CN115189779A - Low-orbit satellite equipment testing method based on unmanned aerial vehicle and unmanned aerial vehicle - Google Patents
Low-orbit satellite equipment testing method based on unmanned aerial vehicle and unmanned aerial vehicle Download PDFInfo
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- CN115189779A CN115189779A CN202210770085.6A CN202210770085A CN115189779A CN 115189779 A CN115189779 A CN 115189779A CN 202210770085 A CN202210770085 A CN 202210770085A CN 115189779 A CN115189779 A CN 115189779A
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- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B17/00—Monitoring; Testing
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- H04B17/0085—Monitoring; Testing using service channels; using auxiliary channels using test signal generators
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- H04B7/00—Radio transmission systems, i.e. using radiation field
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Abstract
The application discloses a low orbit satellite equipment testing method based on an unmanned aerial vehicle and the unmanned aerial vehicle, wherein the method comprises the following steps: acquiring a first flight track of a low-orbit satellite; determining a second flight track of the unmanned aerial vehicle according to the first flight track; controlling the unmanned aerial vehicle to fly along the second flight trajectory; and in the process that the unmanned aerial vehicle flies along the second flight track, controlling a device to be tested to perform signal interaction with the unmanned aerial vehicle so as to test the device to be tested, wherein the unmanned aerial vehicle transmits signals to the device to be tested according to the signal transmission parameters of the low-orbit satellite. Through the method and the device, the problem that in the prior art, the LEO terminal is tested depending on the low testing efficiency caused by the LEO satellite is solved, and then the testing threshold is reduced and the testing efficiency is improved.
Description
Technical Field
The application relates to the field of low-orbit satellites, in particular to a low-orbit satellite equipment testing method based on an unmanned aerial vehicle and the unmanned aerial vehicle.
Background
Low Earth Orbit Satellite Communication (LEO Satcom for short) can provide network transmission service for terminals on the ground or in the air through a Satellite network consisting of a plurality of satellites operating at 500km to 1000 km.
Compared with the GEO Satcom (GEO Satcom) which runs over 20000km, the LEO Satcom has short path propagation distance and short time delay, and can provide network transmission service with lower delay. And the path propagation loss is lower, and the millimeter wave frequency band with richer spectrum resources can be selected to work, so that high-flux network transmission service is provided. Therefore, the new generation LEO Satcom has The characteristics of low delay and high throughput, and becomes The most core technology in The "air-space-ground integration" of The sixth generation mobile communication technology (6G for short).
Fig. 1 is a schematic diagram of the composition of the LEO Satcom system and the SOTM according to the related art, as shown in fig. 1, the LEO Satcom system includes: the system comprises a star link and/or star network formed by low earth orbit satellites, fixed terminals, mobile terminals (which can comprise air mobile terminals and ground mobile terminals) and a gateway station, wherein the fixed terminals and the mobile terminals can be collectively called terminals, low earth orbit satellite terminals or LEO terminals, and the gateway station can be connected with the Internet or an enterprise private network.
The LEO Satcom system relates to a satellite communication in motion technology, namely The Satcom On The Move (SOTM) keeps satellite communication in motion, and generally refers to a technology, a system and an application generated in satellite communication in order to meet The requirement of users On transmitting broadband information in a dynamic mobile scene through a satellite. The technology of the communication-in-motion is very critical in LEO Satcom because of the following two reasons: (1) relative mobility of LEO satellites and terminals: the LEO satellite runs on an asynchronous orbit and is always in a relative motion state relative to a fixed point on the ground; and the terminal of LEO Satcom service can be a fixed terminal or a mobile terminal, and the terminal is always in a relative motion state relative to the satellite. (2) LEO satellite adopts K wave band (18-27 GHz), ka wave band (27-40 GHz) and even Q/V wave band (30-75 GHz) millimeter wave band. In order to combat the high path propagation loss of high frequency signals, both communication parties tend to concentrate energy within a narrow beam range of less than 1 degree, and such a narrow beam communication system has a high requirement on precise alignment of beams at the transmitting and receiving ends.
Therefore, the most critical task in SOTM is to determine the relative angles (heading angle θ and pitch angle φ) of the LEO satellite and the terminal accurately in real time to ensure high quality network connection during movement. The module supporting the SOTM on the terminal is an Antenna control unit (Antenna control unit, abbreviated as ACU), the Antenna control unit is a hardware and software module for completing beam pointing and form control in the phased array, and it calculates the heading angle and pitch angle pointing of the current beam according to the ACU algorithm through the input satellite ephemeris data and sensing data (this step may be referred to as beam pointing decision), and finally sends to the phased array beam controller for execution (this step may be referred to as beam pointing control). The sensing data may include data obtained by GNSS and data obtained by IMU, where the english of GNSS is fully called Global Navigation Satellite System, and the corresponding chinese is Global Navigation Satellite System, which is a generic name of Satellite Navigation systems including beidou, GPS, galileo, and the like. The IMU is called an Inertial Measurement Unit in English, and the corresponding Chinese is an Inertial Measurement Unit which is a sensor for outputting three-axis acceleration, a three-axis gyroscope and three-axis orientation angles.
Because of the importance of the SOTM, many different types of test equipment have been used in the prior art to test various components of the SOTM, such as microwave darkrooms, compact range darkrooms, channel emulators, etc.; or a plurality of test platforms with different integrity degrees are set up to test the overall performance of the SOTM, such as a swing platform test platform, a vehicle-mounted/ship-mounted/airborne test platform and the like. These test means will be described below.
The microwave anechoic chamber is a special room formed by wave-absorbing materials and metal shields, can provide artificial Free-space propagation (Free-space propagation) conditions, and eliminates the influence of multipath propagation on the performance test of a Radio Frequency (RF) system. The anechoic chamber is capable of testing beam pointing control software and hardware of phased arrays in the SOTM, for example, testing the error between the desired beam pointing angle and the actual beam pointing angle. The compact range darkroom is an advanced microwave darkroom, and can convert a spherical electromagnetic field into a planar electromagnetic field by utilizing a specially designed metal reflecting surface to realize far-field parallel wave conditions in a darkroom with a limited volume. The compact field darkroom is also the link of beam control software and hardware capable of measuring the phased array in the SOTM. It can be easily found that the microwave darkroom and the compact range darkroom have the disadvantages that only the accuracy problem of beam pointing control in the SOTM is considered, and the influence of the movement of the LEO satellite and the terminal on the beam pointing decision in the actual environment is not considered.
The channel simulator is a radio frequency instrument for simulating an air interface channel between a sending end and a receiving end, and can comprehensively simulate various parameters of the channel, such as propagation delay, path loss (for example, free space propagation loss, rain attenuation loss, ionospheric loss and the like), phase offset, doppler frequency and the like. The channel simulator can measure the problem that the RF device related to power in the transceiving system in the SOTM can satisfy the actual LEO channel, for example, verify the Signal to Interference plus Noise Ratio (SINR) of the SOTM transceiving system designed under a certain link budget model, and the like. It is easy to find that the channel simulator has the disadvantages that it can only simulate limited LEO channel parameters, it is difficult to simulate channel changes during motion, and it is not possible to test the performance of beam pointing decisions and control.
In order to test the performance of the beam pointing decision and control, a test platform for performing overall performance test on the SOTM may be adopted, including a swing platform test platform, a vehicle-mounted/ship-mounted/airborne test platform, and the like, wherein the actual vehicle-mounted/ship-mounted/airborne test platform is the test platform deployed completely according to the actual use environment of the SOTM user. The swing platform is a test platform for carrying out six-degree-of-freedom accurate rotation control on the platform through a hydraulic press, and is used for simulating the influence of the orientation change of an antenna on the overall performance of the SOTM under the actual test environment such as vehicle-mounted/ship-mounted/vehicle-mounted conditions and the like.
Compared with an actual platform, the swing platform does not depend on the resources of the carrier platform, and the test time after field deployment can be saved. However, the common disadvantage of the above-mentioned overall performance testing platform is that it requires the participation of all links of the whole satellite link, and if it requires the cooperation of actual multiple LEO satellites and a gateway station, it is a method with strong resource dependence. However, the transit time of the low-orbit satellite is short, the quantity of the low-orbit satellite is rare, for example, only about 10 satellites are actually operated in orbit at present, and all orbit resources are extremely rare. In addition, complete star chains and star networks are difficult to form by the current LEO satellites, and for a certain fixed area, the communication time of the satellite passing through the top every day is less than 30 minutes. Therefore, the limited test conditions of the ground antenna alignment (SOTM) technology developed for low earth orbit satellites can greatly affect the test efficiency of the LEO terminal in the SOTM system.
Disclosure of Invention
The embodiment of the application provides a low orbit satellite equipment testing method based on an unmanned aerial vehicle and the unmanned aerial vehicle, and aims to solve the problem that in the prior art, the LEO terminal is tested depending on a LEO satellite, so that the testing efficiency is low.
According to one aspect of the application, a low orbit satellite equipment testing method based on an unmanned aerial vehicle is provided, and comprises the following steps: acquiring a first flight track of a low-orbit satellite; determining a second flight track of the unmanned aerial vehicle according to the first flight track; controlling the unmanned aerial vehicle to fly along the second flight trajectory; and in the process that the unmanned aerial vehicle flies along the second flying track, controlling a device to be tested to perform signal interaction with the unmanned aerial vehicle so as to test the device to be tested, wherein the unmanned aerial vehicle transmits signals to the device to be tested according to the signal transmission parameters of the low-orbit satellite.
According to another aspect of the application, still provide a unmanned aerial vehicle, include: the control part is used for controlling the unmanned aerial vehicle to fly along a second flight track determined according to a first flight track, wherein the first flight track is a flight track of a low orbit satellite acquired in advance; the communication part is used for carrying out signal interaction with the equipment to be tested, and the communication part transmits signals to the equipment to be tested according to the signal transmission parameters of the low-orbit satellite.
In the embodiment of the application, the method comprises the steps of acquiring a first flight track of a low-orbit satellite; determining a second flight track of the unmanned aerial vehicle according to the first flight track; controlling the unmanned aerial vehicle to fly along the second flight trajectory; and in the process that the unmanned aerial vehicle flies along the second flight track, controlling a device to be tested to perform signal interaction with the unmanned aerial vehicle so as to test the device to be tested, wherein the unmanned aerial vehicle transmits signals to the device to be tested according to the signal transmission parameters of the low-orbit satellite. Through the method and the device, the problem that in the prior art, the LEO terminal is tested depending on a low testing efficiency caused by an LEO satellite is solved, so that the testing threshold is reduced, and the testing efficiency is improved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:
FIG. 1 is a schematic diagram of the composition of a LEO Satcom system and SOTM according to the related art;
FIG. 2 is a 2D design view of a retro reflector according to an embodiment of the present application;
fig. 3 is a 3D illustration view of a retro reflector according to an embodiment of the present application;
fig. 4 is a flowchart of a method for testing low earth orbit satellite equipment based on unmanned aerial vehicles according to an embodiment of the application;
fig. 5 is a schematic diagram of a satellite and drone flight trajectory migration according to an embodiment of the present application;
FIG. 6 is a schematic flow chart illustrating overall performance evaluation of a device under test according to an embodiment of the present application;
FIG. 7 is a schematic diagram of a test system architecture according to an embodiment of the present application;
FIG. 8 is a schematic diagram of an open-loop evaluation algorithm according to an embodiment of the present application; and (c) a second step of,
FIG. 9 is a schematic diagram of a closed-loop evaluation algorithm according to an embodiment of the present application.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer-executable instructions and that, although a logical order is illustrated in the flowcharts, in some cases, the steps illustrated or described may be performed in an order different than presented herein.
In the prior art, the SOTM needs to be matched with low-orbit satellites for testing, however, the number of the low-orbit satellites is small at present, so that the available low-orbit satellites have fewer testing resources, and the testing efficiency is low. In order to improve the testing efficiency, in the following embodiment, the unmanned aerial vehicle is adopted to replace a low-orbit satellite for testing, namely, the function after the low-orbit bent pipe satellite is cut is realized on the unmanned aerial vehicle, so that the testing can be carried out at any time according to the requirement. The Bent-pipe satellite (Bent-pipe satellite) refers to a satellite system which only completes transparent forwarding and does not perform on-satellite processing, and is opposite to a normal low-orbit satellite.
In this embodiment, a drone is used instead of a satellite, and therefore, the flight trajectory of the drone needs to be determined with reference to the flight trajectory of a low-orbit satellite. The present embodiment provides an unmanned aerial vehicle including a control unit and a communication unit. The following explains two parts included in the drone in this embodiment.
The control part is used for controlling the unmanned aerial vehicle to fly along a second flight track determined according to a first flight track, wherein the first flight track is a flight track of a low orbit satellite acquired in advance;
and the communication part is used for carrying out signal interaction with the equipment to be tested, wherein the communication part transmits signals to the equipment to be tested according to the signal transmission parameters of the low-orbit satellite.
The unmanned aerial vehicle uses a communication part capable of performing signal interaction with a device to be tested, and the device to be tested can be a terminal of a low-orbit satellite system or other components of the low-orbit satellite system. The communication part can transmit signals to the equipment to be tested according to the signal transmission parameters of the low-orbit satellite, namely, the signal transmission function of the low-orbit satellite is simulated through the communication part. Above-mentioned unmanned aerial vehicle's control part is used for controlling unmanned aerial vehicle's flight orbit, and when unmanned aerial vehicle when flight on the second flight orbit with low orbit satellite when flight on first flight orbit, can use unmanned aerial vehicle to simulate low orbit satellite to the test of human-computer signal interaction can be carried out with unmanned aerial vehicle to the equipment that awaits measuring.
In an optional embodiment, for more accurate simulation of the low earth orbit satellite, the angular velocity and the trajectory aperture angle of the drone when flying along the second flight trajectory are the same as the angular velocity and the trajectory aperture angle of the low earth orbit satellite when flying along the first flight trajectory. In the optional embodiment, the angular velocity and the trajectory opening angle are the same, which means that the device to be tested, the unmanned aerial vehicle and the low-orbit satellite are on the same straight line, and for the device to be tested, the angle between the device to be tested and the unmanned aerial vehicle is the same as the angle between the device to be tested and the low-orbit satellite, so that the position of the low-orbit satellite can be accurately simulated by the unmanned aerial vehicle, and therefore, the device to be tested can perform a signal interaction test with the unmanned aerial vehicle to replace the test between the device to be tested and the low-orbit satellite. The unmanned aerial vehicle is used for testing, the unmanned aerial vehicle can be released at any time according to needs, and the resources of low orbit satellites do not need to be waited, so that the testing efficiency can be improved.
The communication unit may be implemented in various ways as long as the communication unit can communicate with the device under test in accordance with the communication method of the low-earth-orbit satellite. For example, the communication unit may be implemented by using a Phased array (Phased array), which refers to an antenna array technique for changing the beam directivity and shape by adjusting parameters such as the phase and amplitude of a multi-antenna signal. Although the phased array can realize the functions of the communication unit, the phased array also has problems, and the main problems are that the cost is high, the volume of the phased array is large, and the flight load of the unmanned aerial vehicle needs to be increased when the phased array is used on the unmanned aerial vehicle. In view of the above-mentioned problems of the phased array, in an alternative embodiment, a retro reflector may be selected to implement the functions of the communication section described above.
The reflector is a device capable of reflecting incident electromagnetic waves to the direction of an emission source, and a signal from a device to be tested can be transmitted back to the device to be tested through the reflector. In this alternative embodiment, frequency-convertible retro-reflectors are used, which are also referred to as iso-frequency retro-reflectors or tunable iso-frequency retro-reflectors.
Next, a retrospective reflector included in the communication unit in the present alternative embodiment will be described. The retro-reflector is used for carrying out frequency conversion on a received uplink radio frequency signal (or uplink signal for short) according to the frequency of a downlink radio frequency signal (or downlink signal for short) of the low-orbit satellite, wherein the uplink radio frequency signal is from the device to be tested; the backtracking reflector is further configured to obtain a downlink radio frequency signal to be transmitted according to the uplink radio frequency signal after frequency conversion, and transmit the downlink radio frequency signal to be transmitted along an incident direction of the uplink radio frequency signal, where a frequency of the downlink radio frequency signal to be transmitted is the same as a frequency of the downlink radio frequency signal transmitted by the low-earth-orbit satellite.
The backtracking reflector obtains a downlink radio frequency signal to be transmitted by performing frequency conversion processing on the uplink radio frequency signal, wherein the frequency of the downlink radio frequency signal is the same as the frequency of the downlink radio frequency signal generated by the low-earth orbit satellite. For example, the device under test transmits the uplink RF signal using Ka-band, and the downlink RF signal using K-band, and then the frequency of the Ka-band uplink RF signal needs to be converted into K-A frequency of band; wherein, the center frequency f of Ka-band 1 A center frequency f of 28.75GHz, K-band 2 At 18.95GHz, a frequency conversion processing capacity of about 10GHz is required. Thus, for the test purpose, the device to be tested receives the downlink radio frequency signal from the retro reflector of the unmanned aerial vehicle and the downlink signal from the low orbit satellite without substantial frequency difference, so that the test purpose can be obtained.
In another preferred embodiment, the power of the downlink rf signal is compensated in the retro reflector in consideration of the gain and attenuation in signal transmission, and the compensation is to make the power of the downlink rf signal closer to the power of the downlink rf signal transmitted by the real low-earth satellite, so that the power compensation can be performed according to the link budget of the low-earth satellite obtained in advance. The link budget of the low-orbit satellite is used for indicating the total gain and attenuation of the signal of the low-orbit satellite in signal transmission, so that the power compensation can be carried out according to the link budget of the low-orbit satellite and the gain and attenuation of the signal transmitted after the unmanned aerial vehicle is used.
The power compensation function can also be realized by a retrospective reflector, that is, the retrospective reflector is configured to perform power compensation on the frequency-converted uplink radio-frequency signal according to the link budget of the low-earth orbit satellite, and use the uplink radio-frequency signal, which is subjected to power compensation and frequency conversion, as the downlink radio-frequency signal to be transmitted; and the power of the downlink radio frequency signal obtained after power compensation is the same as the power of the downlink radio frequency signal generated by the low-earth orbit satellite.
After the retrospective reflector sends the downlink radio-frequency signal after the power compensation, the device to be tested receives the downlink radio-frequency signal, so that the power processing of the device to be tested can be tested.
The retrospective reflector may be of various structures, whichever structure may be as long as the above-described function is realized. In view of the characteristics of the low-earth orbit satellite, in an alternative embodiment, a retrospective reflector is provided that includes a plurality of sets of transceiving antennas, wherein each set of transceiving antenna in the plurality of sets of transceiving antennas includes a receiving antenna for receiving an uplink radio frequency signal of a first frequency band and a transmitting antenna for transmitting a downlink radio frequency signal of a second frequency band; the first frequency band is a frequency band of the low earth orbit satellite for receiving uplink radio frequency signals, and the second frequency band is a frequency band of the low earth orbit satellite for transmitting downlink radio frequency signals.
Under the condition that the retrospective reflector adopts the receiving and transmitting antenna, the power of the downlink radio-frequency signal can be adjusted according to the relevant gain of the receiving and transmitting antenna. The following description will be made with the device under test as a terminal.
When the actual low-earth orbit satellite is used for the SOTM overall performance test, the link budget is a downlink unidirectional link (the downlink unidirectional link is used for transmitting downlink radio frequency signals): the method comprises the following steps of satellite K-band downlink signal transmitting power, satellite K-band transmitting phased array gain, satellite downlink path attenuation, terminal K-band receiving phased array gain and terminal K-band receiving power compensation.
In this embodiment, retrospective reflection is used, and therefore, the power in the uplink and downlink bidirectional retrospective reflection is considered: the method comprises the steps of terminal Ka-band uplink signal sending power, terminal Ka-band sending phased array gain, unmanned aerial vehicle uplink path attenuation, unmanned aerial vehicle pilot frequency retrospective reflection Ka-band receiving array gain, unmanned aerial vehicle pilot frequency retrospective reflection power compensation, unmanned aerial vehicle pilot frequency retrospective reflection Ka-band to K-band variable frequency insertion loss, unmanned aerial vehicle pilot frequency retrospective reflection K-band sending array gain, unmanned aerial vehicle downlink path attenuation, terminal K-band receiving phased array gain and terminal K-band receiving power compensation.
In order to ensure the consistency of the received power and the frequency of the budget of the two links, the inter-frequency retroactive reflector needs to be subjected to power compensation and frequency offset, and the calculation formula is as follows:
unmanned aerial vehicle pilot frequency backtracking reflected power compensation delta P = (satellite K-band downlink signal transmitting power + satellite K-band transmitting phased array gain + satellite downlink path attenuation) - (terminal Ka-band uplink signal transmitting power + terminal Ka-band transmitting phased array gain + unmanned aerial vehicle uplink path attenuation + unmanned aerial vehicle pilot frequency backtracking reflection Ka-band receiving array gain + unmanned aerial vehicle pilot frequency backtracking reflection Ka-band to K-band variable frequency insertion loss + unmanned aerial vehicle pilot frequency backtracking reflection K-band transmitting array gain + unmanned aerial vehicle downlink path attenuation).
Pilot frequency retrospective reflection frequency offset delta f = f of unmanned aerial vehicle 2 -f 1 ≈10GHz。
The traceback transmitter is relatively simple in structure by means of the antenna group receiving and transmitting, and can receive uplink radio frequency signals and transmit downlink radio frequency signals.
In this optional embodiment, a better layout is provided, in which the multiple groups of transceiving antennas are distributed on multiple concentric rings, wherein each concentric ring is distributed with the same number of groups of transceiving antennas, and each group of transceiving antennas is connected with each other through an arc rf line. This arrangement can support three-dimensional retrospective reflection, as will be described below with reference to fig. 2 and 3.
Fig. 2 is a 2D design view of a retro reflector according to an embodiment of the present application, and as shown in fig. 2, a two-dimensional loop antenna array is arranged to support three-dimensional retroactive, and in fig. 2, the transceiver antennas are connected by an arc radio frequency line, and antenna expansion is performed in a multi-loop nesting manner. Multiple sets of transmit-receive antennas can be arranged on the same ring. Under this design condition, a feasible two-dimensional array layout is shown in fig. 2, which includes 8 loops, each loop having 2 groups of antennas, and 16 groups of antennas. In fig. 2, the frequencies of the receiving antenna and the transmitting antenna are different, and therefore, the sizes of the patch antennas are also different; for example, ka-band differs from K-band by 10GHz frequency, and patch antennas of different sizes are designed in FIG. 2. Fig. 3 is a 3D illustration view of a retro-reflector according to an embodiment of the present application, and in fig. 3, an example of the reflection of the different-frequency retro-reflection from Ka-band to K-band is taken as an illustration, and as shown in fig. 3, a frequency converter needs to be integrated between a receiving Ka-band antenna and a transmitting K-band antenna, so as to implement a frequency conversion of 10 GHz.
Let λ denote the wavelength (λ) 1 And λ 2 Respectively representing Ka-band and K-band wavelengths), and epsilon r The relative dielectric constant is shown, W is an integer multiple, and the length difference of the transmission line needs to be reflected from the same frequency backtracking due to the different frequency backtracking reflection
Become into
The pilot frequency reflection direction of the signal with the incident angle of (theta, phi) is ensured to be (-theta, -phi), so that the backtracking effect is achieved, wherein theta is a heading angle, and phi is a pitch angle.
The unmanned aerial vehicle can be an unmanned aerial vehicle of various models, for example, a commercial suspense unmanned aerial vehicle can be used as an optional unmanned aerial vehicle by configuring a backtracking reflector, and no matter the model and the structure of the unmanned aerial vehicle, the unmanned aerial vehicle can be used for STOM test as long as the functions of the control part and the communication part can be realized. The following describes a method for testing by using the drone in the above embodiments and implementations.
Fig. 4 is a flowchart of a method for testing low-orbit satellite equipment based on an unmanned aerial vehicle according to an embodiment of the present application, and as shown in fig. 4, in this embodiment, a method for testing low-orbit satellite equipment based on an unmanned aerial vehicle is provided, and the method includes the following steps:
step S402, acquiring a first flight track of a low-orbit satellite;
step S404, determining a second flight track of the unmanned aerial vehicle according to the first flight track;
step S406, controlling the unmanned aerial vehicle to fly along the second flight trajectory;
step S408, in the process that the unmanned aerial vehicle flies along the second flight track, controlling a device to be tested to perform signal interaction with the unmanned aerial vehicle so as to test the device to be tested, wherein the unmanned aerial vehicle transmits signals to the device to be tested according to the signal transmission parameters of the low-orbit satellite.
In the above steps, the unmanned aerial vehicle can transmit signals to the device to be tested according to the signal transmission parameters of the low-orbit satellite, i.e. the signal transmission function of the low-orbit satellite is simulated through the communication part; therefore, the unmanned aerial vehicle can be used for simulating the low orbit satellite through the steps, so that the equipment to be tested can be used for testing man-machine signal interaction with the unmanned aerial vehicle.
In an optional embodiment, for more accurate simulation of the low earth orbit satellite, the angular velocity and the trajectory aperture angle of the drone when flying along the second flight trajectory are the same as the angular velocity and the trajectory aperture angle of the low earth orbit satellite when flying along the first flight trajectory. In the optional embodiment, the angular velocity and the trajectory field angle are the same, which means that the device to be tested, the unmanned aerial vehicle and the low-orbit satellite are on the same straight line, and for the device to be tested, the angle between the device to be tested and the unmanned aerial vehicle is the same as the angle between the device to be tested and the low-orbit satellite, so that the position of the low-orbit satellite can be accurately simulated by the unmanned aerial vehicle, and therefore, the device to be tested can perform a signal interaction test with the unmanned aerial vehicle to replace the test between the device to be tested and the low-orbit satellite; and use unmanned aerial vehicle to test and can fly off unmanned aerial vehicle as required at any time, need not wait for the resource of low orbit satellite to can improve efficiency of software testing.
There are many ways to calculate the second flight trajectory of the drone, and in an alternative, the flight height of the drone may be determined according to the linear flight speed of the drone, and then the start point and the end point of the second flight trajectory may be determined according to the flight height. The following describes the determination of the second flight trajectory of the drone.
In this alternative embodiment, a first linear velocity of flight v for the low earth orbit satellite is obtained 1 First flying height h 1 And a second linear flight velocity v of the drone 2 Wherein the first flight path is from a first starting point p 1 To a second end point q 1 And maintaining a constant trajectory for the first flying height; calculating a second flying height h of the second flying track according to the following formula 2 ：h 2 ＝(v 2 /v 1 )·h 1 (ii) a Calculating the starting point p of the second flight path according to the following formula 2 ：p 2 ＝(v 2 /v 1 )·(p 1 -p) + p; wherein, p is the starting point of the movement of the device to be tested in the test process; calculating the end point q of the second flight path according to the following formula 2 ：q 2 ＝(v 2 /v 1 )·(q 1 -q) + q; wherein q is the terminal point of the movement of the device to be tested in the test process; and obtaining the second flight track according to the starting point, the end point and the second flight height of the second flight track.
With the above embodiment, the flight trajectory of the drone is indistinguishable from the flight trajectory of the satellites, except for the height, from the point of view of the device to be tested, and therefore in this alternative it amounts to "migrating" the flight trajectory of the low-orbit satellites onto the flight trajectory of the drone. Fig. 5 is a schematic diagram of the migration of flight trajectories of a satellite and a drone according to an embodiment of the present application, and fig. 5 shows the migration relationship of the flight trajectories of the satellite and the drone, where the core of the migration relationship is that the flight angular velocity ω of the satellite and the drone is consistent with the trajectory opening angle Ω, because the core of the entire SOTM system is the angle-dependent beam pointing decision. In fig. 5, the satellite flight path starting point p is assumed 1 And end point q 1 Height h of track 1 Linear velocity v of flight 1 And the flight linear velocity v of the unmanned aerial vehicle 2 The starting point p of the terminal is known, and other parameters such as the flight angular velocity omega and the track height h of the unmanned aerial vehicle 2 Starting point p of track 2 And end point q 2 The calculation is as follows:
after the second flight trajectory is obtained, the unmanned aerial vehicle can be controlled to take off at any time according to the second flight trajectory for testing when the testing is needed. In another optional manner, after the unmanned aerial vehicle finishes flying along the second flight trajectory, the overall performance of the device to be tested may also be evaluated, fig. 6 is a schematic flow diagram for evaluating the overall performance of the device to be tested according to an embodiment of the present application, and it is described in fig. 6 that the device to be tested is an LEO terminal, as shown in fig. 6, the flight trajectory of the unmanned aerial vehicle is obtained when the system is initialized, then the unmanned aerial vehicle is controlled to fly according to the second flight trajectory, the LEO terminal tracks the unmanned aerial vehicle according to the STOM during flying, and after the trajectory is completed, the overall performance of the LEO terminal may be evaluated.
When the overall performance is evaluated, the power of the device to be tested can be mainly evaluated, for example, the power of the device to be tested receiving the downlink radio frequency signal in the flight process of the unmanned aerial vehicle can be generated into an actual measurement power curve, and the power of the device to be tested is evaluated according to the actual measurement power curve. Or in another alternative embodiment, a way of comparing the measured power curve with the expected power curve is also provided to evaluate the power of the device under test, and this way may also be called closed loop evaluation because of the comparison with the expected power curve.
In the closed-loop evaluation mode, acquiring an expected power curve of the device to be tested; acquiring an actual measurement power curve measured by the device to be tested in the signal interaction process with the unmanned aerial vehicle; and evaluating the power of the device to be tested according to the expected power curve and the measured power curve.
In order to more clearly show the difference between the measured power curve and the expected power curve, the expected power curve and the measured power curve may be further subtracted to obtain a power residual curve, in which case, there are two curves: the measured power curve, the power residual error curve, and the measured power curve can be segmented to obtain a segmented measured power curve, and the power residual error curve can be segmented to obtain a segmented power residual error curve, so that the powers of different time periods can be evaluated; in this case four curves are obtained, from at least one of which an evaluation parameter can be obtained, and the power of the device under test is then evaluated on the basis of the evaluation parameter.
For example, the evaluation parameter may include at least one of: a variance of the measured power curve, a variance of the segmented measured power curve, a variance of the power residual curve, an absolute mean of the power residual curve, a mean of a square of the power residual curve, a maximum of the power residual curve, an absolute mean of the segmented power residual curve, a mean of a square of the segmented power residual curve, a variance of the segmented power residual curve.
The evaluation scheme provided by the embodiment can consider both the fluctuation of the actually measured power curve and various statistical values of the power residual curve, and more evaluation dimensions can better guide the improvement of the SOTM system.
In the above embodiment, the unmanned aerial vehicle may be used to test the device to be tested, the unmanned aerial vehicle device may be a commercial quad-rotor unmanned aerial vehicle equipped with a pilot frequency retro-reflector, and the reason for using the commercial unmanned aerial vehicle is that the commercial unmanned aerial vehicle can provide a high-precision positioning set based on Real-Time Kinematic positioning (RTK for short), and the RIK refers to a technique for performing high-precision positioning by using a GNSS reference base station and a carrier positioning method, which is different from a common GNSS positioning technique without a reference base station and pseudo-range positioning, thereby providing a relatively high precision. Consequently, use the unmanned aerial vehicle who substitutes RTK function to be favorable to improving the accuracy according to flight path flight. The above embodiments can be used to test various types of devices to be tested, for example, LEO terminals, and an alternative embodiment is described below by taking a commercial quad-rotor drone as an example for testing LEO terminals.
In order to improve the test efficiency of the SOTM, the optional embodiment provides a low-orbit satellite communication-in-motion test system based on pilot frequency retroflection of an unmanned aerial vehicle, the core of the system is to realize the function of an LEO Bent pipe satellite after being cut on a commercial quad-rotor unmanned aerial vehicle, and a low-dependency, low-cost and high-efficiency SOTM overall performance test system is built, wherein a Bent pipe satellite (Bent-pipe satellite) refers to a satellite system which only completes transparent forwarding and does not perform on-satellite processing and is opposite to an on-satellite processing satellite.
In this optional embodiment, a test system architecture design, a satellite and drone link budget migration model, a pilot frequency retro-reflector design, an SOTM overall performance evaluation algorithm, and the like are involved, fig. 7 is a schematic diagram of a test system architecture according to an embodiment of the present application, and the following describes the test system in this optional embodiment with reference to fig. 7.
As shown in fig. 7, the test system includes a SOTM LEO terminal including a transmitting end (TX) front and a receiving end (RX) front for transmitting and receiving Radio Frequency (RF) signals, respectively. In the SOTM LEO terminal, a baseband (BB) signal is modulated into an Intermediate Frequency (IF) signal, up-converted into a Ka-band RF signal, and transmitted by a TX phased array of Ka-band. And the Ka-band TX RF signal reaches a pilot frequency retroflector on the unmanned aerial vehicle through an air interface, and is converted into a K-band RX RF signal through power compensation and frequency offset. Due to the retro-reflective design, the RX RF signal will be transmitted in the opposite direction of the TX RF signal incidence. And an RX phased array of the SOTM LEO terminal receives the K-band RF signal, demodulates the K-band RF signal into an IF signal through down-conversion, and divides the IF signal into two paths of IF signals through a radio frequency splitter to respectively reach a baseband and a detection beacon machine. An in-Antenna Control Unit (ACU) is also configured in the terminal, and the ACU is used for controlling the TX front and the RX front. Keeping the information flow of the prior SOTM terminal consistent in the operation process, namely outputting power information to an ACU (adaptive beamforming Unit) after a detection beacon receives an RX IF (received signal), calculating a beam pointing decision (namely an SOTM core part) by the ACU according to satellite position information, self-positioning information, IF signal power and the like, and finally sending the beam pointing decision to a TX and RX phased array for beam pointing control.
The unmanned aerial vehicle comprises an RTK high-precision positioning module, a main control unit (namely a main control part) and a pilot frequency retrospective reflector (namely a communication part), and the parts are explained respectively below. The RTK precision positioning module is used for positioning and providing positioning information. The main control unit is used for controlling according to the acquired flight parameters and the radio frequency parameters of the downlink radio frequency signals. The pilot frequency retrospective reflector comprises a pilot frequency retrospective reflecting antenna, an adjustable compensator and an adjustable frequency converter, wherein the adjustable compensator is used for power compensation, and the adjustable frequency converter is used for frequency conversion of radio-frequency signals.
In this alternative embodiment, a Ka-band to K-band tunable inter-frequency retro-reflector is used. The retro reflector in this optional embodiment supports three-dimensional retro reflection, and it adopts a two-dimensional loop antenna array arrangement as shown in fig. 2 to support three-dimensional retro, and the transceiver antennas are connected by an arc radio frequency line, and antenna expansion is performed in a multi-loop nesting manner. Multiple sets of transmit-receive antennas can be arranged on the same ring. Under this design condition, a feasible two-dimensional array layout is shown in fig. 2, which includes 8 loops, and 2 groups of antennas for each loop, and 18 groups of antennas.
Supporting the different-frequency retroflection from Ka-band to K-band: ka-band differs from K-band by 10GHz frequency, so patch antennas of different sizes can be designed, as shown in fig. 2. A frequency converter needs to be integrated between the received Ka-band antenna and the transmitted K-band antenna, and frequency conversion of 10GHz is achieved. Let λ denote the wavelength (λ) 1 And λ 2 Respectively representing Ka-band and K-band wavelengths), epsilon r The relative dielectric constant is shown, W is an integer multiple, and the length difference of the transmission line needs to be reflected from the same frequency backtracking due to the different frequency backtracking reflection
Become into
To ensure that the inter-frequency reflection direction of the signal with the incident angle (theta, phi) is (-theta, -phi), thereby achieving the backtracking effect, and fig. 3 shows the backtracking reflection effect of the signal in the three-dimensional space.
In fig. 7, two calculation models are also designed, which are a satellite and drone link budget migration model and a SOTM overall performance evaluation algorithm, respectively. The satellite and unmanned aerial vehicle link budget migration model is used for calculating the flight trajectory and the radio frequency signal parameters of the unmanned aerial vehicle according to the trajectory of the low-orbit satellite and the parameters of the radio frequency signal, and therefore the model is called as the satellite and unmanned aerial vehicle link budget migration model. And the satellite and unmanned aerial vehicle link budget migration model calculates flight parameters and retrospective reflector radio frequency parameters according to the LEO terminal and unmanned aerial vehicle position information, and sends the flight parameters and the retrospective reflector radio frequency parameters to a main control unit on the unmanned aerial vehicle to control adjustable parameters for carrying out the pilot frequency retrospective reflector.
Therefore, the satellite and unmanned aerial vehicle link budget migration model migrates the satellite link budget as a simulated object into the unmanned aerial vehicle link budget as a system controllable object, and the following three functions are mainly realized: the method comprises the steps of (i) adjusting parameters such as flight path, height and speed of the unmanned aerial vehicle, (ii) adjusting parameters such as power compensation and frequency offset of a pilot frequency retroactive reflector, and (iii) generating an expected power curve. These three functions are explained below.
(i) And adjusting parameters such as flight path, height and speed of the unmanned aerial vehicle.
Fig. 5 shows the migration relationship of the flight parameters of the satellite and the drone, wherein the core of the migration relationship is that the flight angular velocity ω of the satellite and the drone is consistent with the trajectory opening angle Ω, because the core of the whole SOTM system is the angle-dependent beam pointing decision. Model hypothesis satellite flight path starting point p 1 And end point q 1 High track h 1 Linear velocity v of flight 1 And the linear velocity v of the unmanned aerial vehicle 2 The starting position p and the ending position q of the terminal are known, and other parameters such as the flight angular velocity omega and the track height h of the unmanned aerial vehicle 2 Starting point p of track 2 And end point q 2 The calculation is as follows:
(ii) And adjusting the power compensation and frequency offset parameters of the pilot frequency retrospective reflector.
When the actual satellite is used for the SOTM overall performance test, the link budget is a downlink unidirectional link: the method comprises the steps of satellite K-band downlink signal transmitting power, satellite K-band transmitting phased array gain, satellite downlink path attenuation, terminal K-band receiving phased array gain and terminal K-band receiving power compensation.
The test system in this optional embodiment is an uplink and downlink bidirectional backtracking reflection: terminal Ka-band uplink signal transmitting power + terminal Ka-band transmitting phased array gain + unmanned aerial vehicle uplink path attenuation + unmanned aerial vehicle pilot frequency backtracking reflection Ka-band receiving array gain + unmanned aerial vehicle pilot frequency backtracking reflection power compensation + unmanned aerial vehicle pilot frequency backtracking reflection Ka-band to K-band variable frequency insertion loss + unmanned aerial vehicle pilot frequency backtracking reflection K-band transmitting array gain + unmanned aerial vehicle downlink path attenuation + terminal K-band receiving phased array gain + terminal K-band receiving power compensation.
Therefore, in order to ensure the consistency between the received power and the frequency of the link budgets of the two antennas, the inter-frequency retro reflector needs to be power compensated and frequency offset, and the calculation formula is as follows:
unmanned aerial vehicle different-frequency backtracking reflection power compensation delta P = (satellite K-band downlink signal transmission power + satellite K-band transmission phased array gain + satellite downlink path attenuation) - (terminal Ka-band uplink signal transmission power + terminal Ka-band transmission phased array gain + unmanned aerial vehicle uplink path attenuation + unmanned aerial vehicle different-frequency backtracking reflection Ka-band receiving array gain + unmanned aerial vehicle different-frequency backtracking reflection Ka-band to K-band variable frequency insertion loss + unmanned aerial vehicle different-frequency backtracking reflection K-band transmission array gain + unmanned aerial vehicle downlink path attenuation). Meanwhile, the pilot frequency backtracking reflection frequency deviation delta f = f of the adjustable unmanned aerial vehicle 2 -f 1 ≈10GHz。
After the power compensation delta P is obtained, an adjustable power compensator is integrated between the receiving wavefront and the reflecting wavefront of the backtracking reflecting wavefront, and dynamic power compensation is carried out according to the value of the delta P under different experimental environments.
(iii) Expected power curve generation: and substituting the time sequence of the actual position of the terminal and the time sequence of the actual position of the unmanned aerial vehicle in the test process of the test system into the budget model of the uplink and downlink bidirectional backtracking reflection link to obtain the time sequence of the power of the received signal of the detection beacon machine, namely an expected power curve, which can be used as an evaluation reference value of the SOTM overall performance evaluation algorithm.
The SOTM overall performance evaluation algorithm evaluates the power of the radio frequency signal received by the LEO terminal as a whole after the unmanned aerial vehicle has finished flying according to the flight trajectory, and therefore, the algorithm is called the SOTM overall performance evaluation algorithm. And calculating an expected power curve by the satellite and unmanned aerial vehicle link budget migration model according to the LEO terminal and unmanned aerial vehicle position information, and sending the expected power curve to an SOTM overall performance evaluation algorithm, wherein the SOTM overall performance evaluation algorithm compares the expected power curve with an ACU output measurement power curve to obtain a final overall performance test result.
With reference to the process shown in fig. 6, the unmanned aerial vehicle and the LEO terminal are initialized under the guidance of a satellite and unmanned aerial vehicle link budget migration model, and the model calculates the flight parameters of the unmanned aerial vehicle and the radio frequency parameters of the backtracking reflector according to the position information of the LEO terminal and the unmanned aerial vehicle. Then, the drone starts flying along a predetermined trajectory while the LEO terminal starts SOTM tracking for initial star aiming and continuous star pursuit. When the track is not completed, the unmanned aerial vehicle flies, and the LEO terminal continuously tracks until the track is completed. Finally, the system judges the overall performance of the SOTM LEO terminal according to the expected power curve and the measured power curve.
Fig. 9 is a schematic diagram of a closed-loop evaluation algorithm according to an embodiment of the present application, and in fig. 9, for the SOTM overall performance evaluation algorithm, a closed-loop evaluation manner is adopted, an expected power curve obtained from a link budget migration model of a satellite and a drone is introduced, and a power residual curve is obtained by subtracting a measured power curve obtained from a detection beacon of an LEO terminal. Fig. 8 is a schematic diagram of an open-loop estimation algorithm according to an embodiment of the present application, and fig. 8 is a diagram of an open-loop estimation algorithm without introducing an expected power curve, as compared with fig. 9, which lacks parameters related to a satellite in a satellite link budget (such as transmit-receive power, transmit-receive phased array gain, and the like) and cannot directly obtain the expected power curve, and only can estimate the fluctuation of a measured power curve. The evaluation algorithm provided by the optional embodiment can consider both the fluctuation of the actually measured power curve and various statistical values of the power residual error curve, and more evaluation dimensions can better guide the improvement of the SOTM system.
As shown in FIG. 9, the measured power curve is recorded as x 1 (t) expected power curve x 2 (t) (where t is the time index of the time series), then the open-loop evaluation algorithm can only evaluate x 1 (t) each statistical parameter is evaluated, and the closed-loop evaluation algorithm provided by the embodiment can evaluate x 1 (t) and power residual curve y (t) = | x 1 (t)-x 2 And (t) evaluating all the statistical parameters of the (t) |. As an optional implementation mode, sectional statistical parameters can be introduced, and performance of each stage in the SOTM satellite pursuit process can be better balanced. Specific parameters are shown in table 1.
TABLE 1
| Evaluating parameters | Calculation method |
| Variance of measured power curve | std(x 1 (t)) |
| Variance of piecewise measured power curve | std(x 1 (t)),t∈T i ,T＝T 1 +T 2 +…+T i +… |
| Power residual curve variance | std(y(t) |
| Absolute average power residual | mean(y(t)) |
| Mean square power residual | mean(y 2 (t)) |
| Maximum power residual curve | max(y(t)) |
| Variance of piecewise power residual curve | std(y(t,t∈T i ,T＝T 1 +T 2 +…+T i +… |
| Segmented absolute average power residual | mean(y(t,t∈T i ,T＝T 1 +T 2 +…+T i +… |
| Segmented mean square power residual | mean(y 2 t,t∈T i ,T＝T 1 +T 2 +…+T i +… |
| Variance of piecewise power residual curve | std(y(t,t∈T i ,T＝T 1 +T 2 +…+T i +… |
In this optional embodiment, the low-cost commercial quad-rotor unmanned aerial vehicle that can run uninterruptedly is used to simulate the LEO satellite that has high cost and rare overtop time, and the test efficiency is improved while the test cost is reduced. And this optional embodiment uses retrospective reflector control down beam direction, and not use the phased array that the cost is high, bulky to carry out beam control, can further reduce system cost and can be applicable to that commercial four rotor unmanned aerial vehicle loads.
The optional embodiment is compatible with the SOTM LEO terminal, and only the position information and the power measurement information need to be respectively derived from the ACU and the detection beacon machine of the terminal, and the hardware of the terminal does not need to be modified. Moreover, the optional embodiment is compatible with the current high-flux LEO Satcom system, and can receive Ka-band uplink satellite signals (central frequency f) 1 28.75 GHz), transmit a downlink satellite signal of K-band (center frequency f) 2 18.95 GHz) and performs dynamic power compensation according to the satellite and drone link budget migration model. In addition, the optional embodiment can be compatible with networking forms such as star chains and star networks, and can be expanded to the use of unmanned aerial vehicle clusters for star chain and star network simulation.
In conclusion, this optional embodiment replaces real satellite system with commercial four rotor unmanned aerial vehicle, need not coordinate LEO satellite orbit and gateway station resource. In order to reduce the cost, the alternative embodiment does not use a high-cost phased array on the drone, but uses a retro reflector to perform echo direction control. In order to improve the test efficiency, the scheme does not need to wait for the satellite to cross the top, can continuously and repeatedly run, and improves the SOTM overall performance test efficiency.
In this embodiment, an electronic device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor being configured to execute the computer program to perform the method in the above embodiments, for example, for performing the method involved in the satellite and drone link budget migration model, and/or the SOTM overall performance evaluation algorithm.
The programs described above may be run on a processor or may also be stored in memory (or referred to as computer-readable media), which includes both non-transitory and non-transitory, removable and non-removable media, that implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.
These computer programs may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks, and corresponding steps may be implemented by different modules.
In the above embodiment, the unmanned aerial vehicle is used to replace the LEO satellite for the overall performance test of the simulation environment SOTM. The method has the advantages that the SOTM overall performance test can be carried out by using the characteristics of low resource denial and high test efficiency, hardware resources such as LEO satellites and gateway stations are not needed, service resources such as LEO satellite orbit inferior are not needed, and the test efficiency can be improved by times in expectation.
In the above embodiment, a link budget migration method between an actual satellite communication environment and a simulated unmanned aerial vehicle communication environment is provided, and the data related to the migration model can be used in a system configuration link and a performance evaluation link.
In the above embodiment, the adjustable inter-frequency retro-reflector from Ka-band to K-band is also used, which has the advantage of being capable of supporting three-dimensional retro-reflection with adjustable compensation power and frequency conversion from Ka-band to K-band, thereby supporting LEO uplink and downlink signal retro-reflection in three-dimensional space.
In the above embodiment, an SOTM overall performance evaluation algorithm is also introduced, which performs closed-loop performance evaluation based on a calculable expected power curve, and adds a concept of segment statistic evaluation to perform decibel evaluation on each stage of the SOTM tracking process, which has an advantage of expansion of evaluation dimension.
In conclusion, the above embodiment can achieve almost uninterrupted continuous test by replacing the spare battery of the unmanned aerial vehicle. Compared with the testing time of at most 30 minutes per day of other overall performance testing platforms, the above embodiment can improve the testing efficiency by 16 times according to the calculation expectation of the effective working time of 8 hours per day.
It should be noted that, in a complete SOTM test scheme, the above-mentioned embodiment cannot replace the existing SOTM component performance test instrument and the actual environment overall performance test platform, but provides a high-efficiency simulation environment performance test before entering the actual environment overall performance test after completing the component performance test, thereby reducing the dependence of the test scheme on the actual environment overall performance test and improving the research and development and troubleshooting efficiency.
The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.
Claims (14)
1. A low-orbit satellite equipment testing method based on an unmanned aerial vehicle comprises the following steps:
acquiring a first flight track of a low-orbit satellite;
determining a second flight track of the unmanned aerial vehicle according to the first flight track;
controlling the unmanned aerial vehicle to fly along the second flight trajectory;
and in the process that the unmanned aerial vehicle flies along the second flying track, controlling a device to be tested to perform signal interaction with the unmanned aerial vehicle so as to test the device to be tested, wherein the unmanned aerial vehicle transmits signals to the device to be tested according to the signal transmission parameters of the low-orbit satellite.
2. The method of claim 1, wherein determining a second flight trajectory of the drone from the first flight trajectory comprises:
acquiring a first flight linear velocity v of the low-orbit satellite 1 First flying height h 1 And a second linear flight velocity v of the drone 2 Wherein the first flight path is from a first starting point p 1 To a second end point q 1 And maintaining a constant trajectory for the first flying height;
calculating a second flight height h of the second flight path according to the following formula 2 ：h 2 ＝(v 2 /v 1 )·h 1 ；
Calculating the starting point p of the second flight path according to the following formula 2 ：p 2 ＝(v 2 /v 1 )·(p 1 -p) + p; wherein p is a starting point of the movement of the device to be tested in the test process;
calculating the end point q of the second flight path according to the following formula 2 ：q 2 ＝(v 2 /v 1 )·(q 1 -q) + q; wherein q is the moving terminal point of the device to be tested in the testing process;
and obtaining the second flight track according to the starting point, the end point and the second flight height of the second flight track.
3. The method of claim 1, wherein the drone transmitting signals to the device under test according to the signal transmission parameters of the low earth satellite comprises:
the unmanned aerial vehicle receives an uplink radio frequency signal from the device to be tested;
the unmanned aerial vehicle carries out frequency conversion on the uplink radio frequency signal according to the frequency of the downlink radio frequency signal of the low-orbit satellite;
the unmanned aerial vehicle obtains a downlink radio frequency signal to be transmitted according to the uplink radio frequency signal after frequency conversion, wherein the frequency of the downlink radio frequency signal to be transmitted is the same as the frequency of the downlink radio frequency signal transmitted by the low-earth-orbit satellite;
the unmanned aerial vehicle transmits the downlink radio frequency signal to be transmitted out along the incident direction of the uplink radio frequency signal through a backtracking reflector; wherein the retro reflector is configured on the drone.
4. The method according to claim 3, wherein the obtaining, by the drone, the downlink radio frequency signal to be transmitted according to the frequency-converted uplink radio frequency signal includes:
the unmanned aerial vehicle performs power compensation on the frequency-converted uplink radio-frequency signal according to a link budget of the low-earth orbit satellite, wherein the link budget of the low-earth orbit satellite is used for indicating total gain and attenuation of the signal of the low-earth orbit satellite in signal transmission;
the unmanned aerial vehicle takes the uplink radio frequency signal subjected to power compensation and frequency conversion as the downlink radio frequency signal to be transmitted; and the power of the downlink radio frequency signal obtained after power compensation is the same as the power of the downlink radio frequency signal generated by the low-earth orbit satellite.
5. The method of claim 4, wherein the retro-reflector comprises a plurality of sets of transceiving antennas, wherein each set of transceiving antennas of the plurality of sets of transceiving antennas comprises a receiving antenna for receiving an uplink radio frequency signal of a first frequency band and a transmitting antenna for transmitting a downlink radio frequency signal of a second frequency band; the first frequency band is a frequency band of the low earth orbit satellite for receiving uplink radio frequency signals, and the second frequency band is a frequency band of the low earth orbit satellite for transmitting downlink radio frequency signals.
6. The method of claim 5, wherein the plurality of sets of transceiving antennas are distributed on a plurality of concentric rings, wherein each concentric ring is distributed with the same number of sets of transceiving antennas, and each set of receiving antennas and each set of transmitting antennas are connected by a circular arc radio frequency line.
7. The method of any of claims 1 to 6, further comprising:
acquiring an expected power curve of the device to be tested;
acquiring an actual measurement power curve measured by the device to be tested in the signal interaction process with the unmanned aerial vehicle;
and evaluating the power of the device to be tested according to the expected power curve and the measured power curve.
8. The method of claim 7, wherein evaluating the power of the device under test from the expected power curve and the measured power curve comprises:
obtaining a power residual error curve by subtracting the expected power curve and the actually measured power curve;
obtaining an evaluation parameter based on at least one of: the actual measurement power curve, the power residual error curve, a segmented actual measurement power curve obtained by segmenting the actual measurement power curve, and a segmented power residual error curve obtained by segmenting the power residual error curve;
and evaluating the power of the device to be tested according to the evaluation parameter.
9. The method of any of claims 1-7, wherein the angular velocity and trajectory opening angle of the drone when flying along the second flight trajectory are the same as the angular velocity and trajectory opening angle of the low earth satellite when flying along the first flight trajectory.
10. An unmanned aerial vehicle, comprising:
the control part is used for controlling the unmanned aerial vehicle to fly along a second flight track determined according to a first flight track, wherein the first flight track is a flight track of a low orbit satellite acquired in advance;
the communication part is used for carrying out signal interaction with the equipment to be tested, and the communication part transmits signals to the equipment to be tested according to the signal transmission parameters of the low-orbit satellite.
11. The drone of claim 10, wherein the communication portion comprises a retro-reflector, wherein,
the backtracking reflector is used for carrying out frequency conversion on a received uplink radio frequency signal according to the frequency of a downlink radio frequency signal of the low-orbit satellite, wherein the uplink radio frequency signal is from the device to be tested; the backtracking reflector is further configured to obtain a downlink radio frequency signal to be transmitted according to the frequency-converted uplink radio frequency signal, and transmit the downlink radio frequency signal to be transmitted out along an incident direction of the uplink radio frequency signal, where a frequency of the downlink radio frequency signal to be transmitted is the same as a frequency of the downlink radio frequency signal transmitted by the low-earth-orbit satellite; and/or the presence of a gas in the gas,
the backtracking reflector is used for performing power compensation on the frequency-converted uplink radio-frequency signal according to the link budget of the low-earth orbit satellite, and taking the uplink radio-frequency signal subjected to power compensation and frequency conversion as the downlink radio-frequency signal to be transmitted; the link budget of the low-earth-orbit satellite is used for indicating the total gain and attenuation of signals of the low-earth-orbit satellite in signal transmission, and the power of downlink radio-frequency signals obtained after power compensation is the same as the power of downlink radio-frequency signals generated by the low-earth-orbit satellite.
12. The drone of claim 11, wherein the retro-reflector comprises a plurality of sets of transceiver antennas, wherein each set of transceiver antennas in the plurality of sets of transceiver antennas comprises a receive antenna for receiving an uplink radio frequency signal of a first frequency band and a transmit antenna for transmitting a downlink radio frequency signal of a second frequency band; the first frequency band is a frequency band of the low earth orbit satellite for receiving uplink radio frequency signals, and the second frequency band is a frequency band of the low earth orbit satellite for transmitting downlink radio frequency signals.
13. The drone of claim 12, wherein the plurality of sets of transceiving antennas are distributed on a plurality of concentric rings, wherein each concentric ring has the same number of sets of transceiving antennas, and each set of receiving antennas and each set of transmitting antennas are connected by a circular arc radio frequency line.
14. The drone of any one of claims 10 to 13, wherein the angular velocity and the trajectory opening angle of the drone when flying along the second flight trajectory are the same as the angular velocity and the trajectory opening angle of the low earth satellite when flying along the first flight trajectory.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116015367A (en) * | 2023-01-05 | 2023-04-25 | 航天恒星科技有限公司 | Ground phased array antenna multi-beam tracking test system for satellite communication |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2847766A1 (en) * | 2014-01-20 | 2015-07-20 | Venkateshwara Pillay | A system for mapping and tracking ground targets |
| CN106329120A (en) * | 2016-08-29 | 2017-01-11 | 中国人民解放军火箭军工程大学 | Sitcom On-the-Move (SOTM) low-cost measurement and control method |
| CN106712827A (en) * | 2016-11-17 | 2017-05-24 | 上海卫星工程研究所 | Dynamic beam tracking and testing device and method for satellite-borne digital multi-beam receiving antenna |
| WO2018099970A1 (en) * | 2016-11-29 | 2018-06-07 | Quadsat Ivs | System for testing the accuracy of the automatic positioning means of a signal tracking antenna |
| CN110033687A (en) * | 2019-05-14 | 2019-07-19 | 北京鼎赢科技有限公司 | A kind of satellite navigation ground simulator and method |
| CN111968446A (en) * | 2020-09-09 | 2020-11-20 | 中国人民解放军63811部队 | Ground measurement and control equipment training method, device and system |
| CN113176101A (en) * | 2021-03-26 | 2021-07-27 | 上海卫星工程研究所 | Satellite load imaging test system and method based on distributed control architecture |
| WO2022079278A2 (en) * | 2020-10-16 | 2022-04-21 | Quadsat Aps | Antenna evaluation test system |
-
2022
- 2022-07-01 CN CN202210770085.6A patent/CN115189779A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2847766A1 (en) * | 2014-01-20 | 2015-07-20 | Venkateshwara Pillay | A system for mapping and tracking ground targets |
| CN106329120A (en) * | 2016-08-29 | 2017-01-11 | 中国人民解放军火箭军工程大学 | Sitcom On-the-Move (SOTM) low-cost measurement and control method |
| CN106712827A (en) * | 2016-11-17 | 2017-05-24 | 上海卫星工程研究所 | Dynamic beam tracking and testing device and method for satellite-borne digital multi-beam receiving antenna |
| WO2018099970A1 (en) * | 2016-11-29 | 2018-06-07 | Quadsat Ivs | System for testing the accuracy of the automatic positioning means of a signal tracking antenna |
| CN110033687A (en) * | 2019-05-14 | 2019-07-19 | 北京鼎赢科技有限公司 | A kind of satellite navigation ground simulator and method |
| CN111968446A (en) * | 2020-09-09 | 2020-11-20 | 中国人民解放军63811部队 | Ground measurement and control equipment training method, device and system |
| WO2022079278A2 (en) * | 2020-10-16 | 2022-04-21 | Quadsat Aps | Antenna evaluation test system |
| CN113176101A (en) * | 2021-03-26 | 2021-07-27 | 上海卫星工程研究所 | Satellite load imaging test system and method based on distributed control architecture |
Non-Patent Citations (2)
| Title |
|---|
| SAKI OMI: "Stochastic Filtering Technique for UAV-Based Communications On The Move Terminal Tracking Accuracy Evaluation", 《2021 ANTENNA MEASUREMENT TECHNIQUES ASSOCIATION SYMPOSIUM (AMTA)》 * |
| 荣凤娟;张清华;张杰;徐键卉;: "无人机软连接吊舱的伪卫星定位算法研究", 全球定位系统, no. 04 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116015367A (en) * | 2023-01-05 | 2023-04-25 | 航天恒星科技有限公司 | Ground phased array antenna multi-beam tracking test system for satellite communication |
| CN116015367B (en) * | 2023-01-05 | 2023-09-15 | 航天恒星科技有限公司 | Ground phased array antenna multi-beam tracking test system for satellite communication |
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