CN106508029B - A kind of spacecraft dynamics parametric synthesis discrimination method - Google Patents

Abstract

The invention discloses the spacecraft dynamics parametric synthesis discrimination method of a kind of mutation of comprehensive utilization quality and tail-off machine information.The thrust variation information of quality mutation and tail-off machine during comprehensive utilization spacecraft flight；The independent identification that kinetic parameter is realized using known quality abrupt information and corresponding observation data；Set up the flight that the kinetic model comprising quality mutation and tail-off machine information describes spacecraft in whole process；The identification of spacecraft dynamics parameter is carried out according to this.The method can utilize the observation data estimation parameter of longer time section, and effectively solving alleviates parameter coupling, distributed problem solving error, the problem that observation data effective information is not enough, parameter estimation more stablize with accurate.

Description

A kind of spacecraft dynamics parametric synthesis discrimination method

Technical field

Caused quality mutation is cast aside the present invention relates to annex during one kind comprehensive utilization spacecraft flight with tail-off machine to believe The comprehensive discrimination method of the kinetic parameter of breath.

Background technology

In the Parameter Estimation Problem based on spacecraft movable information, if spacecraft thrust parameter, initial mass parameter, quality stream Amount parameter is unknown, because the multiplying property of parameter is coupled, is only capable of estimating the ratio between parameter, it is impossible to independently pick out foregoing ginseng Quality mutation excitation can be produced by casting the behavior of known quality appurtenances during number, spacecraft flight aside rapidly in short-term, and this can lead Cause the acceleration suffered by object to there is a mutation, contribute to realize that the independent of spacecraft dynamics parameter is recognized using this information, Meanwhile, stress change caused by the suddenly change or tail-off machine of quality (inertia) characteristic can all cause to include and wait to estimate The change of the kinetics equation concrete form of mechanics parameter, is recognized past from the segmentation parameter of the equation progress of these concrete forms Enlarging-Errors, estimation parameter are caused to be that optimal in the short period is estimated using insufficient, parameter distributed problem solving toward existence information Meter (under estimation criterion meaning) the problems such as, set up to be mutated comprising quality and described with the kinetics equation of tail-off machine information The flight of spacecraft in whole process, effectively using the observation information of longer time section, is conducive to improving parameter identification result.

Parameter identification problem based on flight dynamics model, due to kinetic model structure, (acceleration=power/quality, angle accelerates Degree=torque/inertia) determined by physics law, it is likely encountered following point when carrying out parameter identification：

1 multiplying property of parameter is coupled

The coupling of multiplying property of parameter, which refers to two parameters in kinetics equation, can turn to the form for being multiplied or being divided by.

In following equation：

Wherein, F is thrust parameter, m₁For initial mass parameter, m ' is mass flow parameter, and t is the time.

For the inflight phase described with the equation, no matter how many includes the observed quantity of acceleration information, can not all estimate simultaneously Go out thrust parameter, initial mass parameter and mass flow parameter, be only capable of estimating the ratio of three.

2 parameter additivitys are coupled

The coupling of parameter additivity, which refers to two parameters in kinetics equation, can turn to the form for being added or subtracting each other.

In following equation：

Wherein, F₁, F₂For thrust parameter, m₀For initial mass parameter, m₁', m₂' it is mass flow parameter, t is the time, k₁, k₂, k₃, k₄For parameter coefficient, the change for describing thrust, flow integration amount.If coefficient k₁, k₂Or k₃, k₄Change always It is identical or closely, then thrust or flow parameter are difficult to differentiate between in identification problem.

3 distributed problem solving errors

In particular problem, from comprising when the calculating of specific kinetic model concrete form of kinetic parameter is estimated often not The whole parameter to be estimated of explicit physical meaning can be obtained, distributed problem solving need to introduce intermediate parameters or substitute into previous step estimation parameter value Next step, which is calculated, to be continued to solve, because the influence of various errors can cause intermediate parameters or upper step parameter estimation to have deviation, further Using intermediate parameters or the other parameters to be estimated of upper step parametric solution, error can be propagated and may expanded.

4 observation data effective informations are not enough

When the spacecraft inflight phase flight time is too short or section interference is relatively large, the identification kinetic model relative to foundation is seen The effective information surveyed in data may be not enough, and parametric stability can be caused poor, estimate results contrast is scattered.

Such as to certain rocket trip machine work independently section carry out parameter identification when, because this section of flight time is shorter, at the same interference relative to Thrust acceleration is larger, using the time interval being slightly different, estimate parameter differences are larger.

The content of the invention

Caused quality mutation and engine are cast aside it is an object of the invention to provide annex during one kind comprehensive utilization spacecraft flight Switch the spacecraft dynamics parameter identification method of machine information.

The technical scheme is that：This method is specifically included：

(1) the quality mutation during comprehensive utilization spacecraft flight and the thrust variation information of tail-off machine；

(2) the independent identification of kinetic parameter is realized using known quality abrupt information and corresponding observation data；

(3) set up to be mutated comprising quality and describe flying for spacecraft in whole process with the kinetic model of tail-off machine information OK；

(4) the problem of there is bigger difference for quality mutation, the modeling of tail-off machine transient process and practical flight, adopts Measure is taken to eliminate its influence：If observed quantity is directly acceleration information, the data with changeover portion are kept away；If observed quantity is to include acceleration The integration amount of information is spent, new state variable initial parameter is introduced, effectively eliminates the deviation accumulation effect of integral and calculating；

(5) identification of spacecraft dynamics parameter is carried out.

This method preferably make use of the information of dynamics change during spacecraft flight, and promote kinetic parameter has The problem of imitating identification, solution or the coupling of alleviation parameter, distributed problem solving error, observation data effective information deficiency, effectively utilization Observation data in longer time obtain the optimal estimation of parameter.

Introduce first in identification problem contributes to the independence for realizing kinetic parameter to recognize using spacecraft mass abrupt information, then says It is bright to set up the method for being mutated comprising quality and carrying out spacecraft dynamics parameter identification with the kinetic model of tail-off machine information.

In translation dynamics, introducing appurtenances, which cast caused quality abrupt information aside, in the denominator can solve molecule thrust parameter With the multiplying property coupled problem of denominator mass parameter, effective identification of parameter is realized；Equally, in rotational power equation, dividing Inertia abrupt information caused by structural form change is introduced in mother can solve molecule thrust (square) parameter and denominator (quality) inertia The multiplying property coupled problem of parameter, realizes effective identification of parameter.

Consider in t₂There is the translation kinetic model of known quality Sudden Changing Rate Δ m spacecraft in the moment：

Wherein, F is thrust parameter, m₁, m₂Respectively t₁, t₂The mass parameter at moment, m ' is mass flow parameter, and t is Time, t₂At the time of point, F, m are cast aside for spacecraft appurtenances₁, m₂, m ' is parameter to be estimated.To first equation It can estimateWithTwo equations can be estimatedWithBy relationship between quality m₀-m′(t₂-t₁)-Δ m=m₁Achievable pair The estimation of flow parameter：And then thrust parameter, initial mass parameter can be realized Estimation.

Above-mentioned solution can obtain two groupsParametric results, the mode for preferably utilizing spacecraft annex to cast information aside is to set up inclusion The kinetic model of weight abrupt information：

Wherein, F is thrust parameter, m₁For initial mass parameter, m ' is mass flow parameter, and Δ m is cast aside for appurtenances to be drawn The quality knots modification risen, t is time variable, t₁Certain stabilized flight moment point, t before being cast aside for selected spacecraft annex₂For space flight Device appurtenances cast at the time of point, t aside₃Certain stabilized flight moment point after being cast aside for selected spacecraft annex, Step () is step Function, the quality mutation of description object.

(2) formula of analysis, has broken the multiplying property of thrust to be estimated with mass parameter to the utilization for being mutated quality information and has coupled, can Realize estimation to thrust parameter and mass flow parameter, it is to avoid the error propagation of distributed problem solving process intermediate parameters, effectively profit More rational parameter estimation is obtained with the observation data of longer time.

Equally, for there is the spacecraft flight process of tail-off machine, it can also set up comprising tail-off machine information Kinetic model is recognized to relevant parameter.

Consider in t₂Moment engine 1 shuts down, and (herein for convenience, it is assumed that being preferable shutdown, that is, shut down moment thrust, stream Quantitative change is kinetic model 0)：

Wherein, F₁, F₂Respectively engine 1,2 thrust parameter, m₁, m₂Respectively t₁, t₂The initial mass ginseng at moment Number, m₁', m₂' be respectively engine 1,2 mass flow parameter, t is time variable, t₁Thrown for selected spacecraft annex From preceding certain stabilized flight moment point, t₂For the shutdown moment point of engine 1, t₃Certain is stable winged after being cast aside for selected spacecraft annex Row moment point.

From two kinetics equation carry out parameter identifications of above-mentioned (4) formula, no matter parameter Estimation is proceeded by from that, Obtained result is all that the optimal estimation of parameters of data is observed using shorter time period, sets up dynamic comprising tail-off machine information Mechanical model：

Wherein F₁, F₂Respectively engine 1,2 thrust parameter, m₁For t₁The initial mass parameter at moment, m₁', m₂' respectively For the mass flow parameter of engine 1,2, t is time variable, t₁Certain stabilized flight before being cast aside for selected spacecraft annex Moment point, t₂For the shutdown moment point of engine 1, t₃Certain stabilized flight moment point after being cast aside for selected spacecraft annex, Step () For jump function, k₁To describe the thrust coefficient of the thrust variation of engine 1, k₂To describe the thrust system of the thrust variation of engine 2 Number, is k₃The discharge coefficient that engine 1 discharges propellant gross mass, k are described₄For the description discharge propellant gross mass of engine 2 Discharge coefficient.

Coefficient in kinetic model (5) includes the shutdown information of engine 1, distinguishes difference using the different working times and starts Thrust parameter and flow parameter between machine, effectively obtain parameter using the observation data of longer time section and more reasonably estimate.

According to the kinetic model (2) comprising spacecraft mass abrupt information and include the kinetic model of tail-off machine information (5), setting up the kinetic model comprising mass of object mutation and tail-off machine information, (annex is cast aside, engine cutoff is equal Described using ideal model)：

Wherein F₁, F₂Respectively engine 1,2 thrust parameter, m₁For t₁The initial mass parameter at moment, m₁', m₂' respectively For the mass flow parameter of engine 1,2, Δ m casts caused quality knots modification aside for appurtenances, and t is time variable, t₁For Selected spacecraft annex casts preceding certain stabilized flight moment point, t aside₂The time cast aside for spacecraft appurtenances, t₃For engine 1 Shutdown moment point, t₄Certain stabilized flight moment point after being cast aside for selected spacecraft annex, Step () is jump function, k₁For The thrust coefficient of the thrust variation of engine 1, k are described₂To describe the thrust coefficient of the thrust variation of engine 2, k₃Start for description Machine 1 discharges the discharge coefficient of propellant gross mass, k₄The discharge coefficient of propellant gross mass is discharged for description engine 2.

The kinetic model comprising quality abrupt information and tail-off machine process set up can be translation kinetic model or turn Dynamic kinetic model, is targetedly modeled as the case may be.It should be noted that for attached in translation kinetic model Category part casts caused quality abrupt information aside and assume that centroid position instantaneously completes change, does not influence in translation kinetics equation Thrust and quality；But for rotational power model, spacecraft annex casts the change of caused barycenter aside and can change rotational power The moment of thrust and mass inertia in equation are learned, needs to consider amendment during modeling.

Spacecraft mass mutation and tail-off machine information are contained in the kinetic model of foundation, wherein being mutated quality with sending out The model that motivation switching on and shutting down transient process is set up and the possible difference of Live Flying are larger, such as engine start practical flight thrust curve It is larger with hot-firing test data gap.For physical quantity of the observed quantity for measurement spacecraft translation information, translation kinetic model is set up The problem of carrying out dynamic parameters identification, if observed quantity is directly acceleration information, keeps away the data with changeover portion, if observed quantity is Integration amount comprising acceleration information, set up another after changeover portion time point be integrated calculating eliminate error accumulation influence, while shape State variable initial value can also be used as parameter to be estimated.For physical quantity of the observed quantity for measurement spacecraft rotation information, rotational power is set up The problem of model carries out dynamic parameters identification is learned, processing method is similar.

What method was set up is not suitable for kinetic parameter comprising quality abrupt information and the kinetic model of tail-off machine process On-line Estimation, is only applicable to the parameter Estimation focused on afterwards.

What method was set up is only the kinetic model with tail-off machine process comprising quality abrupt information, when carrying out parameter Estimation Need to focus on method afterwards using least square method or maximum-likelihood method etc..

In being mutated comprising spacecraft mass in the kinetic model with tail-off machine information, it is necessary to spacecraft mass for foundation Mutation is described with tail-off machine behavior, and the coefficient of Model Parameter will be used to express these information.Describing mode can be adopted With ideal model or the model based on priori, it is mutated below with quality, tail-off machine thrust, tail-off machine stream Introduced exemplified by the description of amount.

The coefficient k of parameter will not necessarily provide analytical expression, be obtained also by numerical computations.

Quality mutation description：

Mutation quality is described using jump function, coefficient k=Step (t₂), then k~t curves such as Fig. 1：

Tail-off machine thrust is described：

Perfect switch machine model, coefficient k=Step (t can be used to motor power₁)-Step(t₂), then k~t curves such as Fig. 2；

In addition, coefficient k~t can be built by starting shutdown hot-firing test data or engine start shutdown empirical equation using engines ground Curve, so that using exemplified by hot-firing test data, then k~t curves are such as Fig. 3；

Tail-off machine flow is described：

To engine mass-flow rate of propellant, described according to perfect switch machine model, then propellant normalization flow is closed with the time System such as Fig. 4；

In kinetics equation, the propellant flow rate coefficient k~t curves such as Fig. 5 that can be asked is integrated；

It is described with reference to hot-firing test data, then propellant normalization flow and time relationship such as Fig. 6；

In kinetics equation, the propellant flow rate coefficient k~t curves such as Fig. 7 that can be asked are integrated

The advantage of the invention is that：

1st, contribute to realize that the independent of kinetic parameter is recognized using the quality abrupt information during spacecraft flight；

2nd, the effective identification for promoting kinetic parameter with the kinetic model of tail-off machine information comprising quality mutation is set up, Error propagation expands caused by avoiding distributed problem solving, and the optimal estimation of parameter is effectively obtained using the observation data in the longer time；

3rd, the kinetics equation comprising spacecraft mass abrupt information and tail-off machine process set up can be translation dynamics Equation or rotational power equation；

4th, the problem of there is bigger difference for quality mutation, the modeling of tail-off machine transient process and practical flight, if seeing Measurement is directly acceleration information, keeps away and uses transition segment data；If observed quantity is the integration amount comprising acceleration information, introduce newly State variable initial parameter can effectively eliminate the deviation accumulation effect of integral and calculating.

5th, in the kinetic model comprising spacecraft mass abrupt information set up, if initial mass (inertia), flow and thrust Parameter to be estimated is, appurtenances cast the estimation that caused quality (inertia) abrupt information can be used for realizing aforementioned parameters aside.It is real On border, if initial mass (inertia), flow and thrust it is any, it is known that mutation quality (inertia) can also serve as parameter progress Estimation.

6th, set up the kinetic model comprising quality abrupt information in, using quality (inertia) abrupt information realization to thrust, The estimation of flow parameter, if quality (inertia) Sudden Changing Rate contains δ relative error, can cause the thrust parameter and quality estimated The flow parameter also relative error containing δ, but not influence the ratio of the two, thus the ratio parameter (specific impulse) estimated be can Letter.

This method sets up the kinetic model comprising spacecraft mass mutation with tail-off machine information, effectively utilizes the longer time The observation data estimation parameter of section, solves or alleviates parameter coupling, distributed problem solving error, observation data effective information deficiency are asked Topic, parameter estimation is more stablized and accurate.

Brief description of the drawings

Fig. 1 is quality mutation description schematic diagram；

Fig. 2 is ideal engine switching on and shutting down thrust coefficient curve map；

Fig. 3 is the tail-off machine thrust coefficient curve map based on hot-firing test data；

Fig. 4 is ideal engine switching on and shutting down flow normalized curve figure；

Fig. 5 is ideal engine switching on and shutting down discharge coefficient curve map；

Fig. 6 is the tail-off machine flow normalized curve figure based on hot-firing test data；

Fig. 7 is the tail-off machine discharge coefficient curve map based on hot-firing test data.

Embodiment

The application of the present invention：

1 has the dynamic parameters identification for the rocket flight section that radome fairing is cast aside

The kinetic model for casting information aside comprising radome fairing is set up, caused quality abrupt information is cast aside using radome fairing and distinguishes thrust The ratio of parameter and mass flow parameter, thrust and mass flow parameter is specific impulse parameter.

2 have main frame, the dynamic parameters identification of the rocket flight section of slave shutdown

Set up and include main frame, the kinetic model of slave shutdown information, the different time mainly worked using main frame, slave is distinguished Main frame thrust and slave thrust parameter, the different time worked using main frame, slave distinguish main frame and the flow parameter of slave, main Machine is corresponding specific impulse parameter with the ratio of mass flow parameter with secondary thrust.

3 have the dynamic parameters identification of the spacecraft posture adjustment section of attitude control engine co-ordination

The kinetic model for including attitude control engine co-ordination information is set up, the different time worked using attitude control engine is distinguished Thrust and flow parameter between different engines.

4 other spacecraft dynamics parameter identification problems for meeting method and thought.

The kinetic model comprising quality abrupt information and tail-off machine process set up can be translation kinetic model or turn Dynamic kinetic model, is targetedly modeled as the case may be.

Caused quality abrupt information is cast aside for appurtenances assume that centroid position instantaneously completes to change in translation kinetic model Become, the thrust and quality in translation kinetics equation are not influenceed；But for rotational power model, object structures metamorphosis draws The barycenter change risen can change the moment of thrust and mass inertia in rotational power equation.

In the kinetic model comprising quality abrupt information set up, wait to estimate ginseng if initial mass (inertia), flow and thrust are Number, appurtenances cast the estimation that caused quality (inertia) abrupt information can be used for realizing aforementioned parameters aside.If in fact, just Prothyl amount (inertia), flow and thrust is any, it is known that mutation quality (inertia) can also serve as parameter and be estimated.

In the kinetic model comprising quality abrupt information set up, realized using quality (inertia) abrupt information to thrust, stream The estimation of parameter is measured, if quality (inertia) Sudden Changing Rate contains δ relative error, the thrust parameter and quality stream estimated can be caused The parameter also relative error containing δ, but not influence the ratio of the two is measured, therefore the ratio parameter (specific impulse) estimated is credible 's.

The kinetic model of foundation is directed to comprising quality mutation and the spacecraft flight overall process of tail-off machine, and it is not suitable for On-line Estimation, is only applicable to the parameter Estimation focused on afterwards.

Contribute to realize the independent identification of kinetic parameter using the quality abrupt information during spacecraft flight, foundation is included Quality abrupt information and the kinetic model of tail-off machine process, using the observation data estimation parameter of longer time section, Effective solution alleviates parameter coupling, distributed problem solving error, observes the problem of data effective information is not enough, and parameter estimation is more steady It is fixed and accurate.

Claims (3)

1. a kind of spacecraft dynamics parametric synthesis discrimination method, it is characterised in that this method is specifically included：

(1) quality information and tail-off machine information during comprehensive utilization spacecraft flight；

(2) the independent identification of kinetic parameter is realized using known quality information and corresponding observation data；

(3) set up the kinetic model comprising quality information and tail-off machine information and describe flying for spacecraft in whole process OK；The kinetic model is：

$a=\frac{k_1\·F_1+k_2\·F_2}{m_1-k_3\·{m_1}^{\′}-k_4\·{m_2}^{\′}-\mathrm{\Δ}m\·Step\left(t_2\right)}$

k₁=1-Step (t₂)

k₂=1

$k_3=\left\{\begin{array}{cc}t-t_1& t\∈(t_1,t_3)\\ t_3-t_1& t\∈\[t_3,t_4)\end{array}\right.$

k₄=t-t₁

Wherein F₁, F₂Respectively engine 1,2 thrust parameter, m₁For t₁The initial mass parameter at moment, m₁', m₂' respectively For the mass flow parameter of engine 1,2, Δ m casts caused quality knots modification aside for appurtenances, and t is time variable, t₁For Selected spacecraft annex casts preceding certain stabilized flight moment point, t aside₂At the time of point, t are cast aside for spacecraft appurtenances₃To start The shutdown moment point of machine 1, t₄Certain stabilized flight moment point after being cast aside for selected spacecraft annex, Step () is jump function, k₁ To describe the thrust coefficient of the thrust variation of engine 1, k₂To describe the thrust coefficient of the thrust variation of engine 2, k₃For description hair Motivation 1 discharges the discharge coefficient of propellant gross mass, k₄The discharge coefficient of propellant gross mass is discharged for description engine 2；

(4) the problem of there is bigger difference for quality information, the modeling of tail-off machine information and practical flight, takes and arranges Applying elimination, it influences：If observed quantity is directly acceleration information, the data with changeover portion are kept away；If observed quantity is comprising acceleration letter The integration amount of breath, introduces new state variable initial parameter, effectively eliminates the deviation accumulation effect of integral and calculating；

(5) identification of spacecraft dynamics parameter is carried out.

2. a kind of spacecraft dynamics parametric synthesis discrimination method according to claim 1, it is characterised in that foundation is included The kinetic model of quality information and tail-off machine information is translation kinetic model or rotational power model.

3. a kind of spacecraft dynamics parametric synthesis discrimination method according to claim 1, it is characterised in that to quality information The problem of model and the larger possible difference of Live Flying for being set up with tail-off machine information, has carried out effective processing：For observation Measure to measure the physical quantity of spacecraft translation information, set up the problem of translation kinetic model carries out dynamic parameters identification, if seeing Measurement is directly acceleration information, keeps away the data with changeover portion, if observed quantity is the integration amount comprising acceleration information, in transition Section after set up another time point be integrated calculating eliminate error accumulation influence, while state variable initial value is used as parameter to be estimated.