Safety beam design method and system for power system unmanned aerial vehicle

Abstract

The invention discloses a safety beam design method for an unmanned aerial vehicle of a power system. The method comprises the following steps: constructing an unmanned aerial vehicle safety communication experiment platform comprising an unmanned aerial vehicle base station, a ground user and an eavesdropper; modeling a communication process between the unmanned aerial vehicle including an eavesdropper and a ground user; constructing a safe beam design objective function by taking the safe energy consumption efficiency of the unmanned aerial vehicle as an optimization objective; and solving the objective function based on a two-layer optimization algorithm to complete the design of the safety beam for the unmanned aerial vehicle of the power system. The invention also discloses a system for realizing the safety beam design method for the power system unmanned aerial vehicle. According to the method, through the construction of the experimental platform and the modeling and solving of the communication process, the safety beam design for the unmanned aerial vehicle of the power system is realized, and the method is higher in reliability and better in safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of unmanned aerial vehicles, and specifically designs a safety beam design method and system for unmanned aerial vehicles in power systems. Background Art

[0002] With the development of economy and technology and the improvement of people's living standards, electricity has become an indispensable secondary energy source in people's production and life, bringing endless convenience to people's production and life. Therefore, ensuring the stable and reliable supply of electricity has become one of the most important tasks of the power system.

[0003] At present, drones have been widely used in power systems and undertake important tasks such as power system inspection and communication. The safe and stable operation of drones is also directly related to the safe and stable operation of power systems.

[0004] Passive eavesdropping is one of the most subtle attacks in the wireless communication process of drones. In order to enhance the anti-eavesdropping ability of broadcast channels, researchers have proposed broadcast channel anti-eavesdropping technology that utilizes the spatial freedom and physical layer technology of drones. However, due to the lack of fixed and stable infrastructure of drone platforms, the random disturbance characteristics brought about by them, as well as the natural randomness of airflow and body vibration, the implementation effect of existing drone broadcast channel anti-eavesdropping solutions is poor, and the reliability and security of drone communication processes cannot be guaranteed. Summary of the invention

[0005] One of the purposes of the present invention is to provide a safety beam design method for power system UAVs with high reliability and good safety.

[0006] A second object of the present invention is to provide a system for implementing the safety beam design method for power system UAVs.

[0007] The safety beam design method for a power system UAV provided by the present invention comprises the following steps:

[0008] S1. Build a UAV secure communication experimental platform including UAV base stations, ground users and eavesdroppers;

[0009] S2. Model the communication process between the UAV and the ground user including the eavesdropper according to the platform built in step S1;

[0010] S3. Based on the modeling results of step S2, the safety beam design objective function is constructed with the safety energy efficiency of the UAV as the optimization goal;

[0011] S4. The objective function constructed in step S3 is solved based on a two-layer optimization algorithm to complete the design of the safety beam for the power system UAV.

[0012] The construction of the UAV secure communication experimental platform including the UAV base station, the ground user and the eavesdropper described in step S1 specifically includes the following steps:

[0013] Based on the BS communication method, a UAV secure communication experimental platform is constructed, which includes UAV base stations, legal ground users and eavesdroppers.

[0014] The flying altitude of the drone is H0. The drone communicates with legitimate users on the ground. The eavesdropper eavesdrops on the legitimate information of the communication process.

[0015] Both the drone base station and the eavesdropper have uniform linear arrays, and the number of antennas of the drone is N U , the number of antennas of the eavesdropper is N E , the legal ground user is a single antenna.

[0016] Step S2, based on the platform built in step S1, models the communication process between the drone including the eavesdropper and the ground user, specifically including the following steps:

[0017] The UAV's transmission signal vector x is expressed as x=ws+v, where w is the beamforming vector, s is the confidentiality signal, v is the artificial noise vector and satisfies v~CN(0,V), CN is a complex Gaussian distribution, and V is an artificial noise covariance matrix greater than or equal to 0; the UAV base station and the ground legal user are legal communication channels;

[0018] The Rice channel model is used to model the UAV air-ground channel, taking into account both LoS links and non-LoS links;

[0019] The channel vector between the drone and the legal user on the ground is h B , the channel vector between the drone and the eavesdropper is H E ,and

[0020]

[0021] Where A L is the path loss factor of the LoS link; d B is the distance from the drone to the legal user; α L is the path loss index of the LoS link; K B is the Rice factor of the legal channel; h B,L represents the LoS composition, and b U is the antenna spacing on the UAV antenna array, λ c is the wavelength of the carrier center frequency, is the horizontal AOD between the UAV and the legal ground user, θ Bis the vertical AOD between the UAV and the legal ground user, N U A is the number of drone antennas; N is the path loss factor of the non-LoS link; α N is the path loss exponent of the non-LoS link; h B,N It is a legal channel that is not composed of LoS; d E is the distance between the drone and the eavesdropper; K E is the Ricean factor of the eavesdropping channel; H E,L The eavesdropping channel is non-LoS, and is an intermediate variable and b E is the antenna spacing on the eavesdropper’s antenna array, λ c is the wavelength of the carrier center frequency, φ E is the horizontal AOA between the UAV and the eavesdropper, θ E is the vertical AOA between the UAV and the eavesdropper, N E is the number of eavesdropper antennas; H E,N It is the non-LOS component of the eavesdropping channel.

[0022] According to the modeling result of step S2, the safety beam design objective function is constructed with the safety energy consumption efficiency of the drone as the optimization target, which specifically includes the following steps:

[0023] The following formula is used as the safety beam design objective function:

[0024]

[0025] stTr(Q w )+Tr(Q v )≤P tx

[0026] Rank(Q w )=1

[0027] Where R S is the data transmission rate of the legal channel, and R S =log2(1+γ S ), γ S is the signal-to-noise ratio at the legitimate user side and w is the UAV transmitting beam vector, v is the artificial noise vector; Q w is the covariance matrix of w; Q v is the covariance matrix of v; Tr(Q w ) is the UAV transmission power; P tx is the maximum transmission power of the drone.

[0028] Step S4 solves the objective function constructed in step S3 based on a two-layer optimization algorithm, specifically including the following steps:

[0029] First, the Dinkelbach method is used to process the fractional programming problem of the objective function constructed in step S3;

[0030] Then, the s-process and semidefinite programming method are used for transformation to obtain a convex problem of the following form:

[0031]

[0032] stTr(Q w )+Tr(Q v )≤P tx

[0033] R N ≥R th

[0034] Q w ≥0

[0035] Rank(Q w )=1

[0036] Where μ * is the maximum energy efficiency, R th is the minimum UAV transmission rate;

[0037] If and only if When μ in the above convex problem * Get the optimal solution;

[0038] Therefore, the objective function is transformed into

[0039]

[0040] stTr(Q w )+Tr(Q v )≤P tx

[0041] Rank(Q w )=1

[0042] Where μ(t) is the energy efficiency; P tx is the maximum transmission power of the UAV;

[0043] Introducing slack variables in

[0044] is the first slack variable, and

[0045] is the second slack variable, and

[0046] is the third slack variable, and

[0047] is the fourth slack variable, and Where h B is the legal channel vector; is the transpose of the legal channel vector; σ B is the noise power at the legal channel end; H E is the eavesdropping channel vector; is the transpose of the eavesdropping channel vector; Q E is the covariance matrix of the eavesdropper’s decoding vector; σ E is the noise power at the eavesdropper end;

[0048] Introducing slack variables After that, the model is expressed as

[0049]

[0050] stTr(Q w )+Tr(Q v )≤P tx

[0051]

[0052]

[0053] Rank(Q w )=1

[0054] Where Γ is the objective function variable; β1 is the first introduced conversion variable; β2 is the first introduced conversion variable; β3 is the first introduced conversion variable; β4 is the first introduced conversion variable;

[0055] Finally, the obtained model is solved.

[0056] The present invention also provides a system for implementing the safety beam design method for unmanned aerial vehicles in an electric power system, comprising a platform construction module, a communication modeling module, a target design module and a beam design module; the platform construction module, the communication modeling module, the target design module and the beam design module are connected in series in sequence; the platform construction module is used to construct a unmanned aerial vehicle safety communication experimental platform including a unmanned aerial vehicle base station, ground users and eavesdroppers, and upload data information to the communication modeling module; the communication modeling module is used to model the communication process between the unmanned aerial vehicle including the eavesdropper and the ground user according to the received data information and the constructed platform, and upload the data information to the target design module; the target design module is used to construct a safety beam design objective function according to the received data information and the modeling results, taking the safety energy consumption efficiency of the unmanned aerial vehicle as the optimization goal, and upload the data information to the beam design module; the beam design module is used to solve the constructed objective function based on the received data information based on a two-layer optimization algorithm to complete the design of the safety beam for the unmanned aerial vehicle in the electric power system.

[0057] The safety beam design method and system for power system UAVs provided by the present invention not only realize the safety beam design for power system UAVs through the construction of an experimental platform and the modeling and solving of the communication process, but also have higher reliability and better safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 The figure is a schematic diagram of the method flow of the present invention.

[0059] Figure 2 Schematic diagram of the functional modules of the system of the present invention. DETAILED DESCRIPTION

[0060] like Figure 1 The method flow chart of the method of the present invention is shown as follows: The safety beam design method for a power system UAV disclosed in the present invention comprises the following steps:

[0061] S1. Construct a UAV secure communication experimental platform including UAV base stations, ground users and eavesdroppers; specifically include the following steps:

[0062] Based on the BS communication method, a UAV secure communication experimental platform is constructed, which includes UAV base stations, legal ground users and eavesdroppers.

[0063] The flying altitude of the drone is H0. The drone communicates with legitimate users on the ground. The eavesdropper eavesdrops on the legitimate information of the communication process.

[0064] Both the drone base station and the eavesdropper have uniform linear arrays, and the number of antennas of the drone is N U , the number of antennas of the eavesdropper is N E,The legal user on the ground has a single antenna;

[0065] S2. Based on the platform built in step S1, the communication process between the UAV including the eavesdropper and the ground user is modeled; specifically, the following steps are included:

[0066] The UAV's transmission signal vector x is expressed as x=ws+v, where w is the beamforming vector, s is the confidentiality signal, v is the artificial noise vector and satisfies v~CN(0,V), CN is a complex Gaussian distribution, and V is an artificial noise covariance matrix greater than or equal to 0; the UAV base station and the ground legal user are legal communication channels;

[0067] The Rice channel model is used to model the UAV air-ground channel, taking into account both LoS links and non-LoS links;

[0068] The channel vector between the drone and the legal user on the ground is h B , the channel vector between the drone and the eavesdropper is H E ,and

[0069]

[0070] Where A L is the path loss factor of the LoS link; d B is the distance from the drone to the legal user; α L is the path loss index of the LoS link; K B is the Rice factor of the legal channel; h B,L represents the LoS composition, and b U is the antenna spacing on the UAV antenna array, λ c is the wavelength of the carrier center frequency, is the horizontal AOD between the UAV and the legal ground user, θ B is the vertical AOD between the UAV and the legal ground user, N U A is the number of drone antennas; N is the path loss factor of the non-LoS link; α N is the path loss exponent of the non-LoS link; h B,N It is a legal channel that is not composed of LoS; d E is the distance between the drone and the eavesdropper; K E is the Ricean factor of the eavesdropping channel; H E,L The eavesdropping channel is non-LoS, and is an intermediate variable and b E is the antenna spacing on the eavesdropper’s antenna array, λ c is the wavelength of the carrier center frequency, φE is the horizontal AOA between the UAV and the eavesdropper, θ E is the vertical AOA between the UAV and the eavesdropper, N E is the number of eavesdropper antennas; H E,N It is the non-LOS component of the eavesdropping channel;

[0071] S3. Based on the modeling results of step S2, the safety beam design objective function is constructed with the safety energy efficiency of the drone as the optimization target; specifically, the following steps are included:

[0072] For drones, to maximize their security energy efficiency, the confidential information beam and artificial noise vector are jointly optimized; therefore, the following formula is used as the security beam design objective function:

[0073]

[0074] stTr(Q w )+Tr(Q v )≤P tx

[0075] Rank(Q w )=1

[0076] Where R S is the data transmission rate of the legal channel, and R S =log2(1+γ S ), γ S is the signal-to-noise ratio at the legitimate user side and w is the UAV transmitting beam vector, v is the artificial noise vector; Q w is the covariance matrix of w; Q v is the covariance matrix of v; Tr(Q w ) is the UAV transmission power; P tx is the maximum transmission power of the drone;

[0077] Among them, the first constraint represents the maximum transmission power constraint of the UAV;

[0078] S4. Solve the objective function constructed in step S3 based on a two-layer optimization algorithm to complete the design of the safety beam for the power system drone; specifically, the steps include:

[0079] Solve the optimal solution of the objective function of the UAV: ​​Due to the complexity of the objective function and the coupling of the constraints, the problem established is non-convex and cannot be solved directly; first, the Dinkelbach method is used to deal with the fractional programming problem of the objective function constructed in step S3;

[0080] Then, the s-process and semidefinite programming method are used for transformation to obtain a convex problem of the following form:

[0081]

[0082] stTr(Q w )+Tr(Q v )≤P tx

[0083] R N ≥R th

[0084] Q w ≥0

[0085] Rank(Q w )=1

[0086] Where μ * is the maximum energy efficiency; R th is the minimum UAV transmission rate;

[0087] If and only if When μ in the above convex problem * Get the optimal solution;

[0088] Therefore, the objective function is transformed into

[0089]

[0090] stTr(Q w )+Tr(Q v )≤P tx

[0091] Rank(Q w )=1

[0092] Where μ(t) is the energy efficiency; P tx is the maximum transmission power of the UAV;

[0093] Introducing slack variables in

[0094] is the first slack variable, and

[0095] is the second slack variable, and

[0096] is the third slack variable, and

[0097] is the fourth slack variable, and Where h B is the legal channel vector; is the transpose of the legal channel vector; σ B is the noise power at the legal channel end; H E is the eavesdropping channel vector; is the transpose of the eavesdropping channel vector; Q E is the covariance matrix of the eavesdropper’s decoding vector; σ E is the noise power at the eavesdropper end;

[0098] Introducing slack variables After that, the model is expressed as

[0099]

[0100] stTr(Q w )+Tr(Q v )≤P tx

[0101]

[0102]

[0103] Rank(Q w )=1

[0104] Where Γ is the objective function variable; β1 is the first introduced conversion variable; β2 is the first introduced conversion variable; β3 is the first introduced conversion variable; β4 is the first introduced conversion variable;

[0105] Finally, the obtained model is solved.

[0106] like Figure 2The functional module schematic diagram of the system of the present invention is shown as follows: the system for realizing the safety beam design method for unmanned aerial vehicles in power systems disclosed in the present invention comprises a platform construction module, a communication modeling module, a target design module and a beam design module; the platform construction module, the communication modeling module, the target design module and the beam design module are connected in series in sequence; the platform construction module is used to construct a UAV safety communication experimental platform including a UAV base station, a ground user and an eavesdropper, and upload the data information to the communication modeling module; the communication modeling module is used to model the communication process between the UAV including the eavesdropper and the ground user according to the received data information and the constructed platform, and upload the data information to the target design module; the target design module is used to construct a safety beam design objective function according to the received data information and the modeling results, taking the safety energy consumption efficiency of the UAV as the optimization target, and upload the data information to the beam design module; the beam design module is used to solve the constructed objective function according to the received data information based on a two-layer optimization algorithm to complete the design of the safety beam for the unmanned aerial vehicle in the power system.

Claims

1. A safety beam design method for a power system UAV, comprising the following steps: S1. Build a UAV secure communication experimental platform including UAV base stations, ground users and eavesdroppers; S2. Model the communication process between the UAV and the ground user including the eavesdropper according to the platform built in step S1; S3. Based on the modeling results of step S2, the safety beam design objective function is constructed with the safety energy efficiency of the UAV as the optimization goal; S4. The objective function constructed in step S3 is solved based on a two-layer optimization algorithm to complete the design of the safety beam for the power system UAV.

2. The safety beam design method for power system UAV according to claim 1 is characterized in that The construction of the UAV secure communication experimental platform including the UAV base station, the ground user and the eavesdropper described in step S1 specifically includes the following steps: Based on the BS communication method, a UAV secure communication experimental platform is constructed, which includes UAV base stations, legal ground users and eavesdroppers. The flying altitude of the drone is H0. The drone communicates with legitimate users on the ground. The eavesdropper eavesdrops on the legitimate information of the communication process. Both the drone base station and the eavesdropper have uniform linear arrays, and the number of antennas of the drone is N U , the number of antennas of the eavesdropper is N E , the legal ground user is a single antenna.

3. The safety beam design method for power system UAV according to claim 2 is characterized in that Step S2, based on the platform built in step S1, models the communication process between the drone including the eavesdropper and the ground user, specifically including the following steps: The UAV's transmission signal vector x is expressed as x=ws+v, where w is the beamforming vector, s is the confidentiality signal, v is the artificial noise vector and satisfies v~CN(0,V), CN is a complex Gaussian distribution, and V is an artificial noise covariance matrix greater than or equal to 0; the UAV base station and the ground legal user are legal communication channels; The Rice channel model is used to model the UAV air-ground channel, taking into account both LoS links and non-LoS links; The channel vector between the drone and the legal user on the ground is h B , the channel vector between the drone and the eavesdropper is H E ,and Where A L is the path loss factor of the LoS link; d B is the distance from the drone to the legal user; α L is the path loss index of the LoS link; K B is the Rice factor of the legal channel; h BL represents the LoS composition, and b U is the antenna spacing on the UAV antenna array, λ c is the wavelength of the carrier center frequency, is the horizontal AOD between the UAV and the legal ground user, θ B is the vertical AOD between the UAV and the legal ground user, N U A is the number of drone antennas; N is the path loss factor of the non-LoS link; α N is the path loss exponent of the non-LoS link; h B,N It is a legal channel that is not composed of LoS; d E is the distance between the drone and the eavesdropper; K E is the Ricean factor of the eavesdropping channel; H EL The eavesdropping channel is non-LoS, and is an intermediate variable and b E is the antenna spacing on the eavesdropper’s antenna array, λ c is the wavelength of the carrier center frequency, φ E is the horizontal AOA between the drone and the eavesdropper, is the vertical AOA between the UAV and the eavesdropper, N E is the number of eavesdropper antennas; H E,N It is the non-LOS component of the eavesdropping channel.

4. The safety beam design method for power system UAV according to claim 3 is characterized in that According to the modeling result of step S2, the safety beam design objective function is constructed with the safety energy consumption efficiency of the drone as the optimization target, which specifically includes the following steps: The following formula is used as the safety beam design objective function: s.t.Tr(Q w )+Tr(Q v )≤P tx Rank(Q w )=1 Where R S is the data transmission rate of the legal channel, and R S =log2(1+γ S ), γ S is the signal-to-noise ratio at the legitimate user side and w is the UAV transmitting beam vector, v is the artificial noise vector; Q w is the covariance matrix of w; Q v is the covariance matrix of v; Tr(Q w ) is the UAV transmission power; P tx is the maximum transmission power of the drone.

5. The safety beam design method for power system UAV according to claim 4 is characterized in that Step S4 solves the objective function constructed in step S3 based on a two-layer optimization algorithm, specifically including the following steps: First, the Dinkelbach method is used to process the fractional programming problem of the objective function constructed in step S3; Then, the s-process and semidefinite programming method are used for transformation to obtain a convex problem of the following form: s.t.Tr(Q w )+Tr(Q v )≤P tx R N ≥R th Q w ≥0 Rank(Q w )=1 Where μ * is the maximum energy efficiency, R th is the minimum UAV transmission rate; If and only if When μ in the above convex problem * Get the optimal solution; Therefore, the objective function is transformed into s.t.Tr(Q w )+Tr(Q v )≤P tx Rank(Q w )=1 Where μ(t) is the energy efficiency; P tx is the maximum transmission power of the UAV; Introducing slack variables in is the first slack variable, and is the second slack variable, and is the third slack variable, and is the fourth slack variable, and Where h B is the legal channel vector; is the transpose of the legal channel vector; σ B is the noise power at the legal channel end; H E is the eavesdropping channel vector; is the transpose of the eavesdropping channel vector; Q E is the covariance matrix of the eavesdropper’s decoding vector; σ E is the noise power at the eavesdropper end; Introducing slack variables After that, the model is expressed as s.t.Tr(Q w )+Tr(Q v )≤P tx Rank(Q w )=1 Where Γ is the objective function variable; β1 is the first introduced conversion variable; β2 is the first introduced conversion variable; β3 is the first introduced conversion variable; β4 is the first introduced conversion variable; Finally, the obtained model is solved.

6. A system for implementing the safety beam design method for a power system UAV according to any one of claims 1 to 5, characterized in that It includes a platform construction module, a communication modeling module, a target design module and a beam design module; the platform construction module, the communication modeling module, the target design module and the beam design module are connected in series in sequence; the platform construction module is used to build a UAV secure communication experimental platform including a UAV base station, a ground user and an eavesdropper, and upload data information to the communication modeling module; The communication modeling module is used to model the communication process between the UAV, including the eavesdropper, and the ground user according to the received data information and the built platform, and upload the data information to the target design module; The target design module is used to construct the safety beam design objective function based on the received data information and the modeling results, taking the safety energy consumption efficiency of the UAV as the optimization target, and upload the data information to the beam design module; The beam design module is used to solve the constructed objective function based on the received data information and a two-layer optimization algorithm to complete the design of the safety beam for the power system UAV.

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