【作者】 陈哲吾；

【导师】 文桂林；

【作者基本信息】 湖南大学 ， 机械工程， 2013， 博士

【摘要】 对未知世界的探索是人类科技发展的原动力，深空探测就是人类当前探索未知的重要活动，月球作为人类探测太阳系和其它星球最理想的跳板和中转基地，也就成为人类深空探测的首选目标。采用月面巡视探测器（月球车）进行巡视探测是月球探测的重要手段，但月球车不能直接降落到月球表面，必须通过带有缓冲装置的着陆器进行搭载，待着陆器安全软着陆后借助专门的特殊释放装置从着陆器的搭载舱转移到月面之上，这个特殊释放装置就是转移机构。转移机构是月面巡视探测器在着陆器和月球表面之间的桥梁，转移过程是实现工程目标的重要环节。为了保证月球探测任务顺利完成，必须解决转移机构的结构刚度和强度、月面适应性以及巡视器在转移过程中的平稳性和可靠性等难点。在发射和飞行阶段，转移机构需压紧在着陆器上，必须具有足够的刚度和强度，能经受发射过载，能承受着陆器软着陆时复杂的冲击载荷和结构响应；在着陆后，转移机构要求能够适应各种着陆器姿态及月面工况，在可能存在的极限工况下都能保证巡视器安全可靠平稳地转移到月面上并顺利分离。因此，本文直接针对上述重大理论问题和技术难题，进行了大量文献调研，运用航天力学理论、数值计算和试验分析方法，独创性地提出一种新颖转移机构，并以最高的结构刚度、强度并满足其结构质量指标以及发射和工作环境要求为目标，开展转移机构结构优化设计，以确保巡视器释放和转移过程的可行性、可靠性和平稳性。所取得的主要研究成果如下：（1）对比研究了国外已经成功应用的巡视探测器转移机构的典型范例及其构型特点与适用条件，并对国内相关单位提出的转移机构原理样机方案技术特点进行了概述和总结，结合我国探月二期工程任务目标和技术要求及特点，提出了端抱式的转移机构方案。（2）针对月面巡视器转移机构的整个工作过程以及典型极限工况，运用运动学、动力学原理，建立了转移工作各个阶段的力学模型，应用经典力学方法对转移机构主要承载部件各个阶段的力学载荷进行了理论计算，然后再通过多体动力学软件对转移机构工作过程的动力学特性进行了仿真分析，通过理论计算和仿真分析进行相互验证，确定了转移机构各个承载部件的载荷数据。（3）针对目前航天电机环境适应性差、较笨重的特点，本文提出了特殊的开口环形截面薄壁扭杆取代电机作为端抱式转移机构的动力源方案。为了获得开口环形截面薄壁扭杆的性能数据，基于圣维南原理、小变形理论和外轮廓不变假设，建立开口环形截面薄壁扭杆的约束扭转微分方程，采用初参数法对约束扭转微分方程进行了求解，得到开口环形截面薄壁扭杆的扭转性能及其应力应变关系；再通过理论计算与数值计算方法和实验相结合的研究方法，对开口扭杆的力学特性进行了研究，确定了开口环形截面薄壁扭杆的扭转力学特性。（4）针对航天机构的轻量化和环境要求，采用了碳纤维复合材料对转移机构摆臂进行结构设计。针对碳纤维复合材料的特殊性能，基于经典层合板理论研究了各向异性的碳纤维复合材料的应力应变关系，并借助分层实体单元模型建立了各向异性的多层碳纤维复合材料的材料单元模型；然后根据端抱式转移机构的载荷工况定义了转移机构的边界约束条件和在和条件，建立了各个典型工况下的转移机构的有限元模型，并对转移机构所处的力学环境和典型极限工况，进行了谐振分析及力学校核，完成了端抱式转移机构的力学特性研究。（5）针对跨度比较大的摆臂，以结构质量为约束条件，以摆臂的刚度为设计目标函数，采用多目标粒子群算法，对其截面尺寸进行了优化设计；针对空间结构的举升框，以举升框的体积为约束条件，以结构柔度为目标函数，基于变密度法对举升框进行了多工况下的拓扑优化设计。通过对转移机构主要部件的尺寸优化和拓扑优化，完善了端抱式转移机构的方案设计，提高了转移机构的结构刚度、强度以及整个转移机构的可靠性。（6）为了验证整个端抱式转移机构方案的可行性以及合理性，针对转移机构的极限工况，以“共心三轴承”机构为基础，设计了姿态模拟试验平台，并对端抱式转移机构进行了相关的功能验证和环境适应性验证等地面模拟试验，验证了转移机构结构设计的可行性和可靠性。更多还原

【Abstract】 The exploration of the unknown world is the motive power of human technologicaldevelopment. The deep space exploration is an important activity in the process ofexploring the unknown. As an optimal springboard and transfer base of human’sexploring the solar system and other planets, the moon becomes a first target of deepspace exploration. Lunar exploration rover (or Lunar rover vehicle) used to explore isan important means of lunar exploration, but it can not directly descend to the surfaceof the moon. Lunar rover vehicle must be equipped with a lander of buffer device andis transferred to the lunar surface with the dedicated special release device from thelander equipped with tanks after a safe soft landing of the lander. The special releasedevice is transfer mechanism, and directly determines the success of a lunarexploration project as a bridge between the lander and lunar surface.In order to complete the lunar exploration mission successfully, we must solvestructure of the transfer mechanism stiffness and strength, adaptability of the lunarsurface, as well as the stability and reliability in the process of the inspector transfer.In the launch and flight phases, the transfer mechanism which has sufficient stiffnessand strength to withstand emitted overload, and withstand complex impact load andstructural response when a soft landing of the lander need to be pressed against thelander; After landing, the transfer mechanism requires the ability to adapt to the landerattitude and working conditions of the lunar surface, and guarantees safe and reliabletransfer smoothly to the lunar surface and a smooth separation in possible extremeworking conditions.Therefore, to solve the major theoretical and technical problems, this thesis carriesout extensive literature research, uses the aerospace mechanics theory, numericalmethods of calculation and experimental analysis, and originally proposes a noveltransfer mechanism. Targeting to their lightest structural quality meeting its launch andworking environment, it carries out the structural optimization design of transfermechanism to ensure that the feasibility, reliability and stability in the process ofinspections release and transfer. Main research results obtained are as follows:(1) This thesis compares and studies a typical example of the transfer mechanismapplied abroad successfully and its configuration features and applicable conditions,draws an overview and summary of technical characteristics of the transfer mechanism on the principle prototype program, and proposes the hold-type transport mechanismprograms through combining with the second phase of China’s lunar explorationmission objectives and technical requirements and characteristics.(2) For the whole working process of the lunar transfer mechanism as well as thetypical limit conditions, the mechanical models of the various stages of the transferwork are built by use of the principle of kinematics and dynamics, the mechanicalloads of the various stages of transfer mechanism bearing members are calculated bythe application of classical mechanics method, and then the dynamics of the process ofthe transfer mechanism work are analyzed by using the multi-body dynamics software.The payload data of the respective bearing member of the transfer mechanism isdetermined through the comparison between theoretical calculations and simulationanalysis.(3) For the characteristics of heavy and poor environmental adaptability ofaerospace motor, this thesis proposes a special opening annular cross-sectionthin-walled torsion bar to replace the motor as the power source for the program ofhold-type transport mechanism. In order to obtain the performance data of openingannular cross-section thin-walled torsion bar, the torsion differential equations of theopening ring-shaped cross-section thin-walled torsion bar are established based on theSaint-Venant principle, small deformation theory and the outer contour of the sameassumptions, and the torsion properties of the opening ring-shaped cross-sectionthin-walled torsion bar and its stress-strain relationship are obtained by solvingconstrained torsion differential equations with the initial parameter method; Thenthrough theoretical calculations combined with numerical methods and experimentalresearch methods, the mechanical properties of the torsion bar are studies and thetorsion mechanical characteristics of the opening ring-shaped cross-section thin-walledtorsion bar are determined.(4) For the lightweight of space agency and environmental requirements, the swingarms of transfer mechanism are designed by using a carbon fiber composite material.For the special properties of carbon fiber composite materials, the stress-strainrelations of anisotropic carbon fiber composite materials are studied based on theclassical laminated plate theory and the anisotropic multi-layered carbon fibercomposite materials unit model is built by layered solid element model; Then theboundary constraint conditions of the transfer mechanism are defined according to theload conditions of the hold-type transport mechanism, a finite element model of the transfer mechanism of various typical conditions is established and the resonanceanalysis and mechanical check are conducted on the mechanical environment andtypical limit conditions in which the transfer mechanism is, and the study of themechanical properties of hold-type transport mechanism is completed.(5) For the larger span swing arm, the design of its cross-sectional dimension isoptimized by use of multi-objective particle swarm algorithm under the constraintconditions of structure quality and the design objective function of swing arm stiffness;For the lifting frame of the spatial structure, the topology optimization design of liftframe under multiple working conditions is conducted by using variable densitymethod under the constraint conditions of lifting frame’s size and the objectivefunction of structure compliance. Through the size optimization and topologyoptimization of the main components of transfer mechanism, the design of hold-typetransport mechanism is improved, and the structure stiffness, strength and reliability oftransfer mechanism are increased.(6) In order to verify the feasibility and rationality of the entire hold-type transportmechanism programs, the attitude simulation test platform under the limit conditionsof the transfer mechanism is designed based on a concentric three-bearing bodies, andthe feasibility and reliability of the transfer mechanism structure design is verifiedunder the related functional verification and environmental adaptability verification ofhold-type transport mechanism.更多还原