The Solar Battery Orientation System (SOSB) is a mechanism designed to direct solar panels to the Sun. Guidance is performed by turning and then maintaining the required orientation in space of the spacecraft body by means of the COURT (motion control system) and rotation of the solar panels by electromechanical drives relative to the spacecraft body.
Analysis of the patent and scientific and technical documentation (NTD) allows classifying the SOSB as follows.
According to the method of generating signals of deviation of solar cells from the direction to the Sun:
- POS (device / sensor orientation to the Sun, solar sensor), using the visible radiation range of the Sun (ed. St. USSR № № 108661, 591827, 75919, 85175, [1] , etc .;
- determination of the direction to the Sun using SINS [2] [3] [4] ;
- current sensors (current differences) from photovoltaic cells of solar batteries (auths. St. USSR by applications No. 1582573, 2246821);
- temperature sensors (ed. St. USSR № 63381).
By type of orientation SAT:
- orientation of solar panels rigidly mounted on the body of a spacecraft by turning spacecraft, including spacecraft spinning around the direction to the Sun (Molniya satellite [5] , solar sail [6] , Soyuz spacecraft [7] , Salyut " [2] [5] );
- orientation of solar cells by displacement relative to the spacecraft body, in particular, by angular rotations of solar cells (auth. St. USSR No. 28372, 75919, etc.), by deformations of a flexible solar battery using movable rods (USSR application No. 2270285);
- combined control by turning the solar batteries together with the spacecraft body and by means of a rotating solar cell device (UFDS) relative to the spacecraft body (USSR application No. 3020761, [8] ), Patents of the Russian Federation No. 2021173, 2021174 (see sections 1.4.2., 1.4. 3.- http://docme.ru/UO5 ).
According to the number of degrees of freedom (axes of rotation) of the UPSS:
- uniaxial ( [1] , [8] , [9] , [10] , [3] , auth. St. USSR No. 75919, 85175, etc.);
- biaxial (auth. St. USSR number 28372, 81788, 97800, 165245, 1241188, 591827; USSR application No. 1596560, US Patent No. 4031444, [11] , etc.).
By the type of connection of the rotary solar cells with the spacecraft body:
- through a flexible cable (auth. St. USSR No. 28372, 81788, 89628, 165245, etc.);
- through a rotating collector ring device (TKU), allowing you to rotate the solar panels relative to the spacecraft body at an unlimited angle (ed. St. USSR № № 75919, 85175, [1] , etc.).
By the nature of the mutual influence of the contour of the SESB with the contour of the control of the spacecraft and the additional functions of the SASB:
- reduction of the adverse effect of the reactive moment from a change in the speed of rotation of solar cells on the orientation accuracy of the spacecraft:
- by introducing a flywheel-compensator of the kinetic moment of the SB, rotating in the direction opposite to the rotation of the solar batteries (auth. St. USSR No. 28372);
- by introducing a servo-relationship between the control circuits of the solar cells and the spacecraft (auth. St. USSR No. 75574, 89756, 101239);
- by minimizing changes and stabilizing the angular velocity of solar cells (ed. St. USSR number 75919, 85175, [3] );
- by controlling the angular acceleration when recruiting and quenching the angular velocity of the solar batteries (stepwise variation of the angular velocity — USSR Application No. 3050586);
- reducing the harmful effects of elastic oscillations of solar cells on the dynamics of the angular motion of the spacecraft, damping the elastic oscillations of panels SB:
- by placing the means of measuring the parameters of the angular motion (including the elastic deformations of the solar cell) on the solar panel and the formation of control algorithms taking into account the signals from these means;
- by using filtering in measurement channels [12] ;
- by identifying the motion parameters of an elastic spacecraft with the subsequent use of the specified information in the formation of spacecraft and spacecraft control algorithms [13] [14] [15] ;
- by using piezoelectric elements as measuring means (converting elastic deformations into an electrical signal - direct piezoelectric effect) and executive means (converting an electrical signal applied to the piezoelectric element, into its microdisplacement - reverse piezoelectric effect) for damping elastic oscillations of structures [16] [17] ;
- by redistributing the energy of elastic oscillations of elastic external structural elements (SB) from channels with “small” damping characteristics to channels with “strong” damping, for example, for geostationary spacecraft communications — from the pitch channel to the roll and yaw channels (see sections 1.6.2 ., 1.6.3. Http://docme.ru/UO5 ) by providing unequal natural frequencies of symmetric remote elements (north and south panels of the SB, symmetrical traverse of each of the panels of the SB), ensuring the transfer of energy of elastic oscillations from the pitch channel to the channels heel ry Kania due to oblique bending structural element, etc.), due to the gyroscopic effect when administered in the construction of solar panels rotating elements, e.g., girodempferov..;
- the introduction of an artificial relationship between the spacecraft control channels [13] .
By way of interaction of solar panels with external fields ( solar radiation , aerodynamic flow of rarefied gas, gravitational , magnetic fields , etc.):
- angular deviations of solar panels relative to the external field and the spacecraft body to create control moments, for example, for unloading the AIR (auth. St. USSR No. 582638, USSR applications No. 3031366, 3108551, US Patent No. 4426052, applications of Germany No. No. 2550757, 3329955 , UK No. 2122965, France No. 2529165, Japan No. 59024040, etc.);
- linear displacements of solar panels along the body of the spacecraft (ed. St. USSR No. 1099547) to control the magnitude and sign of the moment from interacting with the solar radiation emitted by the atmosphere by changing the position of the center of pressure relative to the center of mass of the spacecraft;
- changing the reflectance of the surface of the solar panel or part of the surface of the solar cell (US Patent No. 3116035).
On the use of solar cells as a receiving antenna, for example, modulated laser radiation with the subsequent release of useful information from the modulated current produced by the photovoltaic panels of solar cells when irradiated with laser radiation.
According to methods for determining failures of the UPSs and switching to the backup set (USSR application No. 32275460).
In the design developments of the UE solar cells of Russian and foreign companies, there has been a tendency to provide an unlimited angle of rotation of solar cells with electric power transmission, command, TM information through a block of collector devices, which has several advantages compared to a flexible cable connection with a limited angle of rotation. The problem is the issue of code exchange for ICE through a rotating current collection device.
In recent years, there have been publications on the modular construction of UE. That is, the unit is mechanical, the unit is collector, the electronic unit is executed in separate units and assembled during the assembly of the spacecraft. Such a point of view is presented, for example, by specialists of the PO Electromechanical Plant , Omsk, NPO Applied Mechanics, Krasnoyarsk-26, NPO named after S. Lavochkin . The collector unit carries out the transmission of electricity, control commands, TMI through the elastic current bearing rings like ball bearings. The advantage of annular current collection devices compared to sliding type current collection devices is the lower heat dissipation during power transmission.
Analysis of scientific and technical information shows that for geostationary spacecraft the most rational is the uniaxial orientation of the satellite, which provides the average daily efficiency of the satellite, differing from the ideal by no more than 8 ... 10%, while the UPS must provide an unlimited angle of rotation of the solar batteries relative to the body The spacecraft, that is, the UPSs must contain rotating current collection ring devices (TCUs) that provide the electrical connection between the rotating solar cells and the spacecraft body. The results of the comparison allow us to recommend for use on geostationary spacecraft SOSB, an analogue of which is the development [3] . In the recommended version of the SOSB, the block diagram of which is shown in Fig. 1.3.7.1 ( http://docme.ru/UO5 ), information on the deviation of the normal to the plane of the panels from the direction of the Sun is used to generate signals for controlling the rotation of the solar panels relative to the spacecraft body, and also about the current angular position of the solar panels relative to the spacecraft body. In this case, the uniaxial orientation of the solar cells can be carried out as follows. In the SINS, the direction vector to the Sun (ANS) is determined in a coordinate system associated with the spacecraft, the orbital angular velocity is calculated. Then, solar panels are aimed at the Sun by forming at the input of a drive a control signal proportional to this speed and correcting the control signal of the angular velocity as measured by the error between the solar panels and the direction to the Sun. The above-described control option allows the solar panels to be aimed at the Sun with an accuracy of 0.5 ... 0.7 degrees.
An alternative may be a variant of relay control of the SB rotation, minimizing the harmful effect of the reactive moment from a change in the SB rotation speed [1] . In this version, the solar panels are aligned with the Sun at a constant stabilized speed (TRACKING mode), the value of which is greater than or equal to the instability of motor speed maintenance of the maximum possible orbital angular velocity of the spacecraft on the GSO (the angular tracking rate of 0.00422 degrees / s stabilizes with accuracy about 1%). The zeroing of the accumulated orientation error of the solar batteries is performed by the orbital rotation of the spacecraft with the panels stopped at a given moment (for example, after the solar batteries are rotated one turn). The realized orientation accuracy of the axis associated with the SB landing pad is not worse than 7 ... 8 degrees with the stability of the drive’s angular velocity not exceeding 1%.
To ensure the forced reduction of the panels to a predetermined position relative to the spacecraft body (technological modes during ground tests, initial search of the Sun, emergencies, etc.), it is necessary to provide a SEARCH mode with angular speed of rotation of the panels 0.1 ... 0.2 deg / s. A stop command is provided for shutting down the solar panels. At the same time, the speed of rotation of the output shaft UPSS in flight may not be reversible, since with a constant orientation of the spacecraft in the USC rotation of the solar panels is performed during the entire period of active existence in one direction. For the above alternative SSSR, each of the control signals for the first and second UPSs (Fig. 1.3.7.1- http://docme.ru/UO5 ) is a vector, the components of which are relay commands for specifying the corresponding angular speeds of rotation of the UPS output shaft TRACK and SEARCH modes.
In order to improve reliability, it is necessary to include in the list of parameters for use in the COURT information from temperature sensors on solar panels from PAGE and voltage sensors from photoconverters from the power supply system, which allow a coarse orientation of solar panels with an accuracy of about 30 ... 40 degrees
In order to reduce the adverse effect of the reactive moment from changing the speed of rotation of solar cells on the orientation accuracy of the spacecraft body, for example, when tracking the Sun using a relay control law (UBPS implements switching on and stopping SB rotation), we can suggest the following control sequence. Determine the deviation from the direction of the Sun of each of the SAT, compare them with each other, issue a command to rotate the SAT, which has a larger deviation, and the STOP command for the second solar cell with a smaller deviation. Moreover, commands to stop one of the solar cells and the beginning of rotation of the other solar batteries are issued at the time point corresponding to the maximum compensation for the change in the kinetic moment of one SB, by changing the kinetic moment of the other SB. In the particular case, with almost instantaneous set of rotational speed, these points in time coincide. When the spacecraft crashes around the normal to the plane of the orbit, the following sequence of control operations can be recommended to maximize the energy input from solar cells' photovoltaic cells. When the OP is emitted by the solar radiation (that is, when the normal to the plane of the solar panel deviates less than 60 degrees), the solar cells are rotated in the opposite direction of the spacecraft's body when twisted, and if there is no OP illumination (there is no current from the AF), the solar panels are rotated , coinciding with the direction of twisting of the spacecraft body.
Notes
- ↑ 1 2 3 4 Miroshnichenko L. A., Raevsky V. A., et al. The system of orientation and stabilization of the Ekran satellite television broadcasting system // Izv. Academy of Sciences of the USSR. Technical cybernetics. - M .: Science, 1977.- № 4.- p. 18-27.
- ↑ 1 2 Gaushus E. V., Zybin Yu. N., Legostaev V. P. Autonomous navigation and control of the Salyut-7 orbital station / / Space Research. - M .: Science, 1986.- T.XXIV, Vol.6.- p. 844-864.
- ↑ 1 2 3 4 Unified space platform. Explanatory note. Part 18. Solar battery orientation system: Preliminary design SLII.374 173.004 ПЗ-1.17; 230GK 0000-OPZ-1.17 / SKBP ON Omsk Electromechanical Plant; RSC Energia named after academician S. P. Korolev. - Omsk; Kaliningrad, Moscow region - 1990.
- ↑ Branets V. N., Shmyglevsky I. P. Introduction to the theory of free inertial navigation systems. - M .: Science, 1992.
- ↑ 1 2 Modi V.D., Srivastava S.K. Angular Motion and Orientation Control of Satellites in the Presence of External Moments // Ser.62, Space Exploration: RJ.- VINITI.- 1985.- № 7.- Abstract 7.62. 184.
- ↑ Vasiliev L. А. Determination of light pressure on spacecraft. - M .: Mashinostroenie, 1985.
- ↑ Chernyavsky G.M., Bartenev V.A., Malyshev V.A. Orbit Control of a Stationary Satellite. - M .: Mashinostroenie, 1984.
- ↑ 1 2 Orbital geophysical station OGO // Sb. Automatic control of spacecraft. - M .: Science, 1968.- with. 94-109.
- ↑ Becker K. Two-tier orientation system of a television and radio broadcasting satellite // Sb. Satellite orientation and stabilization. - M .: Science, 1978.- V.2.
- ↑ Stoma S. A., Averbukh V. Ya., Kurilovich V. P., Miroshnik O. M. Autonomous Electromechanical System of Orientation of Solar Batteries of Earth Artificial Satellites // Electrotechnics. - M., № 9.- 1991.- p. 41-46; Ser.62, Space exploration: HL.- VINITI. - 1992.- № 4.- Abstract 4.62.137.
- ↑ Andronov I. M., Weinberg D. M., Position Control System of the Meteor Satellite // Sat. Management in space. - M .: Science, 1975.- T.1.
- ↑ Reducing the effect of elastic noise by introducing a spiral filter into the measurement channels // Astronautics and Rocket Dynamics. - VINITI.- 1985.- № 11.- p. 20.
- ↑ 1 2 Tkachenko V. А. Stabilization of the angular position of a spacecraft with elastic solar panels by a dynamic regulator // Space Research. - M .: Science, 1984.- T.XXII, issue 4.
- ↑ Study of the creation of promising unified motion and navigation control systems for spacecraft of scientific and national economic purposes autonomously flying astrophysical, environmental, communication modules, transport and cargo ships, modules for operation as part of the orbital station: Scientific and technical report on stage 1 of the research project “Perfection "(Section 10 of the research project" Cosmos-2 ") / RSC Energia named after academician S. P. Korolev; Head V.N. Branets. - P 31486-033. - Kaliningrad, Moscow region - 1992. - Ed. performers V.N. Platonov, L.I. Komarova, A.F. Bragazin and others.
- ↑ Nehoroshy Yu. N., Rutkovsky V. Yu., Sukhanov V. M. Identification of the parameters of the modal-physical model of a deformable spacecraft // Izv. RAS. Automation and remote control. - M .: Science, 1992.- № 7.- with. 19-25.
- ↑ Method of piezoelectric damping and active control of vibrations // Ser.41, Rocket Engineering: AJ. - VINITI.- 1985.- № 12.- Abstract 12.41.260.
- ↑ The use of ceramic piezoelectric control devices on large elastic spacecraft // Ser.41, Rocketry: RJ.- VINITI.- 1985.- № 12.- Abstract 12.41.261.