大视场长焦面光学遥感器双凸轮式焦面调焦机构

为保证焦面长度大于600mm的大视场空间光学遥感器在空间环境下的成像质量,设计了一套在±2 mm调焦范围内焦面组件倾斜小于7”、定位精度优于0.01 mm的焦面调焦机构.针对系统对调焦精度、力学环境、真空环境的要求,该调焦机构采用双凸轮驱动技术来满足调焦精度要求;采用失电制动器自锁技术,使相机经发射等力学环境冲击后像面位置仍保持稳定.此外,采用高刚度导轨和轴承使调焦机构具有较高的动态刚度.设计分析及实验证明,该套焦面调焦机构具有较高的调焦精度和可靠性,能够在复杂的空间环境下完成调焦任务,提高遥感器的成像质量.     

600 mm长焦平面时间延迟积分CCD的交错拼接

为了满足空间宽幅相机大视场的需求,研究了对多片CCD器件进行拼接以获得超长焦平面组件的方法。使用长线阵时间延迟积分(TDI)CCD拼接仪,按照设计位置和精度要求把17片TDICCD器件拼接到焦平面板上,用销钉定位,获得了长为600mm、像元为69 000个的超长焦平面。然后,对完成拼接的焦平面组件进行了高低温循环试验、热真空试验和振动试验。实验结果表明,焦平面组件的结构设计和材料选取满足力学/热学要求。对完成拼接的600mm长焦平面组件进行了TDICCD拼接精度的检测,检测结果显示拼接误差小于3μm。将该超长焦平面组件用于遥感相机,通过成像实验获得了清晰的无缝宽幅图像。上述结果证明600mm长焦平面组件满足空间宽幅相机的应用需求。     

TDICCD交错拼接的精度检测

摘 要：焦平面组件是遥感相机的重要组成部分,TDICCD的交错拼接可以获得大尺寸的焦平面。由于TDICCD交错拼接的焦面长度一般较长,常规的检测方法很难获得准确的检测结果。故采用对拼接TDICCD像元直接监测的方法,使用直线度小于2μm/m的气浮导轨,搭载显微系统对像元进行空间位置检测。并对已经完成拼接的600mm长焦平面进行了精度的检测,得到的检测结果误差小于3μm。根据遥感相机地面成像试验所得到的图像研究分析,图像反映的拼接精度与检测所得到的结果吻合,从而验证了检测结果的准确性及检测方法的可行性,实现了长焦平面的高精度检测。     

空间相机CCD焦平面的光学拼接

为满足空间相机在大视场、高分辨率下进行测量,研究了多片线阵CCD拼接技术,阐述了光学拼接的原理、装调、检测方法和焦面结构.在由长工作距显微镜和精密X-Y导轨组成的拼接设备上,采用分光棱镜、机械微调的方法完成了三片TDICCD的光学拼接,搭接误差不超过1/3像素.光学拼接具有结构简单,成本低和使用灵活的优点.     

遥感相机焦面CCD机械拼接中重叠像元数的确定

针对推扫式遥感相机前后摆成像中焦面拼接的CCD其像片间出现视场漏缝的问题,提出了一种焦面CCD的非均匀重叠像元数机械拼接方法.首先,构造了相机前后摆的成像原理模型;接着,分析了CCD间产生地面视场漏缝的原因,并依据模型推导出相机前摆和后摆时各CCD视场间漏缝大小的数学公式,从而得到各片间容许的最少重叠像元数量公式.在此基础上,进一步给出了后续电子学图像拼接与配准中片间重复像元数的函数形式,为实现图像无缝拼接提供了软件实现依据.分析表明,该方法的理论误差ε小于一个像元尺寸,即|ε/D|＜1.最后,给出了工程应用实例.     

一种航空画幅遥感相机调焦机构的设计

提出了一种用于解决某画幅相机离焦的调焦机构。通过几种调焦方案的对比,选择了一种适合于某型相机的调焦方案。采用调焦凸轮和直线导轨配合使用的方案,将凸轮的旋转运动转化成调焦镜的直线运动,实现了通过调整反射镜的位置来调整相机焦面和成像介质的相对位置,解决离焦问题。通过试验验证调焦镜在动态条件下的调焦精度,满足使用要求。     

低轨TDICCD相机像质地面模拟测试技术研究

为了对特定微结构时间延迟积分电荷耦合器件（TDICCD）相机进行装调及性能测试,提出并搭建了一套动态调制传递函数（ MTF ）地面模拟测试装置。在实现TDICCD相机成像的基础上,利用刃边法对相机的MTF进行测量。经理论分析及实验验证,该装置测量精度优于5%,满足设计要求。并利用该装置分析了速高比v/h、偏流角$ \theta $这两个因素对TDICCD相机像质的影响,其结果与理论相符。所提出的装置满足TDICCD相机地面动态MTF测试技术需求,具有一定工程意义。     

星载多光谱CCD相机研究

研制的星载多光谱 CCD相机采用线阵 CCD推扫方式成像 ,具有蓝、绿、红、近红外、全色五个成像谱段 ,在轨工作时地面像元分辨率为 2 0米 ,覆盖宽度 113公里。相机光学系统采用单镜头焦面分色结构实现多光谱成像 ,每个谱段的探测器阵列由 3片 2 0 4 8元 CCD光学拼接而成 ,以实现地面宽覆盖成像。多片 CCD信号采用串行读出方式 ,使焦面 15片 CCD形成两路视频信号输出给数据传输系统。测试结果显示 ,相机各谱段 MTF典型值为 0 .2 5 ,满足使用要求。     

大视场空间相机的像移速度场模型及卫星三轴姿态稳定度分析

针对大视场空间相机的像移补偿,建立了基于坐标变换和姿态动力学的离轴三反大视场空间相机通用像移速度场模型。建模过程中考虑了离轴三反光学系统的离轴角对像移模型的影响,推导了离轴三反大视场空间相机的像速场解析式。以某大视场空间相机为例,分析了3种典型成像姿态下焦面像移速度和偏流角的分布特点,研究了卫星姿态稳定度对相机成像质量的影响。分析表明,卫星三轴姿态稳定度的降低会导致相机焦面动态传递函数(MTF)下降,其中俯仰姿态稳定度对焦面动态MTF的影响最大;并且随着积分级数增加,下降会愈发明显。相机侧摆姿态成像时,对卫星姿态稳定度的要求更高。以传递函数下降5%为限,积分级数为96级的大视场空间相机,要求卫星姿态稳定度控制在0.001(°)/s以内。实验结果验证了文中对卫星姿态稳定度的分析,证明了像移速度场模型的准确性,为大视场空间相机像移补偿提供了可靠依据。     

空间TDICCD相机动态成像地面检测系统的设计

设计了一种空间TDICCD(时间延迟积分电荷耦合器件)相机动态成像地面检测系统,用于模拟相对空间飞行器的地面像移,验证TDICCD相机的像速匹配能力和动态成像质量。系统采用精密转台和偏流转台模拟卫星绕地球运动和卫星受地球自转影响而在不同纬度产生不同的偏流运动。精密转台用永磁力矩电机驱动,用锁相锁频伺服控制策略控制稳速精度达到0.0297%。偏流转台用步进电机控制,偏流角的平均转角速率约为0.02°/s,偏流角位置的数据引导跟踪精度优于±5′。设计的检测系统的精度满足TDICCD相机动态成像检测的指标要求,已在某型号空间可见光相机的研制中获得了应用。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.