Method of control over spacecraft solar battery orientation with limitation of solar battery turn angle

FIELD: transport.

SUBSTANCE: invention relates to spacecraft electric power supply with the help of solar batteries. Proposed method comprises definition of preset angle of solar battery orientation to the Sun by measured angular position of normal to battery working surface and computation of design angle relative thereto. Solar battery is spinned in direction of decrease in mismatch between preset and design angles. Solar battery acceleration angle (α_AC) and deceleration angle (α_DEC) are defined. Design angle is corrected when angle transducer readings vary by discrete sector of solar battery turn. Threshold of operation and drop-away (α_T) and (α_D) are set to terminate battery spinning if mismatch between preset angle and current angle increases but not over α_T. Solar battery angular velocity is set or the order and larger than maximum angular velocity of spacecraft revolution around the Earth while discrete sector magnitude is set to smaller than α_T. Solar battery working angle (α_W) is set provided that α_T < α_W < (α_"ГОР" - 2·(α_AC + α_DEC)). Angular position of closest beam of angle α_W is assigned to preset angle if direction to the Sun in projection to the plane of spinning of said normal is located outside of α_W. Is angular position of said normal is outside α_W to vary in direction of increase of angle relative to nearest beam of angle α_W, failure warning is generated to terminate control over solar battery.

EFFECT: ruled out jamming and breakage of solar battery panels or spacecraft onboard hardware at turns from 90° to 180°.

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The method of controlling the orientation of the solar panels of the spacecraft with limitation of rotation angle of the solar panels relates to power supply systems of space vehicles (SV), and can be applied in the management of satellites having a circular or elliptical orbit. Electricity onboard equipment SPACECRAFT, including charge his batteries by using solar batteries (SB). The magnitude of the current generated SAT, depends on the orientation of the plane of its working surface relative to the Sun.

Management orientation SB is carried out using on-Board automatic control systems that control device, turning SAT, composed of electronic components and Electromechanical actuators mounted on the output shaft of the panels and position sensors SAT.

The composition of the on-Board automatic control systems include on-Board digital computers, which have implemented the algorithms for motion control of SPACECRAFT, as well as the management of onboard equipment, including control algorithms orientation SAT.

On-Board automatic control system, using the information from the respective sensors (astrogation, position sensors of the Sun and other), determines the position of the SPACECRAFT in space and the direction of the Sun relative to the light of the data from the SPACECRAFT coordinate axes, by means of motion control (engines, orbital maneuvering, gas engines and other) controls the position of the SPACECRAFT in space, and using the device, turn SB controls the orientation of the panels SAT.

Thus, in accordance with laid algorithms, on-Board automatic control system shall determine the current angular positions of the direction vector to the Sun and the normal to the working surface SB relatively associated with the SPACECRAFT coordinate axes. When you reach a mismatch between the specified angular positions onboard automatic control system generates commands to the SB rotation clockwise or counterclockwise to decrease, and the absence of mismatch generates a command for stopping the rotation of the SAT.

Depending on the destination CA, peculiarities of its construction, the required characteristics for power supply, terms of use and other factors, on Board the SPACECRAFT can be installed one or more SAT. Used in modern SPACECRAFT devices turn allow you to rotate the panel SAT in a circle of 360°. However, installed on the SPACECRAFT avionics, for example for scientific research, in certain angular positions may touch panel SS, which may be jammed or broken panels SB is whether airborne equipment. When the specified limit the allowable rotation angle SA is a value less than 180°. At the same time to perform a number of tasks, such as research certain areas and objects of outer space, the position of the SPACECRAFT must vary in a limited range of angles, or fixed relative to the test object. In this regard, the management considers the parameters specified orbit, the required orientation of the SPACECRAFT during long space, and the location of the onboard equipment, limiting the rotation angle of the SAT. Ask these parameters so that the panel SAT ensured the maximum possible current, and the direction to the Sun to SAT during these studies would change in the boundaries or close to the borders of angle constraints. Thus, the challenge of effective management orientation SAT with the aim of ensuring the maximum possible current limitation of rotation angle SA of less than 180°.

The closest technical solution adopted for the prototype, is the method of controlling the position of the SB, the essence of which is that detect the angular speed of the SB, then the time of crossing security boundaries between discrete sectors of the angle sensor calculates the estimated angle relative to the measured angular floor is the supply of SB. This angle is calculated as the product of the angular velocity SS during its rotation. Rotate SB in the direction of reducing the mismatch between the specified and calculated angles. On the respective inclination angles of the normal to the working surface SAT define the corners of his run-up and braking SAT. Corrects the estimated angle on the measured angular position of the specified normals in moments reading changes angle sensor by the value of one discrete sector. At the corners of his run-up and braking, as well as for a minimum and maximum possible currents generated SAT, set the threshold. When exceeding the specified threshold is formed by a mismatch between the specified and calculated angles Coll. Set the threshold of release, below which stops the error between the desired and calculated angles Coll. The rotation stop SB, if the error between the desired and calculated angles starts to increase, but does not exceed threshold [1].

The technical object of the present invention is to enhance the functionality of the method of controlling the orientation of the security Council to avoid jamming or breakage of the panel SAT or airborne equipment KA and ensuring the maximum possible current in the constraints of the rotation angles of the Council.

This technical result is achieved by the fact in a known method of controlling the position of the solar panels of the spacecraft, namely, that define a given angle of the solar battery as the position of the projection unit direction vector to the Sun in the plane of rotation normal to its working surface is relatively related to the spacecraft coordinate axes, measure the angular position of the normal to the working surface of the solar battery is relatively related to the spacecraft coordinate axes in the plane of rotation of the solar battery with precision to a discrete sector of the corresponding angle sensor, determine the angular velocity of the rotation of the solar panels on the crossing time of the solar battery boundaries between discrete sectors of the angle sensor, calculates the estimated angle relative to the measured angular position of the solar battery as the product of the angular velocity of the solar battery at the time of its rotation, rotate the solar panel in the direction of reducing the mismatch between the specified and calculated angles to determine the angle acceleration of the solar battery and the braking angle, adjust the estimated angle on the measured angular position of the specified normals at the points of change of the values of the angle sensor by the value of one discrete sector, set a threshold, above which is formed a mismatch between the specified and calculated angles as:

$$\left({\alpha }_{P\mathrm{And}CG}+{\alpha }_{T\mathrm{About}PM}\right)<{\alpha }_{CP}<\arccos \frac{I_{MIN}}{I_{MAX}}$$,

where α_CP- trigger;

α_ACCEL- the angle of the acceleration of the solar battery;

α_TORM- corner braking solar panels;

I_MIN- the minimum current produced by the solar battery;

I_MAX- maximum current produced by the solar battery,

set the threshold of release, below which stops the error between the desired and calculated angles of the solar battery:

α_OTP≈α_TORM,

where α_OPT- threshold release,

stop the rotation of the solar battery, if the error between the desired and the current angles starts to increase, but does not exceed the threshold, optionally set the angular velocity of the rotation of the solar panels on the order and higher maximum angular velocity of rotation of the spacecraft around the Earth, ask the angular size of the discrete sector of the sensor angle is less than the threshold, and limit the angle of rotation of the solar battery range is:

90°≤α_OGRE<180°,

where α_OGRE- limit the angle of rotation of the solar battery, set the working angle of the solar battery, the bisector of which coincides with the bisector of the angle constraint as:

α_CF<α_SLAVE<(α_ORG-2·((α_ACCEL+α_TORM)),

where α_SLAVE- working angle of the solar battery,

assign a preset angle value of the angular position of the nearest beam working angle, if the position above the projection of the unit vector of the direction the Sun is out working angle, forming a fault signal and stop the management solar panel, if the angular position of the normal to the working surface of the solar battery is outside of the working angle and when it is changed in the direction of increasing angle relative to the nearest beam working angle.

Figure 1 shows the position of the SPACECRAFT relative to the Sun and Earth, figure 2 - angle sensor, made in the form of a circle of rotation of the SAT, figure 3 - possible position normal to the working surface SAT in the circle of rotation of the SAT.

The method of controlling the orientation of the solar panels of the spacecraft with limitation of rotation angle of the solar panels is as follows.

Device rotation has SAT Electromechanical actuator with an angular speed of rotation of the output shaft much more Maxim is through the angular speed of rotation of the SPACECRAFT around the Earth at perigee of the orbit, that is:

ω_SAT>10·ω_About,

where ω_SAT- steady-state angular velocity SS;

ω_About- angular velocity of rotation of the SPACECRAFT around the Earth.

On your passport, as well as the results of experiments on the stands detect the angle acceleration α_ACCELthe output shaft of the Electromechanical drive attached to it SAT as the angular deviation of the normal to the working surface SB relatively associated with the SPACECRAFT coordinate axes from the moment of occurrence of the error between the desired and the current angles before reaching the security Council established the angular velocity SS. In addition, determine the braking angle α_TORMthe output shaft of the Electromechanical drive attached to it SAT as the angular deviation of the normal to the working surface SS from the date of termination of the error between the desired and the current angles SAT in the presence of steady-state angular velocity until the complete cessation of rotation of the SAT.

As is known, the current generated by the panel SAT, determined by the equation:

$$I=I_{MAX}\cdot COS\left|{\alpha }_{C\mathrm{And}D}-{\alpha }_{TEK}\right|,(1)$$

g the e I - the current produced by the SAT;

I_MAX- maximum current produced by the SAT, when the coincidence of the projection unit direction vector to the Sun and the normal to the working surface SAT in the plane of rotation of the normals;

α_TEKthe current angle SAT;

α_ASS- set angle SAT;

|α_ASSα_TECH| is the modulus of the difference between the desired and the current angles of the Council.

Given equation (1), set the threshold as the angle at which a signal is generated the error between the desired and the current angular position SA as:

$$\left({\alpha }_{P\mathrm{And}CB}+{\alpha }_{T\mathrm{About}PM}\right)<{\alpha }_{CP}<\arccos \frac{I_{MIN}}{I_{MAX}},(2)$$

where α_CPthe threshold SAT;

α_ACCEL- corner acceleration SA;

α_TORM- corner braking SAT;

I_MIN- set the minimum allowable current produced SB to power on-Board equipment KA;

I_MAX- maximum current produced SAT with matching normal to the working surface SB and the project is the unit direction vector to the Sun in the plane of rotation of the SAT,

next, set the threshold release, which stops the formation of the error signal between the desired and the current angle of the SAT, as:

$${\alpha }_{\mathrm{About}TP}\approx {\alpha }_{T\mathrm{About}PM},(3)$$

where α_OTP- the threshold of release.

The angle sensor mounted on the output shaft of the Electromechanical drive device to rotate the SAT, is a circle of 360°, which is divided into equal discrete angular sector, thus:

$$\sigma =\frac{360}{n}<{\alpha }_{CP},(4)$$

where σ is the angular size of the discrete sector angle sensor;

n is the number of discrete sectors in the circle of rotation of the SAT.

According to the results of experiments on the stands determine the angle of constraints formed by two positions normal to the working surface SB, in which structural elements of the SPACECRAFT in contact with the structural elements SB, and within the angle limits specified contact is missing, in this case the angle limit is in the range:

$${90}^{\circ }<{\alpha }_{\mathrm{About}GP}<{108}^{\circ },(5)$$

where α_OGRE- angle limit SAT.

Set the working angle SA, the bisector of which coincides with the bisector of the angle constraint as:

$${\alpha }_{P\mathrm{And}B}<{\alpha }_{\mathrm{About}GP}-2\cdot \left({\alpha }_{P\mathrm{And}CG}+{\alpha }_{T\mathrm{About}PM}\right),(6)$$

where α_SLAVE- working angle SAT.

During the flight the SPACECRAFT in an orbit with the help of sensors (sensors the position of the Sun, astrogation), and by calculating a relative associated with the SPACECRAFT coordinate system, determine the angular position of the projection unit direction vector to the Sun in the plane of rotation normal to the working surface SB. In addition, determine the current angle of the SAT as a position above the normal relative to the associated SPACECRAFT coordinate axes.

If the projection of the unit direction vector to the Sun is within the boundaries of the working angle, while the presence of the AI mismatch between the desired and the current angle SAT more angle positives form the team on rotation SAT on the shortest path in the direction of decrease the angle of misalignment. This calculates the current angle as the product of the angular velocity during rotation of the SAT, and in the intersection of the normal to the working surface SB of the boundaries between discrete sectors of the angle sensor, the current corner assigns the actual value cross-border. Thus, the current angle SAT define as:

$${\alpha }_{TEK}{\alpha }_{Fi}{\omega }_{\mathrm{With\; a}B}{t}_i,(7)$$

where α_TECHthe current angle SAT;

α_F- the actual angle SAT in the point of intersection of the i-th boundary between discrete sectors of the angle sensor;

ω_SAT- angular velocity of rotation of the SAT;

t_ithe time of rotation of the SB from the point of intersection of the i-th boundary, with 0≤i≤(n-1).

Form a team to stop rotation of the SAT, if the error between the desired and the current angles reaches the angle of release.

If the position of the projection unit direction vector of the Sun is outside the working angle preset angle assigned a value equal to the angular position of the nearest beam working angle. The angular position of the normal may differ from the angular position of the nearest beam working angle amount is not more than the threshold, but during normal operation is always within the boundaries of this angle.

If the angular position of the normal to the working surface SB is outside the operating angle and continues to change in the direction of increasing from the nearest beam working angle, generate a fault signal and stop the running of the Council.

Figure 1 shows the position of the SPACECRAFT relative to the Sun and Earth,

where

1 - Ground;

2 - orbit SATELLITES;

3 - body KA;

4 - panel SAT;

5 - scientific equipment KA;

6 - angle sensor SA;

7 - direction of radiation from the Sun;

8 - shadow area of the orbit;

9 - the object of observation;

N - set the direction of orientation of the SAT as a projection of the unit direction vector to the Sun in the plane of rotation normal to the working surface SB;

N_SATis normal to the working surface SB;

X, Y, Z - axis associated with the SPACECRAFT coordinate system;

X_SAT, Y_SAT, Z_SAT- axis associated with SB coordinate system;

N_SBAN_SBWposition normal to the working surface SB, in which the panel SAT in contact with the apparatus KA;

ω_O- the direction of the orbital angular velocity of the SPACECRAFT relative to the Earth;

ω_SAT- direction angular velocity SAT along the Z-axis;

α_OGRE- limit the angle of rotation of the panel SAT;

Δ_α- the angle between the normal to the working n the surface SB and given direction orientation SAT.

Around the Earth 1 to orbit 2 with angular velocity ω_Ospinning SPACECRAFT. With case 3 KA rigidly connected to the axis X, Y, Z associated with the SPACECRAFT coordinate system. In the case of 3 KA panel is installed SB 4, and scientific equipment 5 (for example, a radio telescope). Axis X_SAT, Y_SAT, Z_SATform associated with SB coordinate system. SAT rotates around the axis of Z_SATand directions of the axes Z_SATand Z are the same, and the plane formed by axes X_SATand Y_SATparallel to the plane formed by the X and y Direction normal to the working surface SB N_SATcoincides with the direction of the axis X_SAT. The angular position of the specified normals N_SATis determined using the angle sensor 6 SAT, fixed to the body 3 KA, and specified angle sensor 6 generates a zero value when the coincidence of the directions of the axes X_SATand X. In accordance with the direction of radiation of the Sun 7 determine the projection direction of the unit direction vector to the Sun N on the plane formed by the axes X_SATand Y_SAT. During the flight SPACECRAFT in orbit 2, he occasionally falls into the Earth's shadow 8.

The coincidence with the provisions of the normals N_SATwith the provisions of rays N_SBAand N_SBWpanel 4 SB in contact with the equipment of the SPACECRAFT. Thus, rotation of the panel SAT around the axis Z_SATlimited angle α_OGREformed is Okami N _SBAand N_SBW. During the flight panel 4 SAT unfold in such a way as to ensure the minimum angle between Δα between the projection direction of the unit direction vector to the Sun N the plane of rotation normal to the working surface SB formed by the axes X_SATand Y_SATand the specified normal N_SAT, resulting in the formation of the maximum possible current.

In the working position the SPACECRAFT is deployed so that scientific apparatus 5, mounted on Board, provided orientation to the object of observation 9.

On-site rotation pane, SAT, that is, if the normal N_SATis within the angle limits α_OGREand if the misalignment between the position specified normals N_SATand the projection of N becomes more than the threshold, the panel SAT unfolds with angular velocity ω_SATto align the provisions of the normals N_SATwith the projection position N. if the projection of N is outside the angle limitations, normal N_SATtakes position inside of the angle α_OGREclose to the N_SBAand N_SBW.

Ha figure 2 presents the angle sensor, made in the form of a circle of rotation of the SS, where:

10 - circle of rotation normal to the working surface SB;

11 - the center of the circle of rotation normal to the working surface SB;

12 - the elements of design KA limiting the rotation of the SAT;

13, 14 - positions of the SAT;

N_SBAposition normal to the working surface SB, corresponding to the position 13 of the panel;

N_SBWposition normal to the working surface SB corresponding to position 14 of the panel;

α_OGRE- limit the angle of rotation of the SAT.

In the circle of rotation 10 sensor angle measurement position normal to the working surface SB relatively associated with the SPACECRAFT coordinate axes. The drawing shows a fixed value of the angle sensor 0°, 90°, 180°, 270°. The center of the circle 11 coincides with the axis Z_SATdirected perpendicular to the plane of rotation of the normals. The structural members 12 KA in positions 13 and 14 of the panels SAT in contact with it and thus physically limit the rotation of the panel SAT, when the rays of the angle restriction α_OGREcomply with the provisions of the normals N_SBAand N_SBW.

Figure 3 shows a possible position normal to the working surface SAT in the circle of rotation of the SS, where:

15 - circle of rotation normal to the working surface SB;

16 - the center of the circle of rotation normal to the working surface SB;

N₁N₂N₃N_AN_BN_SLAVEN_ZAPposition of the projections of the unit direction vector to the Sun, the plane of rotation normal to the working surface SB;

N SBN_SBN_SBN_SBN_OGREN_OGREN_Ohrvposition normal to the working surface SB;

α_OGRE- limit the angle of rotation of the SAT;

α_ZAP- the angle of turn restriction SAT;

α_SLAVE- working angle SAT;

α_Andα_Inbuffer corners;

Δα_And, Δα_In- the angles of the error between the desired and the current angles of the Council.

In the circle of rotation 15 of the normal to the working surface SB with center 16 to limit the angle of α_OGREangle SA is formed by the rays of the N_OGREand N_Ohrvthe relevant provisions of the normals to the working surface SB, in which avionics KA in contact with the panel SAT.

The angle of turn restriction α_ZAPSB is defined as:

α_ZAP=360-α_OGRE.

The working angle α_SLAVESB is formed by the rays of the N_Andand N_In, the angular position of which correspond to the values of the specified angle, if the projection of the unit direction vector to the Sun beyond its limits.

Buffer angles α_Andand α_In, each of which is more than the sum of the angles of acceleration and deceleration, formed by the rays of the N_AN_OGREand N_Inand N_Ohrvaccordingly, in this case:

$${\alpha }_{\mathrm{And}}={\alpha }_{\mathrm{In}}=\frac{1}{2}\cdot \left({360}^{\circ }-{\alpha }_{C\mathrm{And}P}-{\alpha }_{P\mathrm{And}B}\right)$$.

Management orientation SB depends on the position of the projection of the unit vector of the direction of the Sun in this circle, as well as position normal to the working surface SB.

If this projection holds a position within the boundaries of the working angle N₁then at the end of the rotation SB normal to the working surface SB occupies the position of N_SBcoinciding with the position of the N₁.

If the projection is outside the operating angle, but within the boundaries formed by the rays of the N_InN_ZAPthe normal position N_SBis located within the boundaries of the working angle and may differ from the position of the beam N_Andat a value not greater than the threshold.

If the projection is outside the operating angle, but within the boundaries formed by the rays of the N_BN_ZAPthe normal position N_SBis located within the boundaries of the working angle and may differ from the position of the beam N_Bat a value not greater than the threshold.

If the position of the normals outside the working angle α_SLAVEfor example, complies with the provisions of N_SBor N_SBand this is changing the position of the normals in the direction of blija the damaged beam angle limit, accordingly, N_OGREor N_Ohrvgenerated fault signal and stops the control of the Council.

The proposed method eliminates jamming or breakage of the panel SAT or airborne equipment SPACECRAFT with limited angle SA and to ensure its orientation in such a way as to get the maximum possible current.

Sources of information

1. RF patent 2356788, VS 1/00, 28.12.2007,

The method of controlling the orientation of the solar panels of the spacecraft with limitation of rotation angle of solar panels, namely, that define a given angle of the solar battery as the position of the projection unit direction vector to the Sun in the plane of rotation normal to its working surface is relatively related to the spacecraft coordinate axes, measure the angular position of the normal to the working surface of the solar battery is relatively related to the spacecraft coordinate axes in the plane of rotation of the solar battery with precision to a discrete sector of the corresponding angle sensor, determine the angular velocity of the rotation of the solar panels on the crossing time of the solar battery boundaries between discrete sectors of the angle sensor, calculates the estimated angle relative to the measured angular position of the solar battery as the product of the angular velocity Solna is Noah battery during its rotation, rotate the solar panel in the direction of reducing the mismatch between the specified and calculated angles to determine the angle acceleration of the solar battery and the braking angle, adjust the estimated angle on the measured angular position of the specified normals at the points of change of the values of the angle sensor by the value of one discrete sector, set a threshold, above which is formed a mismatch between the specified and calculated angles, like:
$$\left({\alpha }_{P\mathrm{And}CG}+{\alpha }_{T\mathrm{About}PM}\right)<{\alpha }_{CP}<\arccos \frac{I_{MIN}}{I_{MAX}}$$,
where α_CF- trigger;
α_ACCEL- the angle of the acceleration of the solar battery;
α_TORM- corner braking solar panels;
I_MIN- the minimum current produced by the solar battery;
I_MAX- maximum current produced by the solar battery, set the threshold release below which stops the error between the desired and calculated angles of the solar battery:
α_OTP≈ α_TORM,
where α_OTP- p is horn release,
stop the rotation of the solar battery, if the error between the desired and the current angles starts to increase, but does not exceed the threshold, wherein the set angular speed of rotation of the solar battery on order and higher maximum angular velocity of the spacecraft around the Earth, ask the angular size of the discrete sector of the sensor angle is less than the threshold, and limit the angle of rotation of the solar battery within the range:
90° ≤ α_OGRE< 180°,
where α_OGRE- limit the angle of rotation of the solar battery,
set the working angle of the solar battery, the bisector of which coincides with the bisector of the angle constraint as:
α_CF< α_SLAVE< (α_MOUNTAINS-2·(α_ACCEL+α_TORM)),
where α_SLAVE- working angle of the solar battery,
assign a preset angle value of the angular position of the nearest beam working angle, if the position above the projection of the unit vector of the direction the Sun is out working angle, forming a fault signal and stop the management solar panel, if the angular position of the normal to the working surface of the solar battery is outside of the working angle and when it is changed in the direction of increasing angle relative to the nearest beam working angle.