Electronic stabilization method and system for horizontal omnidirectional array antenna beam

Abstract

The invention discloses an electronic stabilization method and system for a horizontal omnidirectional array antenna beam, and relates to the antenna technology, and the method comprises the steps: obtaining the parameters of an array antenna, the parameters of the array antenna comprise the coordinates of an array antenna unit, the solving frequency, and the out-of-roundness index of a horizontal plane directional diagram; establishing a mathematical model according to the acquired parameters of the array antenna; determining a fitness function according to the established mathematical model, and establishing an optimization process according to the determined fitness function; and according to an optimization result of the fitness function, obtaining a horizontal plane directional diagram of the array antenna under optimal excitation and a corresponding out-of-roundness result. The method provided by the invention is used for solving the problem of out-of-roundness deterioration of a horizontal plane radiation pattern when the cylindrical array antenna rolls transversely on the antenna mounting platform.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a method and system for electronically stabilizing a horizontal omnidirectional array antenna beam. Background Art

[0002] When the cylindrical phased array for shipborne communications works in omnidirectional mode, it is usually necessary to form an omnidirectional radiation pattern in the horizontal plane to achieve full coverage of the horizontal plane, thereby ensuring information interaction for all members in the communication network. This working mode places high requirements on the non-circularity of the radiation pattern of the omnidirectional array antenna in the horizontal plane, that is, the pattern gain has good consistency in the horizontal plane. However, in a shipborne environment, the attitude of the ship, especially the rolling attitude, will cause the pattern to tilt, resulting in a serious deterioration of the non-circularity of the horizontal plane pattern and reduced system performance. The antenna array system based on mechanical beam stabilization technology has a slow response time and poor accuracy, and its application scenarios are greatly limited. How to use electronic stabilization technology to solve the problem of beam performance deterioration of the horizontal omnidirectional array antenna when the attitude of the installation platform changes has become a difficult problem that needs to be solved urgently.

[0003] At present, most relevant literatures only study the beam pointing stability of directional antennas. For example, in the paper "Research on Electronic Stabilization of Shipborne One-Dimensional Phased Array Radar Beam", the author proposed a method to compensate for the pointing deviation of the radar beam caused by the swaying of the ship. Based on the principles of coordinate transformation and vector rotation, the corresponding beam stabilization calculation formula is given. However, as mentioned earlier, the literature only studies the beam pointing of directional antennas, that is, a pointing point in the airspace, and cannot solve the problem of deterioration of the radiation pattern performance of omnidirectional communication antennas in the entire horizontal plane due to changes in the carrier's attitude. Summary of the invention

[0004] The embodiments of the present application provide a method and system for electronically stabilizing the beam of a horizontal omnidirectional array antenna, which are used to solve the problem of deterioration of the non-circularity of the horizontal radiation pattern of the cylindrical array antenna caused by rolling of the antenna mounting platform.

[0005] The embodiment of the present application provides a method for electronically stabilizing a horizontal omnidirectional array antenna beam, comprising:

[0006] Acquiring parameters of the array antenna, wherein the parameters of the array antenna include coordinates of array antenna elements, a solution frequency, and an out-of-roundness index of a horizontal plane pattern;

[0007] Establishing a mathematical model according to the acquired parameters of the array antenna;

[0008] Determining a fitness function according to the established mathematical model, so as to establish an optimization process according to the determined fitness function;

[0009] According to the optimization result of the fitness function, the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding out-of-roundness result are obtained.

[0010] Optionally, parameters of an array antenna are obtained, wherein coordinates of the array antenna are determined based on a geometric structure of the array antenna.

[0011] Optionally, establishing a mathematical model according to the acquired parameters of the array antenna includes:

[0012] In the array coordinate system (x, y, z), let the cylindrical array include M circular arrays with a radius of R, and each circular array has N antenna units evenly distributed;

[0013] Taking the center O of the bottom circle as the reference point for calculating the relative phase of each antenna unit, the radiation pattern of the cylindrical array antenna in space satisfies the following condition when the installation platform does not roll:

[0014]

[0015] Where φ and θ represent the azimuth and elevation angles, respectively, and Ψ mn is the initial excitation phase of the (m,n)th unit, φ mn (n=0,1,…,N-1) represents the azimuth angle of the antenna unit n uniformly distributed on the mth plane circle, θ m represents the pitch angle of the mth plane circle, θ m =arctan(R / h m ), h m represents the distance between the m=0, 1,…, M-1th circular array and the lower bottom surface, and λ represents the wavelength of the electromagnetic wave.

[0016] Optionally, establishing a mathematical model according to the acquired parameters of the array antenna further includes:

[0017] When the installation platform rotates around the Ox axis by an angle ω, in the geodetic coordinate system (x ′ ,y ′ ,z ′ ), the new directional diagram is expressed as:

[0018]

[0019] Among them, φ ′ ,θ ′ Respectively represent the azimuth and elevation angles in the geodetic coordinate system;

[0020] According to the elevation angle θ of the horizontal plane pattern ′ =90°, and converted to decibel values ​​to satisfy:

[0021] F ′ dB(φ′ ,Ψ mn )=20×log10(|F ′ (φ ′ ,Ψ mn )|)

[0022] F ′ dB(φ ′ ,Ψ mn ) represents the pitch angle θ ′ = decibel value of the directional pattern conversion at 90°;

[0023] According to the mathematical model of the horizontal plane pattern, a fitness function is established to satisfy:

[0024] S(Ψ mn )=max(F ′ dB(φ ′ ,Ψ mn ))-min(F ′ dB(φ ′ ,Ψ mn ))

[0025] Among them, φ ′ ∈[0°,360°],S(Ψ mn ) represents the out-of-roundness of the array antenna in the horizontal plane.

[0026] Optionally, according to the established mathematical model and fitness function, establishing an optimization process includes:

[0027] The optimization goal is to minimize the non-circularity of the cylindrical array antenna in the horizontal plane and meet the following requirements:

[0028] minmize S(Ψ mn )=max(F ′ dB(φ ′ ,Ψ mn ))-min(F ′ dB(φ ′ ,Ψ mn ))

[0029] Among them, minmize S(Ψ mn ) indicates that the optimization goal is to minimize the non-circularity of the cylindrical array antenna in the horizontal plane.

[0030] Optionally, according to the optimization result of the fitness function, obtaining the horizontal plane radiation pattern of the array antenna under optimal excitation and the corresponding out-of-roundness result includes:

[0031] Solving based on the fitness function according to the differential evolution algorithm,

[0032] According to the set iteration termination condition, when the termination condition is met, the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding non-circularity result are determined.

[0033] An embodiment of the present application also proposes an electronic stabilization system for a horizontal omnidirectional array antenna beam, comprising a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the electronic stabilization method for the horizontal omnidirectional array antenna beam as described above are implemented.

[0034] The electronic stabilization method of the horizontal omnidirectional cylindrical array antenna beam proposed in the embodiment of the present application can solve the problem of deterioration of the non-circularity of the antenna horizontal plane radiation pattern caused by changes in the ship's posture.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0037] Figure 1 The basic process diagram of the electronic stabilization method of the horizontal omnidirectional array antenna beam of the embodiment of the present application is shown;

[0038] Figure 2 A schematic diagram of a cylindrical array coordinate system for an electronic stabilization method for a horizontal omnidirectional array antenna beam according to an embodiment of the present application;

[0039] Figure 3 The following is a schematic diagram of the iterative process of differential evolution algorithm optimization of the electronic stabilization method of the horizontal omnidirectional array antenna beam according to an embodiment of the present application;

[0040] Figure 4 The cylindrical array antenna and its roll diagram for the application example of this application;

[0041] Figure 5 This is the horizontal plane direction diagram when there is no roll in the application example of this application;

[0042] Figure 6 This is the horizontal plane direction diagram (before optimization) when the roll angle ω=15° of the application example of this application;

[0043] Figure 7This is the horizontal plane direction diagram (after optimization) when the roll angle ω=15° of the application example of this application. DETAILED DESCRIPTION

[0044] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0045] The embodiment of the present application provides a method for electronically stabilizing a horizontal omnidirectional array antenna beam, as shown in the figure, comprising the following steps:

[0046] In step S101, the parameters of the array antenna are obtained, wherein the parameters of the array antenna include the coordinates of the array antenna elements, the solution frequency and the out-of-roundness index of the horizontal plane radiation pattern.

[0047] In step S102, a mathematical model is established according to the acquired parameters of the array antenna.

[0048] In step S103, a fitness function is determined according to the established mathematical model, so as to establish an optimization process according to the determined fitness function, that is, to establish an optimization algorithm iteration process.

[0049] In step S104, according to the optimization result of the fitness function, the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding out-of-roundness result are obtained.

[0050] In some embodiments, parameters of an array antenna are obtained, wherein the coordinates of the array antenna are determined according to a geometric structure of the array antenna.

[0051] In some embodiments, establishing a mathematical model according to the acquired parameters of the array antenna includes:

[0052] In the array coordinate system (x, y, z), let the cylindrical array include M circular arrays with radius R, each circular array has N antenna units evenly distributed, and the distance between the m=0, 1, ..., M-1th circle and the bottom surface is h m , λ represents the wavelength of electromagnetic wave, and the cylindrical array surface layout is as follows Figure 2 shown.

[0053] The center of the lower circle O is used as the reference point for calculating the relative phase of each antenna unit. The azimuth and elevation angles are represented by φ and θ respectively. Point A is a unit on the mth plane circle, and its azimuth angle evenly distributed on the circle is φ mn (n=0,1,…,N-1), the pitch angle is θ m=arctan(R / h m ),and According to Figure 2 As shown in the figure, when the cylindrical array antenna is installed on a platform without rolling, the radiation pattern in space satisfies:

[0054]

[0055] Formula (1) is the radiation pattern of the array antenna when the mounting platform does not roll. In some embodiments, the mathematical model established according to the acquired parameters of the array antenna further includes:

[0056] When the installation platform rotates around the Ox axis by an angle ω, in the geodetic coordinate system (x ′ ,y ′ ,z ′ ), the new directional diagram is expressed as:

[0057]

[0058] Among them, φ ′ ,θ ′ Respectively represent the azimuth and elevation angles in the geodetic coordinate system;

[0059] For the horizontal plane pattern, the elevation angle θ ′ =90°, the above formula (2) can be expressed as

[0060]

[0061] According to the elevation angle θ of the horizontal plane pattern ′ =90°, converted to decibel value:

[0062] F ′ dB(φ ′ ,Ψ mn )=20×log10(|F ′ (φ ′ ,Ψ mn )|) (4)

[0063] F ′ dB(φ ′ ,Ψ mn ) represents the pitch angle θ ′ = decibel value of the directional pattern conversion at 90°;

[0064] According to the mathematical model of the horizontal plane pattern, that is, the expression of the horizontal plane pattern given by equation (4), the mathematical model expression of the horizontal plane non-circularity is established to satisfy:

[0065] S(Ψ mn )=max(F′ dB(φ ′ ,Ψ mn ))-min(F ′ dB(φ ′ ,Ψ mn )) (5)

[0066] Among them, φ ′ ∈[0°,360°],S(Ψ mn ) represents the horizontal plane non-circularity. According to formula (5), the initial excitation phase Ψ of the unit mn It has a direct impact on out-of-roundness.

[0067] In some embodiments, determining a fitness function according to the established mathematical model, and establishing an optimization process according to the determined fitness function includes:

[0068] Taking the minimization of the out-of-roundness of the cylindrical array antenna in the horizontal plane as the optimization goal, the optimization process is determined to meet the following conditions:

[0069] minmize S(Ψ mn )=max(F ′ dB(φ ′ ,Ψ mn ))-min(F ′ dB(φ ′ ,Ψ mn )) (6)

[0070] Among them, minmize S(Ψ mn ) indicates that the optimization goal is to minimize the non-circularity of the cylindrical array antenna in the horizontal plane.

[0071] In some embodiments, according to the optimization result of the fitness function, obtaining the horizontal plane radiation pattern of the array antenna under optimal excitation and the corresponding out-of-roundness result includes:

[0072] The differential evolution algorithm is used to solve the fitness function, that is, the minimum optimization problem given by formula (6) is solved by the differential evolution algorithm. The specific solution process is as follows: Figure 3 shown.

[0073] According to the set iteration termination condition, when the termination condition is met, the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding non-circularity result are determined. Figure 3 The iteration end condition in can be achieved by reaching the maximum number of iterations g max As a standard, we can also give a desired out-of-roundness value δ. When S(Ψ mn )≤δ, the iteration is terminated to determine the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding non-circularity result.

[0074] The embodiment of the present application also provides a specific example of a method for electronically stabilizing a horizontal omnidirectional array antenna beam, including the following steps:

[0075] The first step is to establish the array coordinate system (x, y, z), and calculate the parameter φ of each unit in the array coordinate system based on the geometric parameters M, R and N of the cylindrical array antenna. mn ,θ m and r m .

[0076] The second step is to set the solution parameters, including: mutation factor F, crossover probability CR, population size NP, maximum number of iterations g max , working wavelength λ and platform roll angle ω. Each population represents a set of array unit initial excitation phases, and the roll angle ω is provided by the angle sensor installed on the cylindrical array antenna.

[0077] The third step is to establish the geodetic coordinate system (x ′ ,y ′ ,z ′ ) and the array coordinate system (x, y, z), and solve the directional pattern of the array antenna on the horizontal plane for each population according to formula (3), and then obtain the corresponding out-of-roundness value according to formula (5).

[0078] Step 4: Determine whether to continue iteration according to the iteration termination condition. If it is necessary to continue iteration, go to step 5. If it is necessary to terminate iteration, go to step 6.

[0079] The fifth step is to perform mutation, crossover and selection operations on the current population to generate a new population and go to the third step.

[0080] The sixth step is to terminate the iteration and obtain the best population, that is, the best initial excitation phase of each unit, and obtain the optimized horizontal plane pattern and its non-circularity value.

[0081] As an example, the horizontal beam electronic stabilization problem of a cylindrical array with M = 4, N = 12, and R = 450 mm at a roll angle of ω = 15° is calculated. The antenna structure and its roll schematic are shown in Figure 4 shown.

[0082] When the antenna installation platform does not roll, the horizontal plane radiation pattern is as follows Figure 5 As shown, the out-of-roundness value is less than or equal to 1.52dB. When the roll angle ω=15°, the horizontal plane direction diagram is as follows Figure 6 As shown, the out-of-roundness value is greater than or equal to 5.7 dB, and the performance is seriously deteriorated.

[0083] The above problem is solved by the optimization method of this embodiment, and the parameters F = 0.5, CR = 0.9, NP = 20, g max =500, and finally the optimized horizontal plane direction diagram is as follows Figure 7 As shown, the out-of-roundness is less than or equal to 2.65dB, which is Figure 6 Compared with the results before optimization, its horizontal plane omnidirectional characteristics are greatly improved and the out-of-roundness value is reduced.

[0084] This application proposes a method for electronic stabilization of the beam of a horizontal omnidirectional cylindrical array antenna. For the horizontal omnidirectional array antenna, the deterioration of the non-circularity of the horizontal plane pattern when the antenna mounting platform rolls is analyzed. This application proposes a mathematical model with a solution problem, and uses a differential evolution method to optimize and solve the model, thereby improving the non-circularity of the pattern in the entire horizontal plane, and solving the problem that the existing technology can only solve the electronic stabilization problem of the beam pointing in a specific direction of a directional antenna, but cannot solve the electronic stabilization problem of an omnidirectional beam in a given plane. The method of this application is simple, has a fast convergence speed, the system can be self-closed, and the solution result is good, and has a high engineering application value.

[0085] An embodiment of the present application also proposes an electronic stabilization system for a horizontal omnidirectional array antenna beam, comprising a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of the electronic stabilization method for the horizontal omnidirectional array antenna beam as described above are implemented.

[0086] It should be noted that in the various embodiments of the present application, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0087] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0088] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0089] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A method for electronic stabilization of a horizontal omnidirectional array antenna beam, characterized in that: include: Acquiring parameters of the array antenna, wherein the parameters of the array antenna include coordinates of array antenna elements, a solution frequency, and an out-of-roundness index of a horizontal plane pattern; Establishing a mathematical model according to the acquired parameters of the array antenna; Determining a fitness function according to the established mathematical model, so as to establish an optimization process according to the determined fitness function; According to the optimization result of the fitness function, the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding out-of-roundness result are obtained.

2. The electronic stabilization method of the horizontal omnidirectional array antenna beam as claimed in claim 1, characterized in that: The parameters of the array antenna are obtained, wherein the coordinates of the array antenna are determined according to the geometric structure of the array antenna.

3. The electronic stabilization method of the horizontal omnidirectional array antenna beam according to claim 1, characterized in that: The mathematical model is established based on the acquired parameters of the array antenna, including: In the array coordinate system (x, y, z), let the cylindrical array include M circular arrays with a radius of R, and each circular array has N antenna units evenly distributed; Taking the center O of the bottom circle as the reference point for calculating the relative phase of each antenna unit, the radiation pattern of the cylindrical array antenna in space satisfies the following condition when the installation platform does not roll: Where φ and θ represent the azimuth and elevation angles, respectively, and Ψ mn is the initial excitation phase of the (m,n)th unit, φ mn (n=0,1,…,N-1) represents the azimuth angle of the antenna unit n uniformly distributed on the mth plane circle, θ m represents the pitch angle of the mth plane circle, θ m =arctan(R / h m ), h m represents the distance between the m=0, 1,…, M-1th circular array and the lower bottom surface, and λ represents the wavelength of the electromagnetic wave.

4. The electronic stabilization method of the horizontal omnidirectional array antenna beam as claimed in claim 3, characterized in that: The mathematical model established according to the acquired parameters of the array antenna also includes: When the mounting platform rotates around the Ox axis by an angle ω, the new direction diagram is expressed in the geodetic coordinate system (x′, y′, z′) as follows: Among them, φ′, θ′ represent the azimuth and elevation angles in the geodetic coordinate system respectively; According to the elevation angle θ′=90° where the horizontal plane pattern is located, it is converted into a decibel value to satisfy: F′dB(φ′,Ψ mn )=20×log10(|F′(φ′,Ψ mn )|) F′dB(φ′,Ψ mn ) represents the decibel value of the pattern conversion at an elevation angle θ′=90°; According to the mathematical model of the horizontal plane pattern, a fitness function is established to satisfy: S(Ψ mn )=max(F′dB(φ′,Ψ mn ))-min(F′dB(φ′,Ψ mn )) Among them, φ′∈[0°,360°],S(Ψ mn ) represents the out-of-roundness of the array antenna in the horizontal plane.

5. The electronic stabilization method of the horizontal omnidirectional array antenna beam as claimed in claim 4, characterized in that: Determining a fitness function according to the established mathematical model, and establishing an optimization process according to the determined fitness function includes: Taking the minimization of the non-circularity of the cylindrical array antenna in the horizontal plane as the optimization goal, the optimization process is established to meet the following requirements: minimizeS(Ψ mn )=max(F′dB(φ′,Ψ mn ))-min(FdB(φ′,Ψ mn )) Among them, minmize S(Ψ mn ) indicates that the optimization goal is to minimize the non-circularity of the cylindrical array antenna in the horizontal plane.

6. The electronic stabilization method of the horizontal omnidirectional array antenna beam as claimed in claim 5, characterized in that: According to the optimization result of the fitness function, obtaining the horizontal plane radiation pattern of the array antenna under optimal excitation and the corresponding out-of-roundness result includes: Solving based on the fitness function according to the differential evolution algorithm, According to the set iteration termination condition, when the termination condition is met, the horizontal plane radiation pattern of the array antenna under the optimal excitation and the corresponding non-circularity result are determined.

7. An electronic stabilization system for a horizontal omnidirectional array antenna beam, characterized in that: The invention comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the method for electronic stabilization of the horizontal omnidirectional array antenna beam as described in any one of claims 1 to 6 are implemented.

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