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

Abstract

The application 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 application solves the problems of poor Doppler frequency shift compensation precision, long signal synchronization time and small frequency compensation range among existing high-dynamic motion carriers. In the coordinate system o-xyz, the track dynamics equation set of a target carrier is established, the real-time motion information of the target carrier is calculated by using the dynamics equation set, the target carrier speed law is extrapolated by using a guidance law based on the real-time motion information of the target carrier and the aircraft dynamics theory, the speed of the target carrier is predicted by using the target carrier speed law, a new Doppler variation model of a guidance signal under a fast-varying channel is established, the Doppler frequency shift is calculated by using the predicted speed of the target carrier, the communication signal of the target carrier is compensated by using the Doppler frequency shift, and the synchronization of the communication signal is realized. The application is suitable for high-dynamic carrier communication synchronization.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high dynamic signal synchronization. BACKGROUND

[0002] Satellites, aircrafts and other moving objects have high speed, and the Doppler frequency shift of signals between such high dynamic moving objects changes rapidly with time, that is, there is a strong Doppler effect caused by the high speed of the moving objects. The high dynamic environment not only makes the Doppler frequency shift range of the signal very large, but also has the problem that the change rate of the Doppler frequency shift with time is very fast, and even the high-order change rate is very large, which increases the difficulty of signal acquisition and tracking at the receiving end, and seriously affects the quality of the received signal.

[0003] The relative speed and acceleration between the transmitting and receiving objects are calculated by using the motion characteristics of the objects, and then the estimation results of the Doppler and the Doppler change rate of the signal are predicted, and the normal acquisition range is greatly reduced by pre-compensation at the receiving or transmitting end. This method is very common in low-orbit satellite communication. First, the Doppler parameters are estimated according to the ephemeris information and the terminal position, and then pre-compensation is performed at the signal control station or the transmitting end of the satellite, and then the frequency shift acquisition range is increased by more than ten times.

[0004] The motion characteristics of the satellite have periodicity and regularity, and the ephemeris information can be obtained or calculated in advance. However, for aircrafts, especially for aircrafts with interception function, the flight trajectory changes dynamically and in real time, and the existing estimation and pre-compensation method cannot meet the application requirements. SUMMARY

[0005] The application is to solve the problems of poor Doppler frequency shift compensation precision, long signal synchronization time and small frequency compensation range in the communication between high dynamic moving objects, and provides a high dynamic moving object communication signal synchronization method based on motion information measurement.

[0006] The high dynamic moving object communication signal synchronization method based on motion information measurement provided by the application comprises:

[0007] Step one, establishing an inertial reference coordinate system o-xyz of the high dynamic moving target object, establishing an orbit dynamics equation set of the target object in the coordinate system o-xyz, and calculating the real-time motion information of the target object by using the dynamics equation set;

[0008] Step two, based on the aircraft dynamics theory, the target object speed law is extrapolated by using the real-time motion information of the target object;

[0009] Step three, the speed of the target object is predicted by using the target object speed law;

[0010] Step four, a new model of Doppler shift of the guidance signal in fast time-varying channel is established, and the Doppler shift is calculated by using the predicted speed of the target carrier:

[0011] Step five, the communication signal of the target carrier is compensated by using the Doppler shift, and the synchronization of the communication signal is realized.

[0012] Further, in the present application, in step one, the orbit dynamics equation group of the target carrier is:

[0013]

[0014] Wherein, m is the mass of the aircraft, σ is the roll angle, K D is the induced drag coefficient; L is the lift of the target carrier, D is the resistance borne by the target carrier, g is the gravity 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 altitude z of the target carrier, V is the speed of the target carrier, represents the derivative of the speed of the target carrier, γ is the ballistic angle of the target carrier, and the counterclockwise rotation relative to the horizontal reference line is positive, represents the derivative of the ballistic angle of the target carrier, ψ is the heading angle of the target carrier, the included angle between the horizontal component of the target carrier speed and the x axis is positive, and the counterclockwise rotation relative to the x axis is positive, represents the derivative of the heading angle of the target carrier; wherein the lift L and the resistance D are:

[0015]

[0016] Since then:

[0017]

[0018] ρ represents the atmospheric density; S is the reference area of the wing; the aerodynamic coefficients C L and the resistance coefficient C D are:

[0019]

[0020] Wherein, 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 resistance coefficient, and α is the attack angle of the aircraft.

[0021] Further, in the present application, in step one, the method for calculating the real-time motion information of the target carrier is:

[0022] According to the control mode of the target carrier, the guidance instruction acceleration overload a cmd is obtained, and the attack angle a and the inclination angle s of the target carrier motion are calculated by using the guidance instruction acceleration overload a cmd .

[0023]

[0024] x1=[sin(ψ),-cos(ψ),0] T

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

[0026] Wherein, C L0 is the zero attack angle lift coefficient;

[0027] In combination with the attack angle a and the inclination angle s, the trajectory dynamics equation set of the target carrier is solved by using the fourth-order Runge-Kutta numerical integration method, and the extrapolation results of the trajectory inclination angle g and the motion speed V of the target carrier are obtained, so that the real-time speed of the target carrier at the next time is calculated.

[0028] Further, in the present application, in step two, the method for extrapolating the speed law of the target carrier by using the guidance law is:

[0029] Step two one, according to the real-time motion information of the target carrier, the real-time acceleration is calculated, and the real-time speed and the real-time acceleration are converted into real-time speed and real-time acceleration in the station coordinate system;

[0030] Step two two, the real-time speed and the real-time acceleration in the station coordinate system are decomposed into tangential and normal components;

[0031] Step two three, the real-time speed and the real-time acceleration of the target carrier are decomposed into tangential and normal components, and the speed of the target carrier at the next time is fitted and extrapolated, so that the speed law of the target carrier is obtained.

[0032] Further, in the present application, in step two one, the method for converting the real-time speed and the real-time acceleration into the station coordinate system is:

[0033] The conversion matrix G is established:

[0034]

[0035] Wherein, J represents the longitude, and B represents the latitude; the conversion from the coordinate system o-xyz to the station coordinate system is carried out by using the conversion matrix.

[0036] a s (t) = G · a(t)

[0037] v d (t) = G · v(t)

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

[0039] Further, in the present application, in step two, the formula for decomposing the real-time speed and real-time acceleration in the station coordinate system into tangential and normal components is:

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

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

[0042] wherein ε ⊥ (k) represents the normal component of the measurement random error vector ε(k) at time k, ε / / (k) represents the tangential component of the measurement random error vector ε(k) 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,⊥ (k-T) represents the normal component of the speed of the target carrier at time k-T, v d, / / (k-T) represents the tangential component of the speed of the target carrier at time k-T, 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 systematic error is represented as a function of the system error parameter:

[0043] s(t) = s(t, β)

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

[0045] Further, in the present application, the target carrier velocity law in step 2 is:

[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] wherein v d, / / (k) and v d,⊥ (k) represent the tangential component and the normal component of the target carrier velocity v d (k) at time k in the station coordinate system respectively;

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

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

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

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

[0053] Φ(v d ) = f(a, T)

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

[0055] wherein T is the time elapsed from time k-T to time k.

[0056] Furthermore, in the present invention, in step 4, the Doppler 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-direction components of the velocity vector in the station coordinate system.

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

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

[0064] The method establishes a new Doppler variation model of a guidance signal under a fast-varying channel, estimates an instantaneous frequency shift through a Doppler variation model function, breaks through a calculation power constraint of a missile-borne device, and solves a problem of a large-range fast variation of a Doppler frequency shift caused by super-high overload and three-dimensional random motion of a high-dynamic carrier such as a spacecraft. First, a speed and acceleration information of the spacecraft is obtained by extrapolating a speed law of the spacecraft based on a guidance law by using measured data. Then, a Doppler variation model under a fast-varying channel is established, and a Doppler frequency shift variation value is obtained by taking the speed of the spacecraft as an input. Finally, frequency-to-frequency coarse compensation and frequency-to-frequency fine compensation are performed according to the Doppler variation value, and fast synchronization of a captured signal is realized. Through prior information guidance of the missile-borne device, the method can expand a Doppler capture range by 5 times, reduce a synchronization time to 2 / 3, and realize frequency shift estimation and compensation of a trajectory prediction of a missile. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 A flowchart of the method is shown. DETAILED DESCRIPTION

[0066] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0067] Specific implementation one: reference Figure 1 The high-dynamic motion carrier communication signal synchronization method based on motion information measurement in the embodiment includes the following steps.

[0068] Step one, an inertial reference coordinate system o-xyz of a high-dynamic motion target carrier is established, an orbit dynamics equation set of the target carrier is established in the coordinate system o-xyz, and real-time motion information of the target carrier is calculated and obtained by using the dynamics equation set.

[0069] Step two, a speed law of the target carrier is extrapolated based on a spacecraft dynamics theory according to the real-time motion information of the target carrier.

[0070] Step three, the speed of the target carrier is predicted by using the speed law of the target carrier.

[0071] Step four, a new Doppler variation model of a guidance signal under a fast-varying channel is established, and a Doppler frequency shift is calculated by using the predicted speed of the target carrier.

[0072] Step five, compensating the communication signal of the target carrier by using the Doppler frequency shift, realizing the synchronization of the communication signal.

[0073] Further, in the present application, in step one, the orbit dynamics equation set of the target carrier is:

[0074]

[0075] Wherein, m is the mass of the aircraft, σ is the roll angle (pitch angle), L is the lift, D is the drag, g is the gravity acceleration, represents the derivative of the target carrier longitudinal range x, represents the derivative of the target carrier lateral range y, represents the derivative of the target carrier altitude z, V is the speed of the target carrier, represents the derivative of the target carrier movement speed, γ is the ballistic angle of the target carrier, and the counterclockwise rotation relative to the horizontal reference line is positive, represents the derivative of the ballistic angle of the target carrier movement, ψ is the heading angle of the target carrier, and the included angle between the horizontal component of the target carrier speed and the x axis is positive, and the counterclockwise rotation relative to the x axis is positive, represents the derivative of the heading angle of the target carrier; wherein the lift L and the drag D are:

[0076]

[0077] Since then:

[0078]

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

[0080]

[0081] Wherein, 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 represents the drag coefficient, K D is the induced drag coefficient;

[0082] Further, in the present application, in step one, the method for calculating the real-time movement information of the target carrier is:

[0083] According to the control mode of the target carrier, the guidance instruction acceleration overload a cmd is obtained, and the attack angle α and the inclination angle σ of the target carrier movement are calculated by using the guidance instruction acceleration overload a cmd .

[0084]

[0085] x1=[sin(ψ),-cos(ψ),0] T

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

[0087] Wherein, C L0 is the zero angle of attack lift coefficient;

[0088] Further, the fourth order Runge-Kutta numerical integration method is used to solve the target carrier's orbit dynamics equation set, the extrapolation result of the target carrier's movement trajectory inclination γ and movement velocity V is obtained, and the real-time velocity of the target carrier at the next time is calculated.

[0089] Further, in the application, the method for extrapolating the target carrier's velocity rule in step two is:

[0090] Step two one, according to the real-time movement information of the target carrier, the real-time acceleration is calculated, and the real-time velocity and real-time acceleration are converted into real-time velocity and real-time acceleration in the station coordinate system.

[0091] Step two two, the real-time velocity and real-time acceleration in the station coordinate system are decomposed into tangential and normal components.

[0092] Step two three, the real-time velocity and real-time acceleration of the target carrier are decomposed into tangential and normal components, the velocity of the target carrier at the next time is fitted and extrapolated, and the velocity rule of the target carrier is obtained.

[0093] Further, in the application, in step two one, the method for converting the real-time velocity and real-time acceleration into the station coordinate system is:

[0094] The conversion matrix G is established:

[0095]

[0096] Wherein, J represents longitude, and B represents latitude;The conversion matrix is used for the conversion of 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] Wherein, a(t) is the real-time acceleration of the target carrier in the coordinate system o-xyz, v(t) is the real-time speed of the target carrier in the coordinate system o-xyz, v d (t) is the speed of the target carrier station coordinate system, a s (t) is the acceleration of the target carrier station coordinate system.

[0100] Further, in the present application, in step two, the formula for decomposing the real-time speed and real-time acceleration in the station coordinate system into tangential and normal components is:

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

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

[0103] Wherein, ε ⊥ (k) represents the normal component of the measurement random error vector ε(k) at time k, ε / / (k) represents the tangential component of the measurement random error vector ε(k) 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,⊥ (k-T) represents the normal component of the speed of the target carrier at time k-T, v d, / / (k-T) represents the tangential component of the speed of the target carrier at time k-T, 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 represented as a function of the system error parameter:

[0104] s(t) = s(t, β)

[0105] Wherein, β represents the system error parameter vector.

[0106] Further, in the present application, in step three, the speed law of the target carrier is obtained as:

[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] wherein v d, / / (k) and v d,⊥ (k) represent tangential component and normal component of v d (k) respectively, which is the velocity of the target carrier at k time in the station coordinate system;

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

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

[0112] wherein a s, / / (k) and a s,⊥ (k) represent tangential component and normal component of a s (k) respectively, which is the acceleration at k time in the station coordinate system; ε / / (k) and ε ⊥ (k) represent tangential component and normal component of the measured random error vector ε(k) respectively;

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

[0114] Φ(v d ) = f(a, T)

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

[0116] wherein T is the time elapsed from k-T time to k time.

[0117] Further, in the present application, in step four, 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] wherein f d is the Doppler shift, λ is the carrier wavelength, and θ is the angle between the direction of relative motion and the line connecting the transceiver,

[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 denote the components of the velocity vector of the aircraft in the station coordinate system, Dv' xk ,Dv' yk ,Dv' zk denote the first derivatives of the x, y and z direction components of the velocity vector in the station coordinate system, respectively.

[0123] Further, in the present application, in step five, the method for compensating the communication signal of the target carrier using the Doppler shift is:

[0124] According to the estimated value of the Doppler shift, the frequency range of the received communication signal of the target carrier is divided into a plurality of rate sub-slots, the Doppler shift compensation waveform of each rate sub-slot is obtained by looking up the table, the compensation waveform is multiplied with the received data, and the frequency compensation of the carrier Doppler rate is realized.

[0125] The present application uses the speed, acceleration and high dynamic motion carrier attitude information measured at the current time, combines with the guidance law, estimates and pre-compensates the motion information of the next time period, and further greatly reduces the capture range and improves the synchronization speed.

[0126] This paper analyzes the impact of the velocity of a high-dynamic moving carrier (HDMC) on the nonlinear Doppler variation and establishes a new model for the Doppler variation of guidance signals in rapidly changing channels caused by high-dynamic, highly maneuverable carriers such as HDMCs. After obtaining the predicted HDMC velocity, the instantaneous frequency shift is estimated based on the established Doppler variation model function. Coarse and fine frequency compensation are then performed on the Doppler shift to achieve rapid synchronization of the captured signal, breaking through the constraints of onboard computing power and resolving the problem of large-scale, rapid Doppler frequency shift variations caused by HDMCs and other high-dynamic moving carriers.

[0127] At the same time, based on the measured data of the high-dynamic motion carrier and dynamics theory, the guidance law is used to extrapolate the velocity pattern of the high-dynamic motion carrier. By fitting the test data and using the coordinate transformation matrix, the velocity and acceleration information of the high-dynamic motion carrier in the measuring station coordinate system at time k is obtained. Based on the dynamics theory of high-dynamic motion carriers, the motion information of the high-dynamic motion carrier at time k is modeled. Then, by fitting the measured data of the high-dynamic motion carrier, the model parameters are obtained and further extrapolated to obtain the motion state information of the high-dynamic motion carrier at time k. The extrapolated motion state of the high-dynamic motion carrier serves as the input to the Doppler variation model established in Innovation Point 1, laying the foundation for rapid synchronization of the captured signals.

[0128] Specific embodiments: The present invention aims to provide a method for rapid high-dynamic signal synchronization, aided by motion information measurement. This method addresses the significant reduction in Doppler shift compensation accuracy in highly maneuverable vehicles such as aircraft. By exploring the relationship between aircraft motion and signal time-frequency characteristics, this method proposes a new approach to guidance chain signal compensation, reducing signal synchronization time and expanding the frequency capture range.

[0129] The steps of the high-dynamic signal rapid synchronization method for aircraft motion information measurement assistance are as follows:

[0130] Step 1: First, use the inertial reference coordinate system o-xyz and the related state variables defined in this coordinate system. o-xyz is fixed 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 aircraft's velocity, γ is the aircraft's ballistic inclination angle, 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 velocity 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:

[0131]

[0132] Where m is the mass of the aircraft, σ is the roll angle (roll angle), α is the aircraft angle of attack, L is the lift, D is the drag, and g is the acceleration due to gravity. The lift L is calculated using the lift coefficient C. L Indicates resistance D using resistance coefficient C Dis represented.

[0133]

[0134] The aerodynamic data is calculated by using the fitting formula:

[0135]

[0136] where C L0 is the zero angle of attack lift coefficient, 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:

[0137]

[0138] The aircraft adopts the BTT control mode, and the angle of attack a and the angle of inclination s are taken as the flight control variables. The guidance command acceleration a cmd is calculated as follows:

[0139]

[0140] According to (4) and (5), the fourth-order Runge-Kutta numerical integration method is used to perform nonlinear extrapolation on the target time velocity V.

[0141] The fourth-order Runge-Kutta numerical integration method is used to solve equation (4) to obtain the extrapolation results of the flight vehicle's ballistic inclination angle g and movement velocity V. At the same time, the real-time numerical value of the movement velocity estimate can be obtained by continuing iterative calculation.

[0142] Secondly, based on the measured data of the aircraft obtained in the first step, the guidance law is used to extrapolate the speed law of the aircraft based on the aircraft dynamics theory.

[0143] The specific process of extrapolating the speed law of the aircraft using the guidance law is as follows:

[0144] Step 2.1, coordinate system conversion. The measured data of the aircraft generally refers to the geocentric coordinate system, and the rotation matrix of the geocentric coordinate system to the station coordinate system is denoted as G. The conversion relationship of the aircraft's velocity and acceleration from the geocentric coordinate system to the station coordinate system can be obtained as follows:

[0145] a s (t)=G·a(t) (6)

[0146] v d (t)=G·v(t)

[0147] Step 2.2, extrapolate the speed law of the aircraft. The decomposition acceleration a s(k) is the tangential acceleration and a s, / / (k) and a s,⊥ (k) and a

[0148] v d, / / (k) = v d, / / (k-T) + a s, / / (k) · T + s / / (k) + ε / / (k) (7)

[0149] v d,⊥ (k) = v d,⊥ (k-T) + a s,⊥ (k) · T + s ⊥ (k) + ε ⊥ (k)

[0150] where ε(k) is the measured random error vector, which is assumed to be Gaussian distributed with zero mean, and s(k) is the measured system error vector, which is usually modeled as a function of system error parameters, i.e., s(t) = s(t, β), where β = (β1, β2,..., βp) is the p-dimensional system error parameter vector. p ) T

[0151] Step 2.3, predict the vehicle velocity;

[0152] The system error can be obtained by fitting the measured data of the vehicle, and the predicted value of the vehicle velocity at time k can be further extrapolated as:

[0153] Φ(v d ) = ||v d (k) || = (v d, / / (k) 2 + v d,⊥ (k) 2 ) 1 / 2 (8)

[0154] a = arctan(v d,⊥ (k) / v d, / / (k))

[0155] For convenience of description in the following, this law is simply written as:

[0156] Φ(v d ) = f(a, T) (9)

[0157] a = a t (y t , T)

[0158] ​Third step, according to the aircraft law obtained in the second step to predict the speed of the aircraft;

[0159] Specifically,

[0160] Step 3.1, the aircraft speed vector v k = [v x,k , v y,k , v z,k ] T And three-dimensional acceleration vector a k = [a x,k , a y,k , a z,k ] T Transmitted to the receiving end;

[0161] Step 3.2, the receiving end uses the aircraft guidance law filter obtained by training to filter and smooth the aircraft speed vector and acceleration vector, as shown in the following formula:

[0162] X k = f(X k-1 ) (10)

[0163] Wherein, X - k = [v - k a - k ] T ; v - k And a - k Respectively represent the prior estimate value of the aircraft speed and acceleration at time k; X k = [v k a k ] T Is the output of the filter, which respectively represents the speed vector and acceleration vector output by the filter.

[0164] Step 3.3, according to step 3.2 to obtain the current time of the aircraft speed and acceleration information:

[0165] (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)

[0166] v xd ,v yd ,v zddenote the components of the velocity vector of the aircraft in the station coordinate system, Dv xk yk zk denote the first order derivatives of the x, y and z direction components of the velocity vector at time k in the station coordinate system, v x(k-T) y(k-T) z(k-T) denote the x, y and z direction components of the velocity vector at time k-T in the station coordinate system.

[0167] (a xd yd zd ) = a t (a x(k-T) y(k-T) z(k-T) xk yk zk

[0168] Fourthly, when processing the signal of the communication link of the aircraft, the frequency second order derivative term in the carrier additional phase function caused by the relative motion of the communication carrier is ignored to establish a new model of the Doppler variation of the guidance signal under the fast varying channel. According to the predicted velocity of the aircraft in the third step, the Doppler frequency shift is obtained as follows:

[0169] The Doppler frequency shift is:

[0170] f d = ((Φ(v d ) / λ) × cos(θ))

[0171] = ((f(v x(k-T) y(k-T) z(k-T) xk yk zk

[0172] wherein f d is the Doppler frequency shift, λ is the carrier wavelength, and θ is the included angle between the relative motion direction and the line connecting the transmitting and receiving ends.

[0173] Fifthly, according to the estimated value of the Doppler frequency shift obtained in the fourth step, frequency shift compensation is performed to realize fast synchronization of the captured signal.

[0174] The frequency shift compensation module divides the frequency range into a plurality of variation rate sub-slots according to the estimated value of the Doppler frequency shift, performs frequency compensation of the Doppler frequency shift of the signal, and generates a compensation waveform of the Doppler frequency shift through the look-up table mode to complete the frequency compensation of the carrier Doppler variation rate by multiplying the input data.​​​​​​​​​​​​​​​​​​

[0175] While the application has been described with reference to particular embodiments, it is to be understood that the application is not limited to the particulars disclosed. Rather, it is a continuation of the principles and applications of the present application. It is therefore to be understood that numerous modifications, both as to the details and embodiments illustrated and the application, can be made by those skilled in the art without departing from the spirit and scope of the application as defined by the appended claims. It should be understood that all the features described in connection with the various embodiments can be combined in other combinations than those explicitly described. It should also be understood that features described in connection with one embodiment can be combined with features described in connection with another embodiment.

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 for the highly dynamic moving target carrier, establish a set of orbital dynamic equations for the target carrier in the coordinate system o-xyz, and calculate and obtain real-time motion information of the target carrier using the set of dynamic equations; 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 theory of aircraft dynamics; Step 3: using the target carrier speed law to predict the speed of the target carrier; Step 4: Establish a new Doppler variation model for the guidance signal in a fast-changing channel and calculate the Doppler shift using the predicted target carrier velocity: Step 5: Compensating the communication signal of the target carrier by using the Doppler frequency shift to achieve synchronization of the communication signal; 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 instruction acceleration overload a cmd , using the guidance instructions to accelerate 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; ρ represents the atmospheric density; S is the wing reference area; V is the target carrier's velocity, γ is the target carrier's ballistic inclination angle, which is positive when it rotates counterclockwise relative to the horizontal reference line, ψ is the target carrier's heading angle, the angle between the horizontal component of the target carrier's velocity and the x-axis, which is positive when it rotates counterclockwise relative to the x-axis, and the aerodynamic coefficient C L ; Combining the angle of attack 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 motion velocity V of the target carrier are obtained, and the real-time velocity of the target carrier at the next moment is calculated; 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 real-time acceleration into the real-time speed and real-time acceleration in the measuring station coordinate system; Step 22: Decompose the real-time velocity and acceleration in the measuring station coordinate system into tangential and normal components; Step 2 and 3: Decompose the real-time velocity and acceleration of the target carrier into tangential and normal components for fitting, and perform fitting and extrapolation on the velocity of the target aircraft at the next moment to obtain the velocity law of the target carrier; 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 d is the tangential component of the real-time velocity in the station coordinate system, Φ(v d ) is the velocity law of the final target carrier, 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-direction components of the velocity vector in the station coordinate system, respectively, and kT represents the time.

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: Where 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, and g is the acceleration due to gravity. represents the derivative of the target carrier's longitudinal range x, represents the derivative of the target carrier's lateral range y, represents the derivative of the target carrier's altitude z, represents the derivative of the target carrier's velocity, represents the derivative of the ballistic inclination angle of the target carrier motion, represents the derivative of the target carrier's heading angle; where the lift L and drag D are: because Then we have: 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 aircraft'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 21, the method for converting the real-time velocity and real-time acceleration into the measuring station coordinate system is: Create the transformation matrix G: Where 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) Among them, 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.

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 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.

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 steps 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) represents the acceleration a at time k in the measuring station coordinate system. s The tangential and normal components of (k); ε / / (k) and ε ⊥ (k) denote 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.

6. 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 5, the method for compensating the communication signal of the target carrier by using the Doppler frequency shift is: Based on the Doppler frequency shift, the communication signal frequency range of the target carrier is divided into multiple change rate sub-slots. The Doppler frequency shift compensation waveform of each change rate sub-slot is obtained by table lookup. The compensation waveform is multiplied with the received data to achieve frequency compensation of the carrier Doppler change rate.

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