One method of controlling the motion of an aerospace vehicle during its long flight in the atmosphere

Based on the methods of the theory of optimum control of dynamic systems, as well as the methods of inverse problems of dynamics and the energy principle, a combined method is developed for control of the motion of a flying vehicle of the Aerospace plane type during the long flight in the atmosphere. The disturbed motion is considered under the conditions when there are constraints on the values of control actions and on functions of phase coordinates.     

Disturbance of the upper atmosphere after crash launch of the <Emphasis Type="Italic">Proton</Emphasis> carrier rocket

The data of inclined sounding obtained on July 5, 1999 after explosion of the Proton carrier launcher in the upper atmosphere are discussed. A comparative analysis is performed of the detected disturbances with disturbances recorded during explosion of the Soyuz rocket in the middle atmosphere and with disturbances typical for the standard mode of the rocket flight.     

基于整体级概念的多级固体运载火箭设计与优化

针对多级固体运载火箭小型化需求,采用整体级概念(ISC)进行总体方案改造和优化设计.描述了2种ISC概念的特点,以某三级常规方案固体运载火箭为基准,通过利用级间的剩余空间,完成ISC方案改造.建立了运载火箭的整体级发动机动力计算模型、气动计算模型和弹道计算模型,并结合任务指标要求,提出了运载火箭的总体参数优化模型.在相同的任务条件下,完成了常规方案和2种ISC方案的优化.结果表明,引入ISC概念可将运载火箭体积缩小15%～20%,起飞总重缩小1%～1.5%,满足了总体指标要求,达到了运载火箭小型化设计目的.     

Features of rotational motion of a spacecraft descending in the Martian atmosphere

Angular motion at atmospheric entry is studied in the paper for a spacecraft with a bi-harmonic moment characteristic. Special attention is given to the case when the spacecraft possesses two stable balanced positions, and, hence, it can oscillate in dense atmospheric layers in the ranges of small or large angles of attack. The averaged equations of spacecraft motion are derived, which allow one to increase the speed of calculations by several orders of magnitude. A real example is presented, which concerns a spacecraft specially designed for descending in the Martian atmosphere.     

固体火箭发动机药柱主动段飞行时应力应变分析

为了探讨固体火箭发动机药柱主动段飞行时的形变、应力和应变变化规律,以星形药型发动机为例,采用三维粘弹性有限元法,根据推进剂药柱的燃烧规律,通过计算发动机药柱在整个工作过程中不同烧蚀情况下各构成部分的结构响应,得到了主动段飞行时发动机药柱在不同环境温度、燃气内压与轴向过载联合作用下位移、应力和应变场随时间的变化规律。结果表明,低温点火发射时,内压增压至峰值时为发动机最危险时刻。     

Statistical analysis of attitude motion of a light capsule entering the atmosphere

The laws of distribution of the space angle of attack are analyzed for a light descent capsule on the atmosphere’s conventional boundary and on the segment of motion in dense layers of the atmosphere until the moment of reaching the maximum velocity head. It is assumed that upon detachment from a base spacecraft the angular velocity components of the descent capsule represent independent random quantities distributed according to the normal law. The shape of the descent capsule is close to a body of revolution whose instantaneous aerodynamic characteristic has a sufficiently simple form (one stable and one unstable positions of static equilibrium). It is demonstrated that there is a possibility to approximate the distribution densities by well-known laws and by approximate functions constructed on the basis of simplified models. Evolution of the distribution laws at increasing mass-inertia asymmetry of the descent capsule is studied.     

末修火箭弹抛物线比例导引的特性

基于抛物线比例导引原理,详细分析了弹道修正所需求的脉冲数。结合抛物线比例导引特性,对规定落角进行了理论分析与仿真。结果表明,规定落角越大,脉冲需求数越小,对规定落角的敏感性越大,落点修正距离会越小。提出了确定规定落角的基本原则:弹道修正段前期,规定落角主要由目标点位置决定,可根据火箭结构特点和使用环境特性,采用非线性控制系统确定;弹道修正段末期,规定落角对落点影响较小,可结合战技指标中毁伤效能要求确定。     

Problems of control of a re-entry vehicle with a moderate lift-to-drag ratio during its entry into the atmosphere

We consider the problems of control of the angular and trajectory motion of the Kliper re-entry vehicle. This spacecraft with a moderate hypersonic lift-to-drag ratio is designed according to the load-carrying frame scheme. Gas-dynamic engines, a split balancing flap, and an air brake are used as mounting devices of control.     

Quaternion regularization in celestial mechanics and astrodynamics and trajectory motion control. I

Regularization problems in celestial mechanics and astrodynamics are considered. The fundamental regular quaternion models of celestial mechanics and astrodynamics are presented. It is shown that the efficiency of analytical investigation and numerical solution of boundary problems of optimal trajectory motion control of spacecraft may be increased using quaternion astrodynamics models. The regularization problem of celestial mechanics and astrodynamics that implies eliminating the feature, which arises in the equations of the two-body problem in case of impact of the second body with the central body, is considered in the first section of the paper. The quaternion method for regularizing the equations of the perturbed spatial two-body problem suggested by the author is presented; the method is compared with Kustaanheimo-Stiefel (KS) regularization. Demonstrative geometric and kinematic interpretations of regularizing transformations are provided. Regular quaternion equations for the two-body problem, which generalize the regular Kustaanheimo-Stiefel equations, as well as regular equations in quaternion osculating elements and quaternion regular equations for perturbed central motion of a material point, are considered. The papers on quaternion regularization in celestial mechanics and astrodynamics are briefly analyzed.     

Quaternion regularization and trajectory motion control in celestial mechanics and astrodynamics: II

Problems of regularization in celestial mechanics and astrodynamics are considered, and basic regular quaternion models for celestial mechanics and astrodynamics are presented. It is shown that the effectiveness of analytical studies and numerical solutions to boundary value problems of controlling the trajectory motion of spacecraft can be improved by using quaternion models of astrodynamics. In this second part of the paper, specific singularity-type features (division by zero) are considered. They result from using classical equations in angular variables (particularly in Euler variables) in celestial mechanics and astrodynamics and can be eliminated by using Euler (Rodrigues-Hamilton) parameters and Hamilton quaternions. Basic regular (in the above sense) quaternion models of celestial mechanics and astrodynamics are considered; these include equations of trajectory motion written in nonholonomic, orbital, and ideal moving trihedrals whose rotational motions are described by Euler parameters and quaternions of turn; and quaternion equations of instantaneous orbit orientation of a celestial body (spacecraft). New quaternion regular equations are derived for the perturbed three-dimensional two-body problem (spacecraft trajectory motion). These equations are constructed using ideal rectangular Hansen coordinates and quaternion variables, and they have additional advantages over those known for regular Kustaanheimo-Stiefel equations.     

Ballistics, navigation, and motion control for a spacecraft during its landing on the surface of Phobos

Basic concepts and algorithms laid as foundations of the scheme of landing on the Martian moon Phobos (developed for the Phobos-Grunt project) are presented. The conditions ensuring the landing are discussed. Algorithms of onboard navigation and control are described. The equations of spacecraft motion with respect to Phobos are considered, as well as their use for correction of the spacecraft motion. The algorithm of estimation of the spacecraft’s state vector using measurements with a laser altimeter and Doppler meter of velocity and distance is presented. A system for modeling the landing with a firmware complex including a prototype of the onboard computer is described.     

某平台卫星发射及在轨力学环境测量与分析

为获取航天器准确的发射及在轨力学环境数据,设计了一套具有数据采集、存储和传输功能的星载测量系统。利用该系统对某大型平台卫星发射飞行过程进行了测量,获取了星箭界面及卫星结构典型位置在发射主动段的正弦振动响应、随机振动响应、冲击响应及在轨微振动的环境数据。将测量数据与星箭载荷耦合分析结果、地面力学试验结果进行了详细对比,结果表明:星箭载荷耦合分析的结果在星箭界面处横向相对准确,而纵向在有限频段准确,其他频段及星上分析结果均大于测量结果,即存在极大裕度;地面试验结果大于测量结果,意味着有较大的裁剪设计空间。测量数据对后续卫星模型修正、试验条件设计、相似平台卫星抗力学环境优化、部组件设计等均具有重要的参考价值。     

电磁发射技术的关键问题及其数值模拟

为了分析影响电磁发射性能关键技术问题,研究了电磁发射的相关因素,并进行了仿真分析.对当前提出的几类电磁发射技术进行总结,分析了其在高功率脉冲电源,电力调节控制,轨道、弹丸材料与结构以及抗烧蚀等方面的技术问题.讨论了轨道式发射装置的教学模型,并进行仿真.对发射效率、出口速度和发射精度等指标进行数据分析.结果表明,电源功率、轨道材料性能和电力调节控制方法是影响电磁发射性能的关键因素.     

我国载人登月重型运载火箭动力系统探讨

月球研究与利用是21世纪航天发展的重点之一。根据载人登月的需求,探讨了我国重型运载火箭及其动力系统的技术途径,提出研制大推力液氧/烃和液氧/液氢发动机的设想。重点论证了大推力下面级发动机的推进剂组合、动力循环方式及推力量级,认为该发动机推进剂应选择环保、廉价及高性能的液氧/烃组合,动力循环方式应采用先进的补燃循环或低成本的燃气发生器循环,推力应为4000kN左右。     

利用有限元方法逼近飞行器轨道主动段扰动引力

为了克服引力位系数模型计算飞行器轨道主动段扰动引力所存在的计算量大，并且难以进行实时计算的缺点，提出利用有限元内插的方法对主动段扰动引力进行逼近。根据有限元分析中区域剖分插值的原理，采用了对飞行器轨道周围有限范围的空间区域进行有限元剖分的方式，计算出各剖分单元每个顶点处的扰动引力，然后利用剖分单元各顶点的扰动引力分量内插出飞行器轨道点对应的扰动引力分量值。计算过程和结果表明，这种方法能够快速、精确可靠地逼近飞行器轨道主动段扰动引力，满足了有关文献中所提出的要求。     

运载火箭地面测发控设备研制中的“三化”设计

分析目前我国运载火箭地面测发控设备"三化"的现状,简介我国现有的运载火箭地面测发控"三化"标准,提出进一步开展运载火箭地面测发控设备"三化"工作的设想.     

稳健优化设计及其在固体火箭发动机装药设计中的应用

为了提高固体火箭发动机在干扰因素作用下的性能精度,将稳健优化设计方法引入固体火箭发动机装药设计中。首先介绍了稳健优化设计的基本概念和设计流程,通过装药设计实例分析了稳健优化设计特点及适用性。结果表明,稳健优化设计既可较好地保证设计约束的可行稳健性,又可降低发动机性能在随机因素作用下的散布范围。为解决固体火箭发动机推力不平衡问题提供了很好的解决方法。     

A generalization of the rocket formula and its application to advanced space propulsion systems

A generalized rocket formula is derived from a first principles approach. The resulting expression of the thrust is applied to advanced space propulsion systems and a possible link between the asymptotic propellant velocity and the velocity at thruster exit is given. An estimation of the thrust modification due to spacecraft–plume interactions is also considered.     

水平空中发射固体有翼运载火箭总体/动力/气动/轨道一体化设计与优化

综合考虑固体火箭发动机设计、带翼火箭气动外形设计、轨道设计和总体特性相互作用相互影响的情况下,建立了水平空中发射固体有翼运载火箭总体／动力／气动／轨道一体化设计优化模型和系统分析模型。测试了系统分析软件,应用基于方向的遗传算法优选了某水平空中发射固体有翼运载火箭28个设计参数。结果表明,计算结果与工程实际结果吻合较好,优化设计效果明显,优化所得火箭起飞质量是原方案的84．32％。     

Numerical solutions to exact equations of motion along near-optimal multi-orbit trajectories for a spacecraft in a Newtonian gravitational field

The actual topic of optimization of multi-orbit low-thrust spacecraft inter-orbital transfers is considered. We have developed an original approach to solving this problem, and it is described.