A high-precision measurement method for target angular position of imported aviation equipment

Abstract

A high-precision measurement method for the target angular position of an introduced aviation equipment belongs to the field of semi-physical simulation test technology, including physical measurement and electrical measurement. The physical measurement is used to realize the rapid measurement and positioning of the physical position of the antenna. The electrical measurement is measured by a vector network analyzer using an intermediate frequency measurement method, and then the angle is measured using the phase difference between the target signals received by the two antennas. The beneficial effects of the present invention are: the method of rotating 180° and repeating the measurement to obtain the average can eliminate the amplitude and phase errors caused by the inconsistency of the receiving link, ensure the accuracy of the target angular position, enable the radar of the aviation equipment to correctly find the target, and capture and track the target, so that the performance test of the aviation equipment can be carried out smoothly, and it has good economic benefits and advancement.

Description

Technical Field

[0001] The invention belongs to the technical field of semi-physical simulation testing, and in particular relates to a high-precision measurement method for the target angular position of imported aviation equipment. Background Art

[0002] When conducting semi-physical simulation tests on imported aviation equipment, the accuracy of the target angular position must be guaranteed so that the radar of the aviation equipment can correctly find the target and capture and track the target. Therefore, it is necessary to measure the target first. The phase method is used to measure the angle of the target position during measurement. The phase difference between the target signals received by the two antennas is used to measure the angle. The relative amplitude and phase of the two receiving channels are measured on the premise that the receiving links are of equal amplitude and phase. However, in fact, the two receiving links cannot be completely consistent. In order to eliminate the errors caused by inconsistencies, ensure the accuracy of the target angular position, and meet the semi-physical simulation test requirements of imported aviation equipment, a high-precision measurement method for the target angular position of imported aviation equipment is required. After measurement compensation, the amplitude and phase characteristics are made uniform and consistent to meet the semi-physical simulation test requirements of imported aviation equipment. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to propose a high-precision measurement method for the target angular position of imported aviation equipment, so as to ensure the accuracy of the target angular position and meet the requirements of semi-physical simulation testing of imported aviation equipment.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for high-precision measurement of the target angular position of imported aviation equipment, including physical measurement and electrical measurement. The physical measurement is used to realize the rapid measurement and positioning of the physical position of the antenna. The electrical measurement is measured by a vector network analyzer using an intermediate frequency measurement method, and then the angle is measured using the phase difference between the target signals received by the two antennas. The method of repeated measurement by rotating 180° and averaging is adopted to eliminate the amplitude and phase errors caused by the inconsistency of the receiving link.

[0005] The physical measurement is composed of a physical measurement device, which includes a laser ranging system, an image acquisition system and a computer control and communication system. When performing physical measurement, the laser ranging system is used to measure the distance from the antenna to the center of the turntable, the image acquisition system is used to obtain the optical image of the antenna and convert it into an electronic image, and the computer control and communication system is used to control the steering positioning of the turntable, receive the electronic image generated by the image acquisition system and display it on the screen.

[0006] The laser distance measurement system includes a laser distance meter, a laser distance meter fixture and a laser distance meter trigger device. In order to accurately position the installed antenna, the laser distance meter is accurately installed on the three-axis center of the three-axis turntable using the laser distance meter fixture, so that the optical axis of the laser coincides with the axis of the inner frame of the turntable, and the position indicated by the laser is the position directly opposite to the axis of the turntable; this device ensures that the installation position and spacing of the geometric center of each antenna surface meet the design accuracy requirements, thereby reducing the differences between the amplitude and phase characteristics of each radiation signal of the radiation interface of each antenna unit, and facilitating the fine adjustment of the electrical characteristics.

[0007] The electrical measurement includes a measurement receiving device, a measurement computer, a measurement control and power supply chassis, a local oscillator frequency synthesizer and a vector network analyzer. It adopts an intermediate frequency measurement method. A 2-18GHz signal source radiates a signal. After the signal radiated by the signal source passes through a two-power divider, one signal is transmitted to the turntable test receiving device via a trench cable as a reference signal, and the other signal is input into the precision position control and feeding link. Finally, the antenna radiates the signal, the air-fed signal and the line-fed signal are switched on by a switch and then down-converted by a mixer. After the frequency is converted to 50MHz, it is measured by a vector network analyzer.

[0008] The measuring receiving device selects the air-fed signal and the line-fed signal, and selects different signals to realize different measuring functions. During the amplitude and phase test, the air-fed signal is compared with the line-fed reference signal, and the phase difference and amplitude ratio of each antenna and the reference signal are measured with the reference signal as the benchmark. The signal output by the measuring device enters the vector network analyzer for measurement. The vector network analyzer is connected to the measuring computer via Ethernet or GPIB bus and is controlled by the test software. During the test, the segment scanning method is used to measure the required frequency points. The measuring receiving device adopts the phase method to measure the angle of the target position, and uses the phase difference between the target signals received by the two antennas to measure the angle.

[0009] The method for averaging the repeated measurements by rotating 180° is as follows:

[0010] d1 is the path from the radiation signal source to speaker A, d2 is the path from the radiation signal source to speaker B, c1 is the path from speaker A to the vector network, and c2 is the path from speaker B to the vector network. When measuring, the path difference between the two branches is:

[0011] (d1+c1)-(d2+c2);

[0012] After rotating 180°, the path difference between the two branches is:

[0013] (d1+c2)-(d2+c1);

[0014] The two measurements are averaged to obtain:

[0015] (((d1+c1)-(d2+c2))+((d1+c2)-(d2+c1))) / 2=d1-d2

[0016] This can eliminate the amplitude and phase errors caused by inconsistencies in the receiving chain.

[0017] The beneficial effects of the present invention are as follows: the method of rotating 180° and repeating the measurement to obtain the average value can eliminate the amplitude and phase errors caused by the inconsistency of the receiving link, ensure the accuracy of the target angular position, enable the radar of the aviation equipment to correctly find the target, and capture and track the target, so that the performance test of the aviation equipment can be carried out smoothly, and has good economic benefits and advancement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a physical measurement block diagram of the target angular position measurement of the present invention.

[0019] Figure 2 This is a block diagram of electrical measurement for target angular position measurement of the present invention.

[0020] Figure 3 This is the principle diagram of angle measurement using the phase method of the present invention.

[0021] Figure 4 It is a measurement schematic diagram of the present invention.

[0022] Figure 5 It is a schematic diagram of measurement after rotating 180° according to the present invention.

[0023] Figure 6 It is a schematic diagram of the baseline and reference point of the radome of the present invention.

[0024] Figure 7 It is a schematic diagram of the composition of the electrical measurement system of the present invention.

[0025] Figure 8 This is the error when the method of rotating 180° and repeating the measurement to obtain the average is not adopted.

[0026] Fig. 9 This is the error when the average of repeated measurements is taken after rotating 180°.

[0027] Fig.10 This is a table of typical frequency point errors when the method of rotating 180° and repeating the measurement to obtain the average is adopted.

[0028] In the figure: d1, the path from the radiation signal source to speaker A, d2, the path from the radiation signal source to speaker B, c1, the path from speaker A to the vector network, c2, the path from speaker B to the vector network. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of this specification. It should be noted that the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] See also Figure 1-Figure 10, a high-precision measurement method for the target angular position of introduced aviation equipment, including physical measurement and electrical measurement. The physical measurement is used to realize the rapid measurement and positioning of the physical position of the antenna. The electrical measurement adopts the medium frequency measurement method through a vector network analyzer, and then uses the phase difference between the target signals received by the two antennas to measure the angle. The physical measurement is composed of a physical measurement device, which includes a laser ranging system, an image acquisition system, and a computer control and communication system. When performing physical measurement, the laser ranging system is used to measure the distance from the antenna to the center of the turntable, the image acquisition system is used to obtain the optical image of the antenna and convert it into an electronic image, and the computer control and communication system is used to control the steering and positioning of the turntable, receive the electronic image generated by the image acquisition system, and display it on the screen. The laser rangefinder system includes a laser rangefinder, a laser rangefinder fixture and a laser rangefinder trigger device. In order to accurately locate the installed antenna, the laser rangefinder is accurately installed on the three-axis center of the three-axis turntable using the laser rangefinder fixture, so that the optical axis of the laser coincides with the axis of the inner frame of the turntable, and the position indicated by the laser is the position directly opposite the axis of the turntable; the device makes the installation position and spacing of the geometric center of each antenna surface meet the design accuracy requirements, thereby reducing the difference between the amplitude and phase characteristics of each radiation signal of the radiation interface of each antenna unit, and facilitating the fine adjustment of the electrical characteristics. When performing physical testing, the target angular position measurement physical measurement block diagram principle is shown for measurement. The center of the turntable is located at the center of the spherical screen. The horizontal and vertical baselines on the antenna cover are consistent with the polarization direction of the antenna. By taking three points at the center point of the antenna cover, one point above and below, and one point on the left and right, the physical position of the antenna can be quickly measured and located. The electrical measurement includes a measurement receiving device, a measurement computer, a measurement control and power supply chassis, a local oscillator frequency synthesizer and a vector network analyzer. It adopts an intermediate frequency measurement method. A 2-18GHz signal source radiates a signal. After the signal radiated by the signal source passes through a two-power divider, one signal is transmitted to the turntable test receiving device via a trench cable as a reference signal, and the other signal is input into the precision position control and feeding link. Finally, the antenna radiates the signal, the air-fed signal and the line-fed signal are switched on by a switch and then down-converted by a mixer. After the frequency is converted to 50MHz, it is measured by a vector network analyzer. The measuring receiving device selects the air-fed signal and the line-fed signal, and selects different signals to realize different measuring functions. During the amplitude and phase test, the air-fed signal is compared with the line-fed reference signal, and the phase difference and amplitude ratio of each antenna and the reference signal are measured with the reference signal as the benchmark. The signal output by the measuring device enters the vector network analyzer for measurement. The vector network analyzer is connected to the measuring computer via Ethernet or GPIB bus and is controlled by the test software. During the test, the segment scanning method is used to measure the required frequency points. The measuring receiving device adopts the phase method to measure the angle of the target position, and uses the phase difference between the target signals received by the two antennas to measure the angle.

[0031] Located in θ If there is a distant target in the direction, the radio wave reflected by the target reaching the receiving point is approximately a plane wave. Since the distance between the two antennas is d, the signals they receive have a path difference R, which produces a phase difference:

[0032] (1)

[0033] in λ is the wavelength of the radar signal. If a phase meter is used for phase comparison, the phase difference can be measured. φ , the target direction can be determined;

[0034] Phase Difference φ Inaccurate measurement will result in angle measurement error. The angle measurement error obtained by differentiating both sides of formula (1) is:

[0035] (2)

[0036] Therefore, a higher precision phase meter is used, or d / λ The value of can improve the angle measurement accuracy, but according to formula (1), θ At a certain time, when d / λ When the value of increases to a certain extent, φ The value of may exceed 2, so the actual difference φ If it cannot be determined, there will be a multi-value problem. Therefore, for the dual-antenna angle measurement method, d / λ The value of cannot be too large;

[0037] The premise of measuring the relative amplitude and phase of the two receiving channels is that the receiving links are equal in amplitude and phase. However, the two receiving links of the high-frequency head cannot be completely consistent. In order to eliminate the error caused by the inconsistency, the method of rotating 180° and repeating the measurement to obtain the average is adopted.

[0038] d1 and d2 are the paths from the radiation signal source to speaker A and speaker B, respectively. c1 and c2 are the paths from speaker A and speaker B to the vector network, respectively. Figure 4 When the method is used for measurement, the path difference between the two branches is:

[0039] (d1+c1)-(d2+c2);

[0040] When rotated 180°, Figure 5 During measurement, the path difference between the two branches is:

[0041] (d1+c2)-(d2+c1);

[0042] The two measurements are averaged to obtain:

[0043] (((d1+c1)-(d2+c2))+((d1+c2)-(d2+c1))) / 2=d1-d2

[0044] In this way, the amplitude and phase errors caused by the inconsistency of the receiving chain can be eliminated.

[0045] In the performance test of the imported aviation equipment, the errors of the method of not using the method of rotating 180° and repeating the measurement to obtain the average and the method of using the method of rotating 180° and repeating the measurement to obtain the average are as follows: Figure 8 and Fig. 9 As shown in the figure, when the 180° repeated measurement method is used to obtain the average, the error indicators such as the maximum error and the root mean square error are significantly improved. When the 180° repeated measurement method is used to obtain the average, the typical frequency point error table is shown in Fig.10 .

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0047] The parts not described in detail in this invention are prior art.

Claims

1. A high-precision measurement method for the target angular position of an introduced aviation equipment, characterized by: It includes physical measurement and electrical measurement. The physical measurement is used to quickly measure and locate the physical position of the antenna. The electrical measurement is performed by using a vector network analyzer in the form of intermediate frequency measurement. The angle is then measured using the phase difference between the target signals received by the two antennas. The method of rotating 180° and repeating the measurement to obtain an average is used to eliminate the amplitude and phase errors caused by inconsistent receiving links. The method for averaging the repeated measurements by rotating 180° is as follows: d1 is the path from the radiation signal source to speaker A, d2 is the path from the radiation signal source to speaker B, c1 is the path from speaker A to the vector network, and c2 is the path from speaker B to the vector network. When measuring, the path difference between the two branches is: (d1+c1)-(d2+c2); After rotating 180°, the path difference between the two branches is: (d1+c2)-(d2+c1); The two measurements are averaged to obtain: (((d1+c1)-(d2+c2))+((d1+c2)-(d2+c1))) / 2=d1-d2 This can eliminate the amplitude and phase errors caused by inconsistencies in the receiving chain.

2. The method for high-precision measurement of target angular position of imported aviation equipment according to claim 1 is characterized by: The physical measurement is composed of a physical measurement device, which includes a laser ranging system, an image acquisition system and a computer control and communication system. When performing physical measurement, the laser ranging system is used to measure the distance from the antenna to the center of the turntable, the image acquisition system is used to obtain the optical image of the antenna and convert it into an electronic image, and the computer control and communication system is used to control the steering positioning of the turntable, receive the electronic image generated by the image acquisition system and display it on the screen.

3. The method for high-precision measurement of target angular position of imported aviation equipment according to claim 2 is characterized by: The laser distance measurement system comprises a laser distance meter, a laser distance meter fixture and a laser distance meter trigger device. In order to accurately position the installed antenna, the laser distance meter is accurately installed on the three-axis center of the three-axis turntable using the laser distance meter fixture, so that the optical axis of the laser coincides with the axis of the inner frame of the turntable, and the position indicated by the laser is the position directly facing the axis of the turntable; the device makes the installation position and spacing of the geometric center of each antenna surface meet the design accuracy requirements, thereby reducing the difference between the amplitude and phase characteristics of each radiation signal of the radiation interface of each antenna unit, and facilitating the fine adjustment of the electrical characteristics.

4. The high-precision measurement method for the target angular position of imported aviation equipment according to claim 1 is characterized by: The electrical measurement includes a measurement receiving device, a measurement computer, a measurement control and power supply chassis, a local oscillator frequency synthesizer and a vector network analyzer. It adopts an intermediate frequency measurement method. A 2-18GHz signal source radiates a signal. After the signal radiated by the signal source passes through a two-power divider, one signal is transmitted to the turntable test receiving device via a trench cable as a reference signal, and the other signal is input into the precision position control and feeding link. Finally, the antenna radiates the signal, the air-fed signal and the line-fed signal are switched on by a switch and then down-converted by a mixer. After the frequency is converted to 50MHz, it is measured by a vector network analyzer.

5. The method for high-precision measurement of target angular position of imported aviation equipment according to claim 4 is characterized by: The measuring receiving device selects the air-fed signal and the line-fed signal, and selects different signals to realize different measuring functions. During the amplitude and phase test, the air-fed signal is compared with the line-fed reference signal, and the phase difference and amplitude ratio between each antenna and the reference signal are measured with the reference signal as a benchmark. The signal output by the measuring device enters the vector network analyzer for measurement. The vector network analyzer is connected to the measuring computer via Ethernet or GPIB bus and is controlled by the test software. During the test, the segment scanning method is used to measure the required frequency points. The measuring receiving device adopts the phase method to measure the angle of the target position, and uses the phase difference between the target signals received by the two antennas to measure the angle.

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