CN103253382B - High-precision joint orbital transfer method for engines - Google Patents

Abstract

A high-precision joint orbital transfer method for engines includes a first step of configuring three types of engines, a second step of determining a starting up threshold dvA of an engine A according the minimum starting up time and aftereffects of the engine A and determining a starting up threshold dvB of an engine B according to capacity of an engine C and an additional impulse produced through attitude maneuver of the engine C, a third step of receiving orbit control information sent by the ground by a spacecraft on orbit, and a fourth step of selecting an orbit control mode according to corresponding engine starting up thresholds determined in the second step and an orbit control velocity increment in the third step, wherein the orbit control information includes the orbit control velocity increment dv, velocity increment directions which are expressed by a pitch angle a1 and a pitch angle a2, and a starting up moment t. The fourth step particularly includes the following steps of utilizing an AB joint orbital transfer mode if the orbit control velocity increment dv is larger than the dvA, utilizing a B engine orbital transfer mode if the orbit control velocity increment dv is less than or equal to the dvA but larger than the dvB, and utilizing a transversely-moving engine orbital transfer mode when the velocity increment is less than or equal to the dvB.

Description

A kind of high precision driving engine associating orbit changing method

Technical field

The present invention relates to Technique in Rendezvous and Docking and become a kind of high-precision orbital control driving engine associating orbit changing method used in rail process, can be used for the development of spacecrafts rendezvous GNC control system, also can be applied to the controlling plan design of the higher spacecraft of other orbit control accuracy requirement.

Background technology

Technique in Rendezvous and Docking refers to that two spacecrafts are joined (intersection) by preposition, speed and time in orbit, then through attitude tracking, draw close until the thru-flight course of action of structurally link into an integrated entity (docking).Carry out two spacecrafts of Technique in Rendezvous and Docking, usual one is referred to as target aircraft (abbreviation object machine), and another is referred to as follows the trail of aircraft (abbreviation tracker).In spacecrafts rendezvous process, tracker is initiatively, the general spacecrafts rendezvous realizing two spacecrafts by changing tracker relative to the position of object machine and attitude stage by stage.Spacecrafts rendezvous process generally divides four-stage: remote guiding section, target-seeking section, Approach phase, to draw close and Butt Section.

Remote guiding section enters the orbit to tracker from tracker to arrive initial aiming point, and initial aiming point is the guiding of spacecrafts rendezvous ground and the delivery position from master control.Tracker must direct within the sphere of action of Relative Navigation sensor by ground guiding, and ensure when ground guiding has departure, still can meet the requirement of the capture time of relative measurement sensor, relative position and relative velocity measurement range, create good initial condition (IC) for autonomous control section simultaneously.Therefore the precision height of the guidance of remote guiding section and control directly determines whether tracker can transfer to from master control on request, namely directly affects the success or failure of spacecrafts rendezvous.

Remote guiding section mainly ground support under perform several times orbit maneuver for adjusting the relative status with object machine, need the orbits controlling driving engine using tracker propulsion module afterbody when becoming rail, and orbits controlling driving engine is because thrust is large, aftereffect is also larger on the impact becoming rail precision greatly.Therefore the orbits controlling driving engine become in rail process tracker is needed to use strategy to study.

The use strategy that conventional spacecraft orbit controls driving engine mainly contains the methods such as velocity increment shutdown and time shutdown.Velocity increment shutdown needs to install accelerometer on spacecraft, after driving engine start, the velocity increment of orbit maneuver engine start can be added up by the output of accelerometer, when this velocity increment reaches required value, control system just sends the instruction of closing orbits controlling driving engine, completes change rail.After engine cutoff instruction sends, postpone to engine cutoff life period, and also there is post-thrust after engine cutoff, engine thrust is larger, aftereffect is larger, therefore directly makes the requirement that can not meet spacecrafts rendezvous remote guiding section orbits controlling in this way.Time shutdown does not need to install accelerometer on spacecraft, namely the on time length of orbits controlling driving engine is calculated according to the nominal thrust of driving engine and the required value of velocity increment, the on time of control system to driving engine adds up, upon power-up to rear just send instructions kill engine.Because the actual thrust of driving engine in-orbit and nominal thrust exist deviation, and also carry out gesture stability in track control process, therefore the control accuracy of time shutdown specific rate increment shutdown is poorer, more can not meet the requirement of spacecrafts rendezvous orbits controlling.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiencies in the prior art, provides a kind of high-precision driving engine associating orbit changing method.

Technical solution of the present invention is: a kind of high precision driving engine associating orbit changing method, and step is as follows:

(1) configure three class driving engines, be respectively high thrust orbits controlling driving engine be designated as A driving engine, low-thrust trajectory control driving engine be designated as B driving engine, and three axle translations control driving engine be designated as C driving engine; The thrust of three class driving engines meets F _a>F _b>F _c;

(2) the start thresholding dvA of A driving engine is determined according to minimum on time of A driving engine and aftereffect; The start thresholding dvB of B driving engine is determined according to the ability of C driving engine and the additional momentum of attitude maneuver generation;

(3) spacecraft receives the orbits controlling information that ground sends in-orbit, comprises orbit control velocity increment size dv, velocity increment direction, represents with pitch angle a1 and yaw angle a2, start moment t;

(4) orbit control velocity increment that the corresponding driving engine start thresholding determined according to step (2) and step (3) are determined selects orbits controlling pattern, is specially:

If orbit control velocity increment dv is greater than dvA, then AB is adopted to combine change board pattern;

If orbit control velocity increment dv is less than or equal to dvA, but is greater than dvB, then B driving engine is adopted to become board pattern;

When velocity increment is less than or equal to dvB, translation driving engine is adopted to become board pattern.

AB in described step (4) combines change board pattern and realizes as follows:

First carry out attitude maneuver, make to point in time t attitude to arrive pitch angle a1, yaw angle a2, open A driving engine, and utilize the accelerometer that spacecraft is installed to add up velocity increment, the aggregate-value of velocity increment is designated as dvp; Close A driving engine as residual velocity increment dv-dvp=dvB, and open B driving engine, when accumulative velocity increment is dvB, close B driving engine, terminate to become rail.

Translation driving engine in described step (4) becomes board pattern and realizes as follows:

First, according to orbit control velocity increment direction calculating spacecraft three axle orbit control quantity dvx, dvy, dvz of obtaining in step (3);

Then, three axle translation driving engines open corresponding C driving engine forward or backwards in t according to the symbol of dvx, dvy, dvz, and three axles carry out velocity increment respectively to be added up, when three axle velocity increment aggregate-values are respectively | dvx|, | dvy|, | dvz|, correspondingly closes the driving engine of this axle.

The present invention compared with prior art beneficial effect is:

Carry out in the process of spacecrafts rendezvous at No. eight, divine boat, divine boat's No. nine manned spacecrafts and Heavenly Palace target aircraft, manned spacecraft is tracker.Guide at manned spacecraft, in navigation and vehicle controL subsystem development process, from early stage demonstration, conceptual design, first sample designs, positive sample design, until fly in-orbit, we propose and a kind of high precision driving engine associating of gradual perfection orbit changing method, the method can ensure real engine start produce velocity increment and required value very close, shut down with the velocity increment of routine and to compare with time shutdown method, orbit control accuracy is high, in twice aerial mission, the actual terminal point control precision of remote guiding section is all much better than index request, effectively ensure that satisfactorily completing of spacecrafts rendezvous task.

Accompanying drawing explanation

Fig. 1 is high precision driving engine of the present invention associating orbit changing method design flow diagram.

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention is elaborated, as shown in Figure 1, the thinking that the present invention adopts velocity increment to shut down in implementation procedure, need to install accelerometer on spacecraft, method concrete steps are as follows:

(1) three class orbit maneuver engines are configured.

Implement the more spacecraft of orbits controlling task in-orbit, particularly perform the spacecraft of spacecrafts rendezvous task, be usually furnished with polytype orbits controlling driving engine, comprise high thrust orbits controlling driving engine, low-thrust trajectory controls driving engine and translation driving engine.Driving engine is determined according to the quality of concrete mission requirements and spacecraft, inertia and structure etc. in spaceborne layout and thrust size.For spacecrafts rendezvous task, in horizontal thrust direction configuration high thrust orbit maneuver engine, three directions of translation to configure low-thrust trajectory and control driving engine, also need configuration three-axis attitude to control driving engine simultaneously.Engine configurations also will consider the redundancy backup in engine breakdown situation.

In the present invention, according to orbits controlling engine thrust size, be divided three classes successively:

(1) high thrust orbits controlling driving engine, be called for short A driving engine, thrust is F _a;

(2) low-thrust trajectory controls driving engine, and be called for short B driving engine, thrust is F _b;

(3) three axle translations control driving engine, are called for short C driving engine.F is respectively in the thrust size in x, y, z three directions _cx, F _cy, F _cz.Make F _c=max (F _cx, F _cy, F _cz).

F _a, F _b, F _crequire to determine according to actual task, meet F _a>F _b>F _c.

(2) the orbits controlling information that ground sends is received.

By world observing and controlling communication, spacecraft receives the orbits controlling information that ground sends in-orbit, comprises orbit control velocity increment size dv, velocity increment direction, represents with pitch angle a1 and yaw angle a2, start moment t.

(3) the thresholding selection orbits controlling pattern that requires according to orbits controlling and start shooting also is implemented to become rail.

(1) the start thresholding dvA of A driving engine is determined according to minimum on time of A driving engine and aftereffect.The start thresholding dvB of B driving engine is determined according to the ability of C driving engine and the additional momentum of attitude maneuver generation.Wherein, the aftereffect velocity increment of A driving engine can be estimated according to the characteristic ground of driving engine, and the empirical data in-orbit of driving engine of the same type also can be utilized to estimate.

If the aftereffect velocity increment that the minimum on time of A driving engine is TAmin, A driving engine is dvAres, then dvA=TAmin × FA+dvAres+ allowance.Allowance is empirical value, 10% ~ 20% of such as desirable TAmin × FA.

If the maxim of the additional momentum that attitude maneuver produces is the maximum on time that dvatt, C driving engine allows is TCmax, then design dvB>dvatt and dvB/Fc<TCmax.

(2) if orbit control velocity increment dv is greater than dvA, AB is then adopted to combine change board pattern, namely first attitude maneuver is carried out, make to point in time t attitude to arrive pitch angle a1, yaw angle a2, open A driving engine, and utilizing accelerometer to add up velocity increment, the aggregate-value of velocity increment is designated as dvp.Close A driving engine when residual velocity increment dv-dvp equals dvB, and open B driving engine, when accumulative velocity increment is dvB, close B driving engine, terminate to become rail.The nominal on time of A, B driving engine is respectively TA=(dv-dvB)/F _aand TB=dvB/F _b, total change rail on time is T=TA+TB.

(3) if orbit control velocity increment dv is less than or equal to dvA, but be greater than dvB, B driving engine is then adopted to become board pattern, namely first attitude maneuver is carried out, make to point in time t attitude to arrive pitch angle a1, yaw angle a2, open B driving engine and become rail, and utilize accelerometer to add up velocity increment.When accumulative velocity increment is dv, close B driving engine, terminate to become rail.It is T=dv/F that B driving engine becomes the rail nominal on time _b.

(4) if orbit control velocity increment dv is less than or equal to dvB, then adopt translation driving engine to become board pattern, in this mode without the need to attitude maneuver, require calculating three axle orbit control quantity according to orbits controlling, computing formula is as follows: $\left\{\begin{array}{c}\mathrm{dvx}=\mathrm{dv}\&CenterDot;\cos a1\&CenterDot;\cos a2\\ \mathrm{dvy}=\mathrm{dv}\&CenterDot;\cos a1\&CenterDot;\sin a2\\ \mathrm{dvz}=-\mathrm{dv}\&CenterDot;\sin a1\end{array}\right.$

Three axle translation driving engines open corresponding C driving engine forward or backwards in t according to the symbol of dvx, dvy, dvz, and three axles carry out velocity increment respectively to be added up, when three axle velocity increment aggregate-values are respectively | dvx|, | dvy|, | dvz|, correspondingly closes the driving engine of this axle.The orbits controlling nominal on time of each axle is: Tx=dvx/F _cx, Ty=dvy/F _cy, Tz=dvz/F _cx.

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

Claims (3)

1. a high precision driving engine associating orbit changing method, is characterized in that step is as follows:

(1) configure three class driving engines, be respectively high thrust orbits controlling driving engine be designated as A driving engine, low-thrust trajectory control driving engine be designated as B driving engine, and three axle translations control driving engine be designated as C driving engine; The thrust of three class driving engines meets F _a>F _b>F _c;

(2) the start thresholding dvA of A driving engine is determined according to minimum on time of A driving engine and aftereffect; The start thresholding dvB of B driving engine is determined according to the ability of C driving engine and the additional momentum of attitude maneuver generation;

(3) spacecraft receives the orbits controlling information that ground sends in-orbit, comprises orbit control velocity increment size dv, velocity increment direction, represents with pitch angle a1 and yaw angle a2, start moment t;

(4) orbit control velocity increment that the corresponding driving engine start thresholding determined according to step (2) and step (3) are determined selects orbits controlling pattern, is specially:

If orbit control velocity increment dv is greater than dvA, then AB is adopted to combine change board pattern;

If orbit control velocity increment dv is less than or equal to dvA, but is greater than dvB, then B driving engine is adopted to become board pattern;

When velocity increment is less than or equal to dvB, translation driving engine is adopted to become board pattern.

2. a kind of high precision driving engine associating orbit changing method according to claim 1, is characterized in that: the AB in described step (4) combines change board pattern and realizes as follows:

First carry out attitude maneuver, make to point in time t attitude to arrive pitch angle a1, yaw angle a2, open A driving engine, and utilize the accelerometer that spacecraft is installed to add up velocity increment, the aggregate-value of velocity increment is designated as dvp; Close A driving engine as residual velocity increment dv-dvp=dvB, and open B driving engine, when accumulative velocity increment is dvB, close B driving engine, terminate to become rail.

3. a kind of high precision driving engine associating orbit changing method according to claim 1, is characterized in that: the translation driving engine in described step (4) becomes board pattern and realizes as follows:

First, according to orbit control velocity increment direction calculating spacecraft three axle orbit control quantity dvx, dvy, dvz of obtaining in step (3);

Then, three axle translation driving engines open corresponding C driving engine forward or backwards in t according to the symbol of dvx, dvy, dvz, and three axles carry out velocity increment respectively to be added up, when three axle velocity increment aggregate-values are respectively | dvx|, | dvy|, | dvz|, correspondingly closes the driving engine of this axle.