阅读说明：本技术 一种固体运载火箭大气层外制导控制方法 (Solid carrier rocket atmospheric layer guidance control method ) 是由 钟扬威 于 2021-10-29 设计创作，主要内容包括：本申请涉及运载火箭制导控制技术领域,特别涉及一种固体运载火箭大气层外制导控制方法,包括以下步骤：三级发动机以装订的末级开机点位置为目标点,以装订的末级开机时间为约束,三级发动机点火后进行闭路制导；以末级迭代制导算法为基础进行三级滑行弹道规划,计算末级开机时间；末级开机后进行迭代制导计算飞行程序角,直至末级关机。本申请通过三级主动段的闭路制导以及三级滑行段的弹道规划,以减小末级开机时的位置和速度偏差,以使得末级开机后迭代制导的正常运行,提高了火箭的制导精度。(The application relates to the technical field of carrier rocket guidance control, in particular to a solid carrier rocket atmospheric layer guidance control method, which comprises the following steps: the three-stage engine takes the bound last-stage starting point position as a target point, takes the bound last-stage starting time as constraint, and performs closed-circuit guidance after the three-stage engine is ignited; performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating the starting time of a final level; and after the final stage is started, carrying out iterative guidance to calculate a flight program angle until the final stage is shut down. According to the method, the position and speed deviation of the last stage during starting is reduced through closed-circuit guidance of the three-stage active section and trajectory planning of the three-stage gliding section, so that the iterative guidance can normally run after the last stage is started, and the guidance precision of the rocket is improved.)

1. An extraterrestrial guidance control method of a solid carrier rocket is characterized by comprising the following steps:

the three-stage engine takes the bound last-stage starting point position as a target point and takes the bound last-stage starting time as constraint to perform closed-circuit guidance;

performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating the starting time of a final level;

and after the final stage is started, carrying out iterative guidance to calculate a flight program angle until the final stage is shut down.

2. The solid launch vehicle atmospheric layer guidance control method of claim 1, wherein the three-stage engine performs closed-loop guidance with a bound last-stage starting point position as a target point and bound last-stage starting time as a constraint, comprising:

calculating the corresponding geocentric latitude according to the current point of the rocket, the last-stage starting point of binding and the target point under the launching systemLongitude difference Δ L relative to origin of inertial system_sRadius of earth's center_s；

According to the flight time t of the rocket and the geocentric latitude of the current point of the rocketThe difference of menstruation Δ L_sKRadius of earth's center_sKAnd the geocentric latitude of the target pointThe difference of menstruation Δ L_sTRadius of earth's center_sTLast-stage start-up time T_sIteratively calculating the velocity of the eye and converting to the hairIs V under the inertial system_R；

According to the lower speed V of the rocket launching inertia system_IG gravity acceleration, t nominal working time of three-stage engine_aIgnition time t of three-stage engine_3jTo calculate the speed V to be increased_g；

According to the speed V_RAnd the speed V to be increased_gCalculating the program angle of the closed-circuit guide sectionψ₃₁。

3. The solid launch vehicle atmospheric layer guidance control method of claim 1, wherein the three-stage engine performs closed-loop guidance with a bound last-stage starting point position as a target point and bound last-stage starting time as a constraint, further comprising:

recording the pitch program angle when the rocket enters the attitude modulation section

Iteratively calculating pitch angle modulation amplitude of one-time attitude modulation section

According to pitch program angleCalculating attitude modulation section program angle according to pitch angle modulation amplitudeψ₃₂。

4. The solid launch vehicle atmospheric layer guidance control method of claim 1, wherein the three-stage engine performs closed-loop guidance with a bound last-stage starting point position as a target point and bound last-stage starting time as a constraint, further comprising:

three-stage shutdown point pitch angle according to bindingCalculating constant attitude segment program angleψ₃₃。

5. The method for controlling the external guidance of the atmosphere of the solid launch vehicle according to claim 1, wherein the three-level sliding trajectory planning is performed based on a final-level iterative guidance algorithm, and the calculation of the final-level startup time comprises:

binding the standard change rate of the three-stage ignition to last-stage startup time, last-stage initial yaw angle and pitch angle;

calculating the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction amount;

correcting the time from three-stage ignition to last-stage starting time, last-stage starting time and last-stage yaw angle;

and controlling the last stage to start according to the corrected time length from the three-stage ignition to the last stage.

6. The solid launch vehicle atmospheric layer guidance control method of claim 5, wherein the calculating of the three-stage ignition to last stage power-on duration, last stage yaw angle correction amount comprises:

taking the position and the speed of the rocket at the current moment as initial values, performing unpowered extrapolation to the last-stage starting time, then performing powered extrapolation to the last-stage shutdown time, and calculating the absolute speed V of a shutdown point, the local trajectory inclination angle theta and the orbit inclination angle I;

calculating V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe amount of deviation of (d);

respectively calculate V_BZ、θ_BZ、I_BZRelative toObtaining a Jacobian matrix by partial derivatives of a last-stage startup time, a last-stage startup duration and a last-stage yaw angle;

according to the Jacobian matrix and the V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe deviation value of the deviation value is calculated to obtain the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction.

7. The solid launch vehicle atmospheric layer guidance control method of claim 6, wherein before controlling the power-on of the final stage based on the modified three-stage ignition-to-final stage power-on duration, further comprising:

and repeatedly correcting the time length from three-stage ignition to the last-stage starting time, the time length from the last-stage starting time and the last-stage yaw angle for 5 times according to the corrected rocket state initial values of the time length from three-stage ignition to the last-stage starting time, the time length from the last-stage starting time and the last-stage yaw angle.

8. The solid launch vehicle atmospheric layer guidance control method according to claim 6, wherein the last stage is controlled to start if the actual flight time of the rocket is equal to the corrected time period from the third stage ignition to the last stage starting.

9. The solid launch vehicle atmospheric layer guidance control method of claim 1, wherein the final startup segment iterative guidance method is:

binding standard final pitch angle, yaw angle, startup duration and pitch angle change rate;

calculating the correction quantities of the final pitch angle, the yaw angle, the starting-up time length and the pitch angle change rate;

correcting the last-stage pitch angle, the yaw angle, the startup time length and the pitch angle change rate, and repeatedly calculating the correction values of the last-stage pitch angle, the yaw angle, the startup time length and the pitch angle change rate;

and controlling the final stage shutdown according to the semi-major axis deviation calculated in real time.

10. The method of claim 9, wherein calculating final pitch, yaw, start-up duration, and pitch rate corrections comprises:

taking the position and the speed of the rocket at the current moment as initial values, extrapolating with power to the final shutdown moment, and calculating the geocentric radial R, the absolute speed V, the local trajectory inclination angle theta and the orbit inclination angle I of a shutdown point;

r, V, theta and I are calculated relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZThe amount of deviation of (d);

respectively calculate R_BZ、V_BZ、θ_BZ、I_BZObtaining a Jacobian matrix relative to the partial derivatives of the last-stage pitch angle, the yaw angle, the startup duration and the pitch angle change rate;

according to the Jacobian matrix and the R, V, theta and I relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZCalculating the correction quantity of the final pitch angle, the yaw angle, the startup time and the pitch angle change rate.

Technical Field

The application relates to the technical field of carrier rocket guidance control, in particular to a solid carrier rocket atmospheric layer guidance control method.

Background

The solid carrier rocket has important functions in the field of aerospace launching by virtue of the advantages of quick maneuvering launching, high reliability, low cost and the like. The solid carrier rocket generally adopts a solid boosting and liquid final stage configuration, and in order to improve the mass ratio and reliability, the solid boosting is in an exhaustion shutdown mode. For the solid boosting section, the commonly used guidance modes at present comprise perturbation guidance and closed-circuit guidance. For the last boosting section, the traditional iterative guidance and the improved form thereof are mostly adopted at present.

Through perturbation guidance and traditional iterative guidance simulation for a three-stage solid boosting section and a final boosting section outside the atmospheric layer of the carrier rocket, the perturbation guidance is adopted for the three-stage boosting section, and the deviation between the position and the speed after the engine is exhausted and shut down and the standard state is large, so that the final iterative guidance cannot be converged, and the guidance precision of the carrier rocket is influenced.

Disclosure of Invention

The embodiment of the application provides a solid carrier rocket atmospheric layer guidance control method, and aims to solve the technical problems that in the related technology, the deviation between the position and the speed after deviation from the standard state is large when a three-level engine is exhausted and shut down, so that the final-stage iterative guidance cannot be converged, and the guidance precision of a carrier rocket is influenced.

An extraterrestrial guidance control method of a solid carrier rocket comprises the following steps:

the three-stage engine takes the bound last-stage starting point position as a target point, takes the bound last-stage starting time as constraint, and performs closed-circuit guidance after the three-stage engine is ignited;

performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating the starting time of a final level;

and after the final stage is started, carrying out iterative guidance to calculate a flight program angle until the final stage is shut down.

In some embodiments, the three-stage engine performs closed-loop guidance with the last-stage starting point position of binding as a target point and the last-stage starting time of binding as a constraint, and includes:

calculating the corresponding geocentric latitude according to the current point of the rocket, the last-stage starting point of binding and the target point under the launching systemLongitude difference Δ L relative to origin of inertial system_sRadius of earth's center_s；

According to the flight time t of the rocket and the geocentric latitude of the current point of the rocketThe difference of menstruation Δ L_sKRadius of earth's center_sKAnd the geocentric latitude of the target pointThe difference of menstruation Δ L_sTRadius of earth's center_sTAt the time of final stage start-upInter T_sIteratively calculating the velocity of the eye and converting the velocity into V under the inertia system_R；

According to the lower speed V of the rocket launching inertia system_IG gravity acceleration, t nominal working time of three-stage engine_aIgnition time t of three-stage engine_3jTo calculate the speed V to be increased_g；

According to the speed V_RAnd the speed V to be increased_gCalculating the program angle of the closed-circuit guide sectionψ₃₁。

In some embodiments, the three-stage engine performs closed-loop guidance with the last-stage starting point position of binding as a target point and the last-stage starting time of binding as a constraint, and further includes:

recording the pitch program angle when the rocket enters the attitude modulation section

Iteratively calculating pitch angle modulation amplitude of one-time attitude modulation section

According to pitch program angleCalculating attitude modulation section program angle according to pitch angle modulation amplitudeψ₃₂。

In some embodiments, the three-stage engine performs closed-loop guidance with the last-stage starting point position of binding as a target point and the last-stage starting time of binding as a constraint, and further includes:

three-stage shutdown point pitch angle according to bindingCalculating constant attitude segment program angleψ₃₃。

In some embodiments, performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating a final-level boot time includes:

binding the standard change rate of the three-stage ignition to last-stage startup time, last-stage initial yaw angle and pitch angle;

calculating the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction amount;

correcting the time from three-stage ignition to last-stage starting time, last-stage starting time and last-stage yaw angle;

and controlling the last stage to start according to the corrected time length from the three-stage ignition to the last stage.

In some embodiments, said calculating three stages of ignition-to-last stage on time, and last stage yaw angle correction includes:

taking the position and the speed of the rocket at the current moment as initial values, performing unpowered extrapolation to the last-stage starting time, then performing powered extrapolation to the last-stage shutdown time, and calculating the absolute speed V of a shutdown point, the local trajectory inclination angle theta and the orbit inclination angle I;

calculating V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe amount of deviation of (d);

respectively calculate V_BZ、θ_BZ、I_BZObtaining a Jacobian matrix relative to partial derivatives of the last-stage startup time, the last-stage startup duration and the last-stage yaw angle;

according to the Jacobian matrix and the V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe deviation value of the deviation value is calculated to obtain the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction.

In some embodiments, before said controlling the power-on of the final stage according to the modified duration from the ignition of the three stages to the power-on of the final stage, further comprises:

and repeatedly correcting the time length from three-stage ignition to the last-stage starting time, the time length from the last-stage starting time and the last-stage yaw angle for 5 times according to the corrected rocket state initial values of the time length from three-stage ignition to the last-stage starting time, the time length from the last-stage starting time and the last-stage yaw angle.

In some embodiments, the last stage is controlled to start if the actual flight time of the rocket is equal to the corrected time period from the three-stage ignition to the last stage.

In some embodiments, the final startup segment iterative guidance method is as follows:

binding standard final pitch angle, yaw angle, startup duration and pitch angle change rate;

calculating the correction quantities of the final pitch angle, the yaw angle, the starting-up time length and the pitch angle change rate;

correcting the last-stage pitch angle, the yaw angle, the startup time length and the pitch angle change rate, and repeatedly calculating the correction values of the last-stage pitch angle, the yaw angle, the startup time length and the pitch angle change rate;

and controlling the final stage shutdown according to the semi-major axis deviation calculated in real time.

In some embodiments, said calculating final pitch angle, yaw angle, on-time, pitch rate corrections comprises:

taking the position and the speed of the rocket at the current moment as initial values, extrapolating with power to the final shutdown moment, and calculating the geocentric radial R, the absolute speed V, the local trajectory inclination angle theta and the orbit inclination angle I of a shutdown point;

r, V, theta and I are calculated relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZThe amount of deviation of (d);

respectively calculate R_BZ、V_BZ、θ_BZ、I_BZObtaining a Jacobian matrix relative to the partial derivatives of the last-stage pitch angle, the yaw angle, the startup duration and the pitch angle change rate;

according to the Jacobian matrix and the R, V, theta and I relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZCalculating final pitch angle, yaw angle, and yaw angleMachine duration, pitch angle rate of change correction.

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides a solid carrier rocket atmospheric layer external guidance control method, because a three-level active section takes a bound last-level starting point position as a target point, closed guidance based on flight time constraint is adopted, the exhausted shutdown energy management of the three-level active section is realized, after the energy of the three-level active section is exhausted, the three-level active section enters a three-level gliding section, and one-time ballistic planning is carried out in the three-level gliding section, so that the last-level starting time is optimized. And after the final stage is started, the target track is taken as constraint, and the high-precision in-orbit guidance control is realized by adopting partial derivative type iterative guidance. Through closed-circuit guidance of the three-level active section and trajectory planning of the three-level gliding section, the position and speed deviation during starting of the last stage is reduced, so that iterative guidance can normally run after the last stage is started, and the guidance precision of the rocket is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a solid launch vehicle atmospheric layer guidance control method provided by an embodiment of the application;

FIG. 2 is a schematic diagram of a three-stage active section closed-loop guidance provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of a three-level taxiway trajectory planning provided by an embodiment of the present application;

fig. 4 is a schematic diagram of final-stage iterative guidance provided in an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a solid carrier rocket atmospheric layer guidance control method, which can solve the technical problems that in the related technology, the deviation between the position and the speed after deviation from the standard state is large when a three-level engine is exhausted and shut down, so that the final-stage iterative guidance cannot be converged and the guidance precision of the carrier rocket is influenced.

An extraterrestrial guidance control method of a solid carrier rocket comprises the following steps:

the three-stage engine takes the bound last-stage starting point position as a target point, takes the bound last-stage starting time as constraint, and performs closed-circuit guidance after the three-stage engine is ignited;

performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating the starting time of a final level;

and after the final stage is started, carrying out iterative guidance to calculate a flight program angle until the final stage is shut down.

Referring to fig. 1, the method for controlling the guidance outside the atmosphere of the solid carrier rocket comprises the following steps 101-103:

101. the three-stage engine takes the bound last-stage starting point position as a target point, takes the bound last-stage starting time as constraint, and performs closed-circuit guidance after the three-stage engine is ignited;

the binding last stage starting point position is used as a target point, and the target point is the position of the binding last stage starting point under the launching system. And the bound last stage starting time is taken as constraint, closed-circuit guidance is carried out after the three-stage engine is ignited, and closed-circuit guidance is carried out in the three-stage active stage in a flight state after the three-stage engine is ignited, so that energy management is carried out on the three-stage active stage, and the position and speed deviation of a last stage starting point is reduced.

102. Performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating the starting time of a final level;

after fuel of the three-level engine is exhausted, the three-level engine enters a three-level gliding section flight state, three-level gliding trajectory planning is carried out on the basis of a final-level iterative guidance algorithm, so that the starting time of the final level is calculated and optimized, and the position and speed deviation of a starting point of the final level is reduced.

103. And after the final stage is started, carrying out iterative guidance to calculate a flight program angle until the final stage is shut down.

After the last stage is started, the terminal stage enters a flight state of a last stage starting section, and after the last stage is started, iterative guidance is carried out to calculate a flight program angle so as to adjust the posture of the rocket in real time, so that the rocket is in orbit, and the last stage can be closed after the rocket is in orbit.

According to the arrangement, the three-level active section takes the bound last-level starting point position as a target point, closed guidance based on flight time constraint is adopted, the exhausted shutdown energy management of the three-level active section is realized, after the energy of the three-level active section is exhausted, a three-level gliding section is entered, one-time ballistic planning is carried out on the three-level gliding section, and the last-level starting time is optimized. And after the final stage is started, the target track is taken as constraint, and the high-precision in-orbit guidance control is realized by adopting partial derivative type iterative guidance. Through closed-circuit guidance of the three-level active section and trajectory planning of the three-level gliding section, deviation during starting of the last stage is reduced, so that iterative guidance can normally run after the last stage is started, and the guidance precision of the rocket is improved.

Optionally, the closed-loop guidance performed after the ignition of the three-stage engine includes a closed-loop guidance segment, an attitude modulation segment and a constant attitude segment, a nominal total apparent speed increment of the three-stage engine is preset to be W, and the total apparent speed increment is distributed as follows: closed circuit guide section U₁Constant attitude segment U₃And an attitude modulation section U₂＝W-U₁-U₃；

After the three-level engine is ignited, calculating an axial cumulative apparent speed increment sigma W;

according to sigma W being more than or equal to U₁Sum sigma W is more than or equal to U₁+U₂So as to respectively judge that the rocket enters the attitude modulation section or the constant attitude section.

Referring to fig. 2, the closed-circuit guidance after the ignition of the three-stage engine comprises a closed-circuit guidance section and an attitude adjustmentA system segment and a constant attitude segment. The nominal overall apparent speed increment of the three-stage engine is preset to be W, and the overall apparent speed increment is distributed as follows: closed circuit guide section U₁Constant attitude segment U₃And an attitude modulation section U₂. In this embodiment, U₁Constant value attitude segment U ≈ W.10%₃W.10%, and an attitude modulation section U₂＝W-U₁-U₃。

In this embodiment, the solid rocket enters a 500km sun synchronous orbit as an example. The nominal total apparent speed increment of the three-stage engine is preset to be W3742 m/s. The total apparent velocity increment is assigned as: closed circuit guide section U₁300, constant attitude segment U₃300, attitude modulation segment U₂＝W-U₁-U₃；

After the three-stage engine is ignited, the cumulative axial apparent velocity increment Σ W is calculated from the axial cumulative apparent velocity increment Σ W, and the formula is as follows:

in the formula, W_x1Is the rocket axial apparent velocity.

According to sigma W being more than or equal to U₁Sum sigma W is more than or equal to U₁+U₂So as to respectively judge that the rocket enters an attitude modulation section or a constant attitude section. In this embodiment, when Σ W is not less than U₁When the rocket enters an attitude modulation section, the rocket is started when sigma-delta W is more than or equal to U₁+U₂When the rocket is in the normal attitude section, the rocket enters the normal attitude section. And the judgment process is judged by the energy management system.

Optionally, the three-stage engine performs closed-loop guidance with the bound last-stage starting-up time as a constraint by using the bound last-stage starting-up point position as a target point, and includes:

calculating the corresponding geocentric latitude according to the current point of the rocket, the last-stage starting point of binding and the target point under the launching systemLongitude difference Δ L relative to origin of inertial system_sRadius of earth's center_s；

According to the flight time t of the rocket and the geocentric latitude of the current point of the rocketThe difference of menstruation Δ L_sKRadius of earth's center_sKAnd the geocentric latitude of the target pointThe difference of menstruation Δ L_sTRadius of earth's center_sTLast-stage start-up time T_sIteratively calculating the velocity of the eye and converting the velocity into V under the inertia system_R；

According to the lower speed V of the rocket launching inertia system_IG gravity acceleration, t nominal working time of three-stage engine_aIgnition time t of three-stage engine_3jTo calculate the speed V to be increased_g；

According to the speed V_RAnd the speed V to be increased_gCalculating the program angle of the closed-circuit guide sectionψ₃₁。

In the three-stage active section, the corresponding geocentric latitude is calculated according to the current point of the rocket and the target point under the last stage starting point launching system of bindingLongitude difference Δ L relative to origin of inertial system_sRadius of earth's center_sThe formula is as follows:

ΔL_s＝arcsin(y_s/x_s)

in the formula, A₀For shooting, B₀As the launch point latitude. R_0x、R_0y、R_0zRespectively projection of the geocentric radial of the emission point on the x, y and z axes of the emission system. x is the number of_s、y_s、z_sRespectively are the position coordinates of the rocket under the launching inertial system. And x, y and z are position coordinates of the rocket under the launching system respectively.

According to the flight time t of the rocket and the geocentric latitude of the current point of the rocketThe difference of menstruation Δ L_sKRadius of earth's center_sKAnd the geocentric latitude of the target pointThe difference of menstruation Δ L_sTRadius of earth's center_sTLast-stage start-up time T_sAnd iteratively calculating the target speed, wherein an iterative calculation formula is as follows:

wherein fM is the gravitational constant, ω_eIs the angular velocity of rotation of the earth, theta is the inclination angle of the rocket trajectory, theta_jTrajectory inclination angle theta for the current step number_j+1Is the next step ballistic inclination angle, ξ_K,jIs true azimuth, E_K,jA remote site angle of the current point, E_T,jIs the remote site angle of the target point, t_f,jIs the remaining time of flight.

When | T_s-t-t_f,jAnd (5) exiting iteration after the | is less than the epsilon, and calculating the speed and the direction of the target speed.

Calculating the velocity V of the eye under the inertial system_RThe formula is as follows:

according to the lower speed V of the rocket launching inertia system_IG gravity acceleration, t nominal working time of three-stage engine_aIgnition time t of three-stage engine_3jTo calculate the speed V to be increased_gThe formula is as follows:

according to the speed V_RAnd the speed V to be increased_gCalculating the program angle of the closed-circuit guide sectionψ₃₁The formula is as follows:

in the formula, V_gx、V_gy、V_gzRespectively is the component of the speed to be increased in the generator-inertia system;

optionally, the three-stage engine performs closed-loop guidance with the bound last-stage starting point position as a target point and the bound last-stage starting time as a constraint, and further includes:

recording the pitch program angle when the rocket enters the attitude modulation section

Iteratively calculating pitch angle modulation amplitude of one-time attitude modulation section

According to pitch program angleCalculating attitude modulation section program angle according to pitch angle modulation amplitudeψ₃₂。

Wherein, if Σ W is more than or equal to U₁When the rocket enters the attitude modulation section, the rocket recording the pitching program angle when entering the attitude modulation section

Iteratively calculating pitch angle modulation amplitude of one-time attitude modulation sectionThe iterative calculation formula is as follows:

in this embodiment, the pitch angle modulation amplitude is calculated iteratively onceGet dV₁＝386m/s、dV₂＝800m/s。

According to pitch program angleCalculating attitude modulation section program angle according to pitch angle modulation amplitudeψ₃₂The formula is as follows:

in the formula, dV₁、dV₂Is a binding parameter.

Optionally, the three-stage engine performs closed-loop guidance with the bound last-stage starting point position as a target point and the bound last-stage starting time as a constraint, and further includes:

three-stage shutdown point pitch angle according to bindingCalculating constant attitude segment program angleψ₃₃。

Wherein, when Sigma W is more than or equal to U₁+U₂When the rocket is in a constant attitude section, the rocket is in a pitch angle according to a bound three-stage shutdown pointCalculating constant attitude segment program angleψ₃₃The formula is as follows:

in this embodiment, the bound three-stage shutdown pitch angle

According to the arrangement, through the calculation, in the three-stage active section, the attitude of the rocket is adjusted, closed-circuit guidance is realized, so that the position and speed deviation during the starting of the last stage is reduced, correct iterative guidance after the starting of the last stage is facilitated, and the guidance precision of the rocket is improved.

Optionally, performing three-level sliding trajectory planning based on a final-level iterative guidance algorithm, and calculating a final-level boot time, including:

binding the standard change rate of the three-stage ignition to last-stage startup time, last-stage initial yaw angle and pitch angle;

calculating the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction amount;

correcting the time from three-stage ignition to last-stage starting time, last-stage starting time and last-stage yaw angle;

and controlling the last stage to start according to the corrected time length from the three-stage ignition to the last stage.

Optionally, the calculating of the three-stage ignition to last-stage power-on time, and last-stage yaw angle correction includes:

taking the position and the speed of the rocket at the current moment as initial values, performing unpowered extrapolation to the last-stage starting time, then performing powered extrapolation to the last-stage shutdown time, and calculating the absolute speed V of a shutdown point, the local trajectory inclination angle theta and the orbit inclination angle I;

calculating V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe amount of deviation of (d);

respectively calculate V_BZ、θ_BZ、I_BZObtaining a Jacobian matrix relative to partial derivatives of the last-stage startup time, the last-stage startup duration and the last-stage yaw angle;

according to the Jacobian matrix and the V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe deviation value of the deviation value is calculated to obtain the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction.

Optionally, before the controlling the power-on of the final stage according to the modified duration from the three-stage ignition to the power-on of the final stage, the method further includes:

and repeatedly correcting the time length from three-stage ignition to the last-stage starting time, the time length from the last-stage starting time and the last-stage yaw angle for 5 times according to the corrected rocket state initial values of the time length from three-stage ignition to the last-stage starting time, the time length from the last-stage starting time and the last-stage yaw angle.

Referring to FIG. 3, wherein three stages of engine ignition T are preset_hjAfter the time is long, the three-stage engine is exhausted and shut down, and the rocket enters a three-stage gliding section.

And performing three-stage sliding trajectory planning in the three-stage sliding section, wherein the three-stage sliding trajectory planning method comprises the following steps of 1021:

1021. and binding the standard three-stage ignition to last stage starting time, last stage initial yaw angle and pitch angle change rate.

1022. And calculating the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction amount.

The method comprises the following steps of calculating the starting time from three-stage ignition to the last stage, calculating the starting time of the last stage, and calculating the yaw correction quantity of the last stage, wherein the following steps are included:

and (3) taking the position and the speed of the rocket at the current moment as initial values, performing unpowered extrapolation to the last-stage starting moment, then performing powered extrapolation to the last-stage shutdown moment, and calculating the absolute speed V of a shutdown point, the local trajectory inclination angle theta and the orbit inclination angle I.

The extrapolation algorithm of the absolute speed V of the shutdown point, the local trajectory inclination angle theta and the orbit inclination angle I is as follows:

wherein T is the last stage power-on working time,ψ₄₀、the attitude angle and its rate of change, a is the axial apparent acceleration (0 taken when unpowered extrapolation is performed),mean gravitational acceleration for current and extrapolated points, X, Y, Z position under navigation system, V_x、V_y、V_zThe navigation is the speed of each position.

Calculating V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe amount of deviation of (c).

Wherein V, theta and I are relative to the binding standard value V_BZ、θ_BZ、I_BZThe deviation amount of (a) is obtained by subtraction according to the correspondence.

Respectively calculate V_BZ、θ_BZ、I_BZAnd obtaining a Jacobian matrix relative to partial derivatives of the last-stage startup time, the last-stage startup duration and the last-stage yaw angle.

According to the Jacobian matrix and the V, theta and I relative to the binding standard value V_BZ、θ_BZ、I_BZThe deviation value of the deviation value is calculated to obtain the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction.

1023. And correcting the time from three-stage ignition to last-stage startup, the last-stage startup and the last-stage yaw angle.

Wherein, the correction formulas of the time from three-stage ignition to last-stage startup, the time from last-stage startup and the yaw angle of last stage are as follows:

in the formula, T_4jKJThe time from three-stage ignition of the rocket to the last stage starting is prolonged.

1024. And repeating 5 times to calculate the time length from three-stage ignition to the last stage starting time, the last stage starting time and the last stage yaw angle correction quantity.

After the calculation and the correction of the time from the three-stage ignition to the last stage starting time, the time from the last stage starting time and the last stage yaw angle are repeatedly calculated in an iterative manner for 5 times, the corrected data are recalculated and corrected according to the corrected rocket state initial values of the time from the three-stage ignition to the last stage starting time, the time from the last stage starting time and the last stage yaw angle, wherein the number of the repetition times is 5.

1025. And controlling the last stage to start according to the corrected time length from the three-stage ignition to the last stage.

And after the finally corrected starting time length data from three stages of ignition to the final stage is obtained, the final stage can be controlled to start through the data.

Optionally, if the actual flight time of the rocket is equal to the corrected time length from the three-stage ignition to the last stage starting, controlling the last stage starting.

And after the final data of the time length from the three-stage ignition to the last stage starting is obtained, if the actual flight time of the rocket reaches the time length, the last stage is started.

In this embodiment, the last stage boot time is obtained to be 441s, and if the actual flight time of the rocket reaches 441s, the last stage boot is operated.

According to the arrangement, when the time length from three-stage ignition to last-stage starting is calculated, the last-stage starting time and the last-stage yaw angle are calculated in an iterative mode, the data from the time length from three-stage ignition to last-stage starting is more accurately calculated through the limitation of a plurality of data, the last-stage starting time is convenient to optimize, the position and speed deviation of a rocket during last-stage starting is improved and reduced, and the rocket guidance precision is improved.

Optionally, the final startup segment iterative guidance method is:

binding standard final pitch angle, yaw angle, startup duration and pitch angle change rate;

calculating the correction quantities of the final pitch angle, the yaw angle, the starting-up time length and the pitch angle change rate;

correcting the last-stage pitch angle, the yaw angle, the startup time length and the pitch angle change rate, and repeatedly calculating the correction values of the last-stage pitch angle, the yaw angle, the startup time length and the pitch angle change rate;

and controlling the final stage shutdown according to the semi-major axis deviation calculated in real time.

Referring to fig. 4, the final stage startup segment iterative guidance method includes:

and binding standard final pitch angle, yaw angle, startup duration and pitch angle change rate.

And calculating the correction quantities of the final pitch angle, the yaw angle, the startup time and the pitch angle change rate.

And correcting the final pitch angle, the yaw angle, the startup time length and the pitch angle change rate, and repeatedly calculating the correction values of the final pitch angle, the yaw angle, the startup time length and the pitch angle change rate.

Wherein, the correction formulas of the final pitch angle, the yaw angle, the startup time and the pitch angle change rate are as follows:

after the final pitch angle, the yaw angle, the startup time length and the pitch angle change rate are corrected once, the corrected data are used as binding data, and correction amounts of the final pitch angle, the yaw angle, the startup time length and the pitch angle change rate are recalculated. And (4) repeatedly calculating the correction quantities of the last-stage pitch angle, the yaw angle, the startup duration and the pitch angle change rate of the rocket in the last-stage startup section.

And controlling the final stage shutdown according to the semi-major axis deviation calculated in real time.

And in the last stage of the rocket, when the value obtained by subtracting the standard semi-major axis deviation data from the actually calculated semi-major axis deviation data is changed from a positive value to a negative value, the last stage can be closed, and the rocket is put into orbit.

In this embodiment, the standard semimajor axis deviation is 71.76m, so when the actually calculated semimajor axis deviation is less than 71.76m, the last stage is shut down, and the rocket completes the orbit.

Optionally, the calculating the final pitch angle, the yaw angle, the power-on duration, and the pitch angle change rate correction amount includes:

taking the position and the speed of the rocket at the current moment as initial values, extrapolating with power to the final shutdown moment, and calculating the geocentric radial R, the absolute speed V, the local trajectory inclination angle theta and the orbit inclination angle I of a shutdown point;

r, V is calculated,Theta, I relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZThe amount of deviation of (d);

respectively calculate R_BZ、V_BZ、θ_BZ、I_BZObtaining a Jacobian matrix relative to the partial derivatives of the last-stage pitch angle, the yaw angle, the startup duration and the pitch angle change rate;

according to the Jacobian matrix and the R, V, theta and I relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZCalculating the correction quantity of the final pitch angle, the yaw angle, the startup time and the pitch angle change rate.

Wherein, calculating final pitch angle, yaw angle, startup duration, pitch angle change rate correction includes:

and (3) taking the position and the speed of the rocket at the current moment as initial values, extrapolating with power to the final shutdown moment, and calculating the geocentric radial R, the absolute speed V, the local ballistic inclination angle theta and the orbit inclination angle I of a shutdown point.

R, V, theta and I are calculated relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZThe amount of deviation of (c).

Wherein R, V, theta and I are relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZThe deviation amount of (a) is obtained by subtracting the numerical value.

Respectively calculate R_BZ、V_BZ、θ_BZ、I_BZAnd obtaining a Jacobian matrix according to partial derivatives of the last-stage pitch angle, the yaw angle, the startup time and the pitch angle change rate.

According to the Jacobian matrix and the R, V, theta and I relative to the binding standard value R_BZ、V_BZ、θ_BZ、I_BZCalculating the correction quantity of the final pitch angle, the yaw angle, the startup time and the pitch angle change rate.

Through the calculation, the rocket calculates the correction of the last-stage pitch angle, the yaw angle, the startup time and the pitch angle change rate at the last-stage startup period, and adjusts the posture of the rocket in real time, so that the rocket is convenient to accurately enter the orbit.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.