TDOA positioning method, system, electronic equipment and medium based on single station onboard UAV

Abstract

The present invention provides a TDOA positioning method based on a single station onboard a drone, the method comprising: the drone airborne base station obtains the signal data sent by the target signal source, obtains the duration of a single pilot signal and the time interval of adjacent pilot signals according to the signal data; controls the drone to move according to a preset trajectory, takes the first time as a cycle, and obtains the signal data sent by the target signal source at K moments respectively; calculates the TDOA information of adjacent moments according to the K signal data; establishes a rectangular coordinate system, obtains the coordinate position information of the drone at K moments; establishes the transmission speed of the signal data emitted by the target signal source, the TDOA information of adjacent moments and the coordinate position information of the drone at the corresponding moment, establishes the equation of the transmission distance of the signal data of the target signal source at adjacent moments, and jointly establishes all K-1 equations to determine the position of the target signal source. The method realizes the function of multiple base stations using only one base station, reducing the hardware cost.

Description

Technical Field

[0001] The present invention relates to the field of radio monitoring, and in particular to a TDOA positioning method, system, electronic equipment and medium based on a single station onboard an unmanned aerial vehicle. Background Art

[0002] In radio communications, radar, sonar and other signal processing systems, single-station positioning is an important positioning technology; single-station positioning refers to using only one receiving station to determine the location of the target signal source.

[0003] For single-station positioning, one current approach is to measure the angle of incidence (AOA). This method can determine the direction of the target by measuring the AOA information of the signal reaching the receiving station. In practical applications, devices with directional antennas (such as direction-finding antennas) are usually used to measure the angle of arrival of the signal for rough positioning.

[0004] Another existing approach is to measure the received signal strength. This is because during the transmission of the signal, the signal strength will be affected in the propagation path. The signal can be located based on the strength of the received signal. In the case of a known signal propagation model (such as a spatial path loss model), the received signal strength can be compared with the theoretical strength under the known model to estimate the distance to the target. However, in practical applications, the method based on the received signal strength measurement is greatly affected by environmental factors such as the multipath effect, which reduces the positioning effect.

[0005] However, the above-mentioned prior art method has the problem of insufficient positioning accuracy. Summary of the invention

[0006] The present invention provides a TDOA positioning method, system, electronic device and medium based on a single station onboard an unmanned aerial vehicle, so as to solve the problem of low positioning accuracy of a target signal source in the prior art.

[0007] According to a first aspect of the present invention, a TDOA positioning method based on a single station onboard a UAV is provided, which uses a single base station onboard a UAV to locate a target signal source; the method comprises:

[0008] The base station on the drone obtains the signal data sent by the target signal source, and obtains the duration of a single pilot signal and the time interval between adjacent pilot signals according to the signal data; wherein each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal;

[0009] Control the drone to move along a preset trajectory, and obtain signal data sent by the target signal source at K moments with the first time as a period; wherein the first time is equal to the time interval between two adjacent pilot signals, K is a positive integer, and K≥3;

[0010] According to the obtained K signal data, the TDOA information at adjacent moments is calculated;

[0011] Establish a rectangular coordinate system and obtain the coordinate position information of the drone at K moments according to the preset trajectory of the drone;

[0012] Establish the transmission speed of the signal data emitted by the target signal source, the TDOA information at adjacent moments, and the coordinate position information of the UAV at the corresponding moment, establish the equation for the transmission distance of the signal data of the target signal source at adjacent moments, and jointly establish all K-1 equations to determine the position of the target signal source.

[0013] Optionally, the calculating TDOA information at adjacent moments specifically includes:

[0014] Build a model of the signal data received by the drone at different times, specifically: j (t)=

[0015] hs(t-τ j )+n j (t); where r j represents the signal data received by the drone at time to+jT, where to is the start time of the drone movement, T is the first time, and τ j represents the channel delay caused by the change of the drone's position at time to+jT, n j (t) represents Gaussian white noise in the time domain, and the value of T is within 1 millisecond, so that the channel gain at two adjacent moments is basically unchanged, and the position of the target signal source at two adjacent moments is basically unchanged; where j is a natural number, and the value of j is 0, 1...K-1;

[0016] Establish the correlation equation of the signal data received by the drone at two adjacent moments, specifically: m (t)≈r m-1 (tT-τ m，m-1 ), where r m-1 is the signal data received by the drone at time to+(m-1)T; τ m，m-1 is the actual value of the relative delay of the channel at time to+mT and time to+(m-1)T, and τ m，m-1 =τ m -τ m-1 ;

[0017] The relative delay estimation value τ′ of the channel at three adjacent time points is estimated by generalized cross-correlation m,m-

[0018] and τ′ m-1，m-2 ; where τ′ m，m-1is the estimated value of the relative channel delay between to+mT and to+(m-1)T, τ′ m-1，m-2 It is the estimated value of the relative delay of the channel at to+(m-1)T and t0+(m-2)T; wherein, m is a natural number, and let m=2, 3...K-2, after moving K times, K-1 relative delay estimates of the channel at two adjacent moments are obtained; wherein the relative delay estimate of the channel at two adjacent moments is used as the TDOA information of the corresponding two adjacent moments.

[0019] Optionally, the relative delay estimation value τ′ of the channels at three adjacent time points is estimated by generalized cross-correlation m,m-1 and τ′ m-1，m-2 , specifically including:

[0020] The signal data r received at two adjacent moments m (t) and r m-1 The frequency domain signal r of (t) m (ω) and r m-1 (ω) is used to make a cross-correlation power spectrum, and the formula is:

[0021] R m，m-1 (w) = r m (w)r m-1 * (w), where R m，m-1 (w) is the cross-correlation power spectrum, (·) * represents the conjugation operation;

[0022] Get the cross-correlation power spectrum R m，m-1 (w) The corresponding GCC function, where the formula of the GCC function is:

[0023]

[0024] Find GCC m，m-1 The maximum value of (τ), the τ corresponding to the maximum value can be regarded as τ′ m，m-1 ;

[0025] Using the same method, we can get τ′ m-1，m-2 .

[0026] Optionally, the equation for the transmission distance of the signal data of the target signal source at adjacent times is:

[0027]

[0028] Where c is the transmission speed of the carrier of the signal data sent by the target signal source, x m and m are the X-axis and Y-axis coordinates of the drone in the rectangular coordinate system at time to+mT, respectively. m-1 andm-1 are the coordinates of the X-axis and Y-axis of the drone in the rectangular coordinate system at time to+(m-1)T; x and y are the coordinates of the X-axis and Y-axis of the target signal source in the rectangular coordinate system.

[0029] Optionally, all K-1 equations are combined to determine the location of the target signal source, where the K-1 equations are specifically:

[0030]

[0031] According to the combined equations, the position (x, y) of the target signal source can be obtained.

[0032] According to a second aspect of the present invention, a TDOA positioning system based on a single station onboard a drone is provided, which uses a single base station onboard a drone to locate a target signal source; the system comprises:

[0033] A pilot information acquisition unit is used to obtain the duration of a single pilot signal and the time interval between adjacent pilot signals according to the signal data sent by the target signal source acquired by the airborne base station of the drone; wherein each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal;

[0034] The signal acquisition unit is used to obtain signal data sent by the target signal source at K moments respectively with a first time as a period when the UAV moves according to a preset trajectory; wherein the first time is equal to the time interval between two adjacent pilot signals, K is a positive integer, and K≥3;

[0035] A TDOA information calculation unit, used to calculate TDOA information at adjacent moments according to the obtained K signal data;

[0036] The UAV position information determination unit is used to establish a rectangular coordinate system and obtain the coordinate position information of the UAV at K moments according to the preset trajectory of the UAV;

[0037] The target signal source position determination unit is used to establish the transmission speed of the signal data emitted by the target signal source, the TDOA information at adjacent moments and the coordinate position information of the UAV at the corresponding moment, establish the equation for the transmission distance of the signal data of the target signal source at adjacent moments, and jointly establish all K-1 equations to determine the position of the target signal source.

[0038] Optionally, the TDOA information calculation unit specifically includes:

[0039] The model building subunit is used to build a model of the signal data received by the drone at different times, specifically: j (t) = hs(t-τ j )+n j(t); where r j represents the signal data received by the drone at time to+jT, where to is the start time of the drone movement, T is the first time, and τ j represents the channel delay caused by the change of the drone's position at time to+jT, n j (t) represents Gaussian white noise in the time domain, and the value of T is within 1 millisecond, so that the channel gain at two adjacent moments is basically unchanged, and the position of the target signal source at two adjacent moments is basically unchanged; where j is a natural number, and the value of j is 0, 1...K-1;

[0040] The correlation equation establishment subunit is used to establish the correlation equation of the signal data received by the drone at two adjacent moments, specifically: m (t)≈r m-1 (tT-τ m，m-1 ), where r m-1 is the signal data received by the drone at time to+(m-1)T; τ m，m-1 is the actual value of the relative delay of the channel at time to+mT and time to+(m-1)T, and τ m，m-1 =τ m -τ m-1 ;

[0041] The channel relative delay estimation subunit is used to estimate the relative delay estimation value τ′ of the channel at three adjacent time points using generalized cross-correlation m，m-1 and τ′ m-1，m-2 ; where τ′ m，m-1 is the estimated value of the relative channel delay between to+mT and to+(m-1)T, τ′ m-1，m-2 is the estimated value of the relative delay of the channel between to+(m-1)T and t0+(m-2)T; wherein, m is a natural number, and let m=2, 3...K-2, after K moments, K-1 relative delay estimates of the channel between two adjacent moments are obtained; wherein the relative delay estimate of the channel between two adjacent moments is used as the TDOA information of the corresponding two adjacent moments.

[0042] Optionally, the channel relative delay estimation subunit specifically includes:

[0043] The signal conversion subunit is used to perform cross-correlation power spectrum analysis on the frequency domain signals of the signal data received at two adjacent moments. The formula is:

[0044] R m，m-1 (w) = r m (w)r m-1 * (w), where R m，m-1 (w) is the cross-correlation power spectrum, (·) * represents the conjugation operation;

[0045] The GCC function determines the subunits used to obtain the cross-correlation power spectrum R m，m-1 (w) The corresponding GCC function, where the formula of the GCC function is:

[0046]

[0047] GCC function maximum determination subunit, used to find GCC m，m-1 The maximum value of (τ), the τ corresponding to the maximum value can be regarded as τ′ m，m-1 .

[0048] According to a third aspect of the present invention, there is provided an electronic device, comprising a processor and a memory.

[0049] The memory is used to store codes and related data;

[0050] The processor is used to execute the code in the memory to implement the method involved in the first aspect and its optional solutions.

[0051] According to a fourth aspect of the present invention, there is provided a storage medium having a computer program stored thereon, which, when executed by a processor, implements the method involved in the first aspect and its optional solutions.

[0052] The TDOA positioning method, system, electronic device and medium based on a single station on a drone provided by the present invention make full use of the location information of the drone and the time interval of adjacent pilot signals, and use GCC to estimate the TDOA information of the current moment and the previous moment; by controlling the drone to move according to a preset trajectory, with the help of the correlation between the location information of the drone at different moments and the received signal data, the base station can obtain the TDOA information of the drone at different moments, and then finally determine the relative position of the target signal source and realize the positioning of the target signal source within a certain time period. Thereby, the function of multiple base stations is realized by using only one base station, reducing the hardware cost. And the positioning accuracy is high, which can meet the needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0054] Figure 1 FIG. 1 is a flow chart of a TDOA positioning method based on a single station onboard a UAV in one embodiment of the present invention. Figure 1 ;

[0055] Figure 2 is a schematic diagram of the composition of a time domain signal s(t) sent by a target signal source in one embodiment of the present invention;

[0056] Figure 3 is a schematic diagram of a target signal source and a flight trajectory of a UAV in one embodiment of the present invention;

[0057] Figure 4 is a schematic diagram of a rectangular coordinate system in one embodiment of the present invention;

[0058] Figure 5 FIG. 1 is a flow chart of a TDOA positioning method based on a single station onboard a UAV in one embodiment of the present invention. Figure 2 ;

[0059] Figure 6 It is a schematic diagram of the structure of a TDOA positioning system based on a single station onboard a UAV provided by an embodiment of the present invention;

[0060] Figure 7 Schematic diagram of the structure of the TDOA information calculation unit provided in an embodiment of the present invention;

[0061] Figure 8 Schematic diagram of the structure of a channel relative delay estimation subunit provided by an embodiment of the present invention;

[0062] Fig. 9 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0065] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0066] Figure 1 It is a flow chart of a TDOA positioning method based on a single station onboard a UAV in one embodiment of the present invention.

[0067] Please refer to Figure 1 , based on the TDOA positioning method of a single station onboard a UAV, a single base station onboard a UAV is used to locate the target signal source; the target signal source can be, for example, a small communication device or a UAV. The goal of this application is to use the change in the position of one's own UAV for TDOA positioning, and then determine the position of the other party's target signal source. The method includes:

[0068] S1: The drone onboard base station obtains the signal data sent by the target signal source, and obtains the duration of a single pilot signal and the time interval between adjacent pilot signals based on the signal data; each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal.

[0069] The schematic diagram of the composition of the time domain signal s(t) sent by the target signal source is shown in Figure 2 ,like Figure 2 As shown, the front end of each signal usually carries a repeated pilot signal p(t), where T p Represents the duration of each pilot signal, T s is the time interval between two adjacent pilot signals. When the base station receives the signal, some known methods can be used to obtain T p and T s information.

[0070] S2: Control the drone to move along a preset trajectory, taking the first time as a period T, and obtaining the signal data sent by the target signal source at K moments; wherein the first time T and the time interval T between two adjacent pilot signals are s are equal, K is a positive integer, and K ≥ 3.

[0071] For details, please refer to Figure 3 , Figure 3 is a schematic diagram of a target signal source and a flight trajectory of a UAV in one embodiment of the present invention; Figure 3 It can also be understood as an application scenario of the present invention, which includes a target signal source and a drone. A base station is set on the drone, and this base station is needed to locate the target signal source. The drone moves according to a preset trajectory, T is the time period of each movement of the drone, K is the number of sampling points of the drone receiving the signal, m is a positive integer, m=2,...,K-1 (K≥3). When the drone is in motion, since the value of T is relatively small, generally within 1 mm, specifically, for example, in the range of several hundred microseconds to 1 millisecond, it can be considered that the position of the target signal source remains unchanged within a period T, and the channel gain remains basically unchanged. However, the distance of the base station relative to the target signal source will change, and the signals received by the base station at different positions have relative delays.

[0072] S3: Calculate the TDOA information at adjacent times based on the obtained K signal data;

[0073] S4: Establish a rectangular coordinate system and obtain the coordinate position information of the drone at K moments according to the preset trajectory of the drone.

[0074] in, Figure 4 is a schematic diagram of a rectangular coordinate system provided in an embodiment of the present invention, such as Figure 4 As shown in the figure, the position of the target signal source in the rectangular coordinate system is (x, y), and the position coordinates of the drone at different times are (x0, y0), ... (x m ,y m ),…(x K-1 ,y K-1 ).

[0075] S5: Establish the transmission speed of the signal data emitted by the target signal source, the TDOA information at adjacent moments, and the coordinate position information of the UAV at the corresponding moment, establish the equation for the transmission distance of the signal data of the target signal source at adjacent moments, and jointly establish all K-1 equations to determine the position of the target signal source.

[0076] As can be seen from the foregoing, the embodiment of the present invention makes full use of the location information of the drone and the time interval of adjacent pilot signals, and uses GCC to estimate the TDOA information of the current moment and the previous moment; by controlling the drone to move according to the preset trajectory, with the help of the correlation between the location information of the drone at different moments and the received signal data, the base station can obtain the TDOA information of the drone at different moments, and then finally determine the relative position of the target signal source and realize the positioning of the target signal source within a certain time period. Thereby, the function of multiple base stations is realized by using only one base station, reducing the hardware cost. And the positioning accuracy is high and can meet the needs.

[0077] Figure 5 FIG. 1 is a flow chart of a TDOA positioning method based on a single station onboard a UAV in one embodiment of the present invention. Figure 2 .

[0078] In one implementation, please refer to Figure 5 , the calculation of TDOA information at adjacent moments in step S3 specifically includes:

[0079] S31: Build a model of the signal data received by the drone at different times, specifically: j (t) = hs(t-τ j )+n j (t); where r j represents the signal data received by the drone at time to+jT, where to is the start time of the drone movement, T is the first time, and τ j represents the channel delay caused by the change of the drone's position at time to+jT, n j (t) represents Gaussian white noise in the time domain, and the value of T is within 1 millisecond, so that the channel gain at two adjacent moments is basically unchanged, and the position of the target signal source at two adjacent moments is basically unchanged; where j is a natural number, and the value of j is 0, 1...K-1;

[0080] S32: Establish the correlation equation of the signal data received by the drone at two adjacent moments, specifically: m (t)≈r m-1 (tT-τ m,m-1 ), where r m-1 is the signal data received by the drone at time to+(m-1)T; τ m，m-1 is the actual value of the relative delay of the channel at time to+mT and time to+(m-1)T, and τ m，m-1 =τ m -τ m-1 ;

[0081] S33: Use generalized cross-correlation to estimate the relative delay estimate τ′ of the three adjacent channelsm，m-1 and τ′ m-1，m-2 ; where τ′ m，m-1 is the estimated value of the relative channel delay between to+mT and to+(m-1)T, τ′ m-1，m-2 It is the estimated value of the relative delay of the channel at to+(m-1)T and t0+(m-2)T; wherein, m is a natural number, and let m=2, 3...K-1, after moving K times, K-1 relative delay estimates of the channel at two adjacent moments are obtained; wherein the relative delay estimate of the channel at two adjacent moments is used as the TDOA information of the corresponding two adjacent moments.

[0082] As a specific implementation method, the relative delay estimation value τ′ of the channels at three adjacent time points is estimated by using generalized cross-correlation. m，m-1 and τ′ m-1，m-2 , specifically including:

[0083] The signal data r received at two adjacent moments m (t) and r m-1 The frequency domain signal r of (t) m (ω) and r m-1 (ω) is used to make a cross-correlation power spectrum, and the formula is:

[0084] R m，m-1 (w) = r m (w)r m-1 * (w), where R m,m-1 (w) is the cross-correlation power spectrum, (·) * represents the conjugation operation;

[0085] Get the cross-correlation power spectrum R m，m-1 (w) The corresponding GCC function, where the formula of the GCC function is:

[0086]

[0087] Find GCC m，m-1 The maximum value of (τ), the τ corresponding to the maximum value can be regarded as τ′ m，m-1 ;

[0088] Using the same method, we can get τ′ m-1，m-2 .

[0089] Among them, in a specific implementation manner, the equation for the transmission distance of the signal data of the target signal source at adjacent moments is:

[0090]

[0091] Where c is the transmission speed of the carrier of the signal data sent by the target signal source, x m andm are the X-axis and Y-axis coordinates of the drone in the rectangular coordinate system at time to+mT, respectively. m-1 and m-1 are the coordinates of the X-axis and Y-axis of the drone in the rectangular coordinate system at time to+(m-1)T; x and y are the coordinates of the X-axis and Y-axis of the target signal source in the rectangular coordinate system.

[0092] Based on the above, all K-1 equations are combined to determine the location of the target signal source, where the K-1 equations are specifically:

[0093]

[0094] According to the combined equations, the position (x, y) of the target signal source can be obtained.

[0095] It can be seen that in the embodiment of the present invention, by moving the drone along a preset trajectory and collecting signal data at different times, the base station can obtain the TDOA information of the drone at different times by means of the location information of the drone at different times and the correlation between the received signal data, and then finally determine the relative position of the target signal source and realize the positioning of the target signal source within a certain period of time. This method simulates the effect of multiple base stations through the movement of the drone. It realizes the function of multiple base stations using only one base station, reducing the hardware cost.

[0096] Figure 6 A schematic diagram of the structure of a TDOA positioning system based on a single station onboard an unmanned aerial vehicle provided in an embodiment of the present invention.

[0097] like Figure 6 As shown, the TDOA positioning system 100 based on a single station onboard a UAV provided in an embodiment of the present invention uses a single base station onboard a UAV to realize the positioning of a target signal source; the system 100 includes:

[0098] The pilot information acquisition unit 101 is used to obtain the duration of a single pilot signal and the time interval between adjacent pilot signals according to the signal data sent by the target signal source acquired by the airborne base station of the drone; wherein each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal;

[0099] The signal acquisition unit 102 is used to obtain signal data sent by the target signal source at K moments respectively with a first time as a period when the drone moves according to a preset trajectory; wherein the first time is equal to the time interval between two adjacent pilot signals, K is a positive integer, and K≥3;

[0100] The TDOA information calculation unit 103 is used to calculate the TDOA information at adjacent moments according to the obtained K signal data;

[0101] The drone position information determination unit 104 is used to establish a rectangular coordinate system and obtain the coordinate position information of the drone at K moments according to the preset trajectory of the drone;

[0102] The target signal source position determination unit 105 is used to establish the transmission speed of the signal data emitted by the target signal source, the TDOA information at adjacent moments and the coordinate position information of the drone at corresponding moments, establish the equation for the transmission distance of the signal data of the target signal source at adjacent moments, and determine the position of the target signal source by combining all K-1 equations.

[0103] Please refer to Figure 7 , Figure 7 Schematic diagram of the structure of the TDOA information calculation unit provided in an embodiment of the present invention. Figure 7 As shown, as an implementation manner, the TDOA information calculation unit 103 specifically includes:

[0104] The model building subunit 1031 is used to build a model of the signal data received by the drone at different times, specifically: j (t) = hs(t-τ j )+n j (t); where r j represents the signal data received by the drone at time to+jT, where to is the start time of the drone movement, T is the first time, and τ j represents the channel delay caused by the change of the drone's position at time to+jT, n j (t) represents Gaussian white noise in the time domain, and the value of T is within 1 millisecond, so that the channel gain at two adjacent moments is basically unchanged, and the position of the target signal source at two adjacent moments is basically unchanged; where j is a natural number, and the value of j is 0, 1...K-1;

[0105] The correlation equation establishing subunit 1032 is used to establish the correlation equation of the signal data received by the drone at two adjacent moments, specifically: m (t)≈r m-1 (tT-τ m，m-1 ), where r m-1 is the signal data received by the drone at time to+(m-1)T; τ m，m-1 is the actual value of the relative delay of the channel at time to+mT and time to+(m-1)T, and τ m，m-1 =τ m -τ m-1 ;

[0106] The channel relative delay estimation subunit 1033 is used to estimate the relative delay estimation value τ′ of the channel at three adjacent time points by using generalized cross-correlation.m，m-1 and τ′ m-1，m-2 ; where τ′ m，m-1 is the estimated value of the relative channel delay between to+mT and to+(m-1)T, τ′ m-1，m-2 is the estimated value of the relative delay of the channel between to+(m-1)T and t0+(m-2)T; wherein, m is a natural number, and let m=2, 3...K-1, after K moments, K-1 relative delay estimates of the channel between two adjacent moments are obtained; wherein the relative delay estimate of the channel between two adjacent moments is used as the TDOA information of the corresponding two adjacent moments.

[0107] Please continue to refer to Figure 8 , Figure 8 is a schematic diagram of the structure of a channel relative delay estimation subunit provided in an embodiment of the present invention, such as Figure 8 As shown, the channel relative delay estimation subunit 1033 specifically includes:

[0108] The signal conversion subunit 10331 is used to perform cross-correlation power spectrum analysis on the frequency domain signals of the signal data received at two adjacent moments, and the formula is:

[0109] R m，m-1 (w) = r m (w)r m-1 * (w), where R m，m-1 (w) is the cross-correlation power spectrum, (·) * represents the conjugation operation;

[0110] GCC function determination subunit 10332, used to obtain the cross-correlation power spectrum R m，m-1 (w) The corresponding GCC function, where the formula of the GCC function is:

[0111]

[0112] GCC function maximum determination subunit 10333 is used to find GCC m，m-1 The maximum value of (τ), the τ corresponding to the maximum value can be regarded as τ′ m，m-1 .

[0113] Fig. 9 Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention, such as Fig. 9 As shown, the electronic device 40 includes:

[0114] a processor 41; and

[0115] A memory 42, used to store executable instructions of the processor;

[0116] The processor 41 is configured to execute the above-mentioned method by executing the executable instructions.

[0117] The processor 41 can communicate with the memory 42 via a bus 43 .

[0118] In addition, an embodiment of the present invention further provides a storage medium on which a computer program is stored, and when the program is executed by a processor, the method involved in the aforementioned first aspect and its optional solutions is implemented.

[0119] The TDOA positioning method, system, electronic device and medium based on a single station on a drone provided by the present invention make full use of the location information of the drone and the time interval of adjacent pilot signals, and use GCC to estimate the TDOA information of the current moment and the previous moment; by controlling the drone to move according to a preset trajectory, with the help of the correlation between the location information of the drone at different moments and the received signal data, the base station can obtain the TDOA information of the drone at different moments, and then finally determine the relative position of the target signal source and realize the positioning of the target signal source within a certain time period. Thereby, the function of multiple base stations is realized by using only one base station, reducing the hardware cost. And the positioning accuracy is high, which can meet the needs.

[0120] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A TDOA positioning method based on a single station onboard an unmanned aerial vehicle, characterized in that: A single UAV airborne base station is used to locate the target signal source; the method includes: The base station on the drone obtains the signal data sent by the target signal source, and obtains the duration of a single pilot signal and the time interval between adjacent pilot signals according to the signal data; wherein each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal; Control the drone to move along a preset trajectory, and obtain signal data sent by the target signal source at K moments with the first time as a period; wherein the first time is equal to the time interval between two adjacent pilot signals, K is a positive integer, and K≥3; According to the obtained K signal data, the TDOA information at adjacent moments is calculated; Establish a rectangular coordinate system and obtain the coordinate position information of the drone at K moments according to the preset trajectory of the drone; Establish the transmission speed of the signal data emitted by the target signal source, the TDOA information at adjacent moments, and the coordinate position information of the UAV at the corresponding moment, establish the equation for the transmission distance of the signal data of the target signal source at adjacent moments, and jointly establish all K-1 equations to determine the position of the target signal source.

2. The TDOA positioning method based on a single station onboard an unmanned aerial vehicle according to claim 1 is characterized in that: The calculating of TDOA information at adjacent moments specifically includes: Build a model of the signal data received by the drone at different times, specifically: j (t) = hs(t-τ j )+n j (t); where r j represents the signal data received by the drone at time to+jT, where to is the start time of the drone movement, T is the first time, and τ j represents the channel delay caused by the change of the drone's position at time to+jT, n j (t) represents Gaussian white noise in the time domain, and the value of T is within 1 millisecond, so that the channel gain at two adjacent moments is basically unchanged, and the position of the target signal source at two adjacent moments is basically unchanged; where j is a natural number, and the value of j is 0, 1...K-1; Establish the correlation equation of the signal data received by the drone at two adjacent moments, specifically: m (t)≈r m-1 (tT-τ m，m-1 ), where r m-1 is the signal data received by the drone at time to+(m-1)T; τ m，m-1 is the actual value of the relative delay of the channel at time to+mT and time to+(m-1)T, and τ m，m-1 =τ m -τ m-1 ; The relative delay estimation value τ′ of the channel at three adjacent time points is estimated by generalized cross-correlation m，m-1 and τ′ m-1，m-2 ; where τ′ m，m-1 is the estimated value of the relative channel delay between to+mT and to+(m-1)T, τ′ m-1，m-2 It is the estimated value of the relative delay of the channel at to+(m-1)T and t0+(m-2)T; wherein, m is a natural number, and let m=2, 3...K-1, after moving K times, K-1 relative delay estimates of the channel at two adjacent moments are obtained; wherein the relative delay estimate of the channel at two adjacent moments is used as the TDOA information of the corresponding two adjacent moments.

3. The TDOA positioning method based on a single station onboard an unmanned aerial vehicle according to claim 2 is characterized in that: The relative delay estimation value T′ of the channel at three adjacent time points is estimated by generalized cross-correlation. m，m-1 and τ′ m-1，m-2 , specifically including: The signal data r received at two adjacent moments m (t) and r m-1 The frequency domain signal r of (t) m (ω) and r m-1 (ω) is used to make a cross-correlation power spectrum, and the formula is: R m，m-1 (w) = r m (w)r m-1 * (w), where R m，m-1 (w) is the cross-correlation power spectrum, (·) * represents the conjugation operation; Get the cross-correlation power spectrum R m，m-1 (w) The corresponding GCC function, where the formula of the GCC function is: Find GCC m，m-1 The maximum value of (τ), the τ corresponding to the maximum value can be regarded as τ′ m,m-1 ; Using the same method, we can get τ′ m-1，m-2 .

4. The TDOA positioning method based on a single station onboard an unmanned aerial vehicle according to any one of claims 1 to 3, characterized in that: The equation for the transmission distance of the signal data of the target signal source at adjacent times is: Where c is the transmission speed of the carrier of the signal data sent by the target signal source, x m and m are the X-axis and Y-axis coordinates of the drone in the rectangular coordinate system at time to+mT, respectively. m-1 and m-1 are the coordinates of the X-axis and Y-axis of the drone in the rectangular coordinate system at time to+(m-1)T; x and y are the coordinates of the X-axis and Y-axis of the target signal source in the rectangular coordinate system.

5. The TDOA positioning method based on a single station onboard an unmanned aerial vehicle according to claim 4 is characterized in that: All K-1 equations are combined to determine the location of the target signal source, where the K-1 equations are specifically: According to the combined equations, the position (x, y) of the target signal source can be obtained.

6. A TDOA positioning system based on a single station onboard an unmanned aerial vehicle, characterized in that: A single UAV-mounted base station is used to locate the target signal source; the system includes: A pilot information acquisition unit is used to obtain the duration of a single pilot signal and the time interval between adjacent pilot signals according to the signal data sent by the target signal source acquired by the airborne base station of the drone; wherein each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal; The signal acquisition unit is used to obtain signal data sent by the target signal source at K moments respectively with a first time as a period when the UAV moves according to a preset trajectory; wherein the first time is equal to the time interval between two adjacent pilot signals, K is a positive integer, and K≥3; A TDOA information calculation unit, used to calculate TDOA information at adjacent moments according to the obtained K signal data; The UAV position information determination unit is used to establish a rectangular coordinate system and obtain the coordinate position information of the UAV at K moments according to the preset trajectory of the UAV; The target signal source position determination unit is used to establish the transmission speed of the signal data emitted by the target signal source, the TDOA information at adjacent moments and the coordinate position information of the UAV at the corresponding moment, establish the equation for the transmission distance of the signal data of the target signal source at adjacent moments, and jointly establish all K-1 equations to determine the position of the target signal source.

7. The TDOA positioning system based on a single station onboard an unmanned aerial vehicle according to claim 6, characterized in that: The TDOA information calculation unit specifically includes: The model building subunit is used to build a model of the signal data received by the drone at different times, specifically: j (t) = hs(t-τ j )+n j (t); where r j represents the signal data received by the drone at time to+jT, where to is the start time of the drone movement, T is the first time, and τ j represents the channel delay caused by the change of the drone's position at time to+jT, n j (t) represents Gaussian white noise in the time domain, and the value of T is within 1 millisecond, so that the channel gain at two adjacent moments is basically unchanged, and the position of the target signal source at two adjacent moments is basically unchanged; where j is a natural number, and the value of j is 0, 1...K-1; The correlation equation establishment subunit is used to establish the correlation equation of the signal data received by the drone at two adjacent moments, specifically: m (t)≈r m-1 (tT-τ m，m-1 ), where r m-1 is the signal data received by the drone at time to+(m-1)T; τ m，m-1 is the actual value of the relative delay of the channel at time to+mT and time to+(m-1)T, and τ m，m-1 =τ m -τ m-1 ; The channel relative delay estimation subunit is used to estimate the relative delay estimation value τ′ of the channel at three adjacent time points using generalized cross-correlation m，m-1 and τ′ m-1，m-2 ; where τ′ m，m-1 is the estimated value of the relative channel delay between to+mT and to+(m-1)T, τ′ m-1，m-2 is the estimated value of the relative delay of the channel between to+(m-1)T and t0+(m-2)T; wherein, m is a natural number, and let m=2, 3...K-1, after K moments, K-1 relative delay estimates of the channel between two adjacent moments are obtained; wherein the relative delay estimate of the channel between two adjacent moments is used as the TDOA information of the corresponding two adjacent moments.

8. The TDOA positioning system based on a single station onboard an unmanned aerial vehicle according to claim 7, characterized in that: The channel relative delay estimation subunit specifically includes: The signal conversion subunit is used to perform cross-correlation power spectrum analysis on the frequency domain signals of the signal data received at two adjacent moments. The formula is: R m，m-1 (w) = r m (w)r m-1 * (w), where R m，m-1 (w) is the cross-correlation power spectrum, (·) * represents the conjugation operation; The GCC function determines the subunits used to obtain the cross-correlation power spectrum R m，m-1 (w) The corresponding GCC function, where the formula of the GCC function is: GCC function maximum determination subunit, used to find GCC m，m-1 The maximum value of (τ), the τ corresponding to the maximum value can be regarded as T′ m，m-1 .

9. An electronic device, characterized in that: Including processor and memory, The memory is used to store codes and related data; The processor is used to execute the code in the memory to implement the method according to any one of claims 1 to 5.

10. A storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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