【作者】 赵彪；

【导师】 崔祜涛； 郭继峰；

【作者基本信息】 哈尔滨工业大学 ， 航空宇航科学与技术， 2013， 博士

【摘要】 相比小升阻比飞行器，较高升阻比的气动外形从根本上决定了升力式飞行器具有再入过载小，机动范围大，着陆精度高的优点，具有巨大的吸引力和发展前景。美国、俄罗斯、欧盟均对基于升力式再入的天地往返飞行器研制投入了相当的人力、物力和财力。但历史飞行实践证明，研制上述飞行器所必须的系统可靠性、可重复使用等相关技术成熟度远未达到预计的程度。技术风险导致的重大事故使航天事业重创并促使了技术反思，新一代的天地往返飞行器必须也必然会在功能定位上更加明确，在系统规模上适当缩减，并着力提高系统可靠性。美国在宣布正式退役航天飞机的同时，启动了新一代运载器和新一代飞船的研制；同期，俄罗斯适时的公开了一种介于传统载人飞船和航天飞机的新型天地往返可重复使用飞行器“快船”。快船式飞行器双构型方案设计具有同时满足技术性和可靠性需求的潜力，代表了新一代天地往返飞行器的发展方向。本研究基于对国内外天地往返飞行器技术发展路线的归纳总结，以及对新一代天地往返飞行器技术发展趋势的分析，以类似快船式飞行器两种构型方案设计的一类升力式再入飞行器为具体对象，研究了适于分析其再入段受力环境和轨迹特性的数值计算方法，并以此为基础，分别针对上述两种不同构型的快船式飞行器，研究了具有较强的自主性和稳健性的高精度再入制导方法，主要包括以下几个方面：首先，根据总体设计阶段的任务，针对快船式飞行器双构型方案模型的特点，从系统均衡角度分别选用了工程计算方法和数值计算方法，进行了再入边界条件下的纵向气动特性计算和分析。计算结果表明，快船式飞行器纵向气动系数随攻角和马赫数的变化具有规律性。在小攻角范围，气动系数总体变化平缓，攻角继续增大时，激波干扰诱发气流分离并形成分离旋涡，导致了飞行器表面压力载荷分布的复杂变化，表现为气动系数的非线性变化。其次，研究了一般序列梯度-修复算法在升力式再入飞行器轨迹优化问题中的具体应用，形成了一种改进的序列梯度-修复轨迹优化方法。通过对控制约束和过程约束一般数学模型的转化处理，建立了增广的再入运动方程和控制变量，为减小再入运动模型固有的强非线性的影响，引入了状态积分的更新方法，进行了算法程序仿真分析，研究了不同初值、更新方法、大气模型、约束处理对数值优化结果的影响。基于再入轨迹数值优化结果，综合分析和考虑了初始再入段、平衡滑翔段和末端能量管理段的攻角设计因素，提出“常值大攻角减速+最大升阻比攻角过渡”的攻角方案，针对不同任务背景，具体设计了攻角剖面函数，并用于再入制导算法设计。再次，基于轨迹-跟踪制导方法的框架，研究了一种新型的在线三维轨迹规划-轨迹跟踪再入制导方法。该方法基于桥函数法设计阻力加速度-能量剖面基准形式，并基于二分段更新策略进行在线轨迹规划，在每个规划阶段，基于一次倾侧翻转模式，通过参数调节获得与目标航程匹配的参考阻力加速度-能量剖面，以倾侧角为主要跟踪控制变量实现了标准轨迹-跟踪制导。轨迹规划同时考虑了飞行器的纵横向运动，不需要专门调节倾侧翻转时机的侧向环节。算法程序仿真表明，在线规划出的参考阻力加速度剖面呈现贴近平衡滑翔边界小幅波动变化的趋势，实际上保证了再入轨迹在满足过程约束的同时，沿着平衡滑翔边界平稳下降，直至再入段末端。蒙特卡洛分析表明，该方法能够快速有效地进行三维再入轨迹自主规划，具有较高的末端制导精度、较强的任务适应性和向在线制导应用的发展潜力。最后，基于预测-校正制导方法的框架，研究了一种基于虚拟落点策略的数值预测-校正再入制导方法。该方法在给定攻角剖面条件下，利用平衡滑翔条件，将过程约束转化为倾侧角-速度走廊，作为标称倾侧角剖面的设计约束和预测-校正算法准制导指令输出的截断边界。在侧向制导逻辑中引入了基于虚拟落点瞄准的策略，充分利用高层稀薄大气阻尼的时间累积效应，通过调控初始下降段的倾侧角，导引飞行器产生可观的侧向偏移量，用于抵消地球系下非惯性力的影响。减轻了转入平衡滑翔段后的制导负担。程序仿真分析表明，该方法克服了中低气动品质飞行器轨迹跟踪能力不足导致跟踪制导精度低的矛盾，具有较强的任务适应性和较高的算法稳定性。蒙特卡洛分析表明，基于虚拟落点策略提出的偏置瞄准程序能够有效的提高再入末端制导精度，尤其是在长航程和大轨道倾角再入状况，效果较为明显，且具有简便易操作性。更多还原

【Abstract】 Lifting entry vehicle has advantages of high lift-to-drag ratio, small entry overload,large motorized range, and high landing accuracy, so it has enormous appeal anddevelopment prospects. The United States, Russia and EU have invested a lot ofmanpower, material and financial resources on the research of lifting entrytransportation vehicle. But the history has proved that the system reliability and thereusable technology which is necessary in the development of transportation vehicle arefar from the expected level.While announcing the retired of the space shuttle, the United States starts adevelopment program of new generation of launch vehicle and spacecraft. During thesame period, Russia discloses a new transportation vehicle Clippers, which between thetraditional manned spacecraft and the space shuttle. With two configuration designs, theClippers vehicle has the potential to meet the technical and reliability requirements, andit is considered to be the represent of the new generation transportation vehicle. Thispaper summed up the technology development path and analyzes the technology trendsof the transportation vehicle in the world. It takes the Clippers-type vehicle as theresearch object and focuses on its entry force environment, trajectory characteristics,and autonomous entry guidance method for lifting entry. The study includes thefollowing aspects.First, according to the overall design phase of the mission and features of the twotypical configurations of the Clippers vehicle, engineering calculation methods andnumerical methods were used from the perspective of system balancing in thecalculation and analysis of longitudinal aerodynamic characteristics. The results showthat the longitudinal aerodynamic coefficient Clippers vehicle having remarkableregularity with the change of angle of attack and Mach number. In the range of smallangle of attack, the aerodynamic coefficient changes gently. While the angle of attackcontinues to increase, the shock interaction induced flow separation, and it then formedseparation vortices, which led to complex changes in the vehicle surface pressure loaddistribution, this phenomenon manifests as the nonlinear changes in the aerodynamiccoefficients.Secondly, this paper studies the specific applications of the SG-R algorithm in thetrajectory optimization of lifting entry vehicle, and formed an improved SG-Roptimization method. Through the conversion of the general mathematical model of thecontrol constraints and process constraints, the augmented entry equations of motionand control variables are constructed. In order to reduce the nonlinear effects inherent inthe motion model, a full state integral-update method is introduced. The influence onthe results of numerical optimization of different conditions, such as the initial updatemethod, atmospheric model, constraint processing method, is analyzed by the algorithmsimulation. Based on the numerical optimization results of entry trajectory, various design factors of angle of attack in the initial entry phase, equilibrium glide phase andTerminal Area Energy Management are considered. This paper proposed the program ofconstant high angle of attack and maximum lift-drag ratio angle of attack for differenttasks backgrounds, the specific profile function of the angle of attack is designed andused for entry guidance algorithm design.Thirdly, a new online three-dimensional trajectory planning and trajectory trackingentry guidance method is designed based on drag acceleration versus energy profile isproposed. The trajectory planning is based on two sub-line updating policy. In eachplanning stage, the bank angle reverses only once. The reference drag accelerationenergy profile is matched to the target range by adjusting the parameters, and nominaltrajectory is tracked using the bank angle as the main tracking control variables. Sincethe trajectory planning taking into account the vertical and horizontal movement of thevehicle, it does not need to specifically regulate the bank reverse in lateral channel. Thealgorithm program simulation results show that, online planning reference dragacceleration profile shows the trend of slightly fluctuating by the balanced gliderboundary, which keep the entry trajectory to meet process constraints, decent along thebalanced glider border steadily until the end of the entry phase. Monte Carlo analysisshows that, the method is able to independent planning three-dimensional entrytrajectory quickly and efficiently. It has high guidance precision, strong task adaptabilityand the potential of online application.Finally, in the framework of predictor-corrector guidance, a numerical predictioncorrection entry guidance which based on virtual target strategy is present. By using thebalance gliding conditions, the method transformed the process constraints into the bankangle velocity corridor under the condition of the angle of attack profile is given, whichis used as the design constraints of the nominal bank profile and the output truncatedboundary of quasi-guidance commands. In lateral guidance logic, a virtual targetstrategy is introduced. It makes full use of the time cumulative effect of high-levelatmospheric damping. By regulating the bank angle of initial decrease phase, guidingthe vehicle flight a considerable lateral offset, which is used to offset the impact of thenon-inertial force in the department of earth, and the guidance burden of thequasi-equilibrium glide phase will be reduced. The program simulation analysis showsthat, the method overcomes the contradiction of insufficient accuracy of entry guidancedue to the limited trajectory tracking capability. The algorithm has strong taskadaptability and high stability. Monte Carlo analysis shows that, the bias targetingstrategy has enhanced and ensured the entry terminal guidance accuracy. Especially inthe long range and large orbital inclination entry conditions, the effect is more obvious,and it has a simple and easy maneuverability.更多还原