TDOA positioning method and system based on single unmanned aerial vehicle airborne station, and electronic device and medium

Abstract

A TDOA positioning method based on a single unmanned aerial vehicle airborne station. The method comprises: an unmanned aerial vehicle airborne base station acquiring signal data sent by a target signal source, and obtaining the duration of an individual pilot signal and the time interval between adjacent pilot signals on the basis of the signal data (S1); controlling an unmanned aerial vehicle to move on the basis of a preset trajectory, and by taking a first time as a period, respectively acquiring, at K moments, signal data sent by the target signal source (S2); on the basis of K pieces of signal data, calculating TDOA information at adjacent moments (S3); establishing a rectangular coordinate system, and on the basis of the preset trajectory of the unmanned aerial vehicle, obtaining coordinate position information of the unmanned aerial vehicle at the K moments (S4); and establishing the transmission speed of the signal data transmitted by the target signal source, the TDOA information at adjacent moments, and coordinate position information of the unmanned aerial vehicle at corresponding moments, establishing equations for the transmission distances of the signal data of the target signal source at adjacent moments, and combining all K-1 equations to determine the position of the target signal source (S5). In the method, the functions of multiple base stations are implemented by using only one base station, thereby reducing the hardware costs.

Description

Unmanned aerial vehicle airborne single-station-based TDOA positioning method and system, electronic device and medium TECHNICAL FIELD

[0001] The present application relates to the field of radio monitoring, and in particular to an unmanned aerial vehicle airborne single-station-based TDOA positioning method, system, electronic device and medium. BACKGROUND

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

[0003] For single-station positioning, one current approach is through angle of arrival (AOA) measurement, which can determine the bearing of the target by measuring the AOA information of the signal arriving at the receiving station. In practical applications, a device with a directional antenna (such as a direction-finding antenna) is usually used to measure the angle of arrival of the signal for rough positioning.

[0004] Another current approach is received signal strength measurement, which is based on the fact that the strength of the signal is affected in the propagation path during transmission of the signal, and the signal can be positioned 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 received signal strength measurement is greatly affected by environmental factors such as multipath effects, resulting in a decline in positioning accuracy.

[0005] However, the above-mentioned existing technology has the problem of insufficient positioning accuracy. SUMMARY

[0006] The present application provides an unmanned aerial vehicle airborne single-station-based TDOA positioning method, system, electronic device and medium to solve the problem of low positioning accuracy of target signal sources in the prior art.

[0007] According to a first aspect of the present application, there is provided an unmanned aerial vehicle airborne single-station-based TDOA positioning method for positioning a target signal source using a single unmanned aerial vehicle airborne base station; the method comprises:

[0008] The unmanned aerial vehicle airborne base station acquires signal data transmitted by the target signal source, and obtains the duration of a single pilot signal and the time interval between adjacent pilot signals from the signal data; each signal data comprises a time domain signal and a repeated pilot signal carried at the front end of the time domain signal;

[0009] The unmanned aerial vehicle moves according to a preset track, and signal data transmitted by the target signal source is acquired at K time points in a first time period; the first time is equal to the time interval between two adjacent pilot signals, K is a positive integer, and K is greater than or equal to 3;

[0010] TDOA information of adjacent time points is calculated according to the obtained K pieces of signal data;

[0011] A rectangular coordinate system is established, and coordinate position information of the unmanned aerial vehicle at the K time points is obtained according to the preset track of the unmanned aerial vehicle;

[0012] Transmission speed of the signal data transmitted by the target signal source, TDOA information of adjacent time points, and coordinate position information of the unmanned aerial vehicle at the corresponding time points are established, an equation of transmission distance of the signal data of the target signal source at adjacent time points is established, and the position of the target signal source is determined by solving all K-1 equations.

[0013] Optionally, the calculation of the TDOA information of adjacent time points specifically includes:

[0014] A model of the signal data received by the unmanned aerial vehicle at different time points is established, and the model is specifically as follows: r j (t) = hs (t-τ j ) + n j (t); wherein r j represents signal data received by the unmanned aerial vehicle at to+jT, to represents a starting time of movement of the unmanned aerial vehicle, T represents the first time, τ j represents a channel delay caused by a change in the position of the unmanned aerial vehicle at to+jT, n j (t) represents time-domain Gaussian white noise, and the value of T is within 1 millisecond, so that the channel gain of two adjacent time points is basically unchanged, and the position of the target signal source at two adjacent time points is basically unchanged; wherein j is a natural number, and the value of j is 0, 1, …, K-1;

[0015] A correlation equation of the signal data received by the unmanned aerial vehicle at two adjacent time points is established, and the correlation equation is specifically as follows: r m (t) ≈ r m-1 (t-T-τ m,m-1 ); wherein r m-1 represents signal data received by the unmanned aerial vehicle at to+(m-1)T, τ m,m-1 represents an actual value of the relative delay of the channel at to+mT and to+(m-1)T, and τ m,m-1 = τ m -τ m-1 ;

[0016] The relative delay estimation values τ′ m,m-1 and τ′ m-1,m-2; wherein, τ' m,m-1 is an estimation value of the relative time delay of the channel at the time to+mT and the time to+(m-1)T, τ' m-1,m-2 is an estimation value of the relative time delay of the channel at the time to+(m-1)T and the time to+(m-2)T; wherein, m is a natural number, and let m=2, 3…K-2, K-1 relative delay estimation values of two adjacent time channels are obtained after moving K times; wherein the relative delay estimation values of two adjacent time channels are taken as the TDOA information of the corresponding two adjacent time.

[0017] Optionally, three adjacent time channel relative delay estimation values τ' m,m-1 and τ' m-1,m-2 are estimated by using generalized cross-correlation, and specifically comprising:

[0018] The frequency domain signals r m (ω) and r m-1 (ω) of the signals r m (t) and r m-1 (t) received at two adjacent times are cross-correlated, and the formula is:

[0019] R m,m-1 (w)=r m (w)r m-1 *(w), wherein, R m,m-1 (w) is the cross-correlation power spectrum, and (·)* represents the conjugate operation;

[0020] The GCC function corresponding to the cross-correlation power spectrum R m,m-1 (w) is obtained, and the formula of the GCC function is:

[0021] The maximum value of the GCC m,m-1 (τ) is found, and the τ corresponding to the maximum value can be taken as τ' m,m-1 ;

[0022] In the same way, τ' m-1,m-2 is obtained.

[0023] Optionally, the equation of the transmission distance of the target signal source signal data at adjacent times is:

[0024] wherein, c is the transmission speed of the carrier of the target signal source signal data, x m and y m are the coordinates of the unmanned aerial vehicle in the X-axis and Y-axis of the rectangular coordinate system at the time to+mT, x m-1 and y m-1 are the coordinates of the unmanned aerial vehicle in the X-axis and Y-axis of the rectangular coordinate system at the time to+(m-1)T.X and Y are respectively coordinates of the unmanned aerial vehicle in the X axis and Y axis of the rectangular coordinate system at the time of to+(m-1)T; x and y are respectively coordinates of the target signal source in the X axis and Y axis of the rectangular coordinate system.

[0025] Optionally, the position of the target signal source is determined by simultaneously solving all K-1 equations, wherein the K-1 equations are specifically as follows:

[0026] According to the equations, the position (x, y) of the target signal source can be obtained.

[0027] According to a second aspect of the present application, a single-station TDOA positioning system based on an unmanned aerial vehicle is provided, which uses a single unmanned aerial vehicle base station to realize positioning of a target signal source; the system comprises:

[0028] A pilot information acquisition unit is configured to obtain the duration of a single pilot signal and the time interval between adjacent pilot signals according to the signal data transmitted by the target signal source and acquired by the unmanned aerial vehicle base station; wherein each signal data comprises a time domain signal and a repeated pilot signal carried at the front end of the time domain signal.

[0029] A signal acquisition unit is configured to acquire, in a period of a first time, signal data transmitted by the target signal source at K time points when the unmanned aerial vehicle moves along a preset trajectory; wherein the first time is equal to the time interval between adjacent pilot signals, K is a positive integer, and K≥3.

[0030] A TDOA information calculation unit is configured to calculate TDOA information of adjacent time points according to the K signal data.

[0031] An unmanned aerial vehicle position information determination unit is configured to establish a rectangular coordinate system and obtain coordinate position information of the unmanned aerial vehicle at the K time points according to the preset trajectory of the unmanned aerial vehicle.

[0032] A target signal source position determination unit is configured to establish the transmission speed of the signal data of the target signal source, the TDOA information of adjacent time points, and the coordinate position information of the unmanned aerial vehicle at the corresponding time points, establish an equation of the transmission distance of the signal data of the target signal source at adjacent time points, and determine the position of the target signal source by simultaneously solving all K-1 equations.

[0033] Optionally, the TDOA information calculation unit specifically comprises:

[0034] A model establishment subunit is configured to establish a model of the signal data received by the unmanned aerial vehicle at different time points, specifically as follows: r j (t)=hs(t-τ j )+n j (t); wherein, r jrepresents signal data received by the UAV at time to+jT, to is a starting time of movement of the UAV, and T is the first time j represents channel delay caused by position change of the UAV at time to+jT, n j (t) represents time-domain Gaussian white noise, and T is within 1 millisecond, so that the channel gain of two adjacent time points is basically unchanged, and the position of the target signal source of two adjacent time points is basically unchanged; j is a natural number, and j is 0, 1, …, K-1;

[0035] The correlation equation establishing sub-unit is configured to establish a correlation equation of signal data received by the UAV at two adjacent time points, and the correlation equation is specifically as follows: m (t)≈r m-1 (t-T-τ m,m-1 );wherein, r m-1 is signal data received by the UAV at time to+(m-1)T; τ m,m-1 is an actual value of relative delay of channels at time to+mT and time to+(m-1)T, and τ m,m-1 =τ m -τ m-1 ;

[0036] The channel relative delay estimation sub-unit is configured to estimate relative delay estimation values τ′ m,m-1 and τ′ m-1,m-2 of three adjacent time points of channels by using generalized cross-correlation; wherein, τ′ m,m-1 is an estimation value of relative delay of channels at time to+mT and time to+(m-1)T, and τ′ m-1,m-2 is an estimation value of relative delay of channels at time to+(m-1)T and time to+(m-2)T; m is a natural number, and m is set to 2, 3, …, K-2, so that K-1 relative delay estimation values of two adjacent time points of channels are obtained after K time points; the relative delay estimation values of two adjacent time points of channels are used as TDOA information of the corresponding two adjacent time points.

[0037] Optionally, the channel relative delay estimation sub-unit specifically includes:

[0038] The signal conversion sub-unit is configured to perform cross-correlation power spectrum on frequency domain signals of signal data received at two adjacent time points, and the formula is as follows:

[0039] R m,m-1 (w)=r m (w)r m-1 *(w), wherein, R m,m-1 (w) is cross-correlation power spectrum, and (·)* represents conjugate operation;

[0040] The GCC function determination sub-unit is configured to obtain cross-correlation power spectrum Rm,m-1 (w) the corresponding GCC function, where the formula of the GCC function is:

[0041] a GCC function maximum value determining sub-unit, configured to find the maximum value of the GCC function m,m-1 (tau) respectively, and the tau corresponding to the maximum value can be taken as the tau' m,m-1 .

[0042] According to a third aspect of the present application, an electronic device is provided, comprising a processor and a memory,

[0043] the memory, configured to store codes and related data;

[0044] the processor, configured to execute the codes in the memory to implement the method according to the first aspect and the optional solutions thereof.

[0045] According to a fourth aspect of the present application, a storage medium is provided, which stores a computer program, and the program is executed by a processor to implement the method according to the first aspect and the optional solutions thereof.

[0046] The TDOA positioning method, system, electronic device and medium based on the unmanned aerial vehicle airborne single station provided by the present application make full use of the position information of the unmanned aerial vehicle and the time interval of the adjacent pilot signals, and estimate the TDOA information at the current time and the previous time by using the GCC; by controlling the unmanned aerial vehicle to move along the preset trajectory, the base station can obtain the TDOA information of the unmanned aerial vehicle at different times by means of the correlation between the position information of the unmanned aerial vehicle at different times and 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. Thus, the function of multiple base stations is realized by using only one base station, and the hardware cost is reduced. Moreover, the positioning accuracy is high and can meet the demand. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0048] Fig. 1 is a flowchart of the TDOA positioning method based on the unmanned aerial vehicle airborne single station in an embodiment of the present application;

[0049] Fig. 2 is a schematic diagram of the time-domain signal s(t) sent by the target signal source in an embodiment of the present application;

[0050] Fig. 3 is a schematic diagram of a target signal source and a flight trajectory of a UAV in an embodiment of the present application;

[0051] Fig. 4 is a schematic diagram of a rectangular coordinate system in an embodiment of the present application;

[0052] Fig. 5 is a flowchart of a UAV-borne single-station-based TDOA positioning method in an embodiment of the present application.

[0053] Fig. 6 is a schematic diagram of a UAV-borne single-station-based TDOA positioning system in an embodiment of the present application.

[0054] Fig. 7 is a schematic diagram of a TDOA information calculation unit in an embodiment of the present application.

[0055] Fig. 8 is a schematic diagram of a channel relative time delay estimation subunit in an embodiment of the present application.

[0056] Fig. 9 is a schematic diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application.

[0058] The terms "first", "second", "third", "fourth" and the like (if any) in the description, claims and drawings of the present application are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to include those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0059] The technical solutions of the present application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described in some embodiments.

[0060] Fig. 1 is a flowchart of a UAV-borne single-station-based TDOA positioning method in an embodiment of the present application.

[0061] Referring to FIG. 1, a TDOA positioning method based on a single unmanned aerial vehicle (UAV) airborne base station is used to position a target signal source. The target signal source can be a small communication device or an unmanned aerial vehicle, for example. The application aims to use the position change of the own UAV to perform TDOA positioning and determine the position of the target signal source. The method includes the following steps:

[0062] S1: The UAV airborne base station acquires signal data transmitted 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. Each signal data includes a time domain signal and a repeated pilot signal carried at the front end of the time domain signal.

[0063] As shown in FIG. 2, the front end of each signal segment usually carries a repeated pilot signal p(t), where T p represents the duration of each pilot signal, and T s is the time interval between adjacent pilot signals. When the base station receives the signal, the information of T p and T s can be obtained by using some known methods.

[0064] S2: The UAV is controlled to move along a preset trajectory, and signal data transmitted by the target signal source is acquired at K time points with a first time T as a period; the first time T is equal to the time interval T s between adjacent pilot signals, K is a positive integer, and K≥3.

[0065] Specifically, referring to FIG. 3, which is a schematic diagram of a target signal source and a flight trajectory of a UAV in an embodiment of the application. FIG. 3 can also be understood as an application scenario of the application, which includes a target signal source and a UAV. A base station is arranged on the UAV, and the base station is used to position the target signal source. The UAV moves along a preset trajectory, T is the time period of each movement of the UAV, K is the sampling point number of the signal received by the UAV, and m is a positive integer, m=2,..., K-1 (K≥3). When the UAV is in a moving state, T is relatively small, generally within 1 millimeter, for example, several hundred microseconds to 1 millisecond. Therefore, within a period T, it can be considered that the position of the target signal source remains unchanged, and the channel gain is basically unchanged. The distance between the base station and the target signal source changes, and the signals received by the base station at different positions have a relative delay.

[0066] S3: TDOA information of adjacent time points is calculated according to the K signal data.

[0067] S4: Establish a rectangular coordinate system, and obtain the coordinate position information of the unmanned aerial vehicle at K moments according to the preset trajectory of the unmanned aerial vehicle.

[0068] Wherein, Fig. 4 is a schematic diagram of the rectangular coordinate system provided in the embodiment of the application, as shown in Fig. 4, the position of the target signal source in the rectangular coordinate system is (x, y), and the position coordinates of the unmanned aerial vehicle at different moments are (x0, y0),..., (xK-1, yK-1). m m K-1 K-1

[0069] S5: Establish the transmission speed of the signal data transmitted by the target signal source, the TDOA information of adjacent moments, and the coordinate position information of the unmanned aerial vehicle at the corresponding moment, establish the equation of 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 simultaneously solving all K-1 equations.

[0070] As known from the foregoing, the embodiment of the application makes full use of the position information of the unmanned aerial vehicle and the time interval of adjacent pilot signals, estimates the TDOA information of the current moment and the previous moment by using GCC; by controlling the unmanned aerial vehicle to move according to the preset trajectory, and by means of the position information of the unmanned aerial vehicle at different moments and the correlation between the received signal data, the base station can obtain the TDOA information of the unmanned aerial vehicle at different moments, and 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. Thus, the function of multiple base stations is realized by using only one base station, and the hardware cost is reduced. Moreover, the positioning accuracy is high, and the demand can be met.

[0071] Fig. 5 is a flowchart of the TDOA positioning method based on the unmanned aerial vehicle airborne single station in an embodiment of the application.

[0072] In one embodiment, referring to Fig. 5, the calculation of the TDOA information of adjacent moments in step S3 specifically includes:

[0073] S31: Establish a model of the signal data received by the unmanned aerial vehicle at different moments, specifically: r(t) = hs(t-τ) + n(t); wherein r(t) represents the signal data received by the unmanned aerial vehicle at to+jT, to is the starting moment of the movement of the unmanned aerial vehicle, T is the first time, τ represents the channel delay caused by the change of the position of the unmanned aerial vehicle at to+jT, and n(t) represents the noise. j j j j j j ​​​​​​​​​(t) represents time-domain Gaussian white noise, and T is within 1 millisecond, so that the channel gain of two adjacent time instants is substantially unchanged, and the position of the target signal source of two adjacent time instants is substantially unchanged; where j is a natural number, and the value of j is 0, 1,..., K-1;

[0074] S32: An association equation of the signal data received by the unmanned aerial vehicle at adjacent two time instants is established, specifically as follows: m (t)≈r m-1 (t-T-τ m,m-1 (;wherein r m-1 is the signal data received by the unmanned aerial vehicle at to+(m-1)T; τ m,m-1 is the actual value of the relative time delay of the channel at to+mT and to+(m-1)T, and τ m,m-1 =τ m -τ m-1 ;

[0075] S33: The relative delay estimation values τ′ m,m-1 and τ′ m-1,m-2 of three adjacent time instants of the channel are estimated by using generalized cross-correlation; wherein τ′ m,m-1 is the estimation value of the relative time delay of the channel at to+mT and to+(m-1)T, and τ′ m-1,m-2 is the estimation value of the relative time delay of the channel at to+(m-1)T and t0+(m-2)T; wherein m is a natural number, and m=2, 3,..., K-1 is set, and K-1 relative delay estimation values of two adjacent time instants of the channel are obtained after moving K times; wherein the relative delay estimation values of two adjacent time instants of the channel are used as the TDOA information of the corresponding two adjacent time instants.

[0076] As a specific implementation, the relative delay estimation values τ′ m,m-1 and τ′ m-1,m-2 of three adjacent time instants of the channel are estimated by using generalized cross-correlation, specifically including:

[0077] The frequency domain signals r m (ω) and r m-1 (ω) of the signal data r m (t) and r m-1 (t) received at adjacent two time instants are cross-correlated, and the formula is as follows:

[0078] R m,m-1 (w)=r m (w)r m-1 *(w), wherein R m,m-1 (w) is the cross-correlation power spectrum, and (·)* represents the conjugate operation;

[0079] The cross-correlation power spectrum R m,m-1(w) the corresponding GCC function, where the formula of the GCC function is:

[0080] Finding the GCC m,m-1 The maximum value of (τ) can be regarded as τ' m,m-1 ;

[0081] In the same way, τ' m-1,m-2 is obtained.

[0082] In one embodiment, the equation of the transmission distance of the signal data of the target signal source at adjacent time points is:

[0083] Where c is the transmission speed of the carrier of the signal data sent by the target signal source, x m and y m are the coordinates of the UAV in the X-axis and Y-axis of the rectangular coordinate system at the time point to+mT, x m-1 and y m-1 are the coordinates of the UAV in the X-axis and Y-axis of the rectangular coordinate system at the time point to+(m-1)T; and x and y are the coordinates of the target signal source in the X-axis and Y-axis of the rectangular coordinate system.

[0084] On the basis of the foregoing, the position of the target signal source is determined by simultaneously solving all K-1 equations, where the K-1 equations are specifically:

[0085] According to the simultaneous equations, the position (x, y) of the target signal source can be obtained.

[0086] It can be seen that, in the embodiment of the application, the UAV is caused to move along a preset trajectory, signal data is collected at different time points, and the TDOA information of the UAV at different time points is obtained by the base station based on the correlation between the position information of the UAV at different time points and the received signal data, so that the relative position of the target signal source is finally determined and the positioning of the target signal source within a certain period of time is realized. The movement of the UAV simulates the effect of multiple base stations. The function of multiple base stations is realized by using only one base station, and the hardware cost is reduced.

[0087] Fig. 6 is a structural schematic diagram of a UAV airborne single-station-based TDOA positioning system provided by the embodiment of the application.

[0088] As shown in Fig. 6, the UAV airborne single-station-based TDOA positioning system 100 provided by the embodiment of the application uses a single UAV airborne base station to realize the positioning of a target signal source; the system 100 comprises:

[0089] The pilot information acquisition unit 101 is configured to obtain the duration of a single pilot signal and the time interval of adjacent pilot signals according to the signal data transmitted by the target signal source and acquired by the unmanned aerial base station, wherein each signal data comprises a time domain signal and a repeated pilot signal carried at the front end of the time domain signal.

[0090] The signal acquisition unit 102 is configured to acquire the signal data transmitted by the target signal source at K time points in a period of the first time under the condition that the unmanned aerial vehicle moves along the preset trajectory, wherein the first time is equal to the time interval of adjacent pilot signals, K is a positive integer, and K≥3.

[0091] The TDOA information calculation unit 103 is configured to calculate the TDOA information of adjacent time points according to the obtained K signal data.

[0092] The unmanned aerial vehicle position information determination unit 104 is configured to establish a rectangular coordinate system and obtain the coordinate position information of the unmanned aerial vehicle at the K time points according to the preset trajectory of the unmanned aerial vehicle.

[0093] The target signal source position determination unit 105 is configured to establish the transmission speed of the signal data transmitted by the target signal source, the TDOA information of adjacent time points and the coordinate position information of the unmanned aerial vehicle at the corresponding time points, establish the equation of the transmission distance of the signal data of the target signal source at adjacent time points, and determine the position of the target signal source by simultaneously solving all K-1 equations.

[0094] Referring to FIG. 7, FIG. 7 is a structural schematic diagram of the TDOA information calculation unit according to an embodiment of the present application. As an implementation manner, the TDOA information calculation unit 103 specifically comprises:

[0095] The model establishment sub-unit 1031 is configured to establish a model of the signal data received by the unmanned aerial vehicle at different time points, specifically as follows: r j (t)=hs(t-τ j )+n j (t); wherein r j represents the signal data received by the unmanned aerial vehicle at to+jT, to represents the starting time of the movement of the unmanned aerial vehicle, T represents the first time, τ j represents the channel delay caused by the change of the position of the unmanned aerial vehicle at to+jT, n j (t) represents the time domain Gaussian white noise, and the value of T is within 1 millisecond, so that the channel gain of two adjacent time points is basically unchanged, and the position of the target signal source at two adjacent time points is basically unchanged; wherein j is a natural number, and the value of j is 0, 1…K-1.

[0096] The correlation equation establishing sub-unit 1032 is configured to establish a correlation equation of the signal data received by the unmanned aerial vehicle at two adjacent time instants, and specifically, r m (t)≈r m-1 (t-T-τ m,m-1 ); where r m-1 is the signal data received by the unmanned aerial vehicle at to+(m-1)T, τ m,m-1 is an actual value of the relative time delay of the channel at to+mT and to+(m-1)T, and τ m,m-1 =τ m -τ m-1 .

[0097] The channel relative time delay estimation sub-unit 1033 is configured to estimate the relative delay estimation values τ′ m,m-1 and τ′ m-1,m-2 of the channels at three adjacent time instants by using generalized cross-correlation, where τ′ m,m-1 is an estimation value of the relative time delay of the channel at to+mT and to+(m-1)T, and τ′ m-1,m-2 is an estimation value of the relative time delay of the channel at to+(m-1)T and t0+(m-2)T; where m is a natural number, and m=2, 3, …, K-1, and K-1 relative delay estimation values of the channels at two adjacent time instants are obtained after K time instants; and the relative delay estimation values of the channels at two adjacent time instants are used as the TDOA information of the corresponding two adjacent time instants.

[0098] Please continue to refer to FIG. 8, which is a structural schematic diagram of the channel relative time delay estimation sub-unit according to an embodiment of the present application. As shown in FIG. 8, the channel relative time delay estimation sub-unit 1033 specifically includes:

[0099] The signal conversion sub-unit 10331 is configured to perform cross-correlation power spectrum on the frequency domain signals of the signal data received at two adjacent time instants, and the formula is:

[0100] R m,m-1 (w)=r m (w)r m-1 * (w), where R m,m-1 (w) is the cross-correlation power spectrum, and (·)* represents the conjugate operation.

[0101] The GCC function determination sub-unit 10332 is configured to obtain the GCC function corresponding to the cross-correlation power spectrum R m,m-1 (w), and the formula of the GCC function is:

[0102] The GCC function maximum value determination sub-unit 10333 is configured to find the maximum value of the GCC function R m,m-1The maximum value of (τ) and the τ corresponding to the maximum value respectively can be regarded as τ' m,m-1 .

[0103] Fig. 9 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. As shown in Fig. 9, the electronic device 40 comprises:

[0104] a processor 41; and

[0105] a memory 42 configured to store executable instructions of the processor;

[0106] The processor 41 is configured to execute the above-mentioned method by executing the executable instructions.

[0107] The processor 41 can communicate with the memory 42 through a bus 43.

[0108] In addition, an embodiment of the present application further provides a storage medium having a computer program stored thereon, and the program is executed by a processor to implement the method according to the first aspect and the optional solutions thereof.

[0109] The method and system for TDOA positioning based on a single station of a UAV provided by the present application make full use of the position information of the UAV and the time interval of adjacent pilot signals, and use GCC to estimate the TDOA information at the current time and the previous time. By controlling the UAV to move along a preset trajectory, and by means of the correlation between the position information of the UAV at different times and the received signal data, the base station can obtain the TDOA information of the UAV at different times, and 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. Thus, the function of multiple base stations is realized by using only one base station, and the hardware cost is reduced. Moreover, the positioning accuracy is high and can meet the demand.

[0110] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction-related hardware. The foregoing 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 foregoing storage medium includes ROM, RAM, magnetic disc or optical disc and various storage medium capable of storing program codes.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and such modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A TDOA positioning method based on an airborne single station of an unmanned aerial vehicle (UAV), characterized in that, The method involves using a single UAV-borne base station to locate a target signal source; the method includes: The UAV-borne base station acquires signal data transmitted 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; wherein each signal data includes a time-domain signal and repeating pilot signals carried at the front end of the time-domain signal; The drone is controlled to move along a preset trajectory, and signal data transmitted by the target signal source is acquired at K time points with the first time point as the period; wherein the time interval between the first time point and the two adjacent pilot signal segments is equal, K is a positive integer, and K≥3; Based on the obtained K signal data, calculate the TDOA information at adjacent time points; Establish a Cartesian coordinate system and obtain the coordinate position information of the UAV at K time points based on the UAV's preset trajectory; Establish the transmission speed of the signal data emitted by the target signal source, the TDOA information of adjacent time moments and the coordinate position information of the UAV at the corresponding time moments, establish the equation for the transmission distance of the signal data of the target signal source at adjacent time moments, and solve all K-1 equations to determine the position of the target signal source.

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

3. The TDOA positioning method based on an UAV-borne single station according to claim 2, characterized in that, The relative delay τ′ of the channel at three adjacent time points is estimated using generalized cross-correlation. m,m-1 and τ′ m-1,m-2 Specifically, it includes: For the signal data r received at two adjacent time points m (t) and r m-1 The frequency domain signal r of (t) m (ω) and r m-1 The formula for the cross-correlation power spectrum of (ω) is: R m,m-1 (w)=r m (w)r m-1 * (w), where R m,m-1 (w) represents the cross-correlation power spectrum, (·) * Represents the conjugate operation; Obtain the cross-correlation power spectrum R m,m-1 (w) corresponds to the GCC function, where the formula for the GCC function is: Find GCC m,m-1 The maximum value of (τ), and the τ corresponding to the maximum value can be regarded as τ′. m,m-1 ; τ′ is obtained in the same way m-1,m-2 .

4. The TDOA positioning method based on an unmanned aerial vehicle (UAV) airborne single station according to any one of claims 1-3, characterized in that, The equation for the transmission distance of the target signal source's signal data in adjacent time intervals: Where c is the carrier speed of the signal data transmitted by the target signal source, and x m and y m Let x and y be the coordinates of the UAV on the X and Y axes in the Cartesian coordinate system at time to+mT, respectively. m-1 and y m-1 , , are the X and Y coordinates of the UAV in the Cartesian coordinate system at time to+(m-1)T, respectively; x and y are the X and Y coordinates of the target signal source in the Cartesian coordinate system, respectively.

5. The TDOA positioning method based on an UAV-borne single station according to claim 4, characterized in that, The location of the target signal source is determined by solving all K-1 equations simultaneously, where the K-1 equations are as follows: The position (x, y) of the target signal source can be obtained from the simultaneous equations.

6. A TDOA positioning system based on an unmanned aerial vehicle (UAV) airborne single station, characterized in that, The system utilizes a single UAV-borne base station to locate target signal sources; the system includes: The pilot information acquisition unit is used to obtain the duration of a single pilot signal and the time interval between adjacent pilot signals based on the signal data sent by the target signal source obtained by the UAV airborne base station; wherein each signal data includes a time domain signal and a repeating pilot signal carried at the front end of the time domain signal; The signal acquisition unit is used to acquire signal data sent by the target signal source at K time points, with a first time point as the period, when the UAV moves according to a preset trajectory; wherein the first time point is equal to the time interval between two adjacent pilot signal segments, K is a positive integer, and K≥3; The TDOA information calculation unit is used to calculate the TDOA information of adjacent time points based on 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 time points based on the UAV's preset trajectory. The target signal source location determination unit is used to establish the transmission speed of the signal data transmitted by the target signal source, the TDOA information of adjacent time moments and the coordinate position information of the UAV at the corresponding time moment, establish the equation of the transmission distance of the signal data of the target signal source at adjacent time moments, and solve all K-1 equations to determine the location of the target signal source.

7. The TDOA positioning system based on an unmanned aerial vehicle (UAV) airborne single station 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 UAV at different times, specifically: r j (t)=hs(t-τ j )+n j (t); where r j This represents the signal data received by the UAV at time to+jT, where to is the start time of the UAV's movement, T is the first time, and τ... j n represents the channel delay caused by the change in the UAV's position at time to+jT. j (t) represents time-domain Gaussian white noise, and T takes a value within 1 millisecond, so that the channel gain between two adjacent time points remains basically unchanged, and the position of the target signal source between two adjacent time points remains basically unchanged; where j is a natural number, and the value of j is 0, 1…K-1. The correlation equation establishment sub-unit is used to establish the correlation equation for the signal data received by the UAV at two adjacent time points, specifically: r m (t)≈r m-1 (tT-τ m,m-1 ); where r m-1 The signal data received by the UAV at time to+(m-1)T; τ m,m-1 Let τ be the actual value of the relative channel delay between 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 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 Let τ′ be the estimated relative channel delay at time to+mT and time to+(m-1)T. m-1,m-2 The relative delay of the channel at time to+(m-1)T and time t0+(m-2)T is estimated; where m is a natural number, and let m = 2, 3...K-1, after K times, we get K-1 relative delay estimates of the channel at two adjacent times; where the relative delay estimates of the channel at two adjacent times are used as the TDOA information of the corresponding two adjacent times.

8. The TDOA positioning system based on an unmanned aerial vehicle (UAV) airborne single station according to claim 7, characterized in that, The channel relative time delay estimation subunit specifically includes: The signal conversion subunit is used to perform cross-correlation power spectrum calculation on the frequency domain signals of the signal data received at two adjacent time points. The formula is as follows: R m,m-1 (w)=r m (w)r m-1 * (w), where R m,m-1 (w) represents the cross-correlation power spectrum, (·) * Represents the conjugate operation; The GCC function determines the sub-cells and is used to obtain the cross-correlation power spectrum R. m,m-1 (w) corresponds to the GCC function, where the formula for the GCC function is: The maximum value of the GCC function determines the sub-unit, which is used to find the GCC. m,m-1 The maximum value of (τ), and the τ corresponding to the maximum value can be regarded as τ′. m,m-1 .

9. An electronic device, characterized in that, Including processor and memory, The memory is used to store code and related data; The processor is configured to execute 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, which, when executed by a processor, implements the method of any one of claims 1 to 5.

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