CN115688598A - Method and system for solving offset frequency strategy by Seed pre-generation genetic algorithm - Google Patents

Abstract

The invention provides a method for solving an offset frequency strategy by a Seed pre-generation genetic algorithm, which is used for solving the offset frequency strategy in a space-based gravitational wave detector; the space-based gravitational wave detector comprises three satellites; each satellite comprises two laser interference optical platforms; the method comprises the following steps: establishing a feasible phase-locking scheme switching sequence; setting an initial beat frequency upper limit according to experience; solving the offset frequency solved under the phase-locked scheme switching sequence by adopting a Seed pre-generation genetic algorithm, wherein the offset frequency can not reach the set solving termination time, so that the minimum beat frequency upper limit and a corresponding offset frequency strategy which can be supported under the phase-locked scheme switching sequence are obtained; the offset frequency strategy comprises the offset frequency between two optical platforms in each satellite and the offset frequency between two adjacent optical platforms between two adjacent satellites. The invention has the advantages that: unnecessary operation is avoided, and the defect of low solving efficiency of the traditional genetic algorithm is overcome.

Description

A method and system for solving offset frequency strategy by Seed pre-generated genetic algorithm

technical field

The invention belongs to the technical field of computers, and in particular relates to a method and a system for solving an offset frequency strategy by a Seed pre-generated genetic algorithm.

Background technique

In recent years, space-based gravitational wave detection has become a hot issue in the physics community. In the ultra-long-arm space-based gravitational wave detection mission, due to the existence of the interstellar Doppler frequency shift, the beat frequency signal used to measure the gravitational wave signal fluctuates within a certain range. Due to the limitation of the phase meter bandwidth, the uncontrolled beat frequency will exceed the detection bandwidth of the phase meter, which will lead to the interruption of scientific detection signals. In order to make the beat frequency fall within a reasonable measurement range, it is usually adopted to add an artificial offset frequency to the low-light phase-locked loop, so that the beat frequency can be detected by the phase meter. In addition, since the beat frequency signal is measured by means of heterodyne interference, homodyne interference phenomenon needs to be avoided. In addition, it is also necessary to avoid the interference of the low-frequency laser relative intensity noise on the beat frequency signal. Therefore, the lower limit of the beat frequency also needs to be limited. The selection of the phase-locking scheme will affect the setting of the manual offset frequency and the duration of the offset frequency. At present, the space-based gravitational wave detection missions include the LISA project, the Taiji project, and the Tianqin project, etc. In the Tai Chi project, 5MHz is currently used as the lower limit of the beat frequency, but in fact the lowest lower limit of the beat frequency can reach 3MHz. The upper limit of the beat frequency is usually set to 25MHz. However, in the actual process, although it is possible to manufacture a high-bandwidth phase meter, the increase in the bandwidth of the phase meter will inevitably lead to greater readout noise. Therefore, From the perspective of reducing noise and improving accuracy, it is necessary to lower the upper limit of the beat frequency of the phase meter. On the other hand, if the upper limit of the beat frequency is too low, the offset frequency needs to be changed frequently during the mission, which will lead to the interruption of scientific observation. Therefore, it is necessary to set a reasonable phase-locking scheme at each stage of the mission, and on this basis, reasonably plan the upper limit of the beat frequency to balance the two optimization goals of reducing noise and minimizing the number of offset frequency changes.

Since space-based gravitational wave detectors are usually composed of multiple satellites, there are the following problems: 1. The formulation of an optional phase-locking scheme, 2. The selection of the optimal phase-locking scheme at each stage, 3. Based on the selected phase-locking scheme, The setting of the upper limit of the lowest beat frequency and the setting of the offset frequency in each weak-light phase-locked loop, or called the offset frequency strategy, 4. Which algorithm is used to efficiently solve the corresponding offset frequency strategy. Changing the phase-locking scheme and offset frequency will lead to the interruption of scientific detection signals, so the phase-locking scheme and offset frequency should be kept unchanged as much as possible or at least meet the minimum duration of the actual working conditions. In addition, since a higher beat frequency upper limit will lead to greater phase readout noise, it is necessary to obtain the lowest beat frequency upper limit that satisfies the minimum offset frequency duration by solving.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art that the setting of the upper limit of the lowest beat frequency and the setting and calculation efficiency of the offset frequency in each weak-light phase-locked loop are not high.

In order to achieve the above object, the present invention proposes a method for solving the offset frequency strategy with a Seed pre-generated genetic algorithm, which is used for solving the offset frequency strategy in the space-based gravitational wave detector; the space-based gravitational wave detector includes Three satellites, three satellites are placed in an equilateral triangle; each satellite contains two laser interference optical platforms;

The methods include:

Step 1: Formulate phase-locking scheme switching sequence;

Step 2: Set the upper limit of the initial beat frequency;

Step 3: According to the switching sequence of the phase-locking scheme, according to the set objective function, use the Seed pre-generated genetic algorithm to solve the offset frequency planning results at different times under the dynamic constraint conditions in all time slices; repeat this step many times, Calculate the lowest beat frequency upper limit and the corresponding offset frequency strategy that can be supported under the phase-locking scheme switching sequence;

The offset frequency strategy includes the offset frequency between two optical platforms inside each satellite, and the offset frequency between adjacent optical platforms between two adjacent satellites.

As an improvement of the above method, the step 1 specifically includes:

The phase-locking scheme switching sequence includes 3 kinds of phase-locking sequences and 6 kinds of phase-locking main optical platforms, forming 18 kinds of phase-locking schemes in total;

Set the 3 satellites to be respectively numbered as satellite 1, satellite 2, and satellite 3; A, B, C, D, E, F six optical platforms are placed counterclockwise;

The three phase-locking sequences are respectively recorded as Seq1, Seq2, and Seq3;

The first phase-locking sequence Seq1 is to select one optical table as the master optical table, and the other five optical tables are slave optical tables; The other three optical tables; the laser frequency of the main optical table remains constant, and the lasers from the optical tables on both sides of the main optical table are phase-locked to the received lasers emitted by the adjacent optical tables from near to far;

The second phase-locking sequence Seq2 is to select one optical table as the master optical table, and the other five optical tables are slave optical tables; The other 4 optical tables; the laser frequency of the main optical table remains constant, and the lasers from the optical tables on both sides of the main optical table are phase-locked to the received lasers emitted by the adjacent optical tables from near to far;

The third phase-locking sequence Seq3 is to select one optical table as the master optical table, and the remaining five optical tables are slave optical tables; during the phase-locking process, there are 0 slave optical tables on one side of the main optical table, and The other 5 optical tables; the laser frequency of the main optical table remains constant, and the laser from the optical table on the side of the main optical table is phase-locked to the received laser emitted by the adjacent optical table from near to far;

The 18 phase-locking schemes are respectively <Seq1, main optical platform A>, <Seq1, main optical platform B>, <Seq1, main optical platform C>, <Seq1, main optical platform D>, <Seq1, main optical platform D>, <Seq1, main optical platform Optical table E>, <Seq1, main optical table F>, <Seq2, main optical table A>, <Seq2, main optical table B>, <Seq2, main optical table C>, <Seq2, main optical table D>, <Seq2, main optical table E>, <Seq2, main optical table F>, <Seq3, main optical table A>, <Seq3, main optical table B>, <Seq3, main optical table C>, <Seq3, main optical table Platform D>, <Seq3, primary optical platform E>, <Seq3, primary optical platform F>.

As an improvement of the above method, the satellite where the main optical platform is located is set as satellite 1, and the other two satellites are respectively satellite 2 and satellite 3; the satellite adjacent to the side of the main optical platform is satellite 3, and the other satellite is satellite 2;

The beat frequency calculation method of the phase-locked sequence Seq1 is as follows:

分别表示4个随时间 变化的拍频信号的计算方式，

表示5个不随时间 变化的拍频信号计算方式；MOB表示所选用的主光学平台；Δf_(1,2)表示卫星1与卫 星2相邻光学平台之间的偏移频率；Δf_(1,3)表示卫星1与卫星3相邻光学平台之间的 偏移频率；Δf_(3,3)表示卫星3内部两个光学平台之间的偏移频率；Δf_(1,1)表示卫星1内 部两个光学平台之间的偏移频率；Δf_(2,2)表示卫星2内部两个光学平台之间的偏移频 率；f_d1(t)表示卫星1与卫星2之间随时间变化的多普勒频移；f_d2(t)表示卫星3与 卫星2之间随时间变化的多普勒频移；f_d3(t)表示卫星1与卫星3之间随时间变化的 多普勒频移。Among them, t represents time;

Represent the calculation methods of the four time-varying beat frequency signals,

Indicates the calculation method of 5 beat frequency signals that do not change with time; MOB indicates the selected main optical platform; Δf _(1,2) indicates the offset frequency between the adjacent optical platforms of satellite 1 and satellite 2; Δf _{(1,3 )} represents the offset frequency between the adjacent optical platforms of satellite 1 and satellite 3; Δf ( _{3,3 )} represents the offset frequency between the two optical platforms inside satellite 3; The offset frequency between the two optical platforms; Δf _(2,2) represents the offset frequency between the two optical platforms inside satellite 2; f _d1 (t) represents the Doppler frequency between satellite 1 and satellite 2 with time f _d2 (t) represents the time-varying Doppler frequency shift between satellite 3 and satellite 2; f _d3 (t) represents the time-varying Doppler frequency shift between satellite 1 and satellite 3.

The beat frequency calculation method of the phase-locked sequence Seq2 is as follows:

Among them, Δf _(2,3) represents the offset frequency between the adjacent optical platforms of satellite 2 and satellite 3;

The beat frequency calculation method of the phase-locked sequence Seq3 is as follows:

As an improvement of the above method, the initial beat frequency upper limit f _upper is set to 25MHz.

As an improvement of the above method, the step 3 specifically includes:

Step 3-1: Set time slice start time Start=1, end time End=Start;

Step 3-2: Select the phase-locked main optical platform at the current stage according to the phase-locked scheme switching sequence adopted in step 1;

Step 3-3: Select the phase-locking sequence of the current stage according to the switching sequence of the phase-locking scheme adopted in step 1;

Step 3-4: According to the current start time Start and end time End, construct the dynamic constraints for Seed generation;

Step 3-5: Solve the current offset frequency planning scheme by using the linear programming algorithm;

Step: 3-6: Judging whether a feasible solution can be obtained, if so, go to step 3-7; otherwise, go to step 3-10;

Step 3-7: Save the current start time Start, end time End and offset frequency solution results in the End row of the matrix Result;

Step 3-8: Determine whether the current end time End is the end time EOF, if so, go to step 3-9; otherwise, go to step 3-17;

Step 3-9: Save the current offset frequency planning result, set the beat frequency upper limit f _upper to decrease by 1 unit, and go to step 3-1;

Step 3-10: Set the end time End to decrease by 1 unit;

Step 3-11: the initial Seed of setting genetic algorithm is the solution result of each offset frequency in the End row of the result matrix Result;

Step 3-12: Construct dynamic constraints for the genetic algorithm according to the start time Start and the end time End;

Step 3-13: use genetic algorithm to solve according to the set objective function;

Step 3-14: Determine whether there is a feasible solution, if yes, go to step 3-15; otherwise, go to step 3-18;

Step 3-15: Save the current start time Start, end time End and offset frequency solution results in the matrix Result;

Step 3-16: Determine whether the current end time End is the end time EOF, if so, go to step 3-9; otherwise, go to step 3-19;

Step 3-17 set the end time End to increase by 1 unit, go to step 3-4;

Step 3-18: Determine whether the start time Start and the end time End are equal, if so, go to step 3-21; otherwise, go to step 3-20;

Step 3-19: Set the end time End to increase by 1 unit, go to step 3-12;

Step 3-20: set the start time Start=End, set the end time End=Start; go to step 3-2;

Step 3-21: sort out all the results, including the phase-locking scheme adopted in each time slice and the corresponding offset frequency planning results, and obtain the minimum beat frequency upper limit that can be supported under the set phase-locking scheme switching sequence and the corresponding offset frequency. shift frequency strategy.

As an improvement of the above method, the steps 3-4 specifically include:

The dynamic constraints for seed generation specifically include:

(Start,End)表示从t＝Start到 t＝End的所有拍频1的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频2 的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频3的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频4的数值；

(Start,End)表示 从t＝Start到t＝End的所有拍频5的数值；

(Start,End)表示从t＝Start到t＝End的 所有拍频6的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频7的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频8的数值；

(Start,End)表示 从t＝Start到t＝End的所有拍频9的数值。Among them, LB and UB represent the lower limit and upper limit of the beat frequency respectively;

(Start, End) represents the value of all beat frequencies 1 from t=Start to t=End;

(Start, End) represents the values of all beat frequencies 2 from t=Start to t=End;

(Start, End) represents the numerical values of all beat frequencies 3 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 4 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 5 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 6 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 7 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 8 from t=Start to t=End;

(Start, End) represents the values of all beat frequencies 9 from t=Start to t=End.

As an improvement of the above method, the step 3-12 specifically includes:

The dynamic constraints used in the genetic algorithm specifically include:

表示从t＝Start到 t＝End的所有拍频1的绝对值；

表示从t＝Start到t＝End的所有拍频 2的绝对值；

表示从t＝Start到t＝End的所有拍频3的绝对值；

表示从t＝Start到t＝End的所有拍频4的绝对值；

表示从t＝Start到t＝End的所有拍频5的绝对值；

表示从t＝Start到 t＝End的所有拍频6的绝对值；

表示从t＝Start到t＝End的所有拍频 7的绝对值；

表示从t＝Start到t＝End的所有拍频8的绝对值；

表示从t＝Start到t＝End的所有拍频9的绝对值。Among them, LB and UB represent the lower limit and upper limit of the beat frequency respectively;

Represent the absolute value of all beat frequencies 1 from t=Start to t=End;

Represent the absolute value of all beat frequencies 2 from t=Start to t=End;

Represent the absolute value of all beat frequencies 3 from t=Start to t=End;

Represent the absolute value of all beat frequencies 4 from t=Start to t=End;

Represent the absolute value of all beat frequencies 5 from t=Start to t=End;

Represent the absolute value of all beat frequencies 6 from t=Start to t=End;

Represent the absolute value of all beat frequencies 7 from t=Start to t=End;

Represent the absolute value of all beat frequencies 8 from t=Start to t=End;

Indicates the absolute value of all beat frequencies 9 from t=Start to t=End.

As an improvement of the above method, the objective function is:

Max T

Wherein, T represents the duration of the offset frequency, T=End-Start.

As an improvement of the above method, the end time EOF is set to 1825 days.

The present invention also provides a system for solving the offset frequency strategy by a genetic algorithm, the system comprising:

The phase-locking scheme switching sequence module is used to formulate a feasible phase-locking scheme switching sequence;

Set the initial beat frequency upper limit module, which is used to set the initial beat frequency upper limit according to experience;

Calculate the offset frequency measurement module, which is used to switch the sequence according to the phase-locking scheme, and use the Seed pre-generated genetic algorithm to solve the offset frequency planning results at different times under the dynamic constraint conditions in all time slices according to the set objective function; Repeat this step multiple times to calculate the minimum beat frequency upper limit that can be supported under the phase-locking scheme switching sequence and the corresponding offset frequency strategy;

The offset frequency strategy includes the offset frequency between two optical platforms inside each satellite, and the offset frequency between adjacent optical platforms between two adjacent satellites.

Compared with the prior art, the present invention has the advantages of:

1. Due to the large number of optional phase-locking schemes, the solution space is too large. Using the existing algorithm, the solution efficiency is low. Using the pre-generated method of Seed can reduce the solution time to a certain extent, improve the solution efficiency, avoid unnecessary calculations, and avoid the disadvantages of low solution efficiency of the traditional genetic algorithm.

2. The present invention constructs all possible phase-locking sequences and phase-locking main optical platforms, which are highly complete, and all feasible optimization results can be obtained through algorithmic solutions, providing relevant researchers with comprehensive phase-locking scheme strategies and offset frequencies Strategy.

3. The use of dynamic constraints ensures the solution efficiency in the early stage of the solution process.

Description of drawings

Fig. 1 shows the method flowchart based on Seed pre-generated genetic algorithm of the present invention to solve offset frequency strategy;

Fig. 2 shows three kinds of different phase-lock sequence schematic diagrams that the present invention proposes; Wherein, Fig. 2 (a) is phase-lock sequence Seq1, and Fig. 2 (b) is phase-lock sequence Seq2, and Fig. 2 (c) is phase-lock sequence Seq3;

Fig. 3 shows the schematic diagram of 6 kinds of different phase-locked main optical platforms proposed by the present invention, all adopt phase-locked order Seq3 in the schematic diagram, wherein Fig. 3 (a) adopts A to be the phase-locked main optical platform, and Fig. 3 (b) adopts B is the phase-locked main optical platform, Figure 3(c) adopts C as the phase-locked main optical platform, Figure 3(d) adopts D as the phase-locked main optical platform, and Figure 3(e) adopts E as the phase-locked main optical platform, Fig. 3(f) Use F as the phase-locked main optical platform;

Fig. 4 shows the 1825-day inter-satellite Doppler frequency shift data that the present invention adopts; Wherein, Fig. 4 (a) represents when selecting A optical platform as the main optical platform, the inter-satellite Doppler between satellite 1 and satellite 2 Frequency shift; Figure 4(b) shows the inter-satellite Doppler frequency shift between satellite 2 and satellite 3 when optical platform A is selected as the main optical platform; Figure 4(c) shows when optical platform A is selected as the main optical platform , the inter-satellite Doppler shift between satellite 1 and satellite 3.

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings.

The present invention proposes a method and system for solving the offset frequency strategy by a Seed pre-generated genetic algorithm, which is used for solving the offset frequency strategy in a space-based gravitational wave detector.

Space-based gravitational wave detectors usually contain three satellites, and the three satellites are placed in an equilateral triangle. Satellites can be separated by millions of kilometers. Each satellite contains two laser interferometry optical platforms.

Among the three satellites, each satellite contains two laser interferometry optical platforms, and they are numbered as satellite 1, satellite 2 and satellite 3 respectively. Satellite 1 includes laser interferometry optical benches A and B, satellite 2 includes laser interferometry optical benches C and D, and satellite 3 includes laser interferometry optical benches E and F.

The laser interference optical platform is used to transmit and receive laser light to the adjacent optical platform in the same satellite, and is also used to transmit and receive laser light to the remote optical platform in another satellite adjacent to this satellite.

The method that a kind of Seed pre-generated genetic algorithm of the present invention solves offset frequency strategy comprises:

Formulate a feasible phase-locking scheme switching sequence in advance, that is, the phase-locking sequence and the phase-locking main optical platform used in each time slice of the task operation. After switching the time slice, switch the phase-locking sequence and the phase-locking main optical platform in sequence.

A time slice refers to a time slice from the start time to the end time of a set offset frequency during the running of a task.

Set the upper limit of the initial beat frequency based on experience.

According to the start time of a certain time slice and the selected phase-locking scheme, according to the set objective function (the objective function includes maximizing the offset frequency duration and minimizing the number of offset frequency changes), the Seed pre-generated genetic The algorithm solves the offset frequency planning results at different times under the dynamic constraint conditions in this time slice, until the dynamic constraint conditions cannot be satisfied by adjusting the offset frequency at a certain moment, then the end time of the current time slice and the next time The start time of the slice. According to the phase-locking scheme sequence formulated in advance, select the phase-locking scheme of the next time slice in the sequence, repeat this step, and obtain the offset frequency planning results of different time slices; if the set solution termination time can be reached, output different time slices According to the offset frequency planning results, lower the upper limit of the initial beat frequency, and repeat the above steps; until the set upper limit of the beat frequency makes the offset frequency solved under the switching sequence of the phase-locking scheme unable to reach the set solution termination time, so that in The upper limit of the lowest beat frequency that can be supported under the switching sequence of the phase-locking scheme and the corresponding offset frequency strategy.

The objective function is:

Max T

Wherein, T represents the duration of the offset frequency, T=End-Start.

As shown in Figure 1, the process of solving the offset frequency strategy specifically includes:

Step 1) generating all possible phase-locking scheme switching sequences;

The phase-locking scheme switching sequence includes 3 phase-locking sequences and 6 phase-locking main optical platforms, and there are 18 phase-locking schemes in total.

The three phase-locking sequences are respectively recorded as Seq1, Seq2, and Seq3; the six optical platforms A, B, C, D, E, and F are placed counterclockwise.

The first phase-locking sequence Seq1 is to select one optical table as the master optical table, and the other five optical tables are slave optical tables; The other three optical tables; the laser frequency of the main optical table remains constant, and the lasers from the optical tables on both sides of the main optical table are phase-locked to the received lasers emitted by the adjacent optical tables from near to far.

The second phase-locking sequence Seq2 is to select one optical table as the master optical table, and the other five optical tables are slave optical tables; The other four optical tables; the laser frequency of the main optical table remains constant, and the lasers from the optical tables on both sides of the main optical table are phase-locked to the received lasers emitted by the adjacent optical tables from near to far.

The third phase-locking sequence Seq3 is to select one optical table as the master optical table, and the remaining five optical tables are slave optical tables; during the phase-locking process, there are 0 slave optical tables on one side of the main optical table, and The other 5 optical tables; the laser frequency of the main optical table remains constant, and the laser from the optical table on the side of the main optical table is phase-locked to the received laser emitted by the adjacent optical table from near to far.

The 18 phase-locking schemes are generated by using six optical tables A, B, C, D, E, and F as the main optical table, respectively <Seq1, main optical table A>, <Seq1, main optical table B>, <Seq1, main optical table B>, < Seq1, main optical table C>, <Seq1, main optical table D>, <Seq1, main optical table E>, <Seq1, main optical table F>, <Seq2, main optical table A>, <Seq2, main optical table B>, <Seq2, main optical table C>, <Seq2, main optical table D>, <Seq2, main optical table E>, <Seq2, main optical table F>, <Seq3, main optical table A>, <Seq3 , main optical table B>, <Seq3, main optical table C>, <Seq3, main optical table D>, <Seq3, main optical table E>, <Seq3, main optical table F>.

Figure 2 shows that the three phase-locking sequences uniformly use the optical platform A as the main optical platform, and the six optical platforms A, B, C, D, E, and F are placed counterclockwise.

As shown in Figure 3, it is the phase-locking scheme using six optical platforms A, B, C, D, E, and F as the main optical platform. Among them, black indicates that the current optical platform is the main optical platform. Figure 3(a) indicates that A is selected as the main optical platform, and the phase-locking sequence is Seq1; Figure 3(b) indicates that B is selected as the main optical platform, and the phase-locking sequence is Seq1; Figure 3(c) indicates that C is selected as the main optical platform , the phase-locking sequence is Seq1; Figure 3(d) indicates that D is selected as the main optical platform, and the phase-locking sequence is Seq1; Figure 3(e) indicates that E is selected as the main optical platform, and the phase-locking sequence is Seq1; Figure 3(f) Indicates that F is selected as the main optical platform, and the phase-locking sequence is Seq1.

The beat frequency calculation method of the phase-locked sequence Seq1 is as follows:

分别表示4个随时间变化的拍频信号的计算方式，

表示5个不随时间变化的拍频信 号计算方式。其中，MOB表示所选用的主光学平台。为了表述的通用性，设定主光 学平台所在卫星为卫星1，其余两颗卫星分别为卫星2和卫星3。其中邻近主光学平 台一侧的卫星为卫星3，另一颗卫星为卫星2。其中，Δf_(1,2)表示卫星1与卫星2相 邻光学平台之间的偏移频率；Δf_(1,3)表示卫星1与卫星3相邻光学平台之间的偏移频 率；Δf_(3,3)表示卫星3内部两个光学平台之间的偏移频率；Δf_(1,1)表示卫星1内部两个 光学平台之间的偏移频率；Δf_(2,2)表示卫星2内部两个光学平台之间的偏移频率； f_d1(t)表示卫星1与卫星2之间随时间变化的多普勒频移；f_d2(t)表示卫星3与卫星 2之间随时间变化的多普勒频移；f_d3(t)表示卫星1与卫星3之间随时间变化的多普 勒频移。in,

Represent the calculation methods of the four time-varying beat frequency signals,

Indicates the calculation method of 5 beat frequency signals that do not change with time. Among them, MOB represents the selected main optical bench. For the generality of the expression, the satellite where the main optical platform is located is set as satellite 1, and the other two satellites are respectively satellite 2 and satellite 3. The satellite adjacent to the side of the main optical platform is satellite 3, and the other satellite is satellite 2. Among them, Δf _(1,2) represents the offset frequency between the adjacent optical platforms of satellite 1 and satellite 2; Δf _(1,3) represents the offset frequency between the adjacent optical platforms of satellite 1 and satellite 3; Δf _{( 3,3)} indicates the offset frequency between the two optical platforms inside satellite 3; Δf _(1,1) indicates the offset frequency between the two optical platforms inside satellite 1; Δf _(2,2) indicates the offset frequency between the two optical platforms inside satellite 2 The offset frequency between the two optical platforms; f _d1 (t) represents the Doppler frequency shift between satellite 1 and satellite 2 with time; f _d2 (t) represents the time change between satellite 3 and satellite 2 Doppler frequency shift; f _d3 (t) represents the Doppler frequency shift between satellite 1 and satellite 3 with time.

The beat frequency calculation method of the phase-locked sequence Seq2 is as follows:

分别表示4个随时间变化的拍频信号的计算方式，

表示5个不随时间变化的拍频 信号计算方式。其中，MOB表示所选用的主光学平台。为了表述的通用性，设定主 光学平台所在卫星为卫星1，其余两颗卫星分别为卫星2和卫星3。其中邻近主光学 平台一侧的卫星为卫星3，另一颗卫星为卫星2。其中，Δf_(1,2)表示卫星1与卫星2 相邻光学平台之间的偏移频率；Δf_(1,3)表示卫星1与卫星3相邻光学平台之间的偏移 频率；Δf_(2,3)表示卫星2与卫星3相邻光学平台之间的偏移频率；Δf_(3,3)表示卫星3 内部两个光学平台之间的偏移频率；Δf_(2,2)表示卫星2内部两个光学平台之间的偏移 频率；f_d1(t)表示卫星1与卫星2之间随时间变化的多普勒频移；f_d2(t)表示卫星3 与卫星2之间随时间变化的多普勒频移；f_d3(t)表示卫星1与卫星3之间随时间变化 的多普勒频移。in,

Represent the calculation methods of the four time-varying beat frequency signals,

Indicates the calculation method of 5 beat frequency signals that do not change with time. Among them, MOB represents the selected main optical bench. For the generality of the expression, the satellite where the main optical platform is located is set as satellite 1, and the other two satellites are respectively satellite 2 and satellite 3. The satellite adjacent to the side of the main optical platform is satellite 3, and the other satellite is satellite 2. Among them, Δf _(1,2) represents the offset frequency between the adjacent optical platforms of satellite 1 and satellite 2; Δf _(1,3) represents the offset frequency between the adjacent optical platforms of satellite 1 and satellite 3; Δf _{( 2,3)} represents the offset frequency between the adjacent optical platforms of satellite 2 and satellite 3; Δf _(3,3) represents the offset frequency between the two optical platforms inside satellite 3; Δf _(2,2) represents the 2 is the offset frequency between the two internal optical platforms; f _d1 (t) represents the Doppler frequency shift between satellite 1 and satellite 2 with time; f _d2 (t) represents the time-varying Doppler shift between satellite 3 and Time-varying Doppler shift; f _d3 (t) represents the time-varying Doppler shift between satellite 1 and satellite 3.

The beat frequency calculation method of the phase-locked sequence Seq3 is as follows:

分别表示4个随时间变化的拍频信号的计算方式，

表示5个不随时间变化的拍频信 号计算方式。其中，MOB表示所选用的主光学平台。为了表述的通用性，设定主光 学平台所在卫星为卫星1，其余两颗卫星分别为卫星2和卫星3。其中邻近主光学平 台一侧的卫星为卫星3，另一颗卫星为卫星2。其中，Δf_(1,1)表示卫星1内部两个光 学平台之间的偏移频率；Δf_(1,3)表示卫星1与卫星3相邻光学平台之间的偏移频率； Δf_(2,3)表示卫星2与卫星3相邻光学平台之间的偏移频率；Δf_(3,3)表示卫星3内部两 个光学平台之间的偏移频率；Δf_(2,2)表示卫星2内部两个光学平台之间的偏移频率； f_d1(t)表示卫星1与卫星2之间随时间变化的多普勒频移；f_d2(t)表示卫星3与卫星 2之间随时间变化的多普勒频移；f_d3(t)表示卫星1与卫星3之间随时间变化的多普 勒频移。in,

Represent the calculation methods of the four time-varying beat frequency signals,

Indicates the calculation method of 5 beat frequency signals that do not change with time. Among them, MOB represents the selected main optical bench. For the generality of the expression, the satellite where the main optical platform is located is set as satellite 1, and the other two satellites are respectively satellite 2 and satellite 3. The satellite adjacent to the side of the main optical platform is satellite 3, and the other satellite is satellite 2. Among them, Δf _(1,1) represents the offset frequency between two optical platforms inside satellite 1; Δf _(1,3) represents the offset frequency between satellite 1 and adjacent optical platforms of satellite 3; Δf _{(2, 3)} Indicates the offset frequency between the adjacent optical platforms of satellite 2 and satellite 3; Δf _(3,3) indicates the offset frequency between the two optical platforms inside satellite 3; Δf _(2,2) indicates the internal The offset frequency between the two optical platforms; f _d1 (t) represents the Doppler frequency shift between satellite 1 and satellite 2 with time; f _d2 (t) represents the time change between satellite 3 and satellite 2 Doppler frequency shift; f _d3 (t) represents the Doppler frequency shift between satellite 1 and satellite 3 with time.

Step 2) setting the initial beat frequency upper limit f _upper ;

The initial beat frequency upper limit f _upper is usually set to 25MHz.

Step 3) setting time slice start time Start=1, end time End=Start;

Step 4) Select the phase-locked main optical platform at the current stage according to the phase-locked scheme switching sequence adopted in step 1);

Step 5) Select the phase-locking order of the current stage according to the phase-locking scheme switching sequence adopted in step 1);

Step 6) according to current start time Start and end time End, construct the dynamic constraint condition that is used for Seed generation;

The dynamic constraints for seed generation specifically include:

(Start,End)表示从t＝Start到 t＝End的所有拍频1的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频2 的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频3的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频4的数值；

(Start,End)表示 从t＝Start到t＝End的所有拍频5的数值；

(Start,End)表示从t＝Start到t＝End的 所有拍频6的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频7的数值；

(Start,End)表示从t＝Start到t＝End的所有拍频8的数值；

(Start,End)表示 从t＝Start到t＝End的所有拍频9的数值。随着算法的迭代，End的值在不断变化， 因此每次求解前需重新构建该动态约束条件。Among them, LB and UB represent the lower limit and upper limit of the beat frequency respectively;

(Start, End) represents the value of all beat frequencies 1 from t=Start to t=End;

(Start, End) represents the values of all beat frequencies 2 from t=Start to t=End;

(Start, End) represents the numerical values of all beat frequencies 3 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 4 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 5 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 6 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 7 from t=Start to t=End;

(Start, End) represents the numerical value of all beat frequencies 8 from t=Start to t=End;

(Start, End) represents the values of all beat frequencies 9 from t=Start to t=End. With the iteration of the algorithm, the value of End is constantly changing, so the dynamic constraints need to be rebuilt before each solution.

Taking the phase-locking scheme <Seq1, main optical platform A> as an example, when Start=1, End=2, the dynamic constraints for seed generation are as follows

Step 7) Using a linear programming algorithm to solve the current offset frequency planning scheme;

Step 8) Judging whether a feasible solution can be obtained, if so, go to step 9); otherwise, go to step 12)

Step 9) Save the current start time Start, end time End and offset frequency solution results in the End row of the matrix Result; the offset frequency solution results include Δf _(1,1) , Δf _(2,2) , Δf _(3,3) , Δf _(1,2) , Δf _(1,3) and Δf _(2,3) .

The result matrix Result stores the calculation results of the offset frequency in the current time slice, and stores them in a queue. The latest calculation result is the last row of the scheme matrix.

Step 10) judge whether the current end time End is the end time EOF, if so go to step 11); otherwise go to step 19); the end time EOF is usually set to 1825 days.

Step 11) Save the current offset frequency planning result, update the beat frequency upper limit f _upper = f _upper -1, go to step 3)

Step 12) setting end time End=End-1;

Step 13) the initial Seed of setting genetic algorithm is each offset frequency solution result in the end row of result matrix Result;

Step 14) construct the dynamic constraints for the genetic algorithm according to the start time Start and the end time End.

The dynamic constraints used in the genetic algorithm specifically include:

表示从t＝Start到 t＝End的所有拍频1的绝对值；

表示从t＝Start到t＝End的所有拍频 2的绝对值；

表示从t＝Start到t＝End的所有拍频3的绝对值；

表示从t＝Start到t＝End的所有拍频4的绝对值；

表示从t＝Start到t＝End的所有拍频5的绝对值；

表示从t＝Start到 t＝End的所有拍频6的绝对值；

表示从t＝Start到t＝End的所有拍频 7的绝对值；

表示从t＝Start到t＝End的所有拍频8的绝对值；

表示从t＝Start到t＝End的所有拍频9的绝对值。随着算法的迭代， End的值在不断变化，因此每次求解前需重新构建该动态约束条件。Among them, LB and UB represent the lower limit and upper limit of the beat frequency respectively;

Represent the absolute value of all beat frequencies 1 from t=Start to t=End;

Represent the absolute value of all beat frequencies 2 from t=Start to t=End;

Represent the absolute value of all beat frequencies 3 from t=Start to t=End;

Represent the absolute value of all beat frequencies 4 from t=Start to t=End;

Represent the absolute value of all beat frequencies 5 from t=Start to t=End;

Represent the absolute value of all beat frequencies 6 from t=Start to t=End;

Represent the absolute value of all beat frequencies 7 from t=Start to t=End;

Represent the absolute value of all beat frequencies 8 from t=Start to t=End;

Indicates the absolute value of all beat frequencies 9 from t=Start to t=End. As the algorithm iterates, the value of End is constantly changing, so the dynamic constraints need to be rebuilt before each solution.

Taking the phase-locking scheme <Seq1, main optical platform A> as an example, when Start=1, End=2, the dynamic constraints used in the genetic algorithm are as follows

Step 15) adopt genetic algorithm to solve;

Step 16) Judging whether there is a feasible solution, if so, go to step 17); otherwise, go to step 20)

Step 17) with current start moment Start, end moment End and offset frequency solution result are saved in matrix Result;

Step 18) judge whether the current end time End is the end time EOF, if so go to step 11); otherwise go to step 21);

Step 19) Set End=End+1, go to step 6)

Step 20) judge whether the start time Start and the end time End are equal, if go to step 23); otherwise go to step 22);

Step 21) Set End=End+1, go to step 14)

Step 22) set start time Start=End, set end time End=Start; go to step 4);

Step 23) sort out all the results, including the phase-locking scheme adopted in each time slice and the corresponding offset frequency planning results, and the solution ends.

In one example, using the 5-year inter-satellite Doppler frequency shift data with an arm length of 3 million kilometers, as shown in Figure 4, the abscissa represents time, and the ordinate represents the Doppler frequency shift at this moment, and the unit is MHz. The results obtained by the above method are as follows:

Table 1 Solution results

It can be seen from Table 1 that when the beat frequency upper limit is set to 21MHz, the phase-locking scheme needs to be changed once: in phase 1, the main star is selected as A, and the phase-locking sequence is Seq3, and the duration is 1477 days; in phase 2, the main star is C , the phase-locking sequence is Seq3, and the duration is 328 days.

The offset frequency is set as follows:

Table 2 Offset Frequency Setting

The present invention also provides a computer device comprising: at least one processor, a memory, at least one network interface and a user interface. The individual components in the device are coupled together via a bus system. It can be understood that the bus system is used to realize connection communication between these components. In addition to the data bus, the bus system also includes a power bus, a control bus and a status signal bus.

Wherein, the user interface may include a display, a keyboard or a pointing device. For example, mouse, trackball (trackball), touch pad or touch screen, etc.

It can be understood that the memory in the disclosed embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Wherein, the non-volatile memory may be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electronically programmable Erase Programmable Read-Only Memory (Electrically EPROM, EEPROM) or Flash. The volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of illustration and not limitation, many forms of RAM are available such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDRSDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous connection dynamic random access memory (Synchlink DRAM, SLDRAM) and Direct Memory Bus Random Access Memory (Direct Rambus RAM, DRRAM). The memories described herein are intended to include, but are not limited to, these and any other suitable types of memories.

In some embodiments, the memory stores the following elements, executable modules or data structures, or a subset thereof, or an extension thereof: an operating system and application programs.

Among them, the operating system includes various system programs, such as framework layer, core library layer, driver layer, etc., which are used to realize various basic services and handle hardware-based tasks. The application program includes various application programs, such as a media player (Media Player), a browser (Browser), etc., and is used to implement various application services. Programs for realizing the methods of the embodiments of the present disclosure may be contained in application programs.

In the above-mentioned embodiment, the processor can also be used to:

Perform the steps of the method described above.

The foregoing method may be applied to or implemented by a processor. A processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor or an instruction in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable Logic devices, discrete gate or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed above can be realized or executed. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, and the like. The steps combined with the methods disclosed above can be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field. The storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above method in combination with its hardware.

It should be understood that the embodiments described in the present invention may be implemented by hardware, software, firmware, middleware, microcode or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (Application Specific Integrated Circuits, ASIC), digital signal processor (Digital Signal Processing, DSP), digital signal processing device (DSP Device, DSPD), programmable logic Device (Programmable Logic Device, PLD), Field-Programmable Gate Array (Field-Programmable GateArray, FPGA), general-purpose processor, controller, microcontroller, microprocessor, other electronic units for performing the functions described in this application or a combination thereof.

For software implementation, the technology of the present invention can be realized by executing the functional modules (such as procedures, functions, etc.) of the present invention. Software codes can be stored in memory and executed by a processor. Memory can be implemented within the processor or external to the processor.

The present invention can also provide a non-volatile storage medium for storing computer programs. When the computer program is executed by the processor, various steps in the above method embodiments can be realized.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit them. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent replacements to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all of them should be included in the scope of the present invention. within the scope of the claims.

Claims (10)

1. A method for solving the offset frequency strategy by a Seed pregenerated genetic algorithm, which is used for solving the offset frequency strategy in a space-based gravitational wave detector; the space-based gravitational wave detector comprises three satellites, three satellites Placed in an equilateral triangle; each satellite contains two laser interference optical platforms; The methods include: Step 1: Formulate phase-locking scheme switching sequence; Step 2: Set the upper limit of the initial beat frequency; Step 3: According to the switching sequence of the phase-locking scheme, according to the set objective function, use the Seed pre-generated genetic algorithm to circularly solve the offset frequency planning results at different times under the dynamic constraint conditions in all time slices; repeat this step many times, Calculate the lowest beat frequency upper limit and the corresponding offset frequency strategy that can be supported under the phase-locking scheme switching sequence; The offset frequency strategy includes the offset frequency between two optical platforms inside each satellite, and the offset frequency between adjacent optical platforms between two adjacent satellites. 2. the method that Seed pre-generated formula genetic algorithm according to claim 1 solves offset frequency strategy, is characterized in that, described step 1 specifically comprises: The phase-locking scheme switching sequence includes 3 phase-locking sequences and 6 phase-locking main optical platforms, forming 18 phase-locking schemes in total; Set the 3 satellites to be numbered as satellite 1, satellite 2, and satellite 3 respectively; A, B, C, D, E, F six optical platforms are placed counterclockwise; The three phase-locking sequences are respectively recorded as Seq1, Seq2, and Seq3; The first phase-locking sequence Seq1 is to select one optical table as the master optical table, and the other five optical tables are slave optical tables; The other three optical tables; the laser frequency of the main optical table remains constant, and the lasers from the optical tables on both sides of the main optical table are phase-locked to the received lasers emitted by the adjacent optical tables from near to far; The second phase-locking sequence Seq2 is to select one optical table as the master optical table, and the other five optical tables are slave optical tables; The other 4 optical tables; the laser frequency of the main optical table remains constant, and the lasers from the optical tables on both sides of the main optical table are phase-locked to the received lasers emitted by the adjacent optical tables from near to far; The third phase-locking sequence Seq3 is to select one optical table as the master optical table, and the remaining five optical tables are slave optical tables; during the phase-locking process, there are 0 slave optical tables on one side of the main optical table, and The other 5 optical tables; the laser frequency of the main optical table remains constant, and the laser from the optical table on the side of the main optical table is phase-locked to the received laser emitted by the adjacent optical table from near to far; The 18 phase-locking schemes are respectively <Seq1, main optical platform A>, <Seq1, main optical platform B>, <Seq1, main optical platform C>, <Seq1, main optical platform D>, <Seq1, main optical platform D>, <Seq1, main optical platform Optical table E>, <Seq1, main optical table F>, <Seq2, main optical table A>, <Seq2, main optical table B>, <Seq2, main optical table C>, <Seq2, main optical table D>, <Seq2, main optical table E>, <Seq2, main optical table F>, <Seq3, main optical table A>, <Seq3, main optical table B>, <Seq3, main optical table C>, <Seq3, main optical table Platform D>, <Seq3, primary optical platform E>, <Seq3, primary optical platform F>. 3. the method for solving the offset frequency strategy according to the Seed pre-generated genetic algorithm according to claim 2, is characterized in that: Set the satellite where the main optical platform is located as satellite 1, and the other two satellites are satellite 2 and satellite 3; the satellite adjacent to the main optical platform is satellite 3, and the other satellite is satellite 2; The beat frequency calculation method of the phase-locked sequence Seq1 is as follows:

Among them, t represents time;

Represent the calculation methods of the four time-varying beat frequency signals,

Indicates the calculation method of 5 beat frequency signals that do not change with time; MOB indicates the selected main optical platform; Δf _(1,2) indicates the offset frequency between the adjacent optical platforms of satellite 1 and satellite 2; Δf _{(1,3 )} represents the offset frequency between the adjacent optical platforms of satellite 1 and satellite 3; Δf ( _{3,3 )} represents the offset frequency between the two optical platforms inside satellite 3; The offset frequency between the two optical platforms; Δf _(2,2) represents the offset frequency between the two optical platforms inside satellite 2; f _d1 (t) represents the Doppler frequency between satellite 1 and satellite 2 with time Le frequency shift; f _d2 (t) represents the time-varying Doppler frequency shift between satellite 3 and satellite 2; f _d3 (t) represents the time-varying Doppler frequency shift between satellite 1 and satellite 3; The beat frequency calculation method of the phase-locked sequence Seq2 is as follows:

Among them, Δf _(2,3) represents the offset frequency between the adjacent optical platforms of satellite 2 and satellite 3; The beat frequency calculation method of the phase-locked sequence Seq3 is as follows:

4. the method for solving the offset frequency strategy by the Seed pre-generation formula genetic algorithm according to claim 1, is characterized in that, the initial beat frequency upper limit f _upper is set to 25MHz. 5. the method that Seed pre-generated formula genetic algorithm according to claim 3 solves offset frequency strategy, is characterized in that, described step 3 specifically comprises: Step 3-1: Set time slice start time Start=1, end time End=Start; Step 3-2: Select the phase-locked main optical platform at the current stage according to the phase-locked scheme switching sequence adopted in step 1; Step 3-3: Select the phase-locking sequence of the current stage according to the switching sequence of the phase-locking scheme adopted in step 1; Step 3-4: According to the current start time Start and end time End, construct dynamic constraints for seed generation; Step 3-5: Solve the current offset frequency planning scheme by using the linear programming algorithm; Step: 3-6: judge whether a feasible solution can be obtained, if so, go to step 3-7); otherwise go to step 3-10; Step 3-7: Save the current start time Start, end time End and offset frequency solution results in the End row of the matrix Result; Step 3-8: Determine whether the current end time End is the end time EOF, if so, go to step 3-9; otherwise, go to step 3-17; Step 3-9: Save the current offset frequency planning result, set the beat frequency upper limit f _upper to decrease by 1 unit, and go to step 3-1; Step 3-10: Set the end time End to decrease by 1 unit; Step 3-11: Set the initial Seed of the genetic algorithm as the solution result of each offset frequency in the End row of the result matrix Result; Step 3-12: Construct dynamic constraints for the genetic algorithm according to the start time Start and the end time End; Step 3-13: use genetic algorithm to solve according to the set objective function; Step 3-14: Determine whether there is a feasible solution, if yes, go to step 3-15; otherwise, go to step 3-18; Step 3-15: Save the current start time Start, end time End and offset frequency solution results in the matrix Result; Step 3-16: Judging whether the current end time End is the end time EOF, if so, go to step 3-9; otherwise, go to step 3-19; Step 3-17: Set the end time End to increase by 1 unit, go to step 3-4; Step 3-18: Determine whether the start time Start and the end time End are equal, if so, go to step 3-21; otherwise, go to step 3-20; Step 3-19: Set the end time End to increase by 1 unit, go to step 3-12; Step 3-20: set the start time Start=End, set the end time End=Start; go to step 3-2; Step 3-21: sort out all the results, including the phase-locking scheme adopted in each time slice and the corresponding offset frequency planning results, and obtain the minimum beat frequency upper limit that can be supported under the set phase-locking scheme switching sequence and the corresponding offset frequency. shift frequency strategy. 6. the method that Seed pre-generated formula genetic algorithm according to claim 5 solves offset frequency strategy, is characterized in that, described step 3-4 specifically comprises: The dynamic constraints for seed generation specifically include:

Among them, LB and UB represent the lower limit and upper limit of the beat frequency respectively;

Represents the value of all beat frequencies 1 from t=Start to t=End;

Represent the value of all beat frequencies 2 from t=Start to t=End;

Represent the value of all beat frequencies 3 from t=Start to t=End;

Represent the value of all beat frequencies 4 from t=Start to t=End;

Represent the numerical values of all beat frequencies 5 from t=Start to t=End;

Represent the value of all beat frequencies 6 from t=Start to t=End;

Represent the value of all beat frequencies 7 from t=Start to t=End;

Represent the value of all beat frequencies 8 from t=Start to t=End;

Value representing all beat frequencies 9 from t=Start to t=End. 7. the method for solving the offset frequency strategy according to the Seed pre-generated genetic algorithm of claim 5, is characterized in that, described step 3-12 specifically comprises: The dynamic constraints used in the genetic algorithm specifically include:

Among them, LB and UB represent the lower limit and upper limit of the beat frequency respectively;

| represents the absolute value of all beat frequencies 1 from t=Start to t=End;

| represents the absolute value of all beat frequencies 2 from t=Start to t=End;

Represent the absolute value of all beat frequencies 3 from t=Start to t=End;

| represents the absolute value of all beat frequencies 4 from t=Start to t=End;

Indicates the absolute value of all beat frequencies 5 from t=Start to t=End;|

| represents the absolute value of all beat frequencies 6 from t=Start to t=End;

| represents the absolute value of all beat frequencies 7 from t=Start to t=End;

Represent the absolute value of all beat frequencies 8 from t=Start to t=End;

Indicates the absolute value of all beat frequencies 9 from t=Start to t=End. 8. the method that Seed pregenerated formula genetic algorithm according to claim 5 solves offset frequency strategy, is characterized in that, described objective function is: Max T Wherein, T represents the duration of the offset frequency, T=End-Start. 9. The method for solving the offset frequency strategy by the Seed pre-generated genetic algorithm according to claim 5, wherein the termination moment EOF is set to 1825 days. 10. A system of Seed pre-generated genetic algorithm solving offset frequency strategy, is characterized in that, described system comprises: The phase-locking scheme switching sequence module is used to formulate a feasible phase-locking scheme switching sequence; Set the initial beat frequency upper limit module, which is used to set the initial beat frequency upper limit according to experience; Calculate the offset frequency measurement module, which is used to switch the sequence according to the phase-locking scheme, and use the Seed pre-generated genetic algorithm to solve the offset frequency planning results at different times under the dynamic constraint conditions in all time slices according to the set objective function; Repeat this step multiple times to calculate the minimum beat frequency upper limit that can be supported under the phase-locking scheme switching sequence and the corresponding offset frequency strategy; The offset frequency strategy includes the offset frequency between two optical platforms inside each satellite, and the offset frequency between adjacent optical platforms between two adjacent satellites.

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