Imaging Method and Device for Target Rotating Components Based on Micro-Doppler Phase Compensation

Abstract

The present invention relates to a method and device for imaging a target rotating component based on micro-Doppler phase compensation. The method includes: processing the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target rotating component and the separated echo pulse signal of the target rotating component. Calculating the translational phase compensation coefficient of the target rotating component according to the prior information. Within the coherent processing interval, calculating the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the echo pulse in the angular channel where the starting coherent processing moment is located according to the echo pulse signal. Obtaining the echo accumulation result of all scattering points of the target rotating component according to the translational phase compensation coefficient and the rotational phase compensation coefficient, and calculating the imaging result in the angular domain space according to the echo accumulation result. By using this method, an image of the angular domain space distribution of the rotating components of a low-altitude rotor target can be obtained, thereby improving the accuracy of target feature extraction and enhancing the radar's classification and recognition ability for low-altitude targets.

Description

Technical Field

[0001] The present invention relates to the technical field of radar target imaging, and particularly to a method and device for imaging a target rotating component based on micro-Doppler phase compensation. Background Art

[0002] The rapid development of low-altitude aircraft has brought huge technical challenges to the field of low-altitude target surveillance. How to detect and identify low-altitude aircraft targets in a timely and reliable manner under complex ground clutter conditions is a key problem that needs to be solved urgently. Imaging the target to obtain information such as the size, shape, and attitude of the target is an effective means for target classification and recognition. However, affected by the micro-Doppler modulation of the rotating components on the low-altitude aircraft on the radar signal, traditional ISAR imaging methods often have difficulty obtaining effective images of the target. First, the micro-Doppler modulation affects the accuracy of motion compensation and the imaging quality. Second, the Doppler bandwidth broadening caused by the micro-Doppler modulation, after azimuth compression, the micro-Doppler modulation part cannot be focused, forming azimuth interference strips. Therefore, the micro-Doppler modulation brought by the rotating components is often regarded as an adverse factor in ISAR imaging and is removed. Summary of the Invention

[0003] Based on this, in view of the above technical problems, it is necessary to provide a method and device for imaging a target rotating component based on micro-Doppler phase compensation that can obtain the distribution image of the signal energy of the target rotating blade on the rotating circumference.

[0004] A method for imaging a target rotating component based on micro-Doppler phase compensation, the method comprising:

[0005] Processing the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target rotating component and the separated echo pulse signal of the rotating component.

[0006] Calculating the translational phase compensation coefficient of the target rotating component according to the prior information.

[0007] Within the coherent processing interval, calculating the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the angular channel where the starting coherent processing time is located according to the echo pulse signal of the target rotating component.

[0008] Obtaining the echo accumulation result of all scattering points of the rotating component according to the translational phase compensation coefficient and the rotational phase compensation coefficient, and calculating the imaging result in the angular domain space according to the echo accumulation result.

[0009] A device for imaging a target rotating component based on micro-Doppler phase compensation, the device comprising:

[0010] A spectrum feature processing module, which is used to process the overall echo pulse signal of the target based on the micro-Doppler technology to obtain the prior information of the rotating components of the target and the separated echo pulse signal of the rotating components of the target.

[0011] A translational phase compensation module, which is used to calculate the translational phase compensation coefficient of the rotating components of the target according to the prior information.

[0012] A rotational phase compensation module, which is used to calculate the rotational phase compensation coefficient of the echo pulse of the scattering point of the rotating components of the target in the angular channel where the starting coherent processing time is located according to the echo pulse signal of the rotating components of the target within the coherent processing interval.

[0013] An imaging module, which is used to obtain the echo accumulation result of all scattering points of the rotating components of the target according to the translational phase compensation coefficient and the rotational phase compensation coefficient, and calculate the imaging result in the angular domain space according to the echo accumulation result.

[0014] The above-mentioned method and device for imaging the rotating components of the target based on micro-Doppler phase compensation first extract the prior information of the rotating components of the target through micro-Doppler spectrum analysis, including key parameters such as rotational speed and axis position, and establish a micro-motion model of the rotating components. On this basis, the rotation plane of the rotating components is divided into several angular channels according to the angle, and a two-stage phase compensation strategy is adopted to complete the coherent compensation of the echo signal of the rotating components: the first stage calculates the phase compensation coefficient of the overall translation of the target based on the prior information, and eliminates the phase change of the echo of the rotating components caused by the motion of the target body by compensating the Doppler frequency shift caused by the translation; the second stage calculates the rotational phase compensation coefficient within the coherent processing interval in combination with the unique motion characteristics of the rotating components of the target, and this coefficient accurately reflects the phase change of the echo of each scattering point of the rotating components in a certain angular channel. After two-stage phase compensation, the phase difference between the echo pulses of each rotating component caused by translation and rotation is effectively eliminated. Finally, after accumulating the energy of each pulse according to the angular channel, the imaging result of the rotating components in the angular domain space can be obtained. Aiming at the problem that the Doppler bandwidth broadening caused by micro-motion makes the traditional ISAR imaging method unable to effectively focus in the azimuth direction, which further reduces the feature extraction and recognition ability of the rotating components, this method innovatively proposes a method for imaging in the angular domain space. By compensating the fixed phase difference caused by the position difference of the scattering points of the rotating components, as well as the phase change between the echo pulses of the echo signals of each scattering point caused by the rotational motion, and through energy coherent accumulation processing, finally, a clear distribution image of the signal energy of the target rotating components on the rotation circumference is obtained. The image obtained by this method can support the extraction of physical characteristics such as the size and quantity of the target rotating components, significantly improve the feature estimation accuracy of low-altitude rotor targets, and enhance the radar's classification and recognition ability for low-altitude targets. Description of the Drawings

[0015] Figure 1This is a diagram showing an application scenario of a target rotating component imaging method based on micro-Doppler phase compensation in one embodiment;

[0016] Figure 2 1 is a flow chart of a method for imaging a rotating target component based on micro-Doppler phase compensation in one embodiment;

[0017] Figure 3 An exploded top view of the UAV / helicopter rotor blades in motion in one embodiment;

[0018] Figure 4 A schematic diagram of blade scattering points and rotational angular channel division in one embodiment;

[0019] Figure 5 FIG. 4 is a structural block diagram of a target rotating component imaging device based on micro-Doppler phase compensation in one embodiment. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] The target rotating component imaging method based on micro-Doppler phase compensation provided by the present invention can be applied to Figure 1 The position of the rotor target and the radar is shown. Target and radar position diagram, coordinate system Is a fixed coordinate system in space, with the origin is the location of the radar. is the target fixed coordinate system, whose origin It is also the center of rotation of the rotor blades, which rotate at an angular velocity (The rotation frequency is , ) around Axis rotation. At the start of the rotor movement, the origin of the target coordinate system The initial azimuth and elevation angles in the fixed spatial coordinate system are and , which is the origin of the fixed coordinate system in space The starting distance is .

[0022] In one embodiment, Figure 2 As shown in the figure, a method for imaging a rotating target component based on micro-Doppler phase compensation is provided. Figure 1 The single-rotor target in the example is used to illustrate the process, which includes the following steps:

[0023] Step 202: Process the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target's rotating components and the separated echo pulse signal of the target's rotating components.

[0024] Step 204: Calculate the translational phase compensation coefficient of the target's rotating components according to the prior information.

[0025] Step 206: Within the coherent processing interval, calculate the rotational phase compensation coefficient of the echo pulse of the scattering points of the target's rotating components with respect to the angular channel where the starting coherent processing moment is located according to the echo pulse signal of the target's rotating components.

[0026] Step 208: Obtain the echo accumulation result of all scattering points of the target's rotating components according to the translational phase compensation coefficient and the rotational phase compensation coefficient, and calculate the imaging result in the angular domain space according to the echo accumulation result.

[0027] In the above method for imaging the target's rotating components based on micro-Doppler phase compensation, first, the prior information of the target's rotating components, including key parameters such as rotational speed and axis position, is extracted through micro-Doppler spectrum analysis, and a micro-motion model of the rotating components is established. On this basis, the rotating plane of the rotating components is divided into several angular channels by angle, and a two-stage phase compensation strategy is adopted to complete the coherent compensation of the echo signal of the rotating components: the first stage calculates the phase compensation coefficient of the overall translation of the target according to the prior information, and eliminates the phase change of the echo of the rotating components caused by the main body motion of the target by compensating the Doppler frequency shift caused by translation; the second stage calculates the rotational phase compensation coefficient within the coherent processing interval in combination with the unique motion characteristics of the target's rotating components, and this coefficient accurately reflects the phase change of the echo of each scattering point of the rotating components in a certain angular channel. After two-stage phase compensation, the phase difference between the echo pulses of each rotating component caused by translation and rotation is effectively eliminated. Finally, after accumulating the energies of each pulse according to the angular channels, the imaging result of the rotating components in the angular domain space can be obtained. Aiming at the problem that the traditional ISAR imaging method cannot effectively focus in the azimuth direction due to the Doppler bandwidth broadening caused by micro-motion, which further reduces the feature extraction and recognition ability of the rotating components, this method innovatively proposes a method for imaging in the angular domain space. By compensating the fixed phase difference caused by the position difference of the scattering points of the rotating components and the phase change between the echo pulses of each scattering point signal caused by rotational motion, and through energy coherent accumulation processing, finally, a clear distribution image of the signal energy of the target's rotating components on the rotating circumference is obtained. The image obtained by this method can support the extraction of physical characteristics such as the size and quantity of the target's rotating components, significantly improve the feature estimation accuracy of low-altitude rotor targets, and enhance the radar's classification and recognition ability for low-altitude targets.

[0028] In one embodiment, pulse compression processing is performed on the overall pulse sequence of the target received by the radar based on micro-Doppler technology, and the micro-Doppler spectrum characteristics of the target are analyzed to obtain the prior information on the rotational speed of the target's rotating component, and the echo pulse signal of the target main body is separated to obtain the echo signal of the separated target rotating component.

[0029] In one embodiment, the prior information includes: the wavelength, bandwidth, linear frequency modulation rate, pulse duration, target motion speed, distance from the center point of the target rotating component to the radar, and rotational angular velocity of the target rotating component.

[0030] According to the prior information, the echo signal component of the target main body is separated, and the echo pulse compression result of each scatterer on each blade of the target rotating component is calculated:

[0031] ;

[0032] Wherein, is the distance from the scatterer on the target rotating component to the radar, is the signal after echo pulse compression of the scatterer, is the bandwidth of the radar transmitted signal, is the imaginary unit, is the pulse duration, is the radial distance from the center of the target rotating component to the radar, is the wavelength of the radar transmitted signal, is the Doppler frequency generated by the translational motion of the target main body, is the speed of light, is the amplitude of the echo pulse compression result of the rotating component, is the fixed initial phase of the scatterer, is the translational Doppler modulation phase of the scatterer, is the rotational modulation phase of the echo signal of the scatterer, is the distance from the scatterer to the rotation center, is the initial elevation angle of the center of the target rotating component in the space fixed coordinate system, is the angular velocity of the blade rotation, is the angle between the blade and the positive x-axis of the space fixed coordinate system at the initial moment. The translational phase compensation coefficient of each scatterer on each angular channel of the target rotating component is obtained according to the echo signal of the scatterer:

[0033] ;

[0034] Wherein, is the translational phase compensation coefficient, is the Doppler frequency generated by the translational motion of the target main body, is the total number of angular channels, is the pulse duration.

[0035] In one embodiment, within the coherent processing interval, the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component from the echo pulse of the angular channel where the starting coherent processing moment is located is calculated according to the echo pulse signal of the target rotating component:

[0036] ;

[0037] where is the rotational phase compensation coefficient of the echo pulse signal of the th target rotating component, is the serial number of the scattering point on the blade, is the serial number of the echo pulse, is the interval between adjacent scattering points, is the serial number of the angular channel, is the interval between adjacent angular channels, is the pulse repetition period, is the total number of echo pulse signals of the target rotating component within the coherent processing interval.

[0038] In one embodiment, according to the translational phase compensation coefficient and the rotational phase compensation coefficient, the echo accumulation result of all scattering points in the current angular channel;

[0039] ;

[0040] where is the echo accumulation result of the th angular channel, is the translational phase compensation coefficient of the th echo pulse signal, is the rotational phase compensation coefficient of the echo pulse signal of the th target rotating component, is the pulse compression result of the th echo pulse of the target rotating component.

[0041] In one embodiment, the echo accumulation result after traversing and calculating all angular channels is obtained to get the target echo signal, and the imaging result of the blade of each angular channel on the rotation circumference angle of the target rotating component is calculated according to the target echo signal:

[0042] ;

[0043] where is the imaging result, is the echo accumulation result of the th angular channel, is the pulse repetition period, is the total number of scattering points.

[0044] In one of the embodiments, as Figure 3 shown, assume there is a single-rotor target in the far field of the radar. The rotor has blades, and the entire rotor is in translational motion. At the same time, all the blades on the rotor rotate periodically around the target center point. A model of the radar scattering echo of the rotor target is constructed. According to the analysis shown in the figure, the motion of the rotor blade can be equivalent to the combination of translational motion (translation) and rotational motion (rotation). To simplify the analysis, assume that the rotor rotates on a plane parallel to the horizontal plane. At this time, the pitch and azimuth angles of the rotor blade relative to the radar are both , that is . At this time, a certain scattering point on the blade reaches point after translational motion, and then rotates around the axis with an angular velocity to point . The rotation is positive when counterclockwise and negative when clockwise. Among them, represents the radial velocity of the target's translational motion. The velocity is positive when moving away from the radar and negative when approaching the radar; represents the distance from the scattering point to the rotation center; is the included angle between the blade and the positive axis at the initial moment. Then the rotation angle at moment is . Therefore, the distance from the radar to the point scatterer can be defined as:

[0045] (1)

[0046] Since under far-field conditions, , equation (1) can be approximated as:

[0047] (2)

[0048] When the pitch angle of the rotor blade is not zero, the above formula can be corrected as:

[0049] (3)

[0050] Assume that the LFM signal (linear frequency modulation signal) emitted by the radar is expressed as:

[0051] (4)

[0052] (5)

[0053] where is the pulse duration, is the center frequency, is the time variable, is the linear frequency modulation rate. For the convenience of analysis, without loss of generality, it is assumed here that the amplitudes of the transmitted signal and the echo signal of the scattering point are both 1. Then the radar echo signal of the scattering point can be expressed as:

[0054] (6)

[0055] where is the speed of light. It can be seen that the phase of the echo signal of the scattering point is very sensitive to the change of the target distance.

[0056] After the echo signal passes through frequency mixing, quadrature demodulation, and pulse compression processing, the obtained echo signal of the scattering point is

[0057] (7)

[0058] where is the bandwidth of the radar transmitted signal. Substituting Equation (3) into Equation (7), the echo signal of the blade scattering point can be obtained as:

[0059] (8)

[0060] where is the fixed initial phase, is the wavelength of the radar transmitted signal, denoted as as the fixed phase term; is the Doppler modulation phase caused by the overall translation of the target, called the translational phase, , denoted as as the translational phase term; is the rotational modulation phase of the echo of the blade scattering point, called the rotational phase, denoted as as the rotational phase term.

[0061] It should be noted that the radar echo phases of the scattering points on the target rotor blade are modulated by the translation of the target body and the rotation of the blade. Among them, the translational phase and the rotational phase cause a motion-related phase difference in the echo pulse sequences of each target, so the echo signal of the scattering point is inter-pulse coherent. The fixed phase term is the same for each echo pulse within the imaging processing period and does not affect the blade imaging result; if each blade of the target rotor is regarded as composed of several scattering points distributed linearly, the translational phase term is the same for each scattering point within the same echo pulse, and only the phase change caused by translation between each echo pulse needs to be compensated; the blade rotation plane is divided into several angular channels by angle, such as Figure 4As shown, by compensating for the fixed phase difference caused by the difference in the positions of the scattering points on the blade, as well as the phase change between the echo pulses of each scattering point due to rotational motion, and then performing coherent superposition processing, the distribution of the energy of the blade echo signal on the rotation circumference can be obtained, that is, the angular domain spatial imaging processing of the blade is completed, and then the number of target rotor blades can be distinguished. Thus, the core problem of imaging the helicopter rotor blade is transformed into the precise compensation of the phase of the echo signal of each scattering point on the blade.

[0062] In one embodiment, it is assumed that the echo signal of the target body has been separated and the translational phase of the blade has been compensated. As Figure 3 shown, assume that the adjacent angular channel interval is , the rotation circumference is divided into channels in total, the number of equivalent scattering points on the blade is , and the interval is . The pulse repetition period of the radar transmitted signal is denoted as . According to Equation (8), for the th scattering point on the blade, assuming that it is located in the th angular channel at the start time of the CPI (coherent processing interval), then the rotational phase compensation coefficient of the th echo pulse of this scattering point within the CPI can be expressed as:

[0063] (9)

[0064] is the total number of target echo pulses within the CPI interval.

[0065] If the angular channel where the blade is located at the start time of the CPI matches the above formula, its echo can be coherently accumulated after phase compensation, otherwise it cannot be effectively accumulated. Thus, the echo accumulation result of all scattering points in the th angular channel within the CPI can be expressed as:

[0066] (10)

[0067] where is the target translational phase compensation coefficient.

[0068] Taking the square of the magnitude of the above formula, the distribution of the energy of the blade echo signal of each angular channel on the rotor rotation circumference can be obtained, that is, the blade imaging result:

[0069] (11)

[0070] It should be noted that the above blade imaging algorithm requires prior knowledge of the target rotor speed; secondly, for the value of the equivalent scattering point spacing of the blade, considering the influence of the phase change of the scattering points on the imaging quality and the computational complexity of the algorithm, it can be taken as ; Based on antenna theory and the physical characteristics of the blades on the target rotor, if the blade is regarded as a linear array antenna composed of several array elements, its main lobe width (3dB beam width) is:

[0071] (12)

[0072] where is the blade length, and the constant Considering the broadening of the main lobe caused by the rotation of the blade when the array elements are evenly distributed, it can be taken as . For the convenience of algorithm implementation, the angular channel interval value can refer to the following formula:

[0073] (13)

[0074] where the symbol is rounding up. Generally, for air defense radars in the C and X bands, for the convenience of calculation, the angular channel interval can be taken as to meet the angular domain space imaging requirements of rotating components. At this time, .

[0075] It should be understood that although each step in the flowchart of Figure 2 is shown in sequence according to the indication of the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, Figure 2 at least a part of the steps in 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.

[0076] In one embodiment, as shown in Figure 5 , a target rotating component imaging device based on micro-Doppler phase compensation is provided, including: a spectral feature processing module 502, a translational phase compensation module 504, a rotational phase compensation module 506, and an imaging module 508, where:

[0077] The spectral feature processing module 502 processes the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target rotating component and the separated echo pulse signal of the target rotating component.

[0078] The translational phase compensation module 504 is configured to calculate the translational phase compensation coefficient of the target rotating component according to prior information.

[0079] The rotational phase compensation module 506 is configured to calculate the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the angular channel where the starting coherent processing time is located within the coherent processing interval, based on the echo pulse signal of the target rotating component.

[0080] The imaging module 508 is configured to obtain the echo accumulation result of all scattering points of the target rotating component according to the translational phase compensation coefficient and the rotational phase compensation coefficient, and calculate the imaging result in the angular domain space according to the echo accumulation result.

[0081] For the specific limitations on the imaging device of the target rotating component based on micro-Doppler phase compensation, reference can be made to the limitations on the imaging method of the target rotating component based on micro-Doppler phase compensation in the above text, which will not be elaborated here. Each module in the above imaging device of the target rotating component based on micro-Doppler phase compensation can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so as to facilitate the processor to call and execute the operations corresponding to the above respective modules.

[0082] Those skilled in the art can understand that Figure 5 the structure shown in [the figure] is only a block diagram of some structures related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0083] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present invention can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0084] 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.

[0085] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An imaging method for the rotating components of a target based on micro-Doppler phase compensation, characterized in that The method includes: Processing the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target rotating component and the separated echo pulse signal of the target rotating component; Calculating the translational phase compensation coefficient of the target rotating component according to the prior information; Within the coherent processing interval, calculating the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the echo pulse of the angular channel where the starting coherent processing moment is located according to the echo pulse signal of the target rotating component; Obtaining the echo accumulation result of all scattering points of the target rotating component according to the translational phase compensation coefficient and the rotational phase compensation coefficient, and calculating the imaging result in the angular domain space according to the echo accumulation result.

2. The method according to claim 1, wherein Processing the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target rotating component and the separated echo pulse signal of the target rotating component, including: Performing pulse compression processing on the overall pulse sequence of the target received by the radar based on micro-Doppler technology, and analyzing the micro-Doppler spectrum characteristics of the target to obtain the prior information of the rotational speed of the target rotating component, and separating the echo pulse signal of the target body to obtain the separated echo signal of the target rotating component.

3. The method according to claim 2, wherein The prior information includes: the wavelength, bandwidth, linear chirp rate, pulse duration, target motion speed, distance from the center point of the target rotating component to the radar, and rotational angular velocity of the target rotating component; Calculating the translational phase compensation coefficient of the target rotating component according to the prior information, including: Separating the echo signal component of the target body according to the prior information, and calculating the echo pulse compression result of the scattering point on each blade of the target rotating component; Among them, is the distance from the scattering point on the target rotating component to the radar, is the signal after pulse compression of the echo of the scattering point, is the bandwidth of the radar transmitted signal, is the imaginary unit, is the pulse duration, is the radial distance from the center of the target rotating component to the radar, is the wavelength of the radar transmitted signal, is the Doppler frequency generated by the translational motion of the target body, is the speed of light, is the amplitude of the pulse compression result of the rotating component echo, is the fixed initial phase of the scattering point, is the translational Doppler modulation phase of the scattering point, is the rotational modulation phase of the echo signal of the scattering point, is the distance from the scattering point to the rotation center, is the initial elevation angle of the center of the target rotating component in the space fixed coordinate system, is the angular velocity of the blade rotation, is the angle between the blade and the positive x-axis of the space fixed coordinate system at the initial moment; Obtaining the translational phase compensation coefficient of the scattering point on each angular channel of the target rotating component according to the echo signal of the scattering point; Among them, is the translational phase compensation coefficient, is the Doppler frequency generated by the translation of the target object, is the total number of angular channels, is the pulse duration.

4. The method according to claim 3, wherein Within the coherent processing interval, calculating the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the echo pulse of the angular channel where the starting coherent processing moment is located according to the echo pulse signal of the target rotating component, including: Within the coherent processing interval, calculating the rotational phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the echo pulse of the angular channel where the starting coherent processing moment is located according to the echo pulse signal of the target rotating component; Among them, is the rotational phase compensation coefficient of the echo pulse signal of the th target rotating component, is the serial number of the scattering point on the blade, is the echo pulse serial number, is the interval between adjacent scattering points, is the serial number of the angular channel, is the interval between adjacent angular channels, is the pulse repetition period, is the total number of echo pulse signals of the target rotating component within the coherent processing interval.

5. The method according to claim 4, wherein Obtaining the echo accumulation result of all scattering points according to the translational phase compensation coefficient and the rotational phase compensation coefficient, including: The echo accumulation result of all scattering points within the current angular channel according to the translational phase compensation coefficient and the rotational phase compensation coefficient; Among them, is the echo accumulation result of the th corner channel, is the translational phase compensation coefficient of the th echo pulse signal, is the rotational phase compensation coefficient of the echo pulse signal of the th target rotating component, is the pulse compression result of the th echo pulse of the target rotating component.

6. The method according to claim 5, wherein Calculating the imaging result in the angular domain space according to the echo accumulation result, including: Traversing and calculating the echo accumulation result after accumulating all angular channels to obtain the target echo signal, and calculating the imaging result of each angular channel blade on the rotation circumference angle of the target rotating component according to the target echo signal; Among them, is the imaging result, is the echo accumulation result of the th corner channel, is the pulse repetition period, is the total number of scatter points.

7. An imaging device for a target rotating component based on micro-Doppler phase compensation, characterized in that, The device includes: A spectrum feature processing module, configured to process the overall echo pulse signal of the target based on micro-Doppler technology to obtain the prior information of the target rotating component and the separated echo pulse signal of the target rotating component; A translational phase compensation module, configured to calculate the translational phase compensation coefficient of the target rotating component according to the prior information; A rotation phase compensation module, which is used to calculate the rotation phase compensation coefficient of the echo pulse of the scattering point of the target rotating component with respect to the echo pulse in the angular channel where the starting coherent processing moment is located according to the echo pulse signal of the target rotating component within the coherent processing interval; An imaging module, which is used to obtain the echo accumulation result of all scattering points of the target rotating component according to the translational phase compensation coefficient and the rotation phase compensation coefficient, and calculate the imaging result in the angular domain space according to the echo accumulation result.

Images