阅读说明：本技术 一种基于迭代制导的轨道面精确控制方法 (Orbital plane accurate control method based on iterative guidance ) 是由 韩冬 陈佳晔 解永锋 郑莉莉 张利宾 王传魁 周文勇 陈益 叶成敏 杜大程 张兵 于 2021-08-30 设计创作，主要内容包括：本发明涉及一种基于迭代制导的轨道面精确控制方法,用于执行GEO发射任务的上面级主动段轨道面精确控制。步骤包括：S1、统筹优化升交点赤经控制精度,S2、初步设定迭代制导目标值,S3、实时计算轨道面控制偏差,S4、重新设定上面级主动段迭代制导目标值。本发明采用多目标优化思想,对升交点赤经修正精度进行优化,在提升轨道面控制精度的同时,确保推进剂消耗量工程可接受。(The invention relates to an orbital plane accurate control method based on iterative guidance, which is used for executing the orbital plane accurate control of an upper-level active section of a GEO launching task. The method comprises the following steps: and S1, overall optimizing the control precision of the ascent intersection right ascension, S2, preliminarily setting an iterative guidance target value, S3, calculating the control deviation of the orbital plane in real time, and S4, resetting the iterative guidance target value of the upper-stage active section. The method adopts a multi-objective optimization idea to optimize the correction precision of the ascension crossing point right ascension channel, and ensures that the propellant consumption engineering is acceptable while improving the control precision of the rail surface.)

1. An iterative guidance-based orbital plane accurate control method is characterized by comprising the following steps:

s1, overall optimization of the control precision of the ascent point right ascension: when the upper level executes a GEO launching task, propellant consumption required for correcting the track inclination angle deviation is guaranteed, and if the track inclination angle precision requirement is delta i, the track inclination angle correction precision is required to be less than 0.1 delta i under the single deviation working condition;

s2, initially setting an iterative guidance target value: in the initial stage of iterative guidance in the upper-stage active section, according to six elements of an iterative guidance target point track: semi-major axis a_mEccentricity e_mInclination of track i_mArgument of near place omega_mElevation crossing right ascension omega_mAnd true proximal angle f_mSetting an iterative guidance initial target position R and an initial target speed V;

s3, calculating the control deviation of the track surface in real time: calculating the error of the current orbit surface in real time, namely the right ascension deviation of the ascending intersection point and the inclination deviation of the orbit according to the position and speed information of the upper stage under the transmitting inertial system;

s4, resetting the iteration guidance target value of the upper-stage active segment: judging whether to change the iteration target value according to the current track surface parameter deviation in the upper-level flight process; if the right ascension deviation of the upper-level ascending intersection is within the control precision range, the iterative guidance target value needs to be replaced, iterative guidance is continued after the iterative guidance target value is updated, and the correction precision of the orbital plane deviation and the deviation correction propellant consumption are ensured to be within an acceptable range.

2. The method for controlling the orbital plane accurately based on the iterative guidance of claim 1, wherein in step S1, the maximum propellant consumption for correcting the ascension deviation at the intersection point is calculated according to the following formula:

m_Ω＝m_tj-m_dd-m_i-m_gj-m_ff-m_fzd-m_aq

in the formula, m_ΩFor the maximum propellant consumption, m, which can be used to correct the deviation of the right ascension at the intersection point_tjFor adding propellant, m_ddPropellant consumption for standard trajectory, m_iPropellant consumption m for correcting track pitch deviation_gjPropellant consumption, m, to correct tool errors_ffPropellant consumption, m, required to correct process errors_fzdPropellant consumption, m, to correct for unguided errors_aqTo transmit a task safety margin.

3. The method for accurately controlling the orbital plane based on the iterative guidance as claimed in claim 1, wherein the minimum control accuracy of the ascension at the ascension point is preliminarily determined by correcting the propellant consumption required by the ascension deviation at the ascension point according to the upper level, simulation analysis is performed on various deviation working conditions, and the control accuracy of the ascension at the ascension point is adjusted and finally determined according to the requirement of the launching mission on the tracking accuracy.

4. The method for precisely controlling the orbital plane based on the iterative guidance of claim 1, wherein in the step S2, the iterative guidance initial target position R is calculated according to the following formula:

wherein r is_mFor iterative guidance of the target point geocentric distance, u_mAnd performing iterative guidance on latitude argument of the target point.

5. The orbital plane accurate control method based on iterative guidance according to claim 4The method is characterized in that the method comprises the following steps of,

6. the method for precisely controlling the orbital plane based on the iterative guidance of claim 1, wherein in the step S2, the iterative guidance initial target speed V is calculated according to the following formula:

wherein v is_mModulo, u, for iteratively guiding the velocity of the target point_mFor iterative guidance of the latitude argument, i, of the target point_mFor iterative guidance of the target point orbit inclination angle, omega_mThe distance between the position vector and the velocity vector of the iterative guidance target point is t.

7. The method for precisely controlling the orbital plane based on the iterative guidance as claimed in claim 6, wherein v is_mThe calculation formula of (a) is as follows,

where μ is the earth's gravitational constant.

8. The iterative guidance-based track surface accurate control method according to claim 6, wherein the calculation formula of t is as follows,

9. the method for precisely controlling an orbital plane based on iterative guidance of claim 1, wherein in S3, the equations for calculating the ascension deviation of the ascending intersection and the inclination deviation of the orbit are as follows:

Δi＝|i_m-i|

ΔΩ＝|Ω_m-Ω|

wherein, Delta i is the inclination deviation of the orbit, Delta omega is the deviation of the right ascension channel of the ascending intersection point, i_mFor iterative guidance of the target point orbit inclination angle, i is the upper stage current position orbit inclination angle, omega_mIn order to iteratively guide the target point to ascend the right ascension, Ω is the right ascension of the ascending intersection of the current position of the upper level.

10. The method for precisely controlling the orbital plane based on the iterative guidance as claimed in claim 9, wherein the calculation formula of i is as follows:

wherein h is moment of momentum, h_zIs the z-axis component of the moment of momentum under the earth's center system, | h | is the modulus of the moment of momentum.

11. The iterative guidance-based track surface accurate control method according to claim 10, wherein the calculation formula of h is as follows,

h＝R×V

wherein, R is the current position vector of the upper stage, and V is the current velocity vector of the upper stage.

12. The iterative guidance-based orbital plane accurate control method according to claim 9, wherein the calculation formula of Ω is as follows,

wherein the content of the first and second substances, is a unit vector in a coordinate system, N_X、N_YThe projection of N in the X-axis and Y-axis directions.

13. The iterative guidance-based track surface accurate control method according to claim 1, wherein in S4, the iterative guidance target value replacement method is as follows: the original iteration guidance target value is position and speed information which is calculated by orbit parameters of a standard trajectory active segment end point, and the rising point ascension value in the original target orbit parameters is replaced by the rising point ascension value of the current position of the upper level.

14. The method for precisely controlling an orbital plane based on iterative guidance of claim 1, wherein in S4, the orbital inclination angle is not more than 0.1 ° and the ascension angle at the intersection point is not more than 0.2 °.

15. The method for accurately controlling the orbital plane based on the iterative guidance of claim 1, wherein in the step S4, the deviation correction propellant consumption is not more than 30% of the propellant allowance.

Technical Field

The invention relates to an orbital plane accurate control method based on iterative guidance, which is used for executing the orbital plane accurate control of an upper-level active section of a GEO launching task.

Background

When the upper level executes the GEO satellite launching task, a main engine twice ignition orbital transfer mode is generally adopted, wherein iterative guidance is adopted for the second ignition. Due to the existence of the deviation of the basic-level shift point parameter, the orbital plane needs to be adjusted in the second active section of the upper-level flight so as to ensure the satellite orbit-entering precision.

And the iterative guidance converts the upper-level kinetic equation into a state equation to describe the upper-level motion, takes the upper-level instantaneous state as an initial value, takes the standard trajectory point state as terminal constraint, and takes the shortest residual flight time from the instantaneous point to the point as the optimal control problem of the performance index. The iterative guidance enables the upper level to meet the requirement of the satellite orbit-entering precision by effectively controlling the flight time, the pitching attitude angle and the yawing attitude angle of the spacecraft.

And the iterative guidance controls the attitude angle by calculating the optimal thrust in real time, controls the parameters of the orbit surface of the orbit entering point, and corrects the orbit surface deviation introduced by the basic-level flight segment. However, since the correction of the ascension angle at the intersection point and the inclination angle of the orbit are mutually coupled, in the flight process of the upper stage, when one deviation is corrected by controlling the attitude angle under certain working conditions, the other deviation is increased to cause out-of-tolerance or overlarge propellant consumption.

Disclosure of Invention

The technical problem solved by the invention is as follows: the method is characterized in that the correction precision of the right ascension deviation of the ascending intersection point is set in the iterative guidance process based on analysis of the correction characteristics of the upper GEO launching task active section orbital plane, the correction precision of the ascending intersection point right ascension deviation is optimized by adopting a multi-objective optimization thought, and the control precision of the orbital plane is improved while the acceptability of a propellant consumption project is ensured.

The technical scheme of the invention is as follows:

an iterative guidance-based orbital plane accurate control method comprises the following steps:

s1, overall optimization of the control precision of the ascent point right ascension: when the upper level executes a GEO launching task, propellant consumption required for correcting the track inclination angle deviation is guaranteed, and if the track inclination angle precision requirement is delta i, the track inclination angle correction precision is required to be less than 0.1 delta i under the single deviation working condition;

s2, initially setting an iterative guidance target value: in the initial stage of iterative guidance in the upper-stage active section, according to six elements of an iterative guidance target point track: semi-major axis a_mEccentricity e_mInclination of track i_mArgument of near place omega_mElevation crossing right ascension omega_mAnd true proximal angle f_mSetting an iterative guidance initial target position R and an initial target speed V;

s3, calculating the control deviation of the track surface in real time: calculating the error of the current orbit surface in real time, namely the right ascension deviation of the ascending intersection point and the inclination deviation of the orbit according to the position and speed information of the upper stage under the transmitting inertial system;

s4, resetting the iteration guidance target value of the upper-stage active segment: judging whether to change the iteration target value according to the current track surface parameter deviation in the upper-level flight process; if the right ascension deviation of the upper-level ascending intersection is within the control precision range, the iterative guidance target value needs to be replaced, iterative guidance is continued after the iterative guidance target value is updated, and the correction precision of the orbital plane deviation and the deviation correction propellant consumption are ensured to be within an acceptable range.

Further, in S1, the maximum propellant consumption for correcting the ascension deviation at the ascension point is calculated according to the following formula:

m_Ω＝m_tj-m_dd-m_i-m_gj-m_ff-m_fzd-m_aq

in the formula, m_ΩFor the maximum propellant consumption, m, which can be used to correct the deviation of the right ascension at the intersection point_tjFor adding propellant, m_ddPropellant consumption for standard trajectory, m_iPropellant consumption m for correcting track pitch deviation_gjPropellant consumption, m, to correct tool errors_ffPropellant consumption, m, required to correct process errors_fzdPropellant consumption, m, to correct for unguided errors_aqTo transmit a task safety margin.

Furthermore, the minimum control precision of the ascension point ascension is preliminarily determined according to the propellant consumption required by the upper-level correction of the ascension point ascension deviation, simulation analysis is carried out on various deviation working conditions, and the control precision of the ascension point ascension is adjusted and finally determined according to the requirement of launching task on-orbit precision.

Further, in S2, the calculation formula of the iterative guidance initial target position R is as follows:

R＝[x y z]'

wherein r is_mFor iterative guidance of the target point geocentric distance, u_mAnd performing iterative guidance on latitude argument of the target point.

Further, in the above-mentioned case,

further, in S2, the calculation formula of the iterative guidance initial target speed V is as follows:

V＝[v_x v_y v_z]’

wherein v is_mModulo, u, for iteratively guiding the velocity of the target point_mFor iterative guidance of the latitude argument, i, of the target point_mFor iterative guidance of the target point orbit inclination angle, omega_mThe distance between the position vector and the velocity vector of the iterative guidance target point is t.

Further, v_mThe calculation formula of (a) is as follows,

where μ is the earth's gravitational constant.

Further, the calculation formula of t is as follows,

further, in S3, the equation for calculating the ascension deviation and the inclination deviation of the orbit is as follows:

Δi＝|i_m-i|

ΔΩ＝|Ω_m-Ω|

wherein, Delta i is the inclination deviation of the orbit, Delta omega is the deviation of the right ascension channel of the ascending intersection point, i_mFor iterative guidance of the target point orbit inclination angle, i is the upper stage current position orbit inclination angle, omega_mIn order to iteratively guide the target point to ascend the right ascension, Ω is the right ascension of the ascending intersection of the current position of the upper level.

Further, the calculation formula of i is as follows:

wherein h is moment of momentum, h_zIs the z-axis component of the moment of momentum under the earth's center system, | h | is the modulus of the moment of momentum.

Further, the calculation formula of h is as follows,

h＝R×V

wherein, R is the current position vector of the upper stage, and V is the current velocity vector of the upper stage.

Further, the calculation formula of Ω is as follows,

wherein the content of the first and second substances, is a unit vector in a coordinate system, N_X、N_YThe projection of N in the X-axis and Y-axis directions.

Further, in S4, the method for changing the iterative guidance target value includes: the original iteration guidance target value is position and speed information which is calculated by orbit parameters of a standard trajectory active segment end point, and the rising point ascension value in the original target orbit parameters is replaced by the rising point ascension value of the current position of the upper level.

Compared with the prior art, the invention has the beneficial effects that:

(1) the method is based on the analysis of the correction characteristics of the orbit surface of the active section of the upper-level GEO launching task, and the correction precision of the ascension point right ascension path deviation is set in the iterative guidance process;

(2) the method adopts a multi-objective optimization idea to optimize the correction precision of the ascension crossing point right ascension channel, and ensures that the propellant consumption engineering is acceptable while improving the control precision of the rail surface.

Drawings

FIG. 1 is a schematic view of spacecraft orbital plane deviation correction in accordance with the present invention;

FIG. 2 shows the variation of the track surface deviation of the upper stage active section;

FIG. 3 is a flow chart of the optimization design of the control accuracy of the ascension crossing point right ascension channel;

FIG. 4 is a schematic diagram of a track surface precise control design process;

fig. 5 is a flowchart of an embodiment of a track surface precise control technique.

Detailed Description

The invention is further illustrated by the following examples.

As shown in fig. 1, in the six elements of the orbit, the orientation of the orbit plane in the inertial space is determined by the rising-point right ascension and the orbit inclination angle. The intersection point of the spacecraft orbit from the south to the north crossing the equatorial plane is called an ascenting node (ascenting node) and is denoted by B; the intersection point crossing the equatorial plane from north to south is called the descending node and is denoted by D. In the equatorial plane, the axis Ox pointing from the geocentric O to the spring point is taken_iAs a reference line, axis Ox_iThe angle of the eastward turning to the node line DB is called a right ascension of ascension node (expressed by Ω), and the range of Ω is defined as 0 ≦ Ω ≦ 360 °. The angle between the orbital plane and the equatorial plane is called the orbital inclination (inclination of orbit) and is denoted by i, i being defined in the range 0. ltoreq. i.ltoreq.180.

Based on the analysis of the orbit dynamics, the correction of the rising point right ascension and the orbit inclination parameters of the spacecraft in the orbit is mutually coupled. The upper level executes the GEO launching task and needs to accurately control the precision of the orbit surface of the orbit. As shown in fig. 2 and table 1, it can be known from simulation analysis that under some deviation conditions, if the right ascension deviation at the ascending intersection is corrected in the active segment according to the iterative guidance algorithm, the inclination deviation of the track is greatly increased. Therefore, the accuracy of the track inclination of the track entering point can only be ensured by abandoning the correction of the ascension deviation of the ascending cross point.

TABLE 1 simulation results of upper-level orbital plane deviation

An iterative guidance-based track surface accurate control method comprises the following specific steps:

(1) the control precision of the ascension point right ascension channel is optimized overall.

And comprehensively considering propellant consumption required by correcting other deviations such as track inclination deviation, product deviation, tool deviation and the like, propellant filling amount, takeoff quality, standard trajectory, guidance scheme and the like of the GEO launching task, and calculating the maximum propellant consumption capable of being used for correcting the ascension deviation of the ascending intersection point. And finally determining the lifting point right ascension control precision according to the requirement of launching task on the orbit entering precision.

(2) And preliminarily setting an iterative guidance target value.

In the initial stage of iterative guidance of the upper-stage active segment, six elements (semi-major axis a) of the target point orbit are guided according to the iterative guidance_mEccentricity e_mInclination of track i_mArgument of near place omega_mElevation crossing right ascension omega_mAnd true proximal angle f_m) And setting an iterative guidance initial target position R and an initial target speed V.

(3) And calculating the control deviation of the track surface in real time.

And calculating the error of the current orbit surface in real time, namely the right ascension deviation of the ascending intersection point and the inclination deviation of the orbit according to the position and speed information of the upper stage under the transmitting inertial system.

(4) And resetting the iterative guidance target value of the active segment of the upper stage.

If the right ascension deviation of the upper grade ascending intersection point is within the control precision range (delta omega)<Ω_j) If the target value of the iterative guidance needs to be changed, namely the original iterative guidance target value is the track parameter (a) of the end point of the active segment of the standard trajectory_m、e_m、i_m、ω_m、Ω_m、f_m) The calculated position and speed information is solved, and the ascension value of the ascending intersection point in the original target track parameter is replaced by the ascension value of the ascending intersection point in the current position of the upper level, namely the ascension value is expressed by (a)_m、e_m、i_m、ω_m、Ω、f_m) And re-resolving the iterative guidance target value. And continuing to perform iterative guidance.

As described in detail below, as shown in fig. 3-5:

step one, the right ascension control precision of the ascending intersection point is optimized overall.

When the upper level executes the GEO launching task, the requirement on the track inclination angle precision of the track entering point in the track surface control parameters is high, so that the propellant consumption required for correcting the track inclination angle deviation is ensured at first. If the requirement of the track inclination angle precision is delta i, the track inclination angle correction precision is required to be less than 0.1 delta i under the single-term deviation working condition.

The maximum propellant consumption that can be used to correct the deviation in the right ascension at the lift point is first calculated as follows:

m_Ω＝m_tj-m_dd-m_i-m_gj-m_ff-m_fzd-m_aq

in the formula, m_ΩFor the maximum propellant consumption, m, which can be used to correct the deviation of the right ascension at the intersection point_tjFor adding propellant, m_ddPropellant consumption for standard trajectory, m_iPropellant consumption m for correcting track pitch deviation_gjPropellant consumption, m, to correct tool errors_ffPropellant consumption, m, required to correct process errors_fzdPropellant consumption, m, to correct for unguided errors_aqTo transmit a task safety margin.

And preliminarily determining the minimum control precision of the ascension point and the ascension point according to the propellant consumption required by correcting the ascension point deviation of the ascending intersection point and the ascension point, performing simulation analysis on various deviation working conditions, adjusting according to the requirement of the launching task on the tracking precision, and finally determining the control precision of the ascension point and the ascension point.

And step two, preliminarily setting an iterative guidance target value.

In the initial stage of iterative guidance of the upper-stage active segment, six elements (semi-major axis a) of the target point orbit are guided according to the iterative guidance_mEccentricity e_mInclination of track i_mArgument of near place omega_mElevation crossing right ascension omega_mAnd true proximal angle f_m) And setting an iterative guidance initial target position R and an initial target speed V.

The calculation formula of the iterative guidance initial target position R is as follows:

R＝[x y z]'

wherein r is_mFor iterative guidance of the target point geocentric distance, u_mFor the latitude argument of the iterative guidance target point, the calculation formula is as follows:

u_m＝ω_m+f_m

the calculation formula of the initial target position V of the iterative guidance is as follows:

V＝[v_x v_y v_z]’

wherein v is_mModulo, u, for iteratively guiding the velocity of the target point_mFor iterative guidance of the latitude argument, i, of the target point_mFor iterative guidance of the target point orbit inclination angle, omega_mThe distance between the position vector and the velocity vector of the iterative guidance target point is t.

v_mThe calculation formula of (a) is as follows,

wherein, mu is the gravity constant of the earth, and mu is 3.986005 multiplied by 10¹⁴m³/s²。

the calculation formula of t is as follows,

and step three, calculating the control deviation of the track surface in real time.

According to the position and speed information of the upper stage under the transmitting inertial system, the error of the current orbit surface, namely the right ascension deviation of the ascending intersection point and the inclination deviation of the orbit, is calculated in real time, and the calculation formula is as follows

Δi＝|i_m-i|

ΔΩ＝|Ω_m-Ω|

Wherein, Delta i is the inclination deviation of the orbit, Delta omega is the deviation of the right ascension of the ascending intersection point, i_mFor iterative guidance of the target point orbit inclination angle, i is the upper stage current position orbit inclination angle, omega_mIn order to iteratively guide the target point to ascend the right ascension, Ω is the right ascension of the ascending intersection of the current position of the upper level.

The calculation formula of i is as follows,

wherein h is moment of momentum, h_zIs the z-axis component of the moment of momentum under the earth's center system, | h | is the modulus of the moment of momentum.

The calculation formula of h is as follows,

h＝R×V

wherein, R is the current position vector of the upper stage, and V is the current velocity vector of the upper stage.

The calculation formula of omega is as follows,

wherein the content of the first and second substances, is a unit vector in a coordinate system, N_X、N_YThe projection of N in the X-axis and Y-axis directions.

And step four, resetting the iteration guidance target value of the upper-stage active section.

And judging whether to replace the iteration target value according to the current orbital plane parameter deviation in the upper-stage flight process. If the right ascension deviation of the upper grade ascending intersection point is within the control precision range (delta omega)<Ω_j) If the target value of the iterative guidance needs to be changed, namely the original iterative guidance target value is the track parameter (a) of the end point of the active segment of the standard trajectory_m、e_m、i_m、ω_m、Ω_m、f_m) The calculated position and speed information is solved, and the ascension value of the ascending intersection point in the original target track parameter is replaced by the ascension value of the ascending intersection point in the current position of the upper level, namely the ascension value is expressed by (a)_m、e_m、i_m、ω_m、Ω、f_m) And re-resolving the iterative guidance target value. After the iterative guidance target value is updated, iterative guidance is continued, and the correction precision of the orbital plane deviation and the deviation correction propellant consumption are ensured to be within an acceptable range.

TABLE 2 simulation results of control accuracy of the right ascension at the intersection

According to the simulation results in the table, under the deviation working condition, the higher the control precision of the right ascension at the ascending intersection point is, the larger the propellant consumption required by the deviation correction is; and when the correction of the ascension precision of the ascending intersection point is too high, the inclination angle deviation of the track is greatly increased. Therefore, the accuracy of the control of the ascent point right ascension needs to be optimized overall, and the optimization process is shown in fig. 3.

The method is based on the analysis of the correction characteristics of the orbit surface of the active section of the upper-level GEO launching task, and the correction precision of the ascension point right ascension path deviation is set in the iterative guidance process;

the method adopts a multi-objective optimization idea to optimize the correction precision of the ascension crossing point right ascension channel, and ensures that the propellant consumption engineering is acceptable while improving the control precision of the rail surface.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.