High-dynamic motion carrier communication signal synchronization method based on motion information measurement

Abstract

The invention discloses a high-dynamic motion carrier communication signal synchronization method based on motion information measurement, and belongs to the technical field of high-dynamic signal synchronization. The invention solves the problems of poor communication Doppler frequency shift compensation precision, long signal synchronization time and small frequency compensation range between existing high-dynamic operation carriers. According to the method, an orbital dynamics equation set of a target carrier is established in a coordinate system o-xyz, and real-time motion information of the target carrier is obtained through calculation by utilizing the dynamics equation set; according to the real-time motion information of the target carrier, based on an aircraft dynamics theory, extrapolating a speed rule of the target carrier by using a guidance law; predicting the speed of the target carrier by using the speed rule of the target carrier; establishing a new Doppler change model of the guidance signal under the fast change channel, and calculating Doppler frequency shift by using the predicted speed of the target carrier: compensating the communication signal of the target carrier by using the Doppler frequency shift to realize the synchronization of the communication signal. The method is suitable for high-dynamic carrier communication synchronization.

Description

Technical Field

[0001] The invention belongs to the technical field of high dynamic signal synchronization. Background Art

[0002] Satellites and aircraft move at high speeds. For communications between such highly dynamic carriers, the Doppler shift of the signal changes very quickly over time, that is, there is a strong Doppler effect caused by the high-speed movement of the carrier. The high-dynamic environment not only makes the Doppler shift range of the signal very large, but also has the problem of a very fast rate of change of the Doppler shift over time, and even a very high-order rate of change. This increases the difficulty of the receiving end to capture and track the signal, and seriously affects the quality of the received signal.

[0003] The relative speed and acceleration between the transmitting and receiving carriers are calculated by using the motion characteristics of the carrier, and then the Doppler and Doppler change rate of the signal are estimated, and the normal capture range is greatly reduced by pre-compensation at the receiving or transmitting end. This method is very common in low-orbit satellite communications. First, the Doppler parameters are estimated based on the ephemeris information and the terminal position, and then pre-compensation is performed at the signal control station or the on-board transmitter, thereby increasing the frequency shift capture range by more than ten times.

[0004] The motion characteristics of satellites are periodic and regular, and their ephemeris information can be obtained or calculated in advance. However, for aircraft, especially those with interception functions, their flight trajectories change rapidly in real time, and the existing estimation and pre-compensation methods cannot meet the application requirements. Summary of the invention

[0005] The present invention aims to solve the problems of poor Doppler frequency shift compensation accuracy, long signal synchronization time and small frequency compensation range in existing high dynamic carrier communication. A high dynamic motion carrier communication signal synchronization method based on motion information measurement is provided.

[0006] The high-dynamic moving carrier communication signal synchronization method based on motion information measurement of the present invention comprises:

[0007] Step 1: Establish an inertial reference coordinate system o-xyz of the high-dynamic motion target carrier, establish the orbital dynamics equation group of the target carrier in the coordinate system o-xyz, and use the dynamics equation group to calculate and obtain the real-time motion information of the target carrier;

[0008] Step 2: extrapolating the target carrier's velocity law using the guidance law based on the real-time motion information of the target carrier and the aircraft dynamics theory;

[0009] Step 3: using the speed law of the target carrier to predict the speed of the target carrier;

[0010] Step 4: Establish a new Doppler variation model of the guidance signal under fast-changing channels, and use the predicted speed of the target carrier to calculate the Doppler frequency shift:

[0011] Step 5: Use the Doppler frequency shift to compensate for the communication signal of the target carrier to achieve synchronization of the communication signal.

[0012] Furthermore, in the present invention, in step 1, the orbital dynamics equations of the target carrier are:

[0013]

[0014] Where m is the mass of the vehicle, σ is the roll angle, and K D is the induced drag coefficient; L is the lift of the target carrier, D is the drag borne by the target carrier, g is the gravitational acceleration, represents the derivative of the target carrier's longitudinal range x, represents the derivative of the lateral range y of the target carrier, represents the derivative of the target carrier's altitude z, V is the target carrier's velocity, It represents the derivative of the target carrier's velocity, γ is the target carrier's ballistic inclination angle, and is positive when it rotates counterclockwise relative to the horizontal reference line. It represents the derivative of the ballistic inclination angle of the target carrier's motion, ψ is the heading angle of the target carrier, and the angle between the horizontal component of the target carrier's velocity and the x-axis is positive when it rotates counterclockwise relative to the x-axis. represents the derivative of the heading angle of the target carrier; where the lift L and the drag D are:

[0015]

[0016] because Then we have:

[0017]

[0018] ρ represents the atmospheric density; S is the reference area of ​​the wing; the aerodynamic coefficient C L and the drag coefficient C D for:

[0019]

[0020] in, is the lift coefficient rate, C D0 is the zero-lift drag coefficient, K D is the induced drag coefficient, C L represents the lift coefficient, C D represents the drag coefficient and α is the vehicle's angle of attack.

[0021] Furthermore, in the present invention, in step 1, the method for calculating and obtaining the real-time motion information of the target carrier is:

[0022] According to the control mode of the target carrier, obtain the guidance command acceleration overload a cmd , using the guidance command to accelerate the overload a cmd , calculate the attack angle α and inclination angle σ of the target carrier movement;

[0023]

[0024] x1=[sin(ψ),-cos(ψ),0] T

[0025] x2=[-sin(γ)cos(ψ),-sin(γ)sin(ψ),cos(ψ)] T

[0026] Among them, C L0 is the lift coefficient at zero angle of attack;

[0027] Combined with the attack angle α and the inclination angle σ, the fourth-order Runge-Kutta numerical integration method is used to solve the orbital dynamics equations of the target carrier, and the extrapolated results of the ballistic inclination angle γ and the movement speed V of the target carrier are obtained, and the real-time speed of the target carrier at the next moment is calculated.

[0028] Furthermore, in the present invention, in step 2, the method of using the guidance law to extrapolate the speed law of the target carrier is:

[0029] Step 21: Calculate the real-time acceleration according to the real-time motion information of the target carrier, and convert the real-time speed and the real-time acceleration into the real-time speed and the real-time acceleration in the measuring station coordinate system;

[0030] Step 22: Decompose the real-time velocity and real-time acceleration in the measuring station coordinate system into tangential and normal components;

[0031] Step 2 and 3: Decompose the real-time velocity and real-time acceleration of the target carrier into tangential and normal components for fitting, and fit and extrapolate the velocity of the target aircraft at the next moment to obtain the velocity law of the target carrier.

[0032] Furthermore, in the present invention, in step 21, the method for converting the real-time velocity and real-time acceleration into the measuring station coordinate system is:

[0033] Create the transformation matrix G:

[0034]

[0035] Wherein, J represents longitude and B represents latitude; the conversion matrix is ​​used to convert the coordinate system o-xyz to the station coordinate system:

[0036] a s (t) = G·a(t)

[0037] v d (t) = G·v(t)

[0038] Where a(t) is the real-time acceleration of the target carrier in the coordinate system o-xyz, v(t) is the real-time velocity of the target carrier in the coordinate system o-xyz, and v d (t) is the velocity of the target carrier station coordinate system, a s (t) is the acceleration of the target carrier station coordinate system.

[0039] Furthermore, in the present invention, in step 22, the formula for decomposing the real-time velocity and real-time acceleration in the measuring station coordinate system into tangential and normal components is:

[0040] v d, / / (k) = v d, / / (kT)+a s, / / (k)·T+s / / (k)+ε / / (k)

[0041] v d,⊥ (k) = v d,⊥ (kT)+a s,⊥ (k)·T+s ⊥ (k)+ε ⊥ (k)

[0042] Among them, ε ⊥ (k) represents the normal component of the random error vector ε(k) measured at time k, ε / / (k) represents the tangential component of the random error vector ε(k) measured at time k, a s, / / (k) represents the tangential component of the acceleration of the target carrier at time k, a s,⊥ (k) represents the normal component of the acceleration of the target carrier at time k, v d,⊥ (kT) represents the normal component of the target carrier's velocity at time kT, v d, / / (kT) represents the tangential component of the target carrier's velocity at time kT, s / / (k) represents the tangential component of the system error vector s(k) measured at time k, s ⊥ (k) represents the normal component of the system error vector s(k) measured at time k; the system error is expressed as a function of the system error parameter:

[0043] s(t)=s(t,β)

[0044] Where β represents the system error parameter vector.

[0045] Furthermore, in the present invention, in steps 2 and 3, the target carrier speed law is obtained as follows:

[0046] Φ(v d )=‖v d (k)‖=(v d, / / (k) 2 +v d,⊥ (k) 2 ) 1 / 2

[0047] a = arctan(v d,⊥ (k) / v d, / / (k))

[0048] Among them, v d, / / (k) and v d,⊥ (k) represents the target carrier velocity v at time k in the station coordinate system. d (k) the tangential and normal components;

[0049] v d, / / (k) = v d, / / (kT)+a s, / / (k)·T+s / / (k)+ε / / (k)

[0050] v d,⊥ (k) = v d,⊥ (kT)+a s,⊥ (k)·T+s ⊥ (k)+ε ⊥ (k)

[0051] Among them, a s, / / (k) and a s,⊥ (k) respectively represent the acceleration a at time k in the measuring station coordinate system s (k) tangential and normal components; ε / / (k) and ε ⊥ (k) represent the tangential and normal components of the measured random error vector ε(k), respectively;

[0052] The final target carrier velocity law is simplified to:

[0053] Φ(v d )=f(a,T)

[0054] a=g(v d ,T)

[0055] Where T is the time from time kT to time k.

[0056] Further, in the present invention, in step 4, the Doppler frequency shift is:

[0057] f d =((Φ(v d ) / λ)×cos(θ))

[0058] =((f(v x(k-T) ,v y(k-T) ,v z(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T) / λ)×cos(θ))

[0059] Among them, f d is the Doppler frequency shift, λ is the carrier wavelength, θ is the angle between the relative motion direction and the line connecting the transmitting and receiving ends,

[0060] (v xd ,v yd ,v zd )=f(v x(k-T) ,v y(k-T) ,v z(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T)k

[0061] v xd ,v yd ,v zd The x, y, and z axis components of the velocity vector of the aircraft in the station coordinate system, Dv' xk ,Dv' yk ,Dv 'z k represents the first-order derivative of the x, y and z components of the velocity vector in the station coordinate system.

[0062] Furthermore, in the present invention, in step 5, the method of compensating the communication signal of the target carrier by using the Doppler frequency shift is:

[0063] According to the estimated value of the Doppler frequency shift, the frequency range of the communication signal of the received target carrier is divided into multiple change rate sub-slots. The compensation waveform of the Doppler frequency shift of each change rate sub-slot is obtained by table lookup, and the compensation waveform is multiplied with the received data to achieve frequency compensation of the carrier Doppler change rate.

[0064] The method of the present invention establishes a new Doppler change model of the guidance signal under a fast-changing channel, estimates the instantaneous frequency shift through the Doppler change model function, breaks through the missile-borne computing power constraints, and solves the problem of large-scale rapid changes in Doppler frequency shift caused by ultra-high overload and three-dimensional random motion of high-dynamic carriers such as aircraft. First, the speed law of the aircraft can be extrapolated based on the guidance law using measured data to obtain the speed and acceleration information of the aircraft; then, a Doppler change model under a fast-changing channel is established, and the Doppler frequency shift change value can be obtained by taking the aircraft speed as input; finally, coarse frequency compensation and fine frequency compensation are performed based on the Doppler change value to achieve rapid synchronization of the captured signal. Through the guidance of missile-borne prior information, the method of the present invention can expand the Doppler capture range by 5 times, reduce the synchronization time to 2 / 3, and realize frequency shift estimation and compensation for ballistic trajectory prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 The present invention is a flow chart of the method. DETAILED DESCRIPTION

[0066] The following will be combined with the accompanying 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, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0067] Specific implementation method 1: refer to Figure 1 Specifically describing this embodiment, the high-dynamic motion carrier communication signal synchronization method based on motion information measurement described in this embodiment includes:

[0068] Step 1: Establish an inertial reference coordinate system o-xyz of the high-dynamic motion target carrier, establish the orbital dynamics equation group of the target carrier in the coordinate system o-xyz, and use the dynamics equation group to calculate and obtain the real-time motion information of the target carrier;

[0069] Step 2: extrapolating the target carrier's velocity law using the guidance law based on the real-time motion information of the target carrier and the aircraft dynamics theory;

[0070] Step 3: using the speed law of the target carrier to predict the speed of the target carrier;

[0071] Step 4: Establish a new Doppler variation model of the guidance signal under fast-changing channels, and use the predicted speed of the target carrier to calculate the Doppler frequency shift:

[0072] Step 5: Use the Doppler frequency shift to compensate for the communication signal of the target carrier to achieve synchronization of the communication signal.

[0073] Furthermore, in the present invention, in step 1, the orbital dynamics equations of the target carrier are:

[0074]

[0075] Among them, m is the mass of the aircraft, σ is the roll angle (roll angle), L is the lift, D is the drag, and g is the gravitational acceleration. represents the derivative of the target's longitudinal range x, represents the derivative of the lateral range y of the target carrier, represents the derivative of the target carrier's altitude z, V is the target carrier's velocity, It represents the derivative of the target carrier's velocity, γ is the target carrier's ballistic inclination angle, and is positive when it rotates counterclockwise relative to the horizontal reference line. It represents the derivative of the ballistic inclination angle of the target carrier's motion, ψ is the heading angle of the target carrier, and the angle between the horizontal component of the target carrier's velocity and the x-axis is positive when it rotates counterclockwise relative to the x-axis. represents the derivative of the heading angle of the target carrier; where the lift L and the drag D are:

[0076]

[0077] because Then we have:

[0078]

[0079] ρ represents the atmospheric density; S is the reference area of ​​the wing; the aerodynamic coefficient and the drag coefficient are:

[0080]

[0081] in, is the lift coefficient rate, C D0 is the zero-lift drag coefficient, K is the induced drag coefficient, C L represents the lift coefficient, C D Indicates the drag coefficient, K D is the induced drag coefficient;

[0082] Furthermore, in the present invention, in step 1, the method for calculating and obtaining the real-time motion information of the target carrier is:

[0083] According to the control mode of the target carrier, obtain the guidance command acceleration overload a cmd , using the guidance command to accelerate the overload a cmd , calculate the attack angle α and inclination angle σ of the target carrier movement;

[0084]

[0085] x1=[sin(ψ),-cos(ψ),0] T

[0086] x2=[-sin(γ)cos(ψ),-sin(γ)sin(ψ),cos(ψ)] T

[0087] Among them, C L0 is the lift coefficient at zero angle of attack;

[0088] The fourth-order Runge-Kutta numerical integration method is then used to solve the orbital dynamics equations of the target carrier, and the extrapolated results of the ballistic inclination angle γ and the movement velocity V of the target carrier are obtained, and the real-time velocity of the target carrier at the next moment is calculated.

[0089] Furthermore, in the present invention, in step 2, the method of using the guidance law to extrapolate the speed law of the target carrier is:

[0090] Step 21: Calculate the real-time acceleration according to the real-time motion information of the target carrier, and convert the real-time speed and the real-time acceleration into the real-time speed and the real-time acceleration in the measuring station coordinate system;

[0091] Step 22: Decompose the real-time velocity and real-time acceleration in the measuring station coordinate system into tangential and normal components;

[0092] Step 2 and 3: Decompose the real-time velocity and real-time acceleration of the target carrier into tangential and normal components for fitting, and fit and extrapolate the velocity of the target aircraft at the next moment to obtain the velocity law of the target carrier.

[0093] Furthermore, in the present invention, in step 21, the method for converting the real-time velocity and real-time acceleration into the measuring station coordinate system is:

[0094] Create the transformation matrix G:

[0095]

[0096] Wherein, J represents longitude and B represents latitude; the conversion matrix is ​​used to convert the coordinate system o-xyz to the station coordinate system:

[0097] a s (t) = G·a(t)

[0098] v d (t) = G·v(t)

[0099] Where a(t) is the real-time acceleration of the target carrier in the coordinate system o-xyz, v(t) is the real-time velocity of the target carrier in the coordinate system o-xyz, and v d (t) is the velocity of the target carrier station coordinate system, a s (t) is the acceleration of the target carrier station coordinate system.

[0100] Furthermore, in the present invention, in step 22, the formula for decomposing the real-time velocity and real-time acceleration in the measuring station coordinate system into tangential and normal components is:

[0101] v d, / / (k) = v d, / / (kT)+a s, / / (k)·T+s / / (k)+ε / / (k)

[0102] v d,⊥ (k) = v d,⊥ (kT)+a s,⊥ (k)·T+s ⊥ (k)+ε ⊥ (k)

[0103] Among them, ε ⊥ (k) represents the normal component of the random error vector ε(k) measured at time k, ε / / (k) represents the tangential component of the random error vector ε(k) measured at time k, a s, / / (k) represents the tangential component of the acceleration of the target carrier at time k, a s,⊥ (k) represents the normal component of the acceleration of the target carrier at time k, v d,⊥ (kT) represents the normal component of the target carrier's velocity at time kT, v d, / / (kT) represents the tangential component of the target carrier's velocity at time kT, s / / (k) represents the tangential component of the system error vector s(k) measured at time k, s ⊥ (k) represents the normal component of the system error vector s(k) measured at time k; the system error is expressed as a function of the system error parameter:

[0104] s(t)=s(t,β)

[0105] Where β represents the system error parameter vector.

[0106] Furthermore, in the present invention, in steps 2 and 3, the target carrier speed law is obtained as follows:

[0107] Φ(v d )=‖vd(k)||=(v d, / / (k) 2+v d,⊥ (k) 2 ) 1 / 2

[0108] a = arctan(v d,⊥ (k) / v d, / / ( k))

[0109] Among them, v d, / / (k) and v d,⊥ (k) represents the target carrier velocity v at time k in the station coordinate system. d (k) the tangential and normal components;

[0110] v d, / / (k) = v d, / / (kT)+a s, / / (k)·T+s / / (k)+ε / / (k)

[0111] v d,⊥ (k) = v d,⊥ (kT)+a s,⊥ (k)·T+s ⊥ (k)+ε ⊥ (k)

[0112] Among them, a s, / / (k) and a s,⊥ (k) respectively represent the acceleration a at time k in the measuring station coordinate system s (k) tangential and normal components; ε / / (k) and ε ⊥ (k) represent the tangential and normal components of the measured random error vector ε(k), respectively;

[0113] The final target carrier velocity law is simplified to:

[0114] Φ(v d )=f(a,T)

[0115] a=g(v d ,T)

[0116] Where T is the time from time kT to time k.

[0117] Further, in the present invention, in step 4, the Doppler frequency shift is:

[0118] f d =((Φ(v d ) / λ)×cos(θ))

[0119] =((f(v x(k-T) v y(k-T) ,vz(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T) / λ)×cos(θ))

[0120] Among them, f d is the Doppler frequency shift, λ is the carrier wavelength, θ is the angle between the relative motion direction and the line connecting the transmitting and receiving ends,

[0121] (v xd ,v yd ,v zd )=f(v x(k-T) ,v y(k-T) ,v z(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T)

[0122] v xd ,v yd ,v zd The x, y, and z axis components of the velocity vector of the aircraft in the station coordinate system, Dv' xk ,Dv' yk ,Dv' zk They represent the first-order derivatives of the x, y, and z components of the velocity vector in the station coordinate system, respectively.

[0123] Furthermore, in the present invention, in step 5, the method of compensating the communication signal of the target carrier by using the Doppler frequency shift is:

[0124] According to the estimated value of the Doppler frequency shift, the frequency range of the communication signal of the received target carrier is divided into multiple change rate sub-slots. The compensation waveform of the Doppler frequency shift of each change rate sub-slot is obtained by table lookup, and the compensation waveform is multiplied with the received data to achieve frequency compensation of the carrier Doppler change rate.

[0125] The present invention utilizes the speed, acceleration and posture information of the high-dynamic motion carrier measured at the current moment, combined with the guidance law, to estimate and pre-compensate the motion information of the next time period, thereby greatly reducing the capture range and improving the synchronization speed.

[0126] The present invention analyzes the influence of the speed of a high-dynamic moving carrier (high-dynamic moving carrier) on the nonlinear change of Doppler, and establishes a new model of Doppler change of the guidance signal under the fast-changing channel brought by high-dynamic and highly maneuverable carriers such as high-dynamic moving carriers. After obtaining the predicted speed of the high-dynamic moving carrier, the instantaneous frequency shift is estimated according to the established Doppler change model function, and then the Doppler frequency shift is compensated coarsely and finely to achieve rapid synchronization of the captured signal, break through the constraints of the missile-borne computing power, and solve the problem of large-scale rapid change of Doppler frequency shift brought by high-dynamic carriers such as high-dynamic moving carriers.

[0127] At the same time, according to the measured data of high-dynamic motion carriers, based on the dynamics theory, the guidance law is used to extrapolate the velocity law of high-dynamic motion carriers. Through test data fitting, the velocity and acceleration information of the high-dynamic motion carrier in the coordinate system of the measuring station at time k is obtained through the coordinate transformation matrix. Based on the dynamics theory of high-dynamic motion carriers, the motion information of the high-dynamic motion carrier at time k can be modeled, and then the model parameters are obtained by fitting the measured data of high-dynamic motion carriers. After further extrapolation, the motion state information of the high-dynamic motion carrier at time k can be obtained. The extrapolated motion state of the high-dynamic motion carrier is used as the input of the Doppler change model built in Innovation Point 1, laying the foundation for the rapid synchronization of the capture signal.

[0128] Specific embodiments: The purpose of the present invention is to provide a high-dynamic signal fast synchronization method assisted by motion information measurement. Aiming at the problem that the Doppler frequency shift compensation accuracy is greatly reduced in highly maneuverable carriers such as aircraft, the relationship between the aircraft motion state and the signal time-frequency characteristics is explored, and a new way of signal compensation for the guidance chain is proposed, which reduces the signal synchronization time and expands the frequency capture range.

[0130] The high-dynamic signal rapid synchronization method for aircraft motion information measurement assistance has the following steps:

[0131] Step 1: First, use the inertial reference coordinate system o-xyz and the related state variables defined in this coordinate system. o-xyz is fixedly connected to the ground, and the aircraft is regarded as a particle M, x is the longitudinal range, y is the lateral range, and z is the altitude. V is the speed of the aircraft, γ is the ballistic inclination of the aircraft, and it is positive when it rotates counterclockwise relative to the horizontal reference line. ψ is the heading angle, that is, the angle between the horizontal component of the aircraft's speed and the x-axis, and it is positive when it rotates counterclockwise relative to the x-axis. The orbital dynamics equations of the aircraft are as follows:

[0132]

[0133] Where m is the mass of the aircraft, σ is the roll angle (roll angle), α is the angle of attack of the aircraft, L is the lift, D is the drag, and g is the acceleration due to gravity. The lift L uses the lift coefficient C L Indicates, resistance D uses resistance coefficient C Dexpress.

[0134]

[0135] The aerodynamic data is calculated using the fitting formula:

[0136]

[0137] Among them, C L0 is the lift coefficient at zero angle of attack, is the lift coefficient rate, C D0 is the zero-lift drag coefficient, and K is the induced drag coefficient. The updated dynamic equation is as follows:

[0138]

[0139] The aircraft adopts the BTT control method, with the angle of attack α and the inclination angle σ as the flight control variables, and the guidance command acceleration overload a cmd The calculation results are:

[0140]

[0141] According to (4) and (5), the fourth-order Runge-Kutta numerical integration method is used to perform nonlinear extrapolation of the velocity V at the target time.

[0142] The fourth-order Runge-Taku numerical integration method is used to solve equation (4) and the extrapolated results of the trajectory inclination γ and the velocity V of the aircraft are obtained. At the same time, the estimated velocity can be obtained by continuing the iterative calculation: Real-time value of .

[0143] The second step is to use the guidance law to extrapolate the aircraft speed law based on the actual measured data of the aircraft obtained in the first step and the aircraft dynamics theory.

[0144] The specific process of using the guidance law to extrapolate the aircraft velocity law is as follows:

[0145] Step 2.1, coordinate system conversion. The measured data of the aircraft generally refers to the geocentric coordinate system. Let the rotation matrix from the geocentric coordinate system to the measuring station coordinate system be denoted as G, and the conversion relationship of the aircraft velocity and acceleration from the geocentric coordinate system to the measuring station coordinate system can be obtained:

[0146] a s (t) = G·a(t) (6)

[0147] v d (t) = G·v(t)

[0148] Step 2.2, extrapolate the velocity law of the aircraft. Decompose the acceleration a at the current time k in the station coordinate system s(k) is the tangential acceleration and the normal acceleration a s, / / (k) and a s,⊥ (k), the tangential velocity and normal velocity of the aircraft at time k can be obtained by extrapolation based on the guidance law:

[0149] v d, / / (k) = v d, / / (kT)+a s, / / (k)·T+s / / (k)+ε / / (k) (7)

[0150] v d,⊥ (k) = v d,⊥ (kT)+a s,⊥ (k)·T+s ⊥ (k)+ε ⊥ (k)

[0151] Where ε(k) is the random error vector of the measurement, which is assumed to obey the zero-mean Gaussian distribution, and s(k) is the system error vector of the measurement. Usually, a parameter model is established according to the characteristics of the system error, and the system error is expressed as a function of the system error parameter, that is, s(t) = s(t, β), where β = (β1, β2, ..., β p ) T , β is the p-dimensional system error parameter vector.

[0152] Step 2.3, predict the aircraft speed;

[0153] By fitting the measured data of the aircraft, the system error can be obtained, and the predicted value of the aircraft speed at time k can be further extrapolated:

[0154] Φ(v d )=||v d (k)||=(v d, / / (k) 2 +v d,⊥ (k) 2 ) 1 / 2 (8)

[0155] a = arctan(v d,⊥ (k) / v d, / / (k))

[0156] For the convenience of the following description, this rule is abbreviated as:

[0157] Φ(v d )=f(a,T) (9)

[0158] a=a t (y t ,T)

[0159] The third step is to predict the speed of the aircraft based on the aircraft law obtained in the second step;

[0160] Specifically:

[0161] Step 3.1: Substitute the aircraft velocity vector v obtained at time k into k =[v x,k ,v y,k ,v z,k ] T and the three-dimensional acceleration vector a k =[a x,k ,a y,k ,a z,k ] T Transmit to the receiving end;

[0162] Step 3.2: The receiving end uses the trained aircraft guidance law filter to filter and smooth the aircraft velocity vector and acceleration vector, as shown in the following formula:

[0163] X k =f(X k-1 ) (10)

[0164] Among them, X - k =[v - k a - k ] T ;v - k and a - k They represent the prior estimates of the velocity and acceleration of the aircraft at time k; X k =[v k a k ] T are the outputs of the filter, and represent the velocity vector and acceleration vector of the filter output respectively.

[0165] Step 3.3, according to step 3.2, get the current aircraft speed and acceleration information:

[0166] (v xd ,v yd ,v zd )=f(v x(k-T) ,v y(k-T) ,v z(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T)

[0167] v xd ,v yd ,v zdThe x, y, and z axis components of the velocity vector of the aircraft in the station coordinate system, Dv' xk ,Dv' yk ,Dv' zk They represent the first-order derivatives of the x, y and z components of the velocity vector at time k in the station coordinate system, v x(k-T) ,v y(k-T) ,v z(k-T) They represent the x, y and z direction components of the velocity vector at time kT in the station coordinate system respectively.

[0168] (a xd ,a yd ,a zd )=a t (a x(k-T) ,a y(k-T) ,a z(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T)

[0169] The fourth step is to ignore the frequency second-order derivative term in the carrier additional phase function generated by the relative motion of the communication carrier when processing the signal of the aircraft communication link, and establish a new model of the Doppler change of the guidance signal under the fast-changing channel. Based on the aircraft speed predicted in the third step, the Doppler frequency shift is obtained:

[0170] The Doppler shift is:

[0171] f d =((Φ(v d ) / λ)×cos(θ))

[0172] =((f(v x(k-T) ,v y(k-T) ,v z(k-T) ,Dv' xk ,Dv' yk ,Dv' zk ,T) / λ)×cos(θ))

[0173] Among them, f d is the Doppler frequency shift, λ is the carrier wavelength, and θ is the angle between the relative motion direction and the line connecting the transmitting and receiving ends.

[0174] The fifth step is to perform frequency shift compensation based on the Doppler frequency shift estimation value obtained in the fourth step to achieve rapid synchronization of the captured signal.

[0175] The frequency shift compensation module divides the frequency range into multiple change rate sub-slots according to the estimated value of the Doppler frequency shift, performs frequency compensation for the Doppler frequency shift of the signal, generates a compensation waveform for the Doppler frequency shift by looking up a table, and multiplies it with the input data to complete the frequency compensation of the carrier Doppler change rate.

[0176] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement, characterized in that: include: Step 1: Establish an inertial reference coordinate system o-xyz of the high-dynamic motion target carrier, establish the orbital dynamics equation group of the target carrier in the coordinate system o-xyz, and use the dynamics equation group to calculate and obtain the real-time motion information of the target carrier; Step 2: extrapolating the target carrier's velocity law using the guidance law based on the real-time motion information of the target carrier and the aircraft dynamics theory; Step 3: using the speed law of the target carrier to predict the speed of the target carrier; Step 4: Establish a new Doppler variation model for the guidance signal under fast-changing channels, and use the predicted speed of the target carrier to calculate the Doppler shift: Step 5: Use the Doppler frequency shift to compensate for the communication signal of the target carrier to achieve synchronization of the communication signal.

2. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 1, characterized in that: In step 1, the orbital dynamics equations of the target carrier are: Among them, m is the mass of the aircraft, σ is the roll angle, L is the lift of the target carrier, D is the drag borne by the target carrier, g is the gravitational acceleration, represents the derivative of the longitudinal range x of the target carrier, represents the derivative of the lateral range y of the target carrier, represents the derivative of the target carrier's altitude z, V is the target carrier's velocity, It represents the derivative of the target carrier's velocity, γ is the target carrier's ballistic inclination angle, and is positive when it rotates counterclockwise relative to the horizontal reference line. It represents the derivative of the ballistic inclination angle of the target carrier's motion, ψ is the heading angle of the target carrier, and the angle between the horizontal component of the target carrier's velocity and the x-axis is positive when it rotates counterclockwise relative to the x-axis. represents the derivative of the heading angle of the target carrier; where the lift L and the drag D are: because Then we have: ρ represents the atmospheric density; S is the reference area of ​​the wing; the aerodynamic coefficient C L and the drag coefficient C D for: in, is the lift coefficient rate, C D0 is the zero-lift drag coefficient, K D is the induced drag coefficient, C L represents the lift coefficient, C D represents the drag coefficient and α is the vehicle's angle of attack.

3. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 2, characterized in that: In step 1, the method for calculating and obtaining the real-time motion information of the target carrier is: According to the control mode of the target carrier, obtain the guidance command acceleration overload a cmd , using the guidance command to accelerate the overload a cmd , calculate the attack angle α and inclination angle σ of the target carrier movement; x1=[sin(ψ),-cos(ψ),0] T x2=[-sin(γ)cos(ψ),-sin(γ)sin(ψ),cos(ψ)] T Among them, C L0 is the lift coefficient at zero angle of attack; Combined with the attack angle α and the inclination angle σ, the fourth-order Runge-Kutta numerical integration method is used to solve the orbital dynamics equations of the target carrier, and the extrapolated results of the ballistic inclination angle γ and the movement speed V of the target carrier are obtained, and the real-time speed of the target carrier at the next moment is calculated.

4. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 3, characterized in that: In step 2, the method of using the guidance law to extrapolate the target carrier velocity law is: Step 21: Calculate the real-time acceleration according to the real-time motion information of the target carrier, and convert the real-time speed and the real-time acceleration into the real-time speed and the real-time acceleration in the measuring station coordinate system; Step 22: Decompose the real-time velocity and real-time acceleration in the measuring station coordinate system into tangential and normal components; Step 2 and 3: Decompose the real-time velocity and real-time acceleration of the target carrier into tangential and normal components for fitting, and fit and extrapolate the velocity of the target aircraft at the next moment to obtain the velocity law of the target carrier.

5. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 4, characterized in that: In step 21, the method of converting the real-time velocity and real-time acceleration into the measuring station coordinate system is: Create the transformation matrix G: Wherein, J represents longitude and B represents latitude; the conversion matrix is ​​used to convert the coordinate system o-xyz to the station coordinate system: a s (t)=G·a(t) v d (t)=G·v(t) Where a(t) is the real-time acceleration of the target carrier in the coordinate system o-xyz, v(t) is the real-time velocity of the target carrier in the coordinate system o-xyz, and v d (t) is the velocity of the target carrier station coordinate system, a s (t) is the acceleration of the target carrier station coordinate system.

6. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 5, characterized in that: In step 22, the formula for decomposing the real-time velocity and real-time acceleration in the measuring station coordinate system into tangential and normal components is: v d, / / (k)=v d, / / (kT)+a s, / / (k) T+s / / (k)+ε / / (k) v d,⊥ (k)=v d,⊥ (kT)+a s,⊥ (k) T+s ⊥ (k)+ε ⊥ (k) Among them, ε ⊥ (k) represents the normal component of the random error vector ε(k) measured at time k, ε / / (k) represents the tangential component of the random error vector ε(k) measured at time k, a s, / / (k) represents the tangential component of the acceleration of the target carrier at time k in the measuring station coordinate system, a s,⊥ (k) represents the normal component of the acceleration of the target carrier at time k in the measuring station coordinate system, v d,⊥ (kT) represents the normal component of the target carrier's velocity at time kT in the station coordinate system, v d, / / (kT) represents the tangential component of the target carrier's velocity at time kT in the station coordinate system, s / / (k) represents the tangential component of the system error vector s(k) measured at time k, s ⊥ (k) represents the normal component of the system error vector s(k) measured at time k; Express the systematic error as a function of the systematic error parameter: s(t)=s(t,β) Where β represents the system error parameter vector.

7. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 6, characterized in that: In step 2 and 3, the target carrier speed law is obtained as follows: Φ(v d )=||v d (k)||=(v d, / / (k) 2 +v d,⊥ (k) 2 ) 1 / 2 a=arctan(v d,⊥ (k) / v d, / / (k)) Among them, v d, / / (k) and v d,⊥ (k) represents the target carrier velocity v at time k in the station coordinate system. d (k) the tangential and normal components; v d, / / (k)=v d, / / (kT)+a s, / / (k) T+s / / (k)+ε / / (k) v d,⊥ (k)=v d,⊥ (kT)+a s,⊥ (k) T+s ⊥ (k)+ε ⊥ (k) Among them, a s, / / (k) and a s,⊥ (k) respectively represent the acceleration a at time k in the measuring station coordinate system s (k) tangential and normal components; ε / / (k) and ε ⊥ (k) represent the tangential and normal components of the measured random error vector ε(k), respectively; The final target carrier velocity law is simplified to: Φ(v d )=f(a,T) a=g(v d ,T) Where T is the time from time kT to time k.

8. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 7, characterized in that: In step 4, the Doppler shift is: f d =((Φ(v d ) / λ)×cos(θ)) =((f(v x(k-T) ,v y(k-T) ,v z(k-T) ,Dv’ xk ,Dv’ yk ,Dv’ zk ,T) / λ)×cos(θ)) Among them, f d is the Doppler frequency shift, λ is the carrier wavelength, θ is the angle between the relative motion direction and the line connecting the transmitting and receiving ends, v xd ,v yd ,v zd The x, y, and z axis components of the velocity vector of the aircraft in the station coordinate system, Dv' xk ,Dv' yk ,Dv' zk They represent the first-order derivatives of the x, y, and z components of the velocity vector in the station coordinate system, respectively.

9. The method for synchronizing communication signals of a high-dynamic moving carrier based on motion information measurement according to claim 2, characterized in that: In step 5, the method of using the Doppler frequency shift to compensate the communication signal of the target carrier is: According to the Doppler frequency shift, the communication signal frequency range of the target carrier is divided into multiple change rate sub-slots. The compensation waveform of the Doppler frequency shift of each change rate sub-slot is obtained by table lookup, and the compensation waveform is multiplied with the received data to achieve frequency compensation of the carrier Doppler change rate.

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