RU2539068C2 - Control over orientation of supply spaceship with stationary solar battery panels at jobs under conditions of spinning - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: invention relates to aerospace engineering. Proposed method comprises supply spaceship spinning around perpendicular to solar battery working surface directed to the Sun at angular velocity of at least 1.5 degree/s. During said spinning at time interval of duration making at least one circuit supply angular velocity components are measured in structural system of coordinates. Measured magnitudes are used to define the directions of the main central axis of inertia of supply spaceship. Spaceship is turned to alignment of the central axis of inertia making the minimum angle with perpendicular to solar battery working surface with direction to the Sun. Spaceship is spun around spaceship around said axis to measure solar battery current. After current reaches minimum permissible magnitudes spaceship is, again, turned to align said axis of inertia with direction to the Sun. Again, spaceship is spun around said axis.

EFFECT: higher power yield of solar batteries owing to radiation reflected from the Earth at spaceship gravity orientation with spinning with allowance for actual main central axes of inertia.

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Description

The invention relates to the field of space technology and can be used to control the orientation of spacecraft (SC) during work in terms of rotational motion.

The rotational motion of the spacecraft is used, for example, when conducting experiments and research in the field of microgravity and is realized by the spinning of the spacecraft around the directions specified in the building coordinate system of the spacecraft.

We consider spacecraft of the type of transport cargo ships (TGCs) that make missions to the space orbital station - for example, to the international space station. On the spacecraft data, it is convenient to conduct studies at the stage of their autonomous flight after undocking from the orbital station.

A known method of controlling the orientation of the spacecraft, including the exhibition of the axes of the spacecraft and maintaining the angular position using orientation engines (Alekseev KB, Bebenin GG Control of spacecraft. M: Mechanical Engineering, 1974). However, to use this method, it is necessary to expend the working fluid, which also causes unpredictable microaccelerations onboard the spacecraft.

A known method of controlling the orientation of spacecraft with fixed solar panels when performing experiments in orbits with a maximum duration of the shadow section (RF Patent No. 2457158, priority of 09.22.2010, IPC (2006.01) B64G 1/24, 1/44), including the gravitational orientation of the spacecraft and twist around its longitudinal axis, corresponding to the minimum moment of inertia, when the Sun is close to the orbit plane, combine this plane with the SB plane by the time the morning terminator passes, measure and track the angle between the perpendicular to a active (working) surface of the SB and the direction to the Sun, at the moment of passing the morning terminator, spin the spacecraft in a direction corresponding to a decrease in the specified angle, and the angular speed of spin is selected from a given range of values. The method allows to provide some lighting SB and the arrival of electricity for non-energy-intensive experiments. In this case, solar radiation arrives at the SB from directions substantially spaced from the normal in the working surface of the SB, as a result of which the current generated by the SB significantly differs from the maximum current that the SB can generate. At the same time, when performing a series of experiments, including on crystal growth, it is necessary to ensure a large removal of electricity from the SB, because energy-intensive equipment is used to conduct such experiments.

The closest to the proposed prototype is the method (Belyaev M.Yu. “Scientific experiments on spacecraft and orbital stations.” M .: Mashinostroenie, 1984), including a turn of the TGC, the normal to the SB working surface of which coincides with one of the main axes inertia, until the direction of the normal to the SB working surface is combined with the direction to the Sun and the THC twist around this axis. The prototype method allows to provide the maximum possible supply of electricity from the SB for work with energy-intensive equipment.

TGK is used both to deliver goods to the orbital station, and to remove goods from the station. Moreover, the mass distribution of the removed cargo inside the TGC is poorly predicted and the loaded TGK has inaccurate inertial characteristics - their actual values differ significantly from the design or theoretically predicted design estimates. The prototype method does not allow to take into account the mismatch between the design and actual inertial characteristics of the TGC, including determining the actual inertial characteristics of the TGC after it is loaded with loads removed from the space orbital station. This leads to the use of its approximate (i.e., unreliable) inertial characteristics when controlling the orientation of the THC. In this case, the uncontrolled rotational movement of the THC during the spin process performed around an inaccurately specified main central axis of inertia will have disturbances that are undesirable in experiments and studies in the field of microgravity.

In addition, in the general case, during the spinning of the THC over time, due to the detrimental effect of the external moments on the orientation of the THC, the rotational movement of the THC will “fall apart”, as a result of which the energy supply from the SB will decrease and the conditions for the experiments will worsen.

The problem to which the present invention is directed is to provide control of the orientation of the THC with the fixed panels of the SB during operations under the conditions of the rotational movement of the THC around its main central axes of inertia.

The technical result of the invention is to maximize the energy input from the SB in the spin mode loaded with TGC loads removed from the space orbital station.

The technical result is achieved by the fact that in the method of controlling the orientation of space TGCs with fixed SB panels during work under rotational motion conditions, including turning the TGCs to combine the normal direction to the working surface of the SBs with the direction to the Sun and spinning the TGCs around a given axis, they additionally spin the TGCs around the direction of the normal to the working surface of the SB, directed at the Sun, with an angular velocity of at least 1.5 deg / s, during this twist on a time interval of no less than one revolution measure the components of the angular velocity of the THC in the building coordinate system, determine the directions of the main central axes of inertia of the THC from the measured values of the components of the angular velocity of the THC, deploy the THC until the main central axis of inertia, which is the minimum angle with the normal to the SB working surface, is aligned with the direction The sun also twists the THC around this axis, during this twist measure the current from the SB, when the measured value of the current from the solar panels is the minimum allowable of this value, the TGCs are again deployed until the aforementioned main central axis of inertia coincides with the direction to the Sun and the TGCs are twisted again around this axis.

The essence of the invention is illustrated in figure 1, which shows the orientation of the THC in the process of spinning the THC around the main central axis of inertia.

Figure 1 introduced the notation:

1 - the area of normal to the working surface of the SB in the process of spinning THC;

N is the direction of the normal to the working surface of the SB; S - direction to the sun;

x ₁ x ₂ x ₃ - axis parallel to the main central axis of inertia of the THC;

g is the angle between the normal to the working surface of the SB and the main central axis of inertia of the THC, which is the minimum angle with the normal to the working surface of the SB.

Let us explain the proposed method of action.

We consider the stage of autonomous flight of the TGK. In the proposed method, THC is deployed to combine the direction of the normal to the working surface of the SB with the direction to the Sun and twist the THC around the direction of the normal to the working surface of the SB with an angular velocity of at least 1.5 deg / s.

In this orientation, the maximum power supply from the SB is provided, which is necessary for charging the batteries of the TGK power supply system.

During the spin, the components of the angular velocity of the THC are measured in the construction coordinate system of the THC on a time interval of at least one turn.

From the measured values of the components of the angular velocity of the THC, the current actual values of the components of the directions of the main central axes of inertia of the THC in the construction coordinate system are determined.

The determination can be performed, for example, as follows.

, где а _ij - косинус угла между осями y_i и x_i. Элементы этой матрицы являются функциями введенных углов.We use the following coordinate systems. The construction system at ₁ y ₂ y _{3 is} rigidly connected to the TGC building. We consider, for example, that the axis y _{1 is} parallel to the longitudinal axis of the ship and is directed from the docking unit to the aggregate compartment, the axis y _{2 is} directed normal to the working surface of the SB. The axes of the system x ₁ x ₂ x _{3 are} parallel to the main central axes of inertia of the THC. The position of the system x ₁ x ₂ x ₃ relative to the system y ₁ y ₂ y ₃ will be given by the angles γ, α and β, which we introduce by the following condition. The system y ₁ y ₂ y ₃ can be translated into the system x ₁ x ₂ x _{3 in} three successive rotations: 1) by an angle α around the y axis ₂ , 2) by an angle β around the new axis y ₃ , 3) by an angle γ around the new axis y ₁ , coinciding with the axis x ₁ . We denote the transition matrix from the system x ₁ x ₂ x ₃ to the system y ₁ y ₂ y ₃

, where a _ij is the cosine of the angle between the axes y _i and x _i . Elements of this matrix are functions of the entered angles.

The components of the angular velocity of the THC in the system x ₁ x ₂ x _{3 are} denoted by ω _i (i = 1, 2, 3). To describe the time dependence of the quantities ω _{i, we} use the dynamic Euler equations of a free rigid body, which are not affected by external mechanical moments. These equations have the form

, $${\omega }_2=\frac{\mu \text{'}-\mu }{1-\mu \mu \text{'}}{\omega }_3{\omega }_1$$

, $${\dot{\omega }}_3=\mu \text{'}{\omega }_1{\omega }_2,\left(1\right)$$

$${\dot{\omega }}_{\mathrm{one}}=\mu {\omega }_2{\mathrm{<figure-callout\; id="3"\; label="\omega "\; filenames="00000016.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_3$$

, $${\omega }_2=\frac{\mu \text{'}\text{'}-\mu }{\mathrm{one}-\mu \mu \text{'}\text{'}}{\mathrm{<figure-callout\; id="3"\; label="\omega "\; filenames="00000016.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_3{\omega }_{\mathrm{one}}$$

, $${\dot{\omega }}_3=\mu \text{'}\text{'}{\omega }_{\mathrm{one}}{\omega }_2,\left(\mathrm{one}\right)$$

, $$\mu \text{'}=\frac{J_2-J_1}{J_3}$$

, $$\mu =\frac{J_2-J_3}{J_{\mathrm{one}}}$$

, $$\mu \text{'}\text{'}=\frac{J_2-J_{\mathrm{one}}}{{\mathrm{<figure-callout\; id="3"\; label="J"\; filenames="00000016.png"\; state="\{\{state\}\}">J</figure-callout>}}_3}$$

,

where J _i are the moments of inertia of the THC relative to the x _i axes. The parameters µ, µ ′ and the angles γ, α, and β for a specific flight stage of a particular TGC have some projected predicted values, and their actual values are determined from the processing of the angular velocity measurement data obtained during the TGC twist.

The solution of equations (1), which describes the change in the values of ω _i during the considered swirls, is expressed by approximate formulas

ω ₁ = λ [Asinv (tt ₀ ) + Bcosv (tt ₀ )],

$${\omega }_2=\Omega ,\left(2\right)$$

ω ₃ = Acosv (tt ₀ ) - Bsinv (tt ₀ ),

, $$v=\Omega \sqrt{\mu \mu \text{'}}$$

. $$\lambda =\sqrt{\frac{\mu }{\mu \text{'}\text{'}}}$$

, $$v=\Omega \sqrt{\mu \mu \text{'}\text{'}}$$

.

Here A, B, and Ω are arbitrary constants. Formulas (2) the more accurate, the smaller the absolute values of the relations A / Ω, B / Ω.

During the spin, the angular velocity of the THC is measured. The measurement data have the form

$$t_n,{\Omega }_{\mathrm{one}}^{(n)},{\Omega }_2^{(n)},{\Omega }_2^{(n)}(n=\mathrm{one},2,3,...,N),\left(3\right)$$

- измеренные значения компонент Ω_i угловой скорости в строительной системе координат в момент времени t_n: $${\Omega }_i^{(n)}\approx {\Omega }_i(t_n)$$

, t₁<t₂<…<t_N. Обработка этих данных, относящихся к конкретной закрутке ТГК, состоит в поиске решения уравнений (1), наилучшим образом согласующего эти данные с их расчетными аналогамиWhere $${\Omega }_i^{(n)}(i=\mathrm{one},2,3)$$

- the measured values of the components Ω _{i of the} angular velocity in the construction coordinate system at time t _n : $${\Omega }_i^{(n)}\approx {\Omega }_i(t_n)$$

, t ₁ <t ₂ <... <t _N. The processing of these data related to a specific spin of the THC consists in finding a solution to equations (1) that best matches these data with their calculated analogues

. $${\Omega }_i={\displaystyle \sum _{k=\mathrm{one}}^3{a}_{ik}{\omega }_k}\left(i=\mathrm{one},2,3\right)$$

.

Here, ω _k can be specified both by formulas (2) and by an exact solution of equations (1).

Processing of measurement data (3) is performed by the least squares method and consists in minimizing the expression

. $$\Phi ={\displaystyle \sum _{n=\mathrm{one}}^N{\displaystyle \sum _{i=\mathrm{one}}^3[{\Omega }_i^{\left(n\right)}-{\Omega }_i(t_n)}}{]}^2$$

.

When using formulas (2), minimization is performed according to eight parameters: A, B, Ω, λ, ν, γ, α, and β, which are considered independent. After the estimates of these parameters are found, µ = λµ / Ω, µ ′ = ν / λΩ are calculated. To minimize Ф on exact solutions of equations (1) (this gives somewhat more accurate estimates), eight other parameters are used: ω _i (t ₁ ) (i = 1, 2, 3), µ, µ ′, γ, α and β. The accuracy characteristics of the estimates found are calculated within the framework of standard assumptions of the least squares method.

The result of the described methodology for processing the measurement data (3) obtained for a specific swirl of a specific TGC loaded with loads removed from the orbital station and performing an autonomous flight after undocking from the station, are the mentioned sets of eight parameters that determine the actual directions of the main central inertia axes of the TGC in the building coordinate system and dimensionless combinations of its main central moments of inertia,

In this case, to obtain an acceptable accuracy in determining the main central axes of inertia, the angular velocity of spin of the THC used to determine the main central axes of inertia should be sufficiently large. High spin speed counteracts the harmful effects of external moments, as the higher the spin speed, the wider the time interval the movement of the THC can be considered free and obtain the necessary measurements for their subsequent target processing. The performed calculations and numerical estimates show that the lower guaranteed value of the angular velocity of spin, performed to determine the main central axes of inertia of the THC, is 1.5 deg / s for a duration of the interval of measurements of the angular velocity of at least one revolution.

Thus, according to the computational algorithm described above, the actual values of the components of the directions of the main central axes of inertia of the THC in the construction coordinate system are determined.

After determining the actual values of the components of the directions of the main central axes of inertia of the THC in the building coordinate system, the main central axis of inertia is determined, which constitutes the minimum angle with the direction of the normal to the SB working surface.

Turn the THC to align this main central axis of inertia with the direction to the Sun and twist the THC around this axis.

In the process of such a twist, the angle between the normal to the working surface of the SB and the direction to the Sun, coinciding with the twist axis and the above-defined main central axis of inertia of the THC, will have a constant value. In this case, the arrival of electricity from the SB for one revolution of the rotational movement of the THC will be equal to

$$\text{Ê}\cdot \text{2}\cdot \pi \cdot \text{cosg}\text{(four)}$$

where g is the angle between the normal to the working surface of the SB and the above-defined main central axis of inertia of the THC,

K is a coefficient characterizing the efficiency of SB photoconverters.

However, during this spin with time, due to the influence of external moments, the rotational motion of the THC will evolve, as a result of which the angle between the normal to the working surface of the solar column and the direction to the sun will increase and the energy input from the solar column will decrease.

During the spin, measure the current from the SB and compare it with the minimum allowable current value. When the measured value of the current from the SB reaches the minimum permissible value, the TGCs are again deployed until the aforementioned main central axis of inertia is combined with the direction to the Sun and the TGCs are again twisted around this axis.

We describe the technical effect of the invention.

The proposed technical solution provides the maximum possible energy input from the SB loaded with TGC loads removed from the space orbital station with the fixed SB panels when the TGC swirl mode is performed around one of the actual main central axes of inertia, namely, around the actual main central axis of inertia of the TGK closest to the normal to the working surface of the SB, and the actual main central axis of inertia of the THC are preliminarily determined by measuring the angular velocity of rotation of the THC.

The spinning of the THC around the actual main central axis of inertia ensures the absence of disturbances in the rotational motion of the THC, which is required for experiments and research in the field of microgravity, and the actual axes of inertia obtained can differ significantly from their design estimates.

At the same time, control over the accuracy of the spin and control over the provision of the necessary energy input from the SB by measuring during the current swirling from the SB and restoring all the spin parameters at the moment when the measured current value from the SB becomes less than the minimum allowable value is ensured.

The arrival of electricity from the SB for one revolution of the TGC rotational motion is determined by relation (4), while any other orientation of the TGC relative to the Sun during the spin around the actual main central axis of inertia of the TGC provides a smaller supply of electricity. For example, the arrival of electricity from the SB during one revolution of the TGC rotational motion, provided that at the moment of the start of swirling, the normal to the working surface of the SB is exactly pointed to the Sun, is equal to K2 · π · cosg, which is less than (4). Thus, during the spin process, the maximum possible supply of electricity from the SB is ensured.

The achievement of the technical result is ensured by constructing the proposed orientation of the THC at which the normal to the SB working surface is directed to the Sun, and performing the proposed spinning of the THC around the normal direction to the SB working surface, performing the proposed measurements of the angular velocity of the THC at the proposed time points during this spin and determining from them the current actual values of the inertial characteristics of the THC, constructing the proposed orientation of the THC at which the selected the active main axis of inertia of the THC is directed toward the Sun, and the subsequent spinning of the THC around this axis, as well as due to the proposed measurement during this current swirling from the SB and restoring all the spin parameters at the moment when the measured current value from the SB becomes less than the minimum allowable values.

Currently, everything is technically ready for the implementation of the proposed method on such a TGK as the Progress ship. For the implementation of U-turns, TGC spinning and necessary calculations, the standard means of the Progress ship control system — standard angular velocity sensors (DLS), the Progress ship orientation control system, orientation engines, and on-board computer can be used. To measure and track the angle between the normal to the surface of the SB and the direction to the Sun, standard solar sensors and computing devices can be used. The ship is twisted for the time required for the experiments.

Claims (1)

A method of controlling the orientation of a space transport cargo vehicle with fixed solar panels during work in rotational motion, including turning the ship until the direction of the normal to the working surface of the solar cells coincides with the direction to the Sun and spinning the ship around a given axis, characterized in that the vehicle is spun of a cargo ship around the direction normal to the working surface of solar panels directed at the Sun with an angular velocity of not less than 1.5 deg / s, during this twist, at a time interval of at least one revolution, the components of the angular velocity of the transport cargo ship are measured in the building coordinate system, the directions of the main central axes of inertia of the transport cargo ship are determined from the measured values of the angular velocity components of the transport cargo ship, deploy a cargo ship to align the main central axis of inertia, which is the minimum angle with the normal to the solar working surface batteries, with a direction to the Sun and spin the transport cargo ship around this axis, during this spin measure the current from solar batteries, when the measured value of the current from solar batteries reaches the minimum acceptable value, re-deploy the transport cargo ship to align the aforementioned main central axis of inertia with a direction to the Sun and again spin the transport cargo ship around this axis.

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