CN103332301A - Method for utilizing liquid filling variable inertial flywheel to control attitude of spacecraft and actuating mechanism thereof - Google Patents

Abstract

The invention provides a method of utilizing a liquid filling variable inertial flywheel to control the attitude of a spacecraft and an actuating mechanism thereof. The actuating structure comprises a vacuum framework, a flywheel, a motor, a bearing and a control mechanism, wherein the control mechanism controls the rotational speed of the motor and liquid emission of a liquid filling cavity; the liquid in the liquid filling cavity of the flywheel is filled or discharged through an axial guide pipe and a radial guide pipe. According to the invention, three actuating mechanisms are respectively mounted on the three shafts which are perpendicular to each other, of the spacecraft, and the flywheel symmetry axis of each actuating mechanism is superposed with the coordinate axis where the actuating mechanism is positioned; a relationship between triaxial controlling torque and variation law of momentum moment of the actuating mechanisms can be obtained based on the momentum moment theorem; the filling/discharging of the liquid in the liquid filling cavity of the flywheel is adjusted according to the current speed of the flywheel and the rotational speed threshold value, as a result, the controlling moment for the attitude of the spacecraft can be adjusted unceasingly and timely, so as to allow the attitude to be superposed with the expected attitude. The actuating mechanism has no more requirements on space and quality of the spacecraft and realizes moment requirement for stable attitude and accurate attitude control.

Description

Utilize method and the actuating unit thereof of topping up inertia variable fly wheel control spacecraft attitude

Technical field

The present invention relates to the control actuating unit of spacecraft attitude, specifically, is a kind of method and actuating unit thereof that utilizes topping up inertia variable fly wheel control spacecraft attitude, belongs to spacecraft attitude control field.

Background technology

Satellite often need carry out the wide-angle attitude maneuver satisfying various mission requirementses in flight course, and in order to reduce the satellite quality, will be used for attitude maneuver as the reaction wheel of attitude stabilization actuating unit to improve its functional density usually.Because there is the restriction in saturated rotating speed and slow speed of revolution dead band in counteraction flyback itself, make at the attitude control The controller of extreme problem more complicated or can adopt the method for redundant configuration to address this problem mostly, but list of references [1] Creamer G, Gates D S P.Attitude determination and control of Clementine during lunar mapping[J] .Journal of Guidance, Control and Dynamics, 1996,19 (3): 505-511; Document [2] Wie B, Lu J.Feedback control logic for spacecraft Eigen axis rotations under slew rate and control constraints[J] .Journal of Guidance, Control and Dynamics, 1995,18 (6): 1372-1379. etc.

But the controller of too complex is difficult for using in space mission, and redundant configuration can produce extra quality burden to spacecraft again.For this reason, part Study is from actuating unit itself, with a kind of novel momentum exchange device---become inertia counteraction flyback (VIRW, Variable Inertial Reaction Wheel) attitude that is used for satellite is controlled, utilize the VIRW characteristic of moment output on a large scale to a certain extent, reach the attitude maneuver that adopts simple control algorithm can effectively realize small satellite.VIRW has carried out the attitude control experiment under the microgravity environment by researchist's invention of Georgia Institute of Technology and in 2003.It is that with the difference of general counteraction flyback its rotor inertia is variable.Each VIRW has two motors, and motor 1 is used for controlling the rotation of flywheel, and motor 2 is used for controlling the flexible of pouring weight.The change of pouring weight position causes the change of Rotary Inertia of Flywheel just, has enlarged the scope of flywheel output torque thus, does not damage the precision of low-angle control again.But list of references [3] Christian A J, et al.Development of a Variable Inertia Reaction Wheel System for Spacecraft Attitude Control[J] .AIAA2004-5132, and document [4] Christian A J, et al.Test equipment data package, development of a variable inertia reaction wheel system[R], Georgia Institute of Technology, TEDP, 2003.

Yet the mode of utilizing the displacement of solid masses piece to produce the inertia variation can increase mechanical movement, uses the easier harm such as mechanical moving element wearing and tearing, fracture that occur for a long time, does not satisfy the basic reliability requirement as long period spacecraft attitude control actuating unit.

Summary of the invention

The objective of the invention is in order to solve in the prior art because the needed moment output of spacecraft exists saturated and the extreme case dead band, cause actuating unit speed adjustment ability can not reach mission requirements, and since the restriction that the rotor mechanical acrokinesia causes actuating unit to lose efficacy, a kind of method and actuating unit thereof that utilizes topping up inertia variable fly wheel control spacecraft attitude of proposition.

The invention provides a kind of actuating unit that utilizes topping up inertia variable fly wheel control spacecraft attitude, comprising: vacuum frame, flywheel, motor, bearing and the control mechanism of fixing and install whole flywheel structure.Flywheel comprises solid rotor part, clutch bell, topping up chamber, radial conduit and axial pipe.The position of vacuum frame fixed type bearing and motor.Bearing is installed in the two ends of flywheel rotating shaft.Motor cooperates with the flywheel rotating shaft.Liquid working substance in the flywheel topping up chamber injects and emptying by axial pipe and radial conduit.Liquid in rotating speed of motor and the topping up chamber is injected control mechanism and emptying is controlled.

At spacecraft orthogonal three: on X-axis, Y-axis and the Z axle, a described actuating unit is installed respectively, the axis of symmetry of the flywheel of each execution architecture overlaps with the coordinate axle at place.

The present invention utilizes the method for topping up inertia variable fly wheel control spacecraft attitude, and concrete steps are as follows:

After step 1, the attitude sensor by spacecraft obtain the spacecraft attitude parameter, according to the difference of current attitude and expectation attitude by three required control torque vector T of Lyapunov method design spacecraft _C=[T _C1, T _C2, T _C3] ^T, i=1,2,3, represent X-axis, Y-axis and Z axle that space vehicle coordinates is respectively.

Step 2, three actuating units are installed on three of spacecraft;

Spacecraft and actuating unit are to the aggregate momentum square H=I ω+H of spacecraft barycenter _w, wherein, I represents total rotor inertia of spacecraft, ω represents the cireular frequency of spacecraft, H _wThe expression actuating unit is to the moment of momentum of spacecraft barycenter;

Wherein, Ω=[Ω ₁, Ω ₂, Ω ₃] ^TThe rotating speed of the clutch bell of the actuating unit on representing three, β _Wf=[β _Wf1, β _Wf2, β _Wf3] ^TFollow the tracks of the equivalent rotating speed of the liquid of clutch bell rotating speed in the flywheel topping up chamber on representing three, Ι _Ww=[I _Ww1, I _Ww2, I _Ww3] ^TThe rotor inertia of the clutch bell of the actuating unit on representing three, Ι _Wf=[I _Wf1, I _Wf2, I _Wf3] ^TRepresent three rotor inertias that go up the topping up intracavity liquid;

Have according to the moment of momentum theorem

With moment of momentum H _wRate of change project on X-axis, Y-axis and the Z axle of spacecraft, obtain ${\stackrel{\&CenterDot;}{H}}_w={[{\stackrel{\&CenterDot;}{H}}_{\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">w</figure-callout>}1},{\stackrel{\&CenterDot;}{H}}_{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">w</figure-callout>}2},{\stackrel{\&CenterDot;}{H}}_{w3}]}^T.$

Step 3, according to actuating unit to the moment of momentum of spacecraft barycenter relation, obtain $\left[\begin{array}{c}{\stackrel{\&CenterDot;}{H}}_{w1}\\ {\stackrel{\&CenterDot;}{H}}_{w2}\\ {\stackrel{\&CenterDot;}{H}}_{w3}\end{array}\right]=\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_1+{\mathrm{<figure-callout\; id="1"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}1}\\ {\mathrm{<figure-callout\; id="2"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_2+{\mathrm{<figure-callout\; id="2"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}2}\\ I_{\mathrm{<figure-callout\; id="3"\; label="ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">ww</figure-callout>}3}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_3+{\mathrm{<figure-callout\; id="3"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{<figure-callout\; id="3"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}3}\end{array}\right].$

Step 4, obtain the rotating speed β of the topping up intracavity liquid of i axle _WfiRotating speed Ω with clutch bell _iRelation:

${\mathrm{\&beta;}}_{\mathrm{wfi}}=\frac{I_{\mathrm{wfi}}}{I_{\mathrm{wfi}}+I_{\mathrm{w\&delta;i}}}{\mathrm{\&Omega;}}_i$

Wherein, I _{W δ i}Expression topping up intracavity liquid is because viscosity is former thereby the equivalent moment of inertia of loss.

Therefore the actuating unit of i axle is to the moment of momentum H of spacecraft barycenter _WiCan be expressed as:

When the topping up intracavity liquid is in full state $H_{\mathrm{wi}}=I_{\mathrm{wwi}}{\mathrm{\&Omega;}}_i+I_{\mathrm{wfi}}\frac{I_{\mathrm{wfi}}}{I_{\mathrm{wfi}}+I_{\mathrm{w\&delta;i}}}{\mathrm{\&Omega;}}_i,$ H after the topping up intracavity liquid is drained _Wi=I _WwiΩ _i

Order Rotating speed β for the topping up intracavity liquid of i axle _WfiWith clutch bell rotating speed Ω _iEquivalent coefficient; Then obtain $\left[\begin{array}{c}{T}_{C1}\\ T_{C2}\\ {\mathrm{<figure-callout\; id="3"\; label="T\; C"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">T</figure-callout>}}_C\end{array}\right]=\left[\begin{array}{c}(I_{\mathrm{<figure-callout\; id="1"\; label="ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">ww</figure-callout>}1}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}1}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_1\\ ({\mathrm{<figure-callout\; id="2"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}2}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_2\\ ({\mathrm{<figure-callout\; id="3"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}3}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_3\end{array}\right].$

Step 5, at the change inertia characteristic of actuating unit, determine the transformation of speed rule of clutch bell

Wherein,

G=diag (G _W1, G _W2, G _W3), G _W1, G _W2And G _W3Be respectively I _Wf1, I _Wf2And I _Wf3The coefficient of weight of bearing, obtaining value method is: $G_{\mathrm{wi}}=\left\{\begin{array}{cc}(1-{\mathrm{\&Omega;}}_{\min }/|{\mathrm{\&Omega;}}_i\left|\right),& \left|{\mathrm{\&Omega;}}_i\right|>{\mathrm{\&Omega;}}_{\mathrm{<figure-callout\; id="0"\; label="min"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">min</figure-callout>}}\\ 0,& \left|{\mathrm{\&Omega;}}_i\right|\&le;{\mathrm{\&Omega;}}_{\min }\end{array}\right..$ Rotating speed when the topping up inertia variable fly wheel | Ω _i| Ω _MinThe time, keep topping up chamber internal-filling liquid state; When | Ω _i|≤Ω _MinThe time, emptying topping up intracavity liquid.

Control mechanism in step 6, the actuating unit is according to the relative speed variation that obtains

The horsepower output of control motor is controlled charging and discharging of topping up intracavity liquid.

Step 7, according to principle of conservation of momentum, spacecraft is subjected to the control torque T=[T that actuating unit produces spacecraft ₁, T ₂, T ₃] ^TEffect, attitude changes, the attitude after the change is measured with the expectation attitude by sensor and is compared, and comes back to step 1.

By circulation step 1 to 7 constantly, and adjust the needed attitude control torque of spacecraft in real time, spacecraft attitude and expectation attitude are overlapped.

The method of topping up inertia variable fly wheel control spacecraft attitude and the beneficial effect of actuating unit thereof of utilizing of the present invention is:

(1) the invention solves the slow speed of revolution dead-time problem that moment of momentum exchange class actuating unit occurs in the prior art in the adjustment process that holds position, and the actuating unit redundant configuration that produces in order to address this problem of traditional actuating unit, thereby bring the more problem of multimass and volume requirement burden to spacecraft.Compare with traditional flywheel, in the present invention, change the rotor inertia variation pattern that has replaced solid rotor traction mass with flywheel topping up whether rotor inertia, enlarge spacecraft attitude control torque output area with variable inertia adjustment capability and replace many redundant configuration requirements of installing.Utilized the stability that flows to avoid quiet unbalance dynamic in traditional actuating unit, the design in topping up chamber simultaneously is being much better than the solid rotor structure again aspect life-span and the weight, change control for performance-oriented angular motion and created condition; Avoid actuating unit more to require space and the quality of spacecraft, realized the moment requirement of attitude stabilization simultaneously again, can realize accurate attitude control.

(2) the present invention utilizes liquid as producing the quality body that moment of momentum changes, when using liquid fuel as the working fluid of actuating unit, actuating unit itself also is fuel tank simultaneously, can play simultaneously and save the tank volume, take the effect that spacecraft carries the available quality of capacity weight and reduces liquid sloshing influence in the tank less.

(3) the present invention can adapt to the dead band non-linear problem that motor slowly runs and occurs under the situation according to needs, makes transmission more level and smooth, improves motor service life.

Description of drawings

Fig. 1 a is the structural representation of actuating unit of the present invention;

Fig. 1 b be among Fig. 1 a A-A to shown in the structural representation of flywheel;

Fig. 2 is that three actuating units shown in Figure 1 of the present invention are at spaceborne installation site scheme drawing;

Fig. 3 is three topping up inertia variable fly wheel rotation speed change diagram of curves among the embodiment;

Fig. 4 is the simulation result of the attitude angle control of three axis stabilized satellite among the embodiment.

Wherein:

1-vacuum frame, 2-flywheel bearing, 3-motor, 4-clutch bell, 5-topping up chamber, 6-radial conduit, 7-axial pipe, 8-spacecraft, 9-first actuating unit, 10-the second actuating unit, 11-the three actuating unit.

The specific embodiment

The present invention will be further described below in conjunction with drawings and Examples.

As Fig. 1, realize that the present invention utilizes the actuating unit of topping up inertia variable fly wheel control spacecraft attitude to comprise: vacuum frame 1, flywheel bearing 2, fly-wheel motor 3, flywheel 4 and the control mechanism of fixing and install whole flywheel structure.Flywheel 4 comprises solid rotor part, topping up chamber 5, radial conduit 6 and axial pipe 7.

The position of vacuum frame 1 fixed type bearing 2 and motor 3, bearing 2 is installed in the rotating shaft two ends of flywheel 4, plays the effect of fixing and support flying wheel 4.Motor 3 cooperates with the rotating shaft of flywheel 4, plays the effect of drive shaft.Be filled with liquid working substance in the flywheel topping up chamber 5, inject and emptying by axial pipe 6 and radial conduit 7.Control mechanism is controlled the rotating speed of motor 3 and liquid injection and emptying in the topping up chamber 5.

With actuating unit shown in Figure 1, be installed in spacecraft 8 orthogonal three respectively, namely on X-axis, Y-axis and the Z axle, as shown in Figure 2, the axis of symmetry of each flywheel is that coordinate axle overlaps with corresponding space vehicle coordinates all.Working process is: obtain the control torque that flywheel need provide by control mechanism, according to the tachometer value Ω of current flywheel _iWith rotating speed threshold value Ω _MinRelation, determine that flywheel keeps the topping up state still to discharge liquid working substance, again by rotor inertia value and three required control torque (T of flywheel _C1, T _C2, T _C3) size the rotation speed change that needs flywheel to provide is provided

Control mechanism is controlled motor-driven flywheel rotation speed change, makes the moment of momentum H of actuating unit _wProduce corresponding the variation, thereby obtain actuating unit to three control torques of spacecraft

Realization is to the stable and control of spacecraft attitude.

A kind of method of utilizing topping up inertia variable fly wheel control spacecraft attitude of the present invention, it is as follows specifically to control step:

After step 1, the attitude sensor by spacecraft 8 obtain the spacecraft attitude parameter, according to the difference of current attitude and expectation attitude by three required control torque vector T of Lyapunov method design spacecraft 8 _C=[T _C1, T _C2, T _C3] ^TT _CiThe control torque of expression i axle, i=1,2,3, represent X-axis, Y-axis and Z axle respectively.

Step 2, three actuating units of the present invention are installed in spacecraft 8 orthogonal three respectively, namely on X-axis, Y-axis and the Z axle.

Spacecraft 8 and the aggregate momentum square H=I ω+H of actuating unit to the spacecraft barycenter _w, I represents total rotor inertia of spacecraft 8, ω represents the cireular frequency of spacecraft 8, H _wThe expression actuating unit is expressed as the moment of momentum of spacecraft barycenter:

$H_w=\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\mathrm{\&Omega;}}_1+{\mathrm{<figure-callout\; id="1"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\mathrm{\&beta;}}_{\mathrm{<figure-callout\; id="1"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}1}& 0& 0\\ 0& {\mathrm{<figure-callout\; id="2"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\mathrm{\&Omega;}}_2+{\mathrm{<figure-callout\; id="2"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\mathrm{\&beta;}}_{\mathrm{<figure-callout\; id="2"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}2}& 0\\ 0& 0& {\mathrm{<figure-callout\; id="3"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\mathrm{\&Omega;}}_3+{\mathrm{\&beta;}}_{\mathrm{<figure-callout\; id="3"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}3}\end{array}\right]$

The rotating speed Ω=[Ω of the clutch bell of the actuating unit on X-axis, Y-axis and the Z axle ₁, Ω ₂, Ω ₃] ^T, the liquid in the flywheel topping up chamber is because the agency part of viscosity is followed the tracks of the rotating speed of clutch bell, the equivalent rotating speed β of liquid _Wf=[β _Wf1, β _Wf2, β _Wf3] ^TI _WwiThe rotor inertia of the clutch bell of the actuating unit on the expression i axle, I _WfiThe rotor inertia of topping up intracavity liquid on the expression i axle, i=1,2,3, represent X-axis, Y-axis and Z axle respectively.

The three spool control torque vector Ts required according to spacecraft 8 _C=[T _C1, T _C2, T _C3] ^T, according to the moment of momentum theorem again as can be known

With moment of momentum H _wRate of change project on X-axis, Y-axis and the Z axle of spacecraft 8, obtain ${\stackrel{\&CenterDot;}{H}}_w:$ ${\stackrel{\&CenterDot;}{H}}_w={[{\stackrel{\&CenterDot;}{H}}_{\mathrm{<figure-callout\; id="1"\; label="w"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">w</figure-callout>}1},{\stackrel{\&CenterDot;}{H}}_{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">w</figure-callout>}2},{\stackrel{\&CenterDot;}{H}}_{w3}]}^T.$

Step 3, according to actuating unit to the moment of momentum of barycenter relation, obtain $\left[\begin{array}{c}{\stackrel{\&CenterDot;}{H}}_{w1}\\ {\stackrel{\&CenterDot;}{H}}_{w2}\\ {\stackrel{\&CenterDot;}{H}}_{w3}\end{array}\right]=\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_1+{\mathrm{<figure-callout\; id="1"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}1}\\ {\mathrm{<figure-callout\; id="2"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_2+{\mathrm{<figure-callout\; id="2"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}2}\\ {\mathrm{<figure-callout\; id="3"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_3+{\mathrm{<figure-callout\; id="3"\; label="I\; wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{wf}}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{<figure-callout\; id="3"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}3}\end{array}\right].$ The control torque vector T that the spacecraft that obtains according to step 18 is required _C, and the relation of step 2

Can obtain the required control torque vector T of spacecraft 8 _CClutch bell and liquid working substance by actuating unit provide jointly.

Step 4, according to the viscosity of fluid and the rotating speed of clutch bell, obtain the rotating speed β of liquid in the topping up chamber 5 of i axle _WfiRotating speed Ω with clutch bell _iRelation:

I _{W δ i}Liquid in the expression topping up chamber 5 is because viscosity is former thereby the equivalent moment of inertia of loss.Therefore the actuating unit of i axle is to the moment of momentum H of spacecraft barycenter _WiCan be expressed as: when liquid is in full state in the topping up chamber 5

H after liquid is drained in the topping up chamber 5 _Wi=I _WwiΩ _iOrder

Rotating speed β for liquid in the topping up chamber 5 of i axle _WfiWith clutch bell 4 rotating speed Ω _iEquivalent coefficient.

The three spool control torque vector Ts required according to spacecraft 8 _C=[T _C1, T _C2, T _C3] ^T, with the relation of actuator stem force square $T_C={\stackrel{\&CenterDot;}{H}}_w,$ Then obtain $\left[\begin{array}{c}{T}_{C1}\\ T_{C2}\\ {\mathrm{<figure-callout\; id="3"\; label="T\; C"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">T</figure-callout>}}_C\end{array}\right]=\left[\begin{array}{c}(I_{\mathrm{<figure-callout\; id="1"\; label="ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">ww</figure-callout>}1}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}1}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_1\\ ({\mathrm{<figure-callout\; id="2"\; label="I\; ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ww}}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}2}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_2\\ (I_{\mathrm{<figure-callout\; id="3"\; label="ww"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">ww</figure-callout>}3}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}3}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_3\end{array}\right].$

Step 5, at the change inertia characteristic of actuating unit, rule is handled in the moment output that obtains actuating unit, just the transformation of speed of clutch bell rule $\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}:\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}=-{(I_{\mathrm{ww}}+G{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}})}^{-1}{T}_c,{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}}={[{\stackrel{\&OverBar;}{I}}_{\mathrm{<figure-callout\; id="1"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}1},{\stackrel{\&OverBar;}{I}}_{\mathrm{<figure-callout\; id="2"\; label="wf"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">wf</figure-callout>}2},{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}3}]}^T,$ G=diag (G wherein _W1, G _W2, G _W3), G _W1, G _W2And G _W3Be respectively I _Wf1, I _Wf2And I _Wf3The coefficient of weight of bearing, obtaining value method is:

$G_{\mathrm{wi}}=\left\{\begin{array}{cc}(1-{\mathrm{\&Omega;}}_{\min }/|{\mathrm{\&Omega;}}_i\left|\right),& \left|{\mathrm{\&Omega;}}_i\right|>{\mathrm{\&Omega;}}_{\min }\\ 0,& \left|{\mathrm{\&Omega;}}_i\right|\&le;{\mathrm{\&Omega;}}_{\min }\end{array}\right.$

Namely in order to avoid rotating speed to enter nonlinear area as far as possible, the switch of topping up inertia variable fly wheel group is handled rule and can be described as: when the output of actuating unit moment requires to reduce, rotating speed is during near the dead band, with the liquid emptying in the topping up chamber 5, only use the solid rotor, improve rotating speed, accuracy and the stability of hold torque output.Ω _MinBe the rotating speed threshold value, the rotating speed threshold value is in using according to engineering, the rotating speed of motor dead zone range is selected, the maxim that rotating speed is subjected to the dead band non-linear effects is set at threshold value, like this according to the inventive method and actuating unit, can be when the output of actuating unit moment requires approaching dying, pass through evacuation of liquid, reduce the rotor inertia of actuating unit, thereby corresponding relative speed variation is increased, the rotation speed change of actuating unit is increased, fast by the dead band, reduce the motor dead band to the non-linear effects of moment output.Rotating speed when the topping up inertia variable fly wheel | Ω _i| Ω _MinThe time, flywheel keeps topping up chamber 5 internal-filling liquid states, realizes big moment of momentum exchange requirement with bigger inertia; When | Ω _i|≤Ω _MinThe time, think that spacecraft 8 enters the attitude stabilization control stage, liquid emptyings in the flywheel topping up chamber 5, wheel speed is absorbed in the possibility in dead band when reducing little moment of momentum output.

The installation principle of step 6, actuating unit, installation site are identical with traditional moment of momentum control actuating unit.Control mechanism is according to the relative speed variation that obtains

The horsepower output of three motors 3 of control changes the rotating speed of corresponding clutch bell.Liquid in the flywheel topping up chamber 5 is subjected to the traction that clutch bell rotates, and also produces corresponding rotating speed β under the effect of viscous stress _Wfi, whole topping up inertia variable fly wheel kinematic velocity changes, to the moment of momentum H of spacecraft barycenter _WiChange, then actuating unit is to the control torque T of spacecraft 8 generations _iChange.

Step 7, according to principle of conservation of momentum, spacecraft 8 is subjected to the control torque T=[T that actuating unit produces spacecraft ₁, T ₂, T ₃] ^TEffect, attitude changes, the attitude after it changes is measured with the expectation attitude by sensor and is compared, and comes back to step 1.

By circulation step 1 to 7 constantly, and adjust spacecraft 8 needed attitude control torques in real time, finally reach the control effect that spacecraft attitude and expectation attitude are overlapped.

Embodiment

A kind of method and actuating unit thereof of topping up inertia variable fly wheel control spacecraft attitude of utilizing of realizing the inventive method comprises: spacecraft 8 is respectively I to three rotor inertias of its barycenter _Xb=I _Yb=I _Zb=20kgm ², the topping up inertia variable fly wheel (actuating unit of the present invention) of three quadratures is installed on the spacecraft, the axis of symmetry of each topping up inertia variable fly wheel is that coordinate axle overlaps with corresponding space vehicle coordinates all.The structure of each topping up inertia variable fly wheel is identical with dimensional parameters, and the solid rotor is I around axial rotor inertia _Ww=0.025kgm ², the topping up chamber is I around axial rotor inertia when being full of liquid _Wf=0.025kgm ², flow working medium density is ρ=1.458 * 10 ³Kg/m ³, coefficient of viscosity is μ=0.377 * 10 ^-3Pas.Liquid are driven by separately pressure control mechanism respectively in the topping up chamber 5 of each topping up inertia variable fly wheel, and the rotational angular velocity of flywheel casing 4 is respectively Ω ₁, Ω ₂And Ω ₃The initial attitude of spacecraft 8 ${\mathrm{<figure-callout\; id="0"\; label="Q"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">Q</figure-callout>}}_0=\left[\begin{array}{c}0.9990\\ 0.0262\\ -0.0010\\ 0.0349\end{array}\right],$ Expectation attitude solution is $Q_d=\left[\begin{array}{c}1\\ 0\\ 0\\ 0\end{array}\right].$

Its annexation is: the position of vacuum frame 1 fixed type bearing 2, motor 3, the rotating shaft of flywheel 4 contact with bearing 2, supported by bearing 2, cooperates with motor 3, by motor 3 transmissions.Be filled with liquid working substance in the flywheel chamber 5, inject and emptying by axial pipe 7 and radial conduit 6.Control mechanism injects emptying to liquid in motor 2 rotating speeds and the topping up chamber 5 and controls.

Its working process is: spacecraft 8 usefulness cylinders are replaced, and are initial point with cylindrical center-point as space vehicle coordinates, the actuating unit of the present invention's design are installed, as Fig. 2 on three (X-axis, Y-axis and Z axles) of spacecraft 8 respectively.

Flywheel 4 rotating shafts in first actuating unit 9 are vertical with the X-axis of spacecraft 8, and the rotor inertia of spacecraft 8X axle is designated as I _Ww1=0.025+0.025kgm ², the control torque that spacecraft 8 is produced is designated as T ₁, the cireular frequency of clutch bell is designated as Ω ₁, the liquid flow velocity in the topping up chamber 5 is designated as β _Wf1

Flywheel 4 rotating shafts in second actuating unit 10 are vertical with the Y-axis of spacecraft 8, and the rotor inertia of the Y-axis of spacecraft 8 is designated as I _Ww2=0.025+0.025kgm ², the control torque that spacecraft 8 is produced is designated as T ₂, the cireular frequency of clutch bell 4 is designated as Ω ₂, the liquid flow velocity in the topping up chamber 5 is designated as β _Wf2

Flywheel 4 rotating shafts in the 3rd actuating unit 11 are vertical with the Z axle of spacecraft 8, and the rotor inertia of spacecraft 8Z axle is designated as I _Ww3=0.025+0.025kgm ², the control torque that spacecraft 8 is produced is designated as T ₃, the cireular frequency of clutch bell 4 is designated as Ω ₃, the liquid flow velocity in the topping up chamber 5 is designated as β _Wf3

Concrete working process is as follows:

After step 1, the attitude sensor by spacecraft 8 obtain the spacecraft attitude parameter, according to the difference of current attitude and expectation attitude by three required control torque vector T of Lyapunov method design spacecraft 8 _CFor:

$T_C=\left[\begin{array}{c}{T}_{C1}\\ T_{C2}\\ {\mathrm{<figure-callout\; id="3"\; label="T\; C"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">T</figure-callout>}}_C\end{array}\right]=\left[\begin{array}{c}(-1.50~1.00)\\ (-1.50~1.00)\\ (-1.50~1.00)\end{array}\right]\mathrm{Nm}.$

Step 2, spacecraft 8 and the aggregate momentum square H=I ω+H of actuating unit to the spacecraft barycenter _wAccording to the moment of momentum theorem, actuating unit is to the rate of change of the moment of momentum of spacecraft barycenter

The initial value of step 3, rotating speed Ω all is 0, and the relation by output torque and actuating unit has obtained the change in rotational speed rule, and continuous integration in the step cycle process has then just obtained the value of rotating speed Ω.

To the moment of momentum of barycenter relation, after finishing, emulation obtains the required control torque vector T of spacecraft 8 according to actuating unit _CThe rotating speed of the clutch bell of three actuating units of Shi Yaoqiu $\mathrm{\&Omega;}=\left[\begin{array}{c}{\mathrm{\&Omega;}}_1\\ {\mathrm{\&Omega;}}_2\\ {\mathrm{\&Omega;}}_3\end{array}\right]=\left[\begin{array}{c}(-50~50)\\ (-15~0)\\ (-50~50)\end{array}\right]\mathrm{rad}/{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">s</figure-callout>}}^2,$ As shown in Figure 3.

Step 4, according to the viscosity of fluid and the rotating speed Ω of shell 4, obtain the rotating speed β of liquid working substances in the topping up chamber 5 _Wfi

Step 5, obtain the transformation of speed rule of clutch bell

Change inertia characteristic at actuating unit, in order to avoid rotating speed to enter nonlinear area as far as possible, the switch of topping up inertia variable fly wheel group is handled rule and can be described as: when moment output requires to reduce, rotating speed is during near the dead band, with the liquid emptying in the topping up chamber 5, only use the solid rotor, improve rotating speed, accuracy and the stability of hold torque output.Ω _MinBe the rotating speed threshold value.Rotating speed when the topping up inertia variable fly wheel | Ω _i| Ω _MinThe time, flywheel keeps topping up chamber 5 internal-filling liquid states, realizes big moment of momentum exchange requirement with bigger inertia; When | Ω _i|≤Ω _MinThe time, think that spacecraft 8 enters the attitude stabilization control stage, liquid emptyings in the flywheel topping up chamber 5, wheel speed is absorbed in the possibility in dead band when reducing little moment of momentum output.

Step 6, according to the topping up situation in resulting flywheel 4 rotating speed Ω and topping up chamber 5, the control mechanism of actuating unit is adjusted the topping up state in topping up chamber 5, according to the relative speed variation of required clutch bell 4 The horsepower output of control motor 3 electric currents or voltage controller to the liquid acting in flywheel and topping up chamber, changes the rotating speed Ω of flywheel.The liquid in clutch bell and topping up chamber 5 is subjected to the effect of motor 3, and kinematic velocity changes, to the moment of momentum H of spacecraft 8 barycenter _wChange the control torque that actuating unit produces spacecraft 8 $T=\left[\begin{array}{c}{T}_1\\ T_2\\ {\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">T</figure-callout>}}_3\end{array}\right]=T_C=\left[\begin{array}{c}{T}_{C1}\\ T_{C2}\\ {\mathrm{<figure-callout\; id="3"\; label="T\; C"\; filenames="HDA00003324438300022.png"\; state="\{\{state\}\}">T</figure-callout>}}_C\end{array}\right]=\left[\begin{array}{c}(-1.50~1.00)\\ (-1.50~1.00)\\ (-1.50~1.00)\end{array}\right]\mathrm{Nm}.$

Step 7, according to principle of conservation of momentum, spacecraft 8 is subjected to the effect of the control torque T that three actuating units produce spacecraft 8, attitude changes, the attitude after it changes is measured with the expectation attitude by sensor and is compared, and comes back to step 1.

By circulation step 1 to 7 constantly, finally reach the control effect that spacecraft attitude and expectation attitude are overlapped, thereby realize the stable of spacecraft attitude and control.The quaternion simulation curve represents the attitude changing value among Fig. 4, and as can be seen, under the effect of ring pipe fluid moment of momentum exchange control unit, the attitude of satellite is stabilized to expectation value gradually, and error levels off to zero, and spacecraft is stabilized to expectation attitude value.

Claims (2)

1. an actuating unit that utilizes topping up inertia variable fly wheel control spacecraft attitude is characterized in that this actuating unit comprises: vacuum frame, flywheel, motor, bearing and the control mechanism of fixing and install whole flywheel structure; Flywheel comprises solid rotor part, topping up chamber, radial conduit and axial pipe; The position of vacuum frame fixed type bearing and motor; Bearing is installed in the two ends of flywheel rotating shaft; Motor cooperates with the flywheel rotating shaft; Liquid working substance in the flywheel topping up chamber injects and emptying by axial pipe and radial conduit; Liquid in rotating speed of motor and the topping up chamber is injected control mechanism and emptying is controlled;

At spacecraft orthogonal three: on X-axis, Y-axis and the Z axle, a described actuating unit is installed respectively, the axis of symmetry of the flywheel of each execution architecture overlaps with the coordinate axle at place.

2. based on the described execution architecture of claim 1, a kind of method of utilizing topping up inertia variable fly wheel control spacecraft attitude is characterized in that, comprises the steps:

After step 1, the attitude sensor by spacecraft obtain the spacecraft attitude parameter, according to the difference of current attitude and expectation attitude by three required control torque vector T of Lyapunov method design spacecraft _C=[T _C1, T _C2, T _C3] ^TT _CiThe control torque of expression i axle, i=1,2,3, represent X-axis, Y-axis and Z axle that space vehicle coordinates is respectively;

Step 2, be installed in actuating unit on the spacecraft after, spacecraft and actuating unit to the aggregate momentum square of spacecraft barycenter are:

H＝Iω+H _w

Wherein, I represents total rotor inertia of spacecraft, and ω represents the cireular frequency of spacecraft, H _wThe expression actuating unit is to the moment of momentum of spacecraft barycenter;

Ω=[Ω ₁, Ω ₂, Ω ₃] ^TThe rotating speed of the clutch bell of the actuating unit on representing three, β _Wf=[β _Wf1, β _Wf2, β _Wf3] ^TFollow the tracks of the equivalent rotating speed of the liquid working substance of clutch bell rotating speed in the flywheel topping up chamber on representing three; Ι _Ww=[I _Ww1, I _Ww2, I _Ww3] ^TThe rotor inertia of the clutch bell of the actuating unit on representing three, Ι _Wf=[I _Wf1, I _Wf2, I _Wf3] ^TRepresent three rotor inertias that go up the topping up intracavity liquid;

Have according to the moment of momentum theorem With moment of momentum H _wRate of change project on X-axis, Y-axis and the Z axle of spacecraft, obtain ${\stackrel{\&CenterDot;}{H}}_w={[{\stackrel{\&CenterDot;}{H}}_{w1},{\stackrel{\&CenterDot;}{H}}_{w2},{\stackrel{\&CenterDot;}{H}}_{w3}]}^T;$

Step 3, according to actuating unit to the moment of momentum of spacecraft barycenter relation, have $\left[\begin{array}{c}{\stackrel{\&CenterDot;}{H}}_{w1}\\ {\stackrel{\&CenterDot;}{H}}_{w2}\\ {\stackrel{\&CenterDot;}{H}}_{w3}\end{array}\right]=\left[\begin{array}{c}{I}_{\mathrm{ww}1}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_1+I_{\mathrm{wf}1}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}1}\\ I_{\mathrm{ww}2}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_2+I_{\mathrm{wf}2}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}2}\\ I_{\mathrm{ww}3}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_3+I_{\mathrm{wf}3}{\stackrel{\&CenterDot;}{\mathrm{\&beta;}}}_{\mathrm{wf}3}\end{array}\right];$ The rotating speed Ω of initial clutch bell _iAll be 0;

The rotating speed β of the topping up intracavity liquid of step 4, i axle _WfiRotating speed Ω with clutch bell _iThe pass be:

Wherein, I _{W δ i}The topping up intracavity liquid of expression i axle is because viscosity is former thereby the equivalent moment of inertia of loss;

Therefore, the actuating unit of i axle is to the moment of momentum H of spacecraft barycenter _WiBe expressed as: when the topping up intracavity liquid is in full state

H after the topping up intracavity liquid is drained _Wi=I _WwiΩ _i

Order

Rotating speed β for the topping up intracavity liquid of i axle _WfiWith clutch bell rotating speed Ω _iEquivalent coefficient; Then obtain $\left[\begin{array}{c}{T}_{C1}\\ T_{C2}\\ T_{C3}\end{array}\right]=\left[\begin{array}{c}(I_{\mathrm{ww}1}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}1}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_1\\ (I_{\mathrm{ww}2}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}2}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_2\\ (I_{\mathrm{ww}3}+{\stackrel{\&OverBar;}{I}}_{\mathrm{wf}3}){\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}_3\end{array}\right];$

Step 5, at the change inertia characteristic of actuating unit, determine the transformation of speed rule of clutch bell

Wherein,

G=diag (G _W1, G _W2, G _W3), G _W1, G _W2And G _W3Be respectively I _Wf1, I _Wf2And I _Wf3The coefficient of weight of bearing, obtaining value method is: $G_{\mathrm{wi}}=\left\{\begin{array}{cc}(1-{\mathrm{\&Omega;}}_{\min }/|{\mathrm{\&Omega;}}_i\left|\right),& \left|{\mathrm{\&Omega;}}_i\right|>{\mathrm{\&Omega;}}_{\min }\\ 0,& \left|{\mathrm{\&Omega;}}_i\right|\&le;{\mathrm{\&Omega;}}_{\min }\end{array}\right.;$ Rotating speed when the topping up inertia variable fly wheel | Ω _i| Ω _MinThe time, keep topping up chamber internal-filling liquid state; When | Ω _i|≤Ω _MinThe time, emptying topping up intracavity liquid;

Control mechanism in step 6, the actuating unit is according to the relative speed variation that obtains

The horsepower output of control motor is controlled charging and discharging of topping up intracavity liquid;

Step 7, according to principle of conservation of momentum, spacecraft is subjected to the control torque T=[T that actuating unit produces spacecraft ₁, T ₂, T ₃] ^TEffect, attitude changes, the attitude after the change is measured with the expectation attitude by sensor and is compared, and comes back to step 1;

By circulation step 1 to 7 constantly, adjust the attitude control torque of spacecraft in real time, spacecraft attitude and expectation attitude are overlapped.

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