【作者】 孙德伟；

【导师】 张广玉； Peter Eberhard；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2011， 博士

【摘要】 空间红外遥感器是一种应用于空间环境的精密光学仪器,主要功能是获取地面和高低空运动物体的影像。它可以在短时间内获得宽正面,大纵深的图像信息。特别是在夜间侦察和辨别散发热流体的运动物体,有着CCD相机无法比拟的优势。同时它具有宽广的应用前景:如红外遥感、地质勘察、火灾预警、气象预报等。它的研制对提高我国在空间红外遥感领域的能力和水平具有重大和深远的意义。由于所搭载的卫星平台属于小卫星平台(“试验三号卫星”),所以卫星总体对红外遥感器的质量和结构尺寸都有严格的限制。红外遥感器的整机必须做到结构紧凑,轻巧可靠。红外遥感器机械系统的任务就是使整机的各个部分集成一个整体,并为它们提供一个稳定,可靠的工作平台。考虑到卫星发射和在轨运行过程中系统又必须经历严酷力学环境,结构设计要做到高刚度,高强度,低质量。本文依据光学系统所要求的技术指标和环境要求,设计出机械系统的总体技术方案,详细阐明其中关键部件的设计思想和实施要点。重点研究石墨纤维增强铝基复合材料在镜筒结构中的应用和标定系统中运动部件的磁锁―――力矩器控制技术。为了实现空间遥感器红外探测器的标定功能,设计一套具有锁定机构的运动部件来驱动标准黑体完成标定和非标定两种状态的转化。针对航天器发射和在轨过程中特殊的力学环境,应用永磁锁定―――力矩器驱动技术来控制标定机构中的运动部件。在发射过程中使用永久磁铁吸引运动部件,限制运动部件的转动自由度;在标定过程中,使用电磁力矩器驱动运动部件实现解锁和标定。分析永磁锁定机构的磁场分布,磁吸力情况以及电磁力矩器的工作特性。对标定机构进行动力学分析,验证标定机构在不同形势的干扰力矩下的锁定情况。然后对标定机构进行有限元模态分析,分析其固有频率和振型。还计算在二年末期标定机构的可靠性指标。使用NSGA-Ⅱ多目标优化算法和复刚度模型对镜筒结构隔振系统进行优化设计,此方法可以给出一组优化解集供设计者根据实际情况和目标需求进行筛选。根据隔振器建模和动力学分析的要求,提出一种隔振器迟滞阻尼特性描述的模型―――变刚度变阻尼模型,即把隔振器用并联弹簧和阻尼器表示,并建立弹性系数和阻尼系数随振动幅值和频率变化的数学模型。使含有柔性支撑结构系统的建模过程实现统一化和规范化。应用机械阻抗法分析基础和被隔振体为柔性体时传递率函数的变化,并与刚性模型进行对比说明在一定的条件下考虑柔性体的必要性。采用二阶Krylov子空间投影法表示具有多自由度的柔性子结构,把这种方法与模态综合技术相结合对具有弹簧和阻尼连接的两个子结构系统进行建模和动力学分析,并与传统的模态综合计算方法进行比较以便检验这种方法的有效性。根据卫星总体提供的振动技术试验要求,对空间遥感器进行了正弦、随机和冲击振动试验。通过振动试验获得关键点位置的加速度响应。振动试验后检查整机的各个组件,没有发现螺钉松动和破坏的现象。后期把镜筒组件与焦平面器件加电进行成像试验,图像清晰完整。更多还原

【Abstract】 Space infrared sensor is a kind of precise optical instrument, which is applied in thespace environment, and its main function is to obtain the images of movement objects onthe ground or in the space. Space infrared sensor can acquire large-scale image informa-tion in a short time, which is better than CCD camera, especially reconnaissance in thenight and discerning move objects sending heat. Meanwhile, space infrared sensor alsohas extensive application prospects, for example, in the field of infrared remote sensing,geology investigation, fire early warning and weather forecast and so on. So this researchwill be significant to strengthen capability of infrared remote sensing.Firstly, space infrared sensor must be assembled on a small satellite platform(“Experiment III Satellite”), so its whole mass and structure dimensions are strictlyrestricted by the satellite platform. The mechanical structure must be compacted, light,handy and reliable. Task of space infrared sensor structure system is to integrate each partsof system and provide a stable and reliable work platform for the whole body. Concerningthat launch and on-orbit processes, space infrared sensor must experience the harsh me-chanics environment and the part of mechanical structure should attain the high stiffness,high strength and low mass. According to the technique targets of optical system andenvironmental requirements, a set of overall planning of structural system is designed.All detailed design thoughts and implementation kernel about the key divisions are clar-ified. Application of graphite fiber reinforced aluminium matrix composite on bodytubeof space infrared and the technology of magnet locking-electromagnet equipment drivingare highlighted investigated.Secondly, a suit of calibration mechanism with locking system to drive the standardblack body is designed, in order to realize the calibrating function of infrared sensor inspace camera. According to the special mechanics environment in satellite during theprocess of launch and on-orbit, a technology of magnet locking-electromagnet equipmentdriving is proposed and applied into the design of the calibration mechanism in the spaceinfrared camera. During the process of launch, the motion component of the calibra-tion mechanism is attracted by the magnet so as to suppress the rotation degree of free-dom. During the process of calibration, the motion component is droved by electromagnet equipment to lock up and fulfill calibrating function. The magnetic field distribution andmagnetic force of calibration mechanism and performance characteristic of electromag-net equipment are analyzed. The dynamic analysis is conducted, which can verify thevalidity of design and analysis of this mechanism under difference disturbance torques.Finite element modal analysis and reliability analysis at two year end are also proceededto test this design.Thirdly, optimization design of the bodytube isolation system is conducted usingNSGA-Ⅱmulti-object optimization algorithm and complex stiffness model. This methodcan provide a group of optimal solutions for designer to filter according to reality situa-tion. According to requirements of isolator modeling and dynamics analysis, an approachcalled variable-rate stiffness and damping to describe hysteresis damping characteristicis presented, which consists of a parallel spring and damper. The mathematical mod-els of elasticity coefficient and damping coefficient with variation of vibration amplitudeand frequency would be obtained. Application of this method will make the process ofmodeling and analysis of rubber isolator unification and standardization.Then, the transfer functions of ?exible object and base are analyzed by using me-chanical impedance method and compared with stiffness models. It indicates that spaceinfrared sensor must be considered the ?exible body in?uence for transfer function onsome certain conditions. Using second order Krylov method expresses multi-DOF ?exi-ble substructure, which combines with modal synthesis method to model and analyze twosubstructures connecting with springs and dampers. Compared with traditional modalsynthesis arithmetic is to verify the effectiveness of second order Krylov method.Finally, according to requirements of vibration experiments from satellite, sine, ran-dom and impact vibration experiments are conducted. Acceleration response of crucialpoint is acquired. After vibration experiment checking every parts of space infrared de-tector, there are no bolts loose and parts damage situations. Then imaging experiment ofinfrared detector is carried out and the image is clear and intact.更多还原