Exact solutions and adiabatic invariants for equations of satellite attitude motion under Coulomb torque

This paper focuses on the attitude dynamics of a defunct axisymmetric satellite under the action of Coulomb forces to enable active space debris removal. Touchless Coulomb interaction occurs between an active spacecraft and the passive satellite at a fixed separation distance. The recently developed multi-sphere method of Schaub and Stevenson allows providing a simplified electrostatic force and torque model between non-spherical space objects. The existence of torques between charged bodies makes it necessary to study the attitude motion of the passive satellite for ensuring the safety of the space debris removal. The goal is first to deduce the equations of motion in the canonical form which is suitable for analytical analysis and then to construct a phase portrait, and to obtain exact solutions using Jacobi elliptic functions. Finally, for the disturbed motion of the system of two bodies, when the distance between the active spacecraft and the defunct satellite (or) and charge voltage changes slowly over time, adiabatic invariants are found in terms of the complete elliptic integrals. In this case, the adiabatic invariants are approximately first integrals of the disturbed system and they remain approximately constant for long time intervals during which the parameters change considerably. For a plane motion, the adiabatic invariants used to obtain an analytical solution for envelope of a deflection angle of the defunct satellite. This work extends the theory to the three-dimensional tumbling motion of a satellite on an orbit. The obtained results can be applied to study an opportunity of the space debris removal by the Coulomb interaction with the active spacecraft as a pusher.

     

USEFUL RELATIVE MOTION DESCRIPTION METHOD FOR PERTURBATIONS ANALYSIS IN SATELLITE FORMATION FLYING

Nomenclature OXYZEarth’sequatorialinertialreferenceframeωArgumentofperigee SlxyzLeadingsatelliteorbitframeMMeananomaly SfxyzFollowingsatelliteorbitframefTrueanomalyaSemi majoraxisθ=ω fArgumentoflatitude eEccentricitynMeanmotion iOrbitinclinationrSatel…     

挠性联结双体卫星的混沌运动

本文讨论一挠性联结双刚体航天器模型，通过计算其动力学方程异宿轨道稳定流形与不稳定流形的相交角方法，给出其稳定流形与不稳定流形横截相交的判据，并通过Ｐｏｉｎｃａｒｅ截面的计算，证明其产生混沌运动的可能性。     

Dynamics of a satellite carrying a point mass moving about it

We study the dynamics of a complex system consisting of a solid and a mass point moving according to a prescribed law along a curve rigidly fixed to the body. The motion occurs in a central Newtonian gravitational field. It is assumed that the orbit of the system center of mass is an ellipse of arbitrary eccentricity.We obtain equations that describe the motion of the carrier (satellite) about its center of mass. In the case of a circular orbit, we present conditions that should be imposed on the law of the relative motion of the mass point carried by the satellite so that the latter preserves a constant attitude with respect to the orbital coordinate system. In the case of a dynamically symmetric satellite, we consider the problem of existence of stationary and nearly stationary rotations for the case in which the carried point moves along the satellite symmetry axis.We consider several problems of dynamics of the satellite plane motion about its center of mass in an elliptic orbit of arbitrary eccentricity. In particular, we present the law of motion of the carried point in the case without eccentricity oscillations and study the stability of the satellite permanent attitude with respect to the orbital coordinate system.     

Stability of a planar resonance satellite motion under spatial perturbations

The satellite motion relative to the center of mass in a central Newtonian gravitational field on an elliptic orbit is considered. The satellite is a rigid body whose linear dimensions are small compared with the orbit dimensions. We study a special case of planar motion in which the satellite rotates in the orbit plane and performs three revolutions in absolute space per two revolutions of the center of mass in the orbit. Perturbations are assumed to be arbitrary (they can be planar as well as spatial). In the parameter space of the problem, we obtain Lyapunov instability domains and domains of stability in the first approximation. In the latter, we construct third- and fourth-order resonance curves and perform nonlinear stability analysis of the motion on these curves. Stability was studied analytically for small eccentricity values and numerically for arbitrary eccentricity values.     

Stability of plane oscillations of a satellite in a circular orbit

We study motions of a rigid body (a satellite) about the center of mass in a central Newtonian gravitational field in a circular orbit. There is a known particular motion of the satellite in which one of its principal central axes of inertia is perpendicular to the orbit plane and the satellite itself exhibits plane pendulum-like oscillations about this axis. Under the assumption that the satellite principal central moments of inertia A, B, and C satisfy the relation B = A + C corresponding to the case of a thin plate, we perform rigorous nonlinear analysis of the orbital stability of this motion.In the plane of the problem parameters, namely, the oscillation amplitude ε and the inertial parameter, there exist countably many domains of orbital stability of the satellite oscillations in the linear approximation. Nonlinear orbital stability analysis was carried out in thirteen of these domains. Isoenergetic reduction of the system of equations of the perturbed motion is performed at the energy level corresponding to the unperturbed periodic motion. Further, using the algorithm developed in [1], we construct the symplectic mapping generated by the equations of the reduced system, normalize it, and analyze the stability. We consider resonance and nonresonance cases. For small values of the oscillation amplitude, we perform analytic investigations; for arbitrary values of ε, numerical analysis is used.Earlier, numerical analysis of stability of plane pendulum-like motions of a satellite in a circular orbit was performed in several special cases in [1–4].     

挠性联结双体航天器的稳定性与分岔

研究圆轨道内受万有引力矩作用的挠性联结双体航天器在轨道平面内的姿态运动,讨论其相对轨道坐标系统平衡状态的稳定性与分岔。提出判平衡方程非平凡解存在性的几何方法,并应用Ｌｉａｐｕｎｏｖ直接法、Ｌｉａｐｕｎｏｖ－Ｓｃｈｍｉｄｔ约化方法和奇异性理论导出解析形式的稳定性与分岔的充要条件,从而对系统的全局运动性态作出定性的描述。     

陀螺进动与强迫进动轨道

陀螺进动与轨道进动现象的相似性归因于二者的动力学相似性. 通过类比二者的动力学模型,提出了一类强迫进动轨道. 若以圆轨道为初始轨道,通过施加常值法向力可以实现一种特殊的悬浮型强迫进动轨道. 采用四元数建模方法求解了这种强迫进动轨道的进动规律,给出了解析表达式,据此分析了这种轨道的性质. 分析结果表明这种强迫进动轨道与初始圆轨道在同一球面上,且与初始位置相切. 其角速度为进动角速度与初始轨道角速度的合成,是一种悬浮轨道,即属于非开普勒轨道. 悬浮轨道在地球观测、行星际科学、天文观测、无线电通讯以及地球工程等领域具有潜在应用前景. 从强迫进动的角度出发所作的分析为悬浮轨道的实现提供了一种新途径.     

Satellite rotation stability at a Mercurian type resonance

We consider the satellite plane motion about the center of mass in a central Newtonian gravitational field in an elliptic orbit. This motion is described by a second-order differential equation known as the Beletskii equation. In the framework of the plane problem (under the assumption that the body vibrates in the unperturbed orbit plane), there exists a family of periodic solutions of the Beletskii equation near the 3: 2 resonance between the orbital revolution and axial rotation periods. A nonlinear stability analysis of these periodic solutions is carried out both in the presence of third- and fourth-order resonances and in their absence as well as on the boundaries of the stability regions in the first approximation. The problem is solved numerically. For fixed parameter values (the eccentricity of the center-of-mass orbit and the inertial parameter), the construction of a symplectic mapping of the equilibrium into itself is used to calculate the coefficients of the mapping generating function, which are further used to conclude whether the equilibrium is stable or not.     

Nonlinear dynamics of a satellite with deployable solar panel arrays

The multibody dynamics of a satellite in circular orbit, modeled as a central body with two hinge-connected deployable solar panel arrays, is investigated. Typically, the solar panel arrays are deployed in orbit using preloaded torsional springs at the hinges in a near symmetrical accordion manner, to minimize the shock loads at the hinges. There are five degrees of freedom of the interconnected rigid bodies, composed of coupled attitude motions (pitch, yaw and roll) of the central body plus relative rotations of the solar panel arrays. The dynamical equations of motion of the satellite system are derived using Kane's equations. These are then used to investigate the dynamic behavior of the system during solar panel deployment via the 7-8th-order Runge-Kutta integration algorithms and results are compared with approximate analytical solutions. Chaotic attitude motions of the completely deployed satellite in circular orbit under the influence of the gravity-gradient torques are subsequently investigated analytically using Melnikov's method and confirmed via numerical integration. The Hamiltonian equations in terms of Deprit's variables are used to facilitate the analysis.     

An analytical control law of length rate for tethered satellite system

Based on the nonlinear dynamic equations of a tethered satellite system with three-dimensional attitude motion, an analytical tether length rate control law for deployment is derived from the equilibrium positions of the system and the scheme of the value range of the expected in-plane pitch angle. The proposed control law can guarantee that the tensional force acting on the end of the tether remains positive. The oscillation of the out-of-plane roll motion in conjunction with the in-plane pitch motion is effectively suppressed during deployment control. The analytical control law is still applicable, even if the system runs on a Keplerian elliptical orbit with a large eccentricity. The local stability of the non-autonomous system during deployment control is analyzed using the Floquet theory, and the global behavior is numerically verified using simple cell mapping. The numerical simulations in the paper demonstrate the proposed analytical control law.     

Geometrical nonlinear waves in finite deformation elastic rods

IntroductionSomenewphenomenaofnonlinearwavesinthesolidmediumsuchasshockwave ,solitarywaveetc.arepaidmoreattentiontoincreasinglybyresearchersbecausetheytakeonalotofimportantproperties.ItistheoreticallyanalyzedinRefs.[1 -6]thattheformationmechanismsofshockwaveandsolitarywaveintheelasticthinrodsaswellastheirpropagationproperties.TheexistenceofsolitarywaveintheelasticmediumsuchasarodandaplatehasbeenverifiedinRef.[7]byexperiments.Shockwaveandsolitarywavearesteadilypropagatingtraveling_wavesgenerat…     

Stability of the cylindrical precession of a satellite in an elliptic orbit

We study the linear problem on the stability of rotation of a dynamically symmetric satellite about the normal to the plane of the orbit of its center of mass. The orbit is assumed to be elliptic, and the orbit eccentricity is arbitrary. We assume that the Hamiltonian contains a small parameter characterizing the deviation of the satellite central ellipsoid of inertia from the sphere. This is a resonance problem, since if the small parameter is zero, then one of the frequencies of small oscillations of the symmetry axis in a neighborhood of the unperturbed rotation of the satellite about the center of mass is exactly equal to the frequency of the satellite revolution in the orbit. We indicate a countable set of values of the angular velocity of the unperturbed rotation for which the resonance is even double. The stability and instability domains are obtained in the first approximation with respect to the small parameter.     

Exploitation of non-linear resonance in gravity-stabilized satellites

A perturbation study is presented which investigates the influence of internal non-linear resonance on the angular motion of a gravity-stabilized satellite containing a spinning rotor and a damper. First-order conditions that induce resonance are developed via the KBM method of asymptotic expansions. For a given resonance condition, energy dissipation properties of the system are assessed by a perturbation analysis based on canonical transformation theory. The analyses indicate that during internal resonance a relatively large transfer of energy can occur between satellite in-orbit plane (pitch) librations and out-of-plane (roll-yaw) librations. Moreover, for a limited range of pitch amplitudes, it is possible to induce resonance and dramatically attenuate pitch motion with a damper that is sensitive to yaw axis motion. The results were confirmed for a rotorless satellite by numerically integrating the exact equations of motion.     

Orbital oscillations of an elastic vertically-tethered satellite

The motion of a satellite in a circular orbit with respect to its center of mass is considered. The satellite bears an elastic tether system unrolled along the local vertical. The load at the end of the tether oscillates harmonically. The satellite motion under the action of the gravitational moment and the moment due to the tether tension force is studied. The bifurcation diagram is constructed and the hetero- and homoclinic separatrix trajectories are determined. Mel'nikov's method is used to study the satellite chaotic behavior near separatrices under the action of the periodic tether tension force. The results of the present paper can be used to analyze tether systems of gravitational stabilization and to study the orbital behavior of a satellite with an unrolled tether system with respect to the satellite center of mass.     

To the problem of plane periodic rotations of a satellite in an elliptic orbit

We study the motion of a satellite (a rigid body) with respect to its center of mass in an elliptic orbit of small eccentricity. We analyze the nonlinear problem of the existence and stability of periodic (in the orbital coordinate system) rotations of the satellite with a period multiple of the period of revolution of its center of mass in the orbit. We study the direct and reverse rotations. In particular, we find and investigate the set of bifurcation values of the satellite dimensionless inertial parameter near which the branching of the periodic reverse rotations occurs. We consider three specific examples of application of the obtained general theoretical conclusions. In one of these examples, we prove the stability of the direct resonance rotations of Mercurial type. In the other two examples, we consider the branching problem for reverse rotations with a period whose ratio to the period of motion of the center of mass in the orbit is equal to 1 or 2.     

Birkhoff力学的研究进展

Birkhoff力学是Hamilton力学的一个自然发展,是分析力学发展的一个新阶段,它广泛应用于力学、物理学和工程.本文总结Birkhoff力学的形成和发展,特别是近二十年所取得的成就.首先,从Birkhoff的《动力系统》中的有关段落开始,叙述Birkhoff力学的起源.其次,叙述这个力学的基本原理——Pfaff-Birkhoff原理以及这个力学的基本方程——Birkhoff方程的形成和发展.第三,简述Birkhoff力学的一些专门问题,包括约束Birkhoff系统,Birkhoff方程的积分方法,Birkhoff动力学逆问题,Birkhoff方程的运动稳定性,Birkhoff系统的几何方法,Birkhoff系统的全局分析等.最后,对Birkhoff力学的未来研究提出一些建议.      

Extension of Melnikov criterion for the differential equation with complex function

The present paper presents an extension of Melnikov's theory for the differential equation with complex function. The sufficient condition for the existence of a homoclinic orbit in the solutions of a perturbed equation is given. The method shown in the paper is used to derive a precursor criterion for chaos. Suitable conditions are defined for the parameters of equations for which the equation possesses a strange attractor set. The analytical results are compared with numerical ones, and a good agreement is found between them.     

三体轨道动力学研究进展

三体系统轨道动力学问题是航天动力学领域中的经典问题, 具有丰富的理论与工程意义, 并将在人类由近地延伸到深空的航天活动过程中起到至关重要的作用. 本文回顾并总结了三体系统轨道动力学相关研究进展, 并结合未来的深空探测的发展趋势, 展望了三体系统轨道动力学研究中的热点与挑战. 首先阐述了三体问题的研究背景及意义, 简要回顾了三体系统动力学模型的发展历程. 其次, 系统概述了三体系统平衡点附近的局部运动特性, 介绍了平衡点附近周期轨道解析与数值求解方法, 给出了拟周期运动的最新进展. 同时总结了共振轨道、循环轨道、自由返回轨道等三类三体系统全局周期运动的动力学特性与研究进展. 再次, 从不变流形理论和弱稳定边界理论两个方面综述了三体系统中低能量转移与捕获轨道设计的研究进展. 最后, 综述了三体系统轨道动力学在编队飞行、导航星座设计两方面的应用, 并展望了全月面覆盖轨道设计、三体系统下的小推力轨道优化和三体系统的三角平衡点开发利用中值得关注的轨道动力学与控制问题.      

On periodic motions of an orbital dumbbell-shaped body with a cabin-elevator

The motion of a dumbbell-shaped body (a pair of massive points connected with each other by a weightless rod along which the elevator, i.e., a third point, is moving according to a given law) in an attractive Newtonian central field is considered. In particular, such a mechanical system can be considered as a simplified model of an orbital cable system equipped with an elevator. The practically most interesting case where the cabin performs periodic ??shuttle??motions is studied. Under the assumption that the elevator mass is small compared with the dumbbell mass, the Poincaré theory is used to determine the conditions for the existence of families of system periodic motions analytically depending on the arising small parameter and passing into some stable radial steady-state motion of the unperturbed problem as the small parameter tends to zero. It is also proved that, for sufficiently small parameter values, each of the radial relative equilibria generates exactly one family of such periodic motions. The stability of the obtained periodic solutions is studied in the linear approximation, and these solutions themselves are calculated up to terms of the firstorder in the small parameter. The contemporary studies of the motion of orbital dumbbell systems apparently originated in Okunev??s papers [1, 2]. These studies were continued in [3], where plane motions of an orbit tether (represented as a dumbbell-shaped satellite) in a circular orbit were considered in the satellite approximation. In [4], in the case of equal masses and in the unbounded statement, the energy-momentum method was used to perform the dynamic reduction of the problem and analyze the stability of relative equilibria. A similar technique was used in [5], where, in contrast to the above-mentioned problems, the massive points were connected by an elastic spring resisting to compression and forming a dumbbell with elastic properties. Under such assumptions, the stability of radial configurations was investigated in that paper. The bifurcations and stability of steady-state configurations of a deformable elastic dumbbell were also studied in [6]. Various obstacles arising in the construction of orbital cable systems, in particular, the strong deformability of known materials, were discussed in [7]. In [8], the problem of orbital motion of a pair of massive points connected by an inextensible weightless cable was considered in the exact statement. In other words, it was assumed that a unilateral constraint is imposed on themassive points. The conditions of stability of vertical positions of the relative equilibria of the cable system, which were obtained in [8], can be used for any ratio of the subsatellite and station masses. In turn, these results agree well with the results obtained earlier in the studies of stability of vertical configurations in the case of equal masses of the system end bodies [3, 4]. One of the basic papers in the dynamics of three-body orbital cable systems is the paper [9]. The steady-state motions and their bifurcations and stability were studied depending on the elevator cabin position in [10].