RU2579406C1 - Correction method and orbital gyrocompass device designed for controlling spacecraft angular motion - Google Patents

Abstract

FIELD: space technology.

SUBSTANCE: invention relates to space engineering and can be used for spacecraft (SC) controlling. Device of orbital gyrocompass (WGC) for spacecraft angular motion control contains device for orientation by Earth, adders, integrators, newly introduced adders and integrators, correction modules, modules for compensation of interference between channels, gyroscopic angular velocity metering unit. These devices measure signals and WGC output signal in channels of roll, add autocompensation signal defined depending on new and existing correction signals, roll signal from device for orientation by Earth, WGC output roll signal, integration factors, correct readings of gyroscopic angular velocity metering unit simultaneously in roll and heading channels, provide in roll and heading channels with data of SC orientation.

EFFECT: invention improves accuracy of spacecraft angular motion control.

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Description

The present invention relates to the field of space technology and can be used to improve the accuracy of the angular orientation of the spacecraft (SC) using the orbital gyrocompass (OGK).

As an analogue, the method and device of the OGK KA can be taken (see. "Orientation and stabilization system, ed. 14F133. Sketch design", p.122-124, Fig. 19.7. FSUE "NIIEM"). In this solution, an isodrome is used in the OGK correction channel at the heading, to the input of which the measured difference of the signals of the Earth orientation device (RPS) and the OGK in the roll channel is fed. With this method and device for correction of OGKs, the spacecraft orientation error in the heading channel is eliminated, but at the same time accuracy decreases in the roll channel - the OGK orientation error and, together with it, the spacecraft orientation error increases and becomes equal to the REF error in the roll channel.

There is also a known method and device in which the OGK (SC) orientation errors are measured and accumulated along the roll and heading and introduced into the SC stabilization loop as corrections to the SC orientation in the form of constant displacements (Spacecraft control systems based on the Almaz orbital station). Outline design. Orientation system, pp. 6, 72, 188. "NPO Mashinostroyeniya", 1990). The essence of the compensation lies in the fact that in the WGC correction signal from PMV there is information about the indicated errors in proportions that can be easily scaled. In accordance with this, the correction signal is measured and stored. In the calculating-decisive instrument, the stored correction signal is scaled in proportion to the errors in the heading and roll channels and connected to the corresponding inputs of the spacecraft executive bodies, which leads to a shift in the stabilization angles of the spacecraft in the course and roll and, therefore, compensation for orientation errors. The specified method and its implementing device has the following significant disadvantages:

- orientation errors are not automatically compensated, but are accumulated and introduced as offsets into the spacecraft stabilization circuit in roll and pitch relative to the OGK when the OGK is in the orbital gyro memory mode;

- it is not OGK errors that are compensated, but the spacecraft errors that they generate, in the indicated mode the compensation effect is achieved only for a short period of time - several minutes, then the errors begin to increase and after half the period of the orbital motion the initial spacecraft orientation errors are doubled;

- the orientation system is not sensitive to slowly changing errors REF.

The closest analogue may be the technical solution presented in the article by Campbell, Coffey, “Digital Angle Reference Systems”. The journal "Issues of rocket technology", 1971, No. 11, p. 63 ÷ 88. It discusses a method and device for controlling the angular motion of a spacecraft using an OGK, which includes a strapdown gyroscopic angular velocity meter (CIUS), an Earth orientation device (RPS) and a computer.

In this solution, a WGC correction method is used to control the angular motion of the spacecraft, which consists in the fact that to build the spacecraft orientation in the roll and heading channels, the difference between the POS signals and the WGC output signal in the roll channels is ε _γ , which is used to correct the CIU readings simultaneously in roll and course channels.

The disadvantage of this method and the device associated with it is that it does not allow to compensate for the OGK errors in the direction and roll and the corresponding errors in the orientation of the spacecraft in the direction and roll, arising due to the determined error of the POS in roll. The indicated orientation errors will be:

where α, β are the errors in constructing the OSK according to the roll and heading, respectively, to ₁ , and to ₂ are the OGK correction coefficients in the heading and roll channels, respectively, Ω is the orbital angular velocity, Δγ _pos is the total deterministic and slow-varying error of the POS in the roll channel.

The aim of the proposed solution is to eliminate these disadvantages, i.e. creation of a correction method and an OGK device with increased accuracy for controlling the angular motion of the spacecraft with automatic compensation (auto-compensation) of OGK errors both in the heading channel and in the roll channel relative to the USS caused by deterministic and slow-changing errors of the REF for the roll, including errors in the setting of the REF for the spacecraft according to roll relative to the associated axes.

Proposed solutions The difference lies in the fact that employed a new method for correcting OGC in roll channel, and rate at which directly into difference (correction) signal ε _γ - REF and OGC introduced signal autocompensation μ _γ in roll channel, the new correction signal OGC u _{γ is} determined in accordance with the formulas

;

;

;

;

where u _γ is the new correction signal;

ε _γ is the old correction signal;

µ _γ — auto compensation signal;

γ _pos - signal REF in roll;

Δγ is the output signal of the OGK roll;

a ₁ , ... a _n are the integration coefficients;

n is a degree, n is not limited.

Consider the proposed device that allows you to implement a new method of correction of OGKs.

According to the decision, the spacecraft’s angular orientation device using the orbital gyrocompass according to claim 1, which contains a POS, the output of which through the roll channel is connected to the first adder, the first correction module (MK), the second adder, the third adder, the first integrator, the output of which forms the output of the OGK along the roll channel, the output of the first adder along the channel of the course is connected to the second MK, the fourth adder, the fifth adder, and the second integrator, the output of which forms the output OGK along the channel of the channel, the output of the OCR along the pitch channel is connected to the sixth adder, the third MK, the seventh adder and the third integrator, the output of which forms the OGK output along the pitch channel, as well as the first and second channel interference compensation modules (ICWC) and gyroscopic unit angular velocity meter (CIUS), while the second input of the first adder is connected to the output of the first integrator, the second input of the sixth adder is connected to the output of the third integrator, and the second inputs of the second, fourth and seventh the adders are connected to the outputs of the CIUS according to the roll, course and pitch, and the second inputs of the third and fifth adders are connected respectively to the outputs of the first and second ICWCs, the inputs of which are connected to the outputs of the second and first integrators, respectively; in addition, n series adders are added to the circuit of the first adder , as well as n series-connected integrators, while the input of the first of n input adders is connected to the output of the first adder, and the output of the n-th adder is connected simultaneously enno newly inputted to the input n-th bank of the integrator and the first and second inputs of the IC, and outputs each input integrators starting from n-th integrator connected to the second inputs of the respective numbers of the newly introduced adders.

Figure 1 shows an example implementation of the device. The structural and functional diagram indicates:

1 - REF with exits along the roll γ _REF and pitch ϑ _REF, respectively;

2 - CIUS with measuring axes of angular velocity of the spacecraft in projections on its own axes: the longitudinal axis X (roll) - ω _X , the vertical axis Y (course) - ω _Y and the axis Z (pitch) pitch - ω _Z ;

3-12 - adders;

13-15 - newly introduced adders: 13th - first, 15th - n-th;

16-18 - integrators;

19-21 - newly introduced integrators: 19th - 1st, ..., 21st - nth;

22-23 - correction modules (MK);

24-25 - channel interference compensation modules (ICWC);

, Δψ,

, Δϑ,

- выходы СО по углам и угловым скоростям соответственно по крену, курсу и тангажу, поступающие в контур стабилизации КА;Δγ,

, Δψ,

, Δϑ,

- CO outputs at angles and angular velocities according to roll, heading and pitch, respectively, entering the spacecraft stabilization loop;

γ _REF , ϑ _REF - signals REF in roll and pitch;

ε _γ , ε _ϑ - OGK correction signals for roll and pitch, respectively;

µ _γ — auto compensation signal;

ω _X , ω _Y , ω _Z - signals CIUS corresponding to the projections of the absolute angular velocity of the spacecraft on the connected axis along the roll, heading and pitch;

K ₁ , K ₂ , K ₃ - correction factors;

and ₁ ... a _n - auto-compensation coefficients;

Ω is the orbital angular velocity of the spacecraft.

The BIUS 2 signals are integrated on the integrators 16, 17, 18 and enter the spacecraft stabilization loop along the roll Δγ, along the course Δψ and along the pitch Δϑ. To bring the spacecraft to the local vertical along the roll and pitch, the signals of the gyroscopic sensor must be adjusted. To this end, the signals REF 1 and the integrals of the angular velocity of the CIU in the roll channels - Δγ and pitch - Δϑ are compared on adders 3 and 12, from where the difference signals - ε _γ and ε _ϑ through the correction modules 22 and 23 respectively are fed to adders 7 and 9 , where the bius readings are corrected 2. The satellite is brought in the orbit plane in the gyrocompassing mode at the heading. For this, the difference signal ε _γ (vertical plotter REF 1 for roll and integrator 16 — OGK output for roll) is supplied to correction module 23 in the channel of the course. The amplified signal is compared with the BIUS signal 2 on the adder 9 and fed to the integrator 17, the output of which is formed by the satellite stabilization signal along the channel Δψ and the spacecraft is brought into the orbit plane. In the process of bringing the spacecraft to the orbital coordinate system, the ICWC blocks 25 and 26 eliminate the interference of the heading and roll channels (respectively) due to the arising projections of the orbital angular velocity on the associated roll axis and the heading of the spacecraft in the process of stabilization of the spacecraft at angles Δψ and Δγ.

The newly introduced elements - integrators 19, 20, 21, and adders 13, 14, 15, and new connections - allow one to completely compensate for the above OGK errors in heading and roll and the corresponding spacecraft orientation errors by generating a self-compensation signal - μ _γ . Moreover, this happens automatically, i.e. errors are automatically compensated.

We show this by example. In accordance with figure 1, the linearized equations of motion of the OGKs have the form:

;

;

;

;

;

;

;

;

where u _γ is the new roll correction signal of the OGK;

ε _γ is the old roll correction signal of the OGK;

µ _γ — auto compensation signal;

γ _REF - signal REF in roll;

Δγ is the output signal of the OGK roll;

and ₁ ... a _n are the integration coefficients;

n is the degree of the correction system;

ε _ϑ - OGK pitch correction signal.

;

;

;

;

;

;

;

;

;

;

;

;

;

;

,

,

where it is additionally indicated:

,

,

- углы и угловые скорости КА относительно ОСК по курсу, тангажу и крену соответственно;ψ, ϑ, γ,

,

,

- angles and angular velocity of the spacecraft relative to the USC at the heading, pitch and roll, respectively;

α, θ, β are the errors in the orientation of the OGK relative to the USC at the heading, pitch, and roll, respectively;

Δγ _REF, Δθ _REF - deterministic instrumental error REF channels in roll and pitch, respectively, also including setting mistake REF on the spacecraft relative to the associated axes of roll and pitch.

Figure 2, 3 shows the simulation results of the full equations of motion of the spacecraft (flywheel engines were used as executive bodies).

Figure 2 shows the motion and steady errors of the spacecraft without the elements of auto-compensation (correction factors a ₁ ... a _n = o), while:

,

,

, Δγ_ПОЗ=Δϑ_ПОЗ=0,5°=30 угл. мин.

,

,

, Δγ = Δθ _{REF REF} = 0,5 ° = 30 charcoal. min

It can be seen from the graph that, for zero initial orientation conditions:

orientation system after the completion of the transients (t → ∞) under the influence REF errors in the roll channel Δγ _REF accumulates large errors in the channels course ψ and roll angle γ, the analytic form where and numerical values the following (pitch channel is independent and not further considered here):

At the same time, in the course channel, the spacecraft orientation error is approximately half the POS error in roll, and in the roll channel, the spacecraft orientation error is almost equal to the total roll POS error.

. Здесь для простоты взят случай для а ₂…a _n=0, т.е. степень астатизма системы равна 1.In FIG. 3 shows graphs of spacecraft errors with auto-compensation enabled.

. Here, for simplicity, we have taken the case for a ₂ ... a _n = 0, i.e. the degree of astatism of the system is 1.

It can be seen from the graph that the errors accumulated earlier (see Fig. 2) after turning on the auto-compensation tend to zero in both channels (roll and course) and at the end of the transient processes (t → ∞) take zero values:

ψ = α = 0 ang. min;

γ = β = 0 angle min

Thus, complete and automatic compensation of the determinate errors of the spacecraft orientation is achieved not only in the course channel, but also in the roll channel.

The considered example is given for n = 1. With increasing degree n, the amplitude-frequency characteristic of the correction loop improves, but the synthesis of the system becomes more complicated.

OGK in the autocompensation mode is absolutely stable, which is confirmed by theoretical calculations and the above simulation over a time interval of 86400 s, which corresponds to 16 turns or 24 hours of the spacecraft orbital flight.

In the general case, the characteristic equation of the system has the form:

оператор Лапласа,Where

Laplace operator

.

.

In accordance with the Routh-Hurwitz criterion, the correction system is stable at any degree - n, because the characteristic equation directly implies the positivity of all the coefficients for powers of s, and the Routh-Hurwitz determinants can always be chosen positive, since the coefficients b _n = a ₁ ... a _n are selected and assigned arbitrarily, i.e. they are not burdened with their own properties of the OGK correction system. In this regard, an interesting case is when a ₁ ... a _n are chosen so small that the OGK correction loop will work, almost noticing the influence of μ _γ on the dynamics of movement. However, auto-compensation of errors in the roll and heading channels will occur over time.

,Due to the fact that the system is sensitive to deterministic errors of the REF in the roll channel, including the error of setting the REF relative to the coupled axes of the spacecraft, slowly varying errors with periods of change significantly longer than the transition process in the autocompensation loop will be automatically compensated, which is quite sufficient for practical purposes. In FIG. Figure 4 illustrates the self-compensation of SD errors for the case of a slowly varying harmonic error in the RRP, the amplitude of which is set by a wound 10% (0.05 °) of the initial value (0.5 °) of the determined RR error:

,

those. in this example, the REF has a constant and slowly varying (with a frequency of change 10 times lower than the frequency of the orbital motion) errors.

It can be seen from the simulation results that auto-compensation affects both errors of the spacecraft orientation — heading and roll, completely compensates for the constant components of errors and almost completely eliminates their slowly changing components.

Claims (2)

1. The correction method of the orbital gyrocompass (OGK) for controlling the angular motion of the spacecraft (SC), which consists in the fact that to build the orientation of the SPACECRAFT in the roll and heading channels, measure the difference between the signals of the orientation device on the Earth (REF) and the output signal of the GGC in the roll channels - ε _γ, which is corrected by reading the block gauges gyroscopic angular velocities (CICS) simultaneously roll and heading channels, characterized in that the residual signal ε _γ μ _γ autocompensation added signal, the new correction signal u determined in accordance with the formulas
u _γ = ε _γ -µ _γ ;

where u _γ is the new correction signal;
ε _γ is the old correction signal;
µ _γ — auto compensation signal;
γ _pos - signal REF in roll;
Δγ is the output signal of the OGK roll;
a ₁ , a ₂ , ..., a _n - integration coefficients;
n is a degree, n is not limited. 2. The OGK device for controlling the angular motion of the spacecraft according to claim 1, containing a REF, the output of which through the roll channel is connected to the first adder, the first correction module (MK), the second adder, the third adder, the first integrator, the output of which forms the OGK output on the roll channel, the output of the first adder on the channel of the course is connected to the second MK, fourth adder, fifth adder, and second integrator, the output of which forms the OGK output on the course channel, the output of the REF on the pitch channel It is connected to the sixth adder, the third MK, the seventh adder and the third integrator, connected in series, the output of which forms the OGK output along the pitch channel, as well as the first and second channel interference compensation modules (ICWC) and the gyroscopic block of angular velocity meters (CIU), while the second the input of the first adder is connected to the output of the first integrator, the second input of the sixth adder is connected to the output of the third integrator, and the second inputs of the second, fourth and seventh adders are connected to the outputs of the CIUS respectively according to roll, heading and pitch, and the second inputs of the third and fifth adders are connected respectively to the outputs of the first and second ICWCs, the inputs of which are connected to the outputs of the second and first integrators, respectively, characterized in that n series adders are introduced into the circuit of the first adder, and there are also n series-connected integrators, while the input of the first of n input adders is connected to the output of the first adder, and the output of the n-th adder is connected simultaneously to the input of the newly introduced n-th ad the integrator and the first and second inputs of the MC, and outputs each input integrators starting from n-th integrator connected to the second inputs of the respective numbers of the newly introduced adders.

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