CN104567545B - The method of guidance of RLV endoatmosphere powered phase - Google Patents

Abstract

The present invention provides the method for guidance of a kind of RLV endoatmosphere powered phase, including S1, by flying height, is divided into flight leading portion and flight back segment the ascent stage of the flight track of RLV；S2, flight leading portion uses open loop guidance, and flight back segment uses closed loop guidance；S3, during the closed loop guidance of flight back segment, takes height and/or the compensation scheme of trajectory tilt angle.Present invention advantage compared with prior art is: (1) present invention will be divided into two sections the ascent stage by flying height, take open loop guidance and closed loop guidance respectively, both the problem that the strong jamming factor being prevented effectively from dense atmosphere reduces closed loop guidance robustness, in turn ensure that guidance high-precision requirement, take into account robustness and the high accuracy of guidance algorithm.(2) arrow borne computer amount of storage and on-line calculation are required little by the program, i.e. can be guidanceed command by interpolation and simple computation, and reliability is high, it is ensured that engineering realizability.

Description

The method of guidance of RLV endoatmosphere powered phase

Technical field

The invention belongs to aerospace flight vehicle guidance field, particularly relate to a kind of RLV endoatmosphere The method of guidance of powered phase.

Background technology

The ascent stage of RLV (Control System for Reusable Launch Vehicle) is omnidistance all in endoatmosphere flight.If used for reference Use the RLV open loop aiming means at trace routine angle, endoatmosphere such as carrier rocket or external X-33, The uncertainty of thrust and aerodynamic force can cause parameter and the target offset of the ascent stage terminal state of RLV Bigger.And ascent stage terminal state determines aircraft and reenters energy state and the initial position of return.By Taking unpowered return in RLV, its existence adaptation original state warping capability is limited and can not go around Feature.Therefore, higher ascent stage terminal guidance precision for RLV aircraft on predetermined airport Safe landing is most important.

Flying in endoatmosphere for the RLV ascent stage, existing open loop Celestial Guidance Scheme cannot meet high-precision Degree requirement, needs to use closed loop guidance mode to improve guidance precision, to ensure that ascent stage end state is permitting The deviation range permitted.Specialty scholar proposes a lot of method for endoatmosphere closed loop guidance both at home and abroad, as Feedback linearization method and optimization guidance algorithm, but owing to algorithm completeness is not enough or on-line calculation is led greatly The factors such as cause engineering practicability is poor, the method obtaining engineer applied is little.

Summary of the invention

The technical problem to be solved in the present invention is: provides the closed loop guidance mode that a kind of RLV uses, carries High guidance precision, to ensure that ascent stage end state is in preferable deviation range.

The technical scheme is that

A kind of method of guidance of RLV endoatmosphere powered phase, including: S1, by flying height by RLV Ascent stage of flight track be divided into flight leading portion and flight back segment；S2, flight leading portion uses open loop system Leading, flight back segment uses closed loop guidance；S3, during the closed loop guidance of flight back segment, it is right to take Height and/or the compensation scheme of trajectory tilt angle.

Also include during the closed loop guidance of S3: S4, it will thus provide standard pitching, driftage and rolling The program angle substitution ascent stage equation of motion carries out ballistic computation and obtains normal trajectory parameter height, speed and bullet Road inclination section.

Also include during the closed loop guidance of S3: S5, remain turned off spot speed and inclination angle is constant, and Highly there is deviation, obtain trajectory peak state parameter, trajectory peak state parameter and normal trajectory Peak parameter compares and obtains the trajectory peak height tolerance that Burnout height tolerance causes, thus obtains Burnout height tolerance affects COEFFICIENT K H to trajectory peak height tolerance.

, also include: S6 with S5 simultaneously, keep the Burnout height of standard state and speed constant, and bullet There is deviation in road inclination, obtains trajectory peak state parameter, trajectory peak state parameter and reference rounds Road peak parameter compares and obtains the trajectory peak height tolerance that Burnout trajectory tilt angle deviation causes, from And obtain Burnout trajectory tilt angle deviation and trajectory peak height tolerance affected COEFFICIENT K_Θ。

The compensation scheme of S3 specifically includes, and compensates height tolerance with trajectory tilt angle, i.e. to normal trajectory Trajectory tilt angle compensates:Wherein, Θ_cxAnd H_cxFor inserting according to present speed The trajectory tilt angle that value normal trajectory dip section and altitude profile obtain and height instruction, H is that aircraft is worked as Front height, K_H、K_ΘFor Burnout height tolerance, trajectory tilt angle deviation to trajectory peak height tolerance Affect coefficient, Θ_dInstruct for the trajectory tilt angle after compensating approach.

Guidance revised angle of pitch instruction in S3Wherein,

N_yc=N_y+W_x1·sinΦ_cx, $N_{\mathrm{xc}}=\sqrt{W_{x1}\·W_{x1}-N_{\mathrm{yc}}\·N_{\mathrm{yc}}},$

N_y=K₁·(H_cx-H)+K₂·V·(sinΘ_d-sinΘ)；Wherein, K₁、K₂For all radix scrophulariae of guidance after normalization Number；W_x1For the used group of axial apparent acceleration recorded, Φ_cxFor standard pitch program angle, H_cxAccording to when The height instruction that front speed interpolation normal trajectory altitude profile obtains, H is aircraft present level, K_H、 K_ΘFor Burnout height tolerance, the trajectory tilt angle deviation coefficient that affects on trajectory peak height tolerance, Θ_d Instruct for the trajectory tilt angle after compensating approach.

Including, S7, when engine is duty, and after the flight time is more than allowing the unused time, sentence Whether disconnected cut-off condition meets, and then sends shutdown command as met.

Cut-off condition includes, aircraft speed is more than V_k。

Present invention advantage compared with prior art is:

(1) present invention will be divided into two sections the ascent stage by flying height, take open loop guidance and closed loop respectively Guidance, the strong jamming factor being both prevented effectively from dense atmosphere reduces the problem of closed loop guidance robustness, In turn ensure that guidance high-precision requirement, take into account robustness and the high accuracy of guidance algorithm.

(2) arrow borne computer amount of storage and on-line calculation are required little, by interpolation and letter by the program Single calculating i.e. can be guidanceed command, and reliability is high, it is ensured that engineering realizability.

Accompanying drawing explanation

Fig. 1 shows the step schematic diagram of the method for guidance of the RLV endoatmosphere powered phase of the present invention.

Detailed description of the invention

The method of guidance of the RLV endoatmosphere powered phase of the present invention, specifically includes below scheme:

(1) two sections will be divided into the ascent stage by flying height: flight leading portion uses open loop guidance to be main, flies Row back segment uses standard trajectory closed loop guidance, and the strong jamming factor being both prevented effectively from dense atmosphere reduces The problem of closed loop guidance robustness, in turn ensure that guidance high-precision requirement, has taken into account the robust of guidance algorithm Property and high accuracy.

(2) at flight back segment, the compensation scheme of height and trajectory tilt angle is taked, by on-line tuning journey Sequence angle realizes height and the tracking of trajectory tilt angle instruction so that during shutdown, height, inclination angle, speed meet Requirement, thus realize zero-miss guidance.The program is to arrow borne computer amount of storage and on-line calculation requirement Little, i.e. can be guidanceed command by interpolation and simple computation, reliability is high.

Specifically, comprise the following steps:

Step (one), to set up the RLV ascent stage equation of motion as follows:

$\left\{\begin{array}{c}\left(\begin{array}{c}{\stackrel{\·}{V}}_{\mathrm{ax}}\\ {\stackrel{\·}{V}}_{\mathrm{ay}}\\ {\stackrel{\·}{V}}_{\mathrm{az}}\end{array}\right)=\left(\begin{array}{c}{\stackrel{\·}{W}}_x\\ {\stackrel{\·}{W}}_y\\ {\stackrel{\·}{W}}_z\end{array}\right)+\left(\begin{array}{c}{g}_{\mathrm{ax}}\\ g_{\mathrm{ay}}\\ g_{\mathrm{az}}\end{array}\right)\\ \left(\begin{array}{c}{\stackrel{\·}{x}}_a\\ {\stackrel{\·}{y}}_a\\ {\stackrel{\·}{z}}_a\end{array}\right)=\left(\begin{array}{c}{V}_{\mathrm{ax}}\\ V_{\mathrm{ay}}\\ V_{\mathrm{az}}\end{array}\right)\end{array}\right.---\left(1\right)$

Wherein, state variable x_a、y_a、z_a、V_ax、V_ay、V_azThe position being respectively under launch inertial coordinate system is divided Amount and velocity component.g_ax、g_ay、g_azFor terrestrial gravitation component under launch inertial coordinate system, W_x、W_y、W_zFor apparent acceleration component under launch inertial coordinate system, W_x1、W_y1、W_z1For apparent acceleration Component under aircraft body coordinate system,, ψ, γ be body coordinate system relative transmission inertial system the angle of pitch, Yaw angle and roll angle, F_ax1、F_ay1、F_az1For aerodynamic force component under aircraft body coordinate system (for the angle of attack α, highly H and the function of Mach number Ma) P_ax1、P_ay1、P_az1For motor power at aircraft body coordinate Component under Xi, m is aircraft real-time quality.

Step (two), standard pitching, driftage and the rolling program angle Φ that will provide_cx、Ψ_cx、γ_cxIn substitution The liter section equation of motion carries out ballistic computation and obtains normal trajectory parameter height, speed and trajectory tilt angle section H_cx、V_cx、Θ_cx。

Ballistic computation input initial parameter include missile mass parameter, engine parameter, aerodynamic parameter, Earth environment parameter, mission program angular dimensions etc., be organized into data file by above-mentioned parameter.Based on flight The original state of device, advances trajectory to calculate according to given integration step, thus obtains aircraft Whole trajectory parameter.Appearance Ge-Ku Ta quadravalence the single-step method that integration method is fixed step size used, long-pending Substep is long is taken as 0.01s.

After ballistic computation terminates, trajectory parameter is exported in data file, i.e. can get reference rounds Road parameter height, speed and trajectory tilt angle section H_cx、V_cx、Θ_cx。

Step (three), the analysis shutdown characteristic quantity impact on trajectory peak parameter.

Normal trajectory Burnout state based on aircraft, remains turned off spot speed and inclination angle is constant, and high There is deviation delta Y in degree, advances trajectory to calculate according to given integration step, can obtain trajectory High point state parameter, compares with normal trajectory peak parameter and can obtain Burnout height tolerance Δ Y and draw The trajectory peak height tolerance Δ H risen, such that it is able to obtain Burnout height tolerance to trajectory peak Height tolerance affect coefficient

The Burnout height and the speed that keep standard state are constant, and trajectory tilt angle exists deviation delta Θ, presses The process of the preceding paragraph obtains Burnout trajectory tilt angle deviation affects coefficient to trajectory peak height tolerance

$K_{\mathrm{\Θ}}=\frac{\mathrm{\ΔH}}{\mathrm{\Δ\Θ}}.$

Step (four), result of calculation according to step (three) determine that the trajectory tilt angle of height tolerance compensates Scheme.

After aircraft flies out dense atmosphere, the most highly more than 30km after, start to mend with trajectory tilt angle Repay height tolerance, i.e. the trajectory tilt angle of normal trajectory compensated:

${\mathrm{\Θ}}_d={\mathrm{\Θ}}_{\mathrm{cx}}+\frac{K_H}{K_{\mathrm{\Θ}}}(H_{\mathrm{cx}}-H)$

Wherein, Θ_cxAnd H_cxFor obtaining according to present speed interpolation criteria trajectory tilt angle section and altitude profile Trajectory tilt angle and height instruction, H is aircraft present level, K_H、K_ΘFor step (three) obtains The Burnout height tolerance that arrives, the trajectory tilt angle deviation coefficient that affects on trajectory peak height tolerance, Θ_d Instruct for the trajectory tilt angle after compensating approach.

Step (five), result according to step (four) determine that the angle of pitch instructs.

After aircraft altitude is more than 30km, aircraft Closed loop track normal trajectory height and inclination angle track Section, forms normal acceleration by height and trajectory tilt angle feedback and instructs

N_y=K₁·(H_cx-H)+K₂·V·(sinΘ_d-sinΘ)

Wherein, K₁、K₂For the guidance firing data after normalization.Typically can all be taken as 0.5, it is possible to root It is adjusted according to actual conditions.Θ is the current trajectory tilt angle of aircraft.Thus, normal acceleration is with axial Acceleration instruction is

N_yc=N_y+|W_x1|·sinΦ_cx

$N_{\mathrm{xc}}=\sqrt{W_{x1}\·W_{x1}-N_{\mathrm{yc}}\·N_{\mathrm{yc}}}$

Wherein, W_x1For the used group of axial apparent acceleration recorded, Φ_cxFor standard pitch program angle.

Therefore, guiding the instruction of the revised angle of pitch is

${\mathrm{\Φ}}_d={\mathrm{tg}}^{-1}\left(\frac{N_{\mathrm{yc}}}{N_{\mathrm{xc}}}\right)$

Step (six), shutdown algorithm.

Cut-off condition is designed as flying speed more than normal trajectory Burnout speed V being previously set_k。

When engine is duty, and the flight time is more than allowing unused time t_yAfter, start to judge shutdown Whether condition meets, if meeting cut-off condition, i.e. aircraft speed is more than V_k, control system sends pass Machine instructs.When the flight time is more than forced shutdown time t_q, control system sends shutdown command immediately.

Step (seven), determine ascent stage all way guidance scheme according to abovementioned steps.

Aircraft after take off, when flying height less than 30km time, use open-loop tracking standard pitching, Driftage and the Celestial Guidance Scheme at rolling program angle, aerocraft real parameter does not feed back to guidance loop, does not enters Row closed loop guidance.

$\left\{\begin{array}{c}{\mathrm{\Φ}}_p={\mathrm{\Φ}}_{\mathrm{cx}}\\ {\mathrm{\Ψ}}_p={\mathrm{\Ψ}}_{\mathrm{cx}}\\ {\mathrm{\γ}}_p={\mathrm{\γ}}_{\mathrm{cx}}\end{array}\right.$

After flying height is more than 30km, aerocraft real height and trajectory tilt angle is fed back to system and leads back to Road, is modified angle of pitch instruction according to step (five), uses and guides the instruction of the revised angle of pitch Φ_d, and updating angle of pitch instruction according to guidance cycle real-time online, driftage uses standard with rolling program angle Driftage and rolling program angle.

$\left\{\begin{array}{c}{\mathrm{\Φ}}_p={\mathrm{\Φ}}_d\\ {\mathrm{\Ψ}}_p={\mathrm{\Ψ}}_{\mathrm{cx}}\\ {\mathrm{\γ}}_p={\mathrm{\γ}}_{\mathrm{cx}}\end{array}\right.$

Shutdown Logic judgment is performed according to the shutdown algorithm of step (six).Whole Celestial Guidance Scheme such as Fig. 1 institute Show.

The unspecified part of the present invention belongs to general knowledge as well known to those skilled in the art.

Claims (8)

1. the method for guidance of a RLV endoatmosphere powered phase, it is characterised in that including:

S1, is divided into flight leading portion and flight back segment by flying height by the ascent stage of the flight track of RLV, It is flight leading portion when flying height is less than 30km；It is flight back segment when flying height is more than 30km；

S2, described flight leading portion uses open loop guidance, and described flight back segment uses closed loop guidance；

S3, during the closed loop guidance of described flight back segment, takes height and/or trajectory tilt angle Compensation scheme.

The method of guidance of RLV endoatmosphere the most according to claim 1 powered phase, its feature exists In, also include during the closed loop guidance of S3:

S4, it will thus provide standard pitching, driftage and rolling program angle substitute into the ascent stage equation of motion and carry out Ballistic computation obtains normal trajectory parameter height, speed and trajectory tilt angle section.

The method of guidance of RLV endoatmosphere the most according to claim 1 powered phase, its feature exists In, also include during the closed loop guidance of S3:

S5, remains turned off spot speed and inclination angle is constant, and highly there is deviation, obtains trajectory peak shape State parameter；Compared with normal trajectory peak parameter by trajectory peak state parameter that to obtain Burnout high The trajectory peak height tolerance that degree deviation causes, thus obtain Burnout height tolerance to trajectory peak Height tolerance affect COEFFICIENT K_H。

The method of guidance of RLV endoatmosphere the most according to claim 3 powered phase, it is characterised in that With S5 simultaneously, also include:

S6, keeps the Burnout height of standard state and speed constant, and trajectory tilt angle exists deviation, To trajectory peak state parameter, by trajectory peak state parameter and normal trajectory peak parameter ratio Relatively obtain the trajectory peak height tolerance that Burnout trajectory tilt angle deviation causes, thus obtain Burnout bullet Road inclination deviation affects COEFFICIENT K to trajectory peak height tolerance_Θ。

The method of guidance of RLV endoatmosphere the most according to claim 4 powered phase, its feature exists In, the compensation scheme of S3 specifically includes, and compensates height tolerance with trajectory tilt angle, i.e. to normal trajectory Trajectory tilt angle compensates:

${\mathrm{\Θ}}_d={\mathrm{\Θ}}_{cx}+\frac{K_H}{K_{\mathrm{\Θ}}}(H_{cx}-H),$

Wherein, Θ_cxAnd H_cxFor obtaining according to present speed interpolation criteria trajectory tilt angle section and altitude profile Trajectory tilt angle and height instruction, H is aircraft present level, K_H、K_ΘFor Burnout height tolerance, The trajectory tilt angle deviation coefficient that affects on trajectory peak height tolerance, Θ_dFor the trajectory after compensating approach Bank angle command.

The method of guidance of RLV endoatmosphere the most according to claim 5 powered phase, it is characterised in that Guidance revised angle of pitch instruction in S3Wherein, normal acceleration instruction N_yc=N_y+|W_x1|·sinΦ_cx, axial acceleration instructs N_y=K₁·(H_cx-H)+K₂·V·(sinΘ_d-sinΘ)；Wherein, K₁、K₂For all radix scrophulariae of guidance after normalization Number；W_x1For the used group of axial apparent acceleration recorded, Φ_cxFor standard pitch program angle, Θ is that aircraft is worked as Front trajectory tilt angle.

The method of guidance of RLV endoatmosphere the most according to claim 1 powered phase, it is characterised in that Including, S7, when engine is duty, and after the flight time is more than allowing the unused time, it is judged that Whether cut-off condition meets, and then sends shutdown command as met.

The method of guidance of RLV endoatmosphere the most according to claim 7 powered phase, it is characterised in that Described cut-off condition includes, aircraft speed is more than V_k, V_kFor the normal trajectory shutdown spot speed being previously set Degree.