RU2403190C1 - Multirotor gyroscopic device and method for spacecraft spatial position control - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: inventions relate to inertia-gyroscopic systems for spacecraft (SC) angular position control. This device represents dynamically symmetrical system of solid bodies-rotors rotating on multiple axes symmetrically fixed in SC frame. The rotors are centrally-symmetrically positioned on axes. For each rotor there is its own symmetrical linked rotor with equivalent mass-inertia parametres. SC orientation change is performed according to law of conservation of kinetic momentum. For this purpose following is executed: linked rotors are synchronously accelerated in opposite directions and then single rotors are quickly (virtually instantaneously) captured-braked. The latter action is feasible by means of rotor engagements with frame or through creation of high frictional forces in axes. In this process, at first one of the pair of linked rotors is captured-braked and after SC has turned by required angle the mating linked rotor is captured-braked to stop the SC.

EFFECT: inertialess and fast execution of SC reorientation manoeuvres without constant maintaining high angular rotational speeds of rotors, and independent of nonlinearity of accelerating engine characteristics.

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Description

The invention relates to gyroscopic control systems for the spatial (angular) position of spacecraft.

Currently, such well-known gyroscopic devices are used (1. Alekseev K.B. et al. Control of spacecraft. - M .: Mashinostroenie, 1974. 2. Sidi MJ Spacecraft Dynamics & Control. Cambridge, 1997. 3. PWLikins, Spacecraft Attitude Dynamics and Control - A Personal Perspective on Early Developments, J. Guidance Control Dyn. Vol.9, No.2, 1986. Pp. 129-134. 4. CDHall, Escape from gyrostat trap states, J. Guidance Control Dyn. 21, 1998. Pp. 421-426. 5. WHSteyn, A dual-wheel multi-mode spacecraft actuator for near-minimum-time large angle slew maneuvers, Aerospace Science and Technology, Vol.12, Issue 7, 2008 Pp.545-554) for the spatial reorientation of spacecraft, as single-stage gyrostabilizers, I represent s-rotors are massive flywheels on internal drives the motor (Momentum wheels), two-stage gyrostabilizers representing power gyroscopes with two degrees gimbal (gyrodynes, Control moment gyros), and said binder system and devices.

The method of reorientation using a single-stage gyrostabilizer is based on the creation of a torsional moment by an internal engine, untwisting the rotor-flywheel in one direction, while the spacecraft body is untwisted in the opposite direction (1. Alekseev KB and other control of spacecraft. - M .: Engineering, 1974. 2. CDHall, Momentum Transfer Dynamics of a Gyrostat with a Discrete Damper, J. Guidance Control Dyn., Vol.20, No.6, 1997. Pp.1072-1075).

The method of reorientation using two-stage gyrostabilizers (gyrodinos) is based on the use of gyroscopic moments that occur when the frames of the cardan suspension of a power gyroscope are deflected. In such a reorientation scheme, “gyroscopic amplification” of small control moments (moments of the deflection forces of the frames) takes place due to the large kinetic moment of the force gyroscope, which must be maintained. Usually, several gyrodines and their paired systems are used in the spacecraft for reorientation along different spatial axes (1. Alekseev KB, et al. Control of spacecraft. - M.: Mashinostroenie, 1974. 2. WHSteyn, A dual-wheel multi-mode spacecraft actuator for near-minimum-time large angle slew maneuvers, Aerospace Science and Technology, Vol.12, Issue 7, 2008. Pp.545-554. 3. US Patent 6154691 - Orienting a satellite with controlled momentum gyros) .

The closest in technical essence is a multi-rotor gyroscopic device, which is a system of single-stage gyrostabilizers - a system of flywheel rotors driven by internal engines mounted on the spacecraft’s spacecraft, including the well-known designs of a gyrostat satellite and spacecraft with double rotation (1. CDHall, Momentum Transfer Dynamics of a Gyrostat with a Discrete Damper, J. Guidance Control Dyn., Vol.20, No.6, 1997. Pp.1072-1075. 2. KJ Kinsey, DLMingori, RHRand, Non-linear control of dual-spin spacecraft during despin through precession phase lock, J. Guidance Control Dyn. No. 19, 1996. Pp. 60-67).

The closest way to reorientation is to reorientation according to the scheme of a single-stage gyrostabilizer, when the creation of the angular velocity of the body is provided by bringing the rotor-flywheel into rotation in the opposite direction by turning on the internal spinning engine (1. Alekseev KB, et al. Control of spacecraft. - M .: Mechanical Engineering, 1974. 2. CDHall, Momentum Transfer Dynamics of a Gyrostat with a Discrete Damper, J. Guidance Control Dyn., Vol.20, No.6, 1997. Pp.1072-1075).

The objective of the invention is to reduce energy consumption, ensure inertia and speed of performing reorientation maneuvers, the rejection of the constant support of large angular rotational speeds of rotors, independence from non-linearity of the characteristics of spinning motors.

The problem is solved due to the fact that in a multi-rotor gyroscopic device containing rotors rotating on axes fixed in the spacecraft body, the axis of rotation of the rotors are placed on the spacecraft body in a centrally symmetrical manner and form an unplanar set of counter-directional pairs, while the rotors are also located on the axes in a centrally-symmetrical manner and for each rotor there is its own symmetric conjugate rotor with equivalent inertial mass parameters, with each rotor located on the the internal engine spinning it, fixed on the spacecraft body.

The problem is also solved due to the fact that in the method for controlling the spatial position of the spacecraft, including the spinning of the rotors, according to the invention, the rotors are untwisted by paired pairs synchronously in opposite directions until certain angular velocities are reached, after which an instant capture-braking of one of the pair of paired rotors is carried out, at In this case, the angular velocity of the reorientation of the spacecraft hull arises with its rotation to the required angle, after which instant capture-braking is performed in pairs a conjugate of the rotor and the body stops spacecraft.

The method also involves the promotion of one, several or all available pairs of conjugate rotors, as well as a complex sequence of grippers-brakes of the rotors to perform a complex program of reorientation of the spacecraft.

The invention is illustrated by drawings of a multi-rotor gyroscopic device and a description of the sequence of actions within the framework of the method of performing the reorientation.

Figure 1 schematically shows a multi-rotor device containing N paired pairs of rotors along each axial direction.

Figure 2 shows a multi-rotor device with one pair of conjugated rotors in each direction, which corresponds to the minimum possible number of rotors, allowing reorientation according to the proposed method.

Figure 3 shows a multi-rotor device with an excessive number of pairs of conjugated rotors and axes, which allows for complex program reorientations.

The multi-rotor device shown in Fig. 1 consists of a central spacecraft body-body (body 0) and six orthogonal pairwise counter-directional axis-rays, which are rotor axes. The system is made according to a centrally symmetric scheme. The rotors are placed on the axes so that for each of them there is a centrally symmetric rotor that is equivalent in mass inertia to the opposite beam and is called “conjugated” (for example, rotors 12 and 22 are conjugated, rotor pairs {3N and 4N}, {51 and 61} are also conjugate). The numbering of the rotors is such that the first digit of the double-digit number indicates the number of the beam, and the second is the number of the layer of the conjugated rotors. The direction of the rays: 1 - on the connected x-axis, 2 - on the opposite x-axis, 3 - on the connected y-axis, 4 - on the opposite y-axis, 5 - on the connected z-axis, 6 - on the opposite z-axis. The rotor layer number determines the proximity of the rotor to the central body-body: the rotor closest to the body has a layer number of 1, the next rotor of the same beam next to the body is number 2, etc. The rotor number IJ means its location on the beam number I and in the layer number J. Each rotor can have a relative angular velocity (with respect to the spacecraft body) of rotation around its axis, which varies in accordance with the torque of the spinning motor attached to it, fixed to spacecraft body. Each rotor on its own spin engine is a separate single-stage gyrostabilizer. Thus, the proposed multi-rotor gyroscopic device is a system consisting of many pairs of paired anti-directional single-stage gyrostabilizers.

Figure 2 schematically shows a partial view of the previous scheme (figure 1). So there is a central body-spacecraft body and six orthogonal pairwise counter-directional rays and one layer of rotors. Due to the fact that the layer is the only one, the numbering of the rotors is carried out in one digit, describing only the number of the direction of the beam. Thus, there are three pairs of conjugate rotors: {1,2}, {3,4}, {5,6}.

Figure 3 schematically depicts a centrally-symmetric multi-beam multi-rotor system with a large number of pairwise opposite rays and containing a large number of layers of rotors. The specified system has a large number of pairs of conjugate rotors.

A method for controlling the spatial position of a spacecraft includes the following sequence of actions.

1. Synchronous unwinding of any pair of conjugated rotors in opposite directions under the action of the same largest moments of forces of internal untwisting engines.

2. Capture one of the rotors of the paired pair to create the angular velocity of the reorientation of the spacecraft. After performing the capture of the rotor, the housing acquires some calculated angular velocity and performs the required angular reorientation.

3. Capture of the second rotor of the paired pair for an instant stop of the spacecraft hull.

Note the following features of the proposed method, distinguishing it from known methods:

- Items 1-3 of the sequence of actions on the proposed method of reorientation can be performed for any one pair of conjugated rotors, several pairs or for all pairs of conjugated rotors.

- Captures of rotors can be simultaneous or can be performed at different points in time for individual rotors.

- Reorientation of the spacecraft according to the proposed scheme can be carried out from a state of absolute rest with zero kinetic moment of the system. Such a reorientation scheme will occur without reinforcing gyroscopic moments and can be characterized as the development of a single-stage gyrostabilizer scheme, which is independent of the non-linearity of engine characteristics and is inertialess and significantly faster.

- Reorientation of the spacecraft according to the proposed scheme can be carried out from a state with a non-zero kinetic moment of the system. In this case, gyroscopic moments of forces will arise, which can be used to enhance the effects of reorientation, making it possible to use lower values of the angular velocities of the spacecraft’s hull, which are initiated due to conjugate spins and captures. The presence of a gyroscopic moment in this case is similar to gyroscopic amplification in two-stage gyrostabilizers (gyrodynes), which is one of the advantages of the proposed multi-rotor reorientation system.

- Multi-rotor systems (figures 1 and 3), having a large number of pairs of conjugate rotors and pairs of beams with conjugate rotors, can carry out complex program reorientations due to complex sequences of captures. Also, such systems allow the formation of a “charge” for subsequent reorientations, which implies the conjugate unwinding of all available pairs of conjugate rotors (which does not affect the dynamics of the spacecraft body), and further reorientation (including a complex reorientation program) is performed later as necessary.

Next, we present the results of calculations of the dynamics of the systems, confirming the above method for the spatial reorientation of the spacecraft.

Consider the movement of the system shown in figure 2. The kinetic moment of the system in projections on the axis associated with the body-body of the spacecraft Oxyz coordinate system is

- главные моменты инерции основного тела корпуса; I - продольный м момент инерции ротора; J - экваториальный момент инерции ротора, вычисленный относительно точки О.where K _m is the kinetic body-body together with the rotors “frozen” in it; K _r is the relative kinetic moment of the rotors, ω = [p, q, r] ^T is the absolute angular velocity of the main body-body, σ _i is the relative angular velocity of the rotor i with respect to the main body.

- the main moments of inertia of the main body body; I is the longitudinal m moment of inertia of the rotor; J is the equatorial moment of inertia of the rotor calculated with respect to point O.

The equations of motion are written on the basis of the theorem on the change in the kinetic moment (in the moving coordinate system Oxyz) in the following form

where M ^e is the moment of external forces. The scalar form of the vector equation (3) is a system of the following equations

Where

The equations of relative motion of the rotors have the form written also on the basis of the theorem on the change in the kinetic moment

- момент внутренних сил, действующих со стороны основного тела на ротор j;

- моменты внешних сил, отдельно действующих на ротор j. Уравнения (4) и (6) полностью описывают динамику многороторной системы (фиг.2).Where

- the moment of internal forces acting from the main body on the rotor j;

- moments of external forces acting separately on the rotor j. Equations (4) and (6) fully describe the dynamics of the multi-rotor system (figure 2).

To determine the angular position of the carrier body, we will use the well-known Rodrig-Hamilton parameters (indicated in the foreign literature as Euler parameters) {λ ₀ , λ ₁ , λ ₂ , λ ₃ }, which determine the final rotation of the main body by an angle χ about some axis in space coinciding with the direction of the unit vector e = [cosα, cosβ, cosγ] ^T in the inertial coordinate system OXYZ, which initially coincides with the initial position of the coupled system Oxyz (Fig. 4).

As is known, the Rodrigue-Hamilton parameters can be determined by the following relations connecting the angle of the final rotation and the direction cosines of the rotation axis

The kinematic system of equations in the parameters of Rodrigue Hamilton has a known form

Where

Let us now consider the scheme of the reorientation algorithm with zero initial kinetic moment. We give several definitions that summarize and repeat the above steps performed within the framework of the claimed method of reorientation.

"Paired rotors" will be called rotors on opposite beams, located symmetrically relative to the main body, for example, these are rotors 3 and 4 (figure 2), rotors 52 and 62 (figure 1), etc.

By “conjugate unwinding” we mean the spinning of conjugated rotors with internal moments (internal untwisting engines) in different directions, equal in magnitude and different in sign of the moments of internal forces. The spin-up occurs until the conjugate rotors acquire specified angular velocities equal in absolute value and opposite in direction (in sign).

“Capture of a rotor” will be called instantaneous (fast-flowing) braking of the relative angular velocity of the rotor to zero. The capture can be carried out, for example, due to the instantaneous coupling of the rotor and the main body-body (gear and similar gears), or due to the formation ("inclusion") of strong friction (dry or viscous) in the rotor rotation bearing on its own axis. Thus, the capture of the rotor implies its instantaneous (quick) stop in relation to the main body-body.

и начального кинетического момента системы (КА с роторами)Consider the principle of reorientation of the spacecraft through conjugate spins and successive captures of the rotors in the absence of external forces

and the initial kinetic moment of the system (spacecraft with rotors)

In the simplest case, piecewise constant internal moments of forces can be used for the conjugate spin of the rotors. Consider the conjugate promotion of the mating rotors 1 and 2 (figure 2) the following internal moments

- время раскрутки (длительность) роторов 1 и 2; M₁₂=const>0.Where

- spin time (duration) of the rotors 1 and 2; M ₁₂ = const> 0.

относительной угловой скорости (σ₁=S₁₂, σ=-S₁₂), причем основное тело-корпус остается в абсолютном покое, как и ранее. После сопряженной закрутки в момент времени

захватывается ротор 1.After the conjugate spin, the rotors 1 and 2 reach the value

relative angular velocity (σ ₁ = S ₁₂ , σ = -S ₁₂ ), and the main body-body remains in absolute rest, as before. After conjugate spin at time

rotor 1 is gripped.

After capturing rotor 1, it loses the relative angular velocity (σ ′ ₁ = 0), and the main body-body acquires the angular velocity p in the direction of the beam of conjugated rotors (in this case, the axis Ox), and rotor 2 changes the value of the relative angular velocity by σ ′ ₂ . These values can be calculated from the condition of conservation of the kinetic moment of the system

The condition of conservation of the kinetic moment of the rotor 2 leads to the expression

From the last relations the values of angular velocities follow

выполняется захват ротора 2 и послеFurther at time

rotor 2 is gripped and after

of this, according to the condition of conservation of the kinetic moment, all the bodies of the system (main body-body and rotors 1, 2) receive zero values of angular velocities and, thus, again turn into absolute rest.

Therefore, in the process of conjugate unwinding of rotors 1, 2 and their successive captures, a piecewise constant angular velocity of the spacecraft body-hull is provided in the direction of the Ox axis

The body-body carries out angular reorientation around the axis Ox to an angle

Similarly, due to the conjugate spins and successive captures of the conjugate rotors, it is possible to provide piecewise constant angular velocities of the spacecraft body-body along other axes, for example, for the velocity component along the Oy axis, the following quantities can be obtained

- моменты времен (длительности) раскрутки сопряженных роторов i и j;

- момент времени захвата ротора i; M_ij - абсолютное значение внутреннего момента сил раскрутки сопряженных роторов i и j; S_ij - абсолютное значение относительной угловой скорости сопряженных роторов i и j после сопряженной раскрутки; σ′_i, - величина относительной угловой скорости ротора i после захвата его сопряженного ротора i*.Where

- moments of time (duration) of the promotion of the conjugate rotors i and j;

- the moment of time of capture of the rotor i; M _ij is the absolute value of the internal moment of the spin-up forces of the conjugate rotors i and j; S _ij is the absolute value of the relative angular velocity of the mating rotors i and j after the mating promotion; σ ′ _i , is the value of the relative angular velocity of the rotor i after the capture of its conjugate rotor i *.

It is easy to show that in the absence of external forces and a zero initial kinetic moment of the system of projection of the kinetic moment on the fixed axes of the coordinate system OXYZ and on the connected axes of the coordinate system Oxyz will be identically zero

Consequently, in the processes of conjugate spins and successive captures of conjugate rotors, piecewise-constant values of the angular velocity of the body-body will take place

Let the time instants of the conjugate grips of the system (Fig. 1) be the same for each conjugate pair {1, 2}, {3, 4}, {5, 6}, and also the initial coincidence of the fixed and connected coordinate systems

In this case, the kinematic equations (8) have the following analytical solutions

основное тело-корпус КА выполнило конечный поворот вокруг единичного вектора е на угол χ (Фиг.4)Solutions (22) demonstrate that at time

the main body of the spacecraft performed a final rotation around a unit vector e by an angle χ (Figure 4)

χ = ΩΤ

Thus, solutions (22) show the possibility of spatial reorientation of the spacecraft to any given vector of the final rotation. The required direction and magnitude of the final rotation is provided by the conjugate rotor spin-ups to the required relative angular velocities and time parameters for performing rotor grips. The reorientation process under consideration at zero kinetic moment is similar to the reorientation process using a single-stage gyrostabilizer (flywheel housing), but does not depend on the nonlinearity of the characteristics of the spinning internal engine and, of course, has more favorable energy characteristics. So the conjugate unwinding can be carried out by arbitrary values of the moments of the spinning internal engines, for example, by small moments on a long time interval, which allows you to gradually “accumulate” the required relative angular velocities of the conjugated rotors for further reorientations using their conjugated captures.

In the case of a non-zero initial value of the kinetic moment, there will be non-zero gyroscopic terms in dynamic equations (4) and variable components of the kinetic moment in the coupled axes (of course, the kinetic moment vector is constant in the fixed axes)

In this case, there is a gyroscopic enhancement of reorientation processes similar to gyroscopic moments in systems of two-stage gyrostabilizers (gyrodines). The reorientation processes in this case have more complex algorithms taking into account the variability of the angular velocities of the body-body in time. Nevertheless, the reorientation scheme based on conjugate spins and captures remains effective and efficient. Optimization of algorithms and reorientation processes in this case is a scientific and engineering-computational task.

The multi-rotor systems shown in FIGS. 1, 3 have a large number of pairs of conjugate rotors and also beams with conjugate rotors, therefore, they may imply complex sequences of conjugate spins and captures for implementing complex spacecraft reorientation programs in space.

Thus, the possibility of using the proposed device and method for spatial reorientation of the spacecraft is shown.

Claims (2)

1. A multi-rotor gyroscopic device containing rotors rotating on axes fixed in the spacecraft body, characterized in that the axes are placed on the body in a centrally symmetrical manner and form a non-coplanar set of counter-directional pairs, while the rotors are also located on the axes in a centrally symmetrical manner, and for each rotor there is a symmetric conjugate rotor with equivalent inertial-mass parameters, and each rotor is placed on a separate inner spinning it an engine mounted in the spacecraft body, and the rotors of each paired pair have the same internal engines. 2. A method of controlling the spatial position of the spacecraft, including the spinning of the rotors, characterized in that the conjugated rotors are unwound in pairs synchronously in opposite directions until certain angular velocities are reached, after which one of the pair of conjugated rotors is instantly locked-braked to create the angular velocity of the spacecraft reorientation turning it to the required angle, after which an instant capture-braking of the paired conjugated rotor is carried out to stop the spacecraft hull.

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