The -th array element corresponds to the element in the weight vector at the current moment , where is a complex number and can be expressed as: , and through Euler's formula, it is converted to polar coordinate representation as , where, ;

[0091] The received signal of the -th array element at the current moment has the expression , where A represents the amplitude, is the angular frequency, is the time;

[0092] Therefore, the adjusted transmission signal of the -th array element at the current moment is:

[0093]

[0094]

[0095]

[0096] It should be noted that is the phase part. When the amplitude of the weight value corresponding to a certain array element When it is larger, the transmitted signal of this array element contributes more to the synthesized beam; conversely, the contribution is smaller. By adjusting the amplitude , the shape of the beam and the sidelobe level can be controlled, the signal intensity in the sidelobe region can be suppressed, and the target resolution ability of the radar can be improved. According to the principle of phased array radar, by precisely controlling the phase difference between adjacent array elements, the direction of the beam can be controlled. When the beam needs to be directed to a specific direction, according to the angle between this direction and the normal direction of the array, the phase values in the weight vector Adjust the phase of the transmitted signals of each array element, so that the signals interfere and superimpose in space, and form a main lobe in the desired direction.

[0097] Secondly, when the weight vector changes, the amplitude and phase of the transmitted signals of each array element change accordingly, resulting in a change in the interference situation of the signals in space. If the adjustment of the weight vector makes the transmitted signals of each array element superimpose in phase within a wider angular range, the beam width increases; if it makes the transmitted signals of each array element superimpose in phase within a narrower angular range, the beam width decreases, thereby realizing the effective control of the beam width.

[0098] Thus, the adjusted transmitted signal of each array element at the current moment is obtained.

[0099] Step 4, each array element emits signals with the adjusted transmitted signal, and when the signal intensity received by the antenna on the projectile body shows a minimum value, measure the roll angle of the projectile body.

[0100] Furthermore, through the adjusted transmitted signal of each array element, beamforming is realized, so that the electronic control device in the projectile body continuously obtains the radar signals received by the paired antennas. Specifically:

[0101] Each array element emits signals with the adjusted transmitted signal, and the electronic control device in the projectile body continuously obtains the radar signals received by the paired antennas;

[0102] Due to the rotation of the projectile body, there is a sequential change in the radar signals received by the paired antennas. By recording the time when these extreme values appear, the relative position change of the antennas during the rotation of the projectile body can be obtained. Therefore, calculate the roll angle of the projectile body according to the time sequence of the extreme values of the radar signals received by the paired antennas.

[0103] First, according to the offset direction and magnitude between the center of the projectile body and the center of the beam, and the time sequence of the maximum and minimum values in the radar signals of the paired antennas, determine the angular value where the paired antennas are located. Specifically:

[0104] Obtain the radius of the projectile body. When the signal intensity received by the antenna is at the minimum point, establish a polar coordinate system with the center of the radar beam as the origin, and obtain the position coordinates of the center of the projectile body; calculate the antenna angle according to the position coordinates and the radius of the projectile body.

[0105] In this embodiment, it is assumed that the radius of the projectile is r, and the position coordinates of the center of the projectile are . When the minimum value of the signal strength received by the antenna is reached, it is assumed that the antenna angle is . Then , the antenna angle can be deduced from the radius of the projectile and the position coordinates of the center of the projectile.

[0106] According to the mathematical relationship between the installation position of the antenna on the projectile and the roll angle of the projectile, combined with the antenna angle, calculate the roll angle of the projectile; thus realizing the measurement of the dynamic roll angle.

[0107] In this embodiment, for example, taking antenna 1 as a reference, the angle of rotation around the center of the circular cross-section of the projectile is the same as the roll angle of the projectile. When the signal strength received by antenna 1 reaches the minimum value, the corresponding antenna angle is equal to the roll angle of the projectile at this time.

[0108] It should be understood that although Figure 1 the steps in the flowchart are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, Figure 1 at least a part of the steps in

[0109] can include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

[0110] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0110] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation to the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application shall fall within the protection scope of the technical solution of the present application.

Claims

1. A dynamic roll angle measurement method based on the change trend of antenna intensity, characterized in that The method includes the following steps: Design a phased array radar beam to track the target of the projectile body, obtain the desired signal in real time, and obtain the received signal reflected by the antenna on the projectile body after the signal is transmitted by each array element; Perform modal decomposition on the received signal of each array element at the current moment, analyze the degree of dispersion of the amplitudes in each modal component, and the difference in the degree of dispersion of the amplitudes in different modal components, and calculate the disorder coefficient of each modal component; Analyze the correlation degree of the received signals between each array element and the remaining array elements at the current moment, and the difference degree of the disorder coefficients of all modal components between each array element and the remaining array elements, and determine the interference coefficient of each array element at the current moment; Based on the interference coefficients of all array elements at the current moment, determine the step size parameter of the least mean square algorithm at the current moment; Based on the desired signal and the step size parameter, combine the least mean square algorithm to adjust the beam direction of the transmitted signal of each array element in real time; Each array element transmits a signal with the adjusted transmitted signal, and when the signal intensity received by the antenna on the projectile body shows a minimum value, measure the roll angle of the projectile body.

2. The dynamic roll angle measurement method based on the antenna intensity change trend according to claim 1, wherein The degree of dispersion is the coefficient of variation of all amplitudes of each modal component.

3. The dynamic roll angle measurement method based on the antenna intensity change trend according to claim 1, wherein The calculation of the disorder coefficient of each modal component includes: Calculate the sum of the differences in the degree of dispersion between any two modal components corresponding to each array element at the current moment, which is denoted as the relative difference degree; Perform positive fusion on the degree of dispersion and the relative difference degree to obtain the disorder coefficient of each modal component.

4. The dynamic roll angle measurement method based on the antenna intensity change trend according to claim 3, wherein The further determination process of the positive fusion is: calculate the product of the degree of dispersion and the relative difference degree.

5. The dynamic roll angle measurement method based on the antenna intensity change trend according to claim 1, characterized in that The further measurement process of the correlation degree is: calculate the Pearson correlation coefficient of the received signals between each array element and the remaining array elements at the current moment.

6. The dynamic roll angle measurement method based on the change trend of antenna strength as claimed in claim 5, wherein The further measurement process of the difference degree is: calculate the metric distance of the disorder coefficients of all modal components between each array element and the remaining array elements at the current moment.

7. The dynamic roll angle measurement method based on the change trend of antenna strength as claimed in claim 6, wherein The determination of the interference coefficient of each array element at the current moment includes: Calculate the ratio between the metric distance and the absolute value of the Pearson correlation coefficient; Take the fusion result of the ratio between each array element and the remaining all array elements at the current moment as the interference coefficient of each array element at the current moment.

8. The dynamic roll angle measurement method based on the antenna intensity change trend according to claim 7, characterized in that The further measurement method of the fusion result is: calculate the cumulative sum of the ratios between each array element and the remaining all array elements at the current moment.

9. The dynamic roll angle measurement method based on the change trend of antenna intensity according to claim 1, characterized in that The determination of the step size parameter of the least mean square algorithm at the current moment includes: Perform normalization processing on the interference coefficients of all array elements at the current moment, and calculate the average value of all normalization results; The step size parameter of the least mean square algorithm at the current moment The calculation formula is as follows: , where is the preset minimum step size parameter, is the difference between the preset maximum step size parameter and the preset minimum step size parameter, is the said average value.

10. The dynamic roll angle measurement method based on the antenna intensity change trend according to claim 1, wherein, The measurement of the roll angle of the projectile body includes: when the signal intensity received by the antenna is at the minimum value point, establish a polar coordinate system with the center of the radar beam as the origin to obtain the position coordinates of the center of the circle of the projectile body; Calculate the antenna angle according to the position coordinates and the radius of the projectile body; Based on the antenna angle corresponding to the minimum value of the signal intensity received by the antenna, obtain the roll angle of the projectile body.

Images