非协作式无人机跟踪障碍物改进方法(英文)

针对非协作式无人机检测与避障系统,采用多传感器进行信息融合的方式进行检测与跟踪,提出了采用正交积分点卡尔曼滤波(QKF)实时跟踪运动目标以提高检测精度和增强有效性。首先,对设计的检测与避障系统进行了简述,由两个子系统构成:由捷联惯性导航系统(SINS)与GPS组成的导航单元及由雷达和光电传感器组成的检测单元。其次,以拐弯模型与Singer模型两个机动运动模型为例测试了QKF算法跟踪检测障碍物的性能,并与无迹卡尔曼滤波(UKF)进行比较。仿真结果表明,相比于UKF算法,QKF算法可以更快速、更准确的检测与跟踪目标。     

封装材料对压阻式加速度传感器性能的影响

通过实验测试的方法研究分析封装材料对压阻式高量程加速度传感器性能的影响。对使用陶瓷 材料和不锈钢材料封装的加速度传感器,利用拉曼光谱仪测试研究封装前后传感器结构中残余应力和压敏 电阻阻值的变化,采用落锤、Hopkinson杆测试分析传感器的灵敏度、高过载能力,并在实弹环境中测试不同 封装传感器的测试精度的差别。实验结果显示,与陶瓷材料封装的压阻式加速度传感器相比,不锈钢材料封 装的压阻式加速度传感器在封装后结构的残余应力和压敏电阻阻值的变化更大,但不锈钢封装传感器的灵 敏度更大、高过载能力更强,同时实弹环境中可靠性和测试精度更高。     

转台测角系统标定方法的研究

本文提出一种高精度转台测角系统标定的新方法，该方法以光电自准直仪作为标定基准，用齿盘、多面棱镜作角度给定，转台工作在速率状态下，自动完成高精度转台测角系统标定任务，给出标定精度和误差曲线。该方法避免了人为因素造成的测量和计算误差，使标定过程更加快捷、准确、可靠。     

竖直轴系倾角回转误差的两种测试方法的比较

在某回转轴系上建立了一系列坐标系,通过坐标系之间的姿态关系分别推导了用水平仪测试法和自准直光管测试法测试主轴轴系倾角回转误差时水平仪和光管的读数表达式。根据水平仪和自准直光管读数中的各个误差组成部分和倾角回转误差在它们中的表达式的区别,得出了水平仪法能测试出主轴回转误差中的一次谐波成分,而自准直光管法则不能测试出回转误差的一次谐波成分的结论。     

自由转子偏角信号的四象限法读取

提出了一种陀螺仪自由转子偏角信号读取的方法，这种方法基于对反射光斑的四象限分割。与其它光电式读取方案相比，该方法减少了所需传感器的数量，通过一个极轴传感器就可以得到转子自转轴的偏角大小及方位信号，从而可以简化陀螺的结构，提高陀螺的可靠性。     

光电探测组件电源抑制比测试方法

抑制电磁干扰是解决光纤陀螺尤其是轻小型光纤陀螺低速灵敏度的关键问题,为了从电源完整性角度研究光纤陀螺检测电路干扰传导特性,需要对光电探测组件的电源抑制比进行测试。针对光纤陀螺微弱信号检测的特点,提出一种基于锁相放大器的光电探测组件电源抑制比测试方案,通过测量普通运算放大器的电源抑制比并与手册给定的典型值进行对比,校验了测试系统的准确性。以中低精度光纤陀螺调制-解调频率范围为例,利用该测试系统测量了光电探测组件100 k Hz~3 MHz内电源抑制比频率特性曲线。实验结果表明,光电探测组件的电源抑制比呈明显的高通特性,在100 k Hz频率点处+PSRR约为29.5 d B,到达3 MHz处衰减为17.8 d B,为后续计算电源传导干扰抑制要求和优化电源退耦网络提供了依据。     

基于Model 1221的小型加速度测量系统

采用微机械传感器Model1221,通过扩展外部储存器SD卡,设计并制作了由2块直径2.3cm的电路板构成、基于LPC2132微处理器的小型加速度测量系统,并结合该系统的RS232在PC机上设计了对测量数据读取、存储和去噪的分析处理软件。为了准确掌握系统静态和动态性能,分别开展了向心加速度静态标定和冲击加速度动态对比测试,结果表明该系统在测量范围((-50～50)g)和频响范围(0～2kHz)内性能较好,同时可进行长时间存储,具有一定的应用前景。     

智能车辆捷联视线稳定跟踪平台设计与实现

基于智能车辆环境识别传感器系统的特点,设计了隔离车体角运动,提供稳定传感器视线给智能车辆环境识别传感器系统的捷联稳定跟踪平台系统.详细分析了稳定平台系统的机械结构、伺服机构和捷联稳定算法,实时通信测试和动态性能检测试验表明,车载捷联视线稳定跟踪平台系统的设计满足智能车辆使用要求,为智能车辆的自主驾驶奠定了应用基础.     

微负荷摩擦测试系统

研究了采用浮力原理施力，用高灵敏度应变传感器测力的微负荷摩擦试验方法。测试结果表明，微负荷摩擦测试系统具有较高的分辨率和测试精度。     

小型霍普金森杆多级电磁发射系统的优化

根据小型霍普金森杆(Mini-SHB)对发射效率高、体积小、噪声污染小的要求及动态性能测试对高应变率的要求,本文对磁阻式小型霍普金森杆电磁发射系统进行了优化。利用电磁发射原理、电磁仿真计算和控制变量方法,对影响子弹发射速度的五个因素:电容组电容量、电路初始电压、电磁线圈匝数、线圈用漆包线直径、子弹初始位置分别进行了仿真优化。根据仿真得到的各个最优参数研制的电磁发射系统获得了单级16.16m/s、二级21m/s的最高子弹出口速度,达到了微小型试件动态性能测试对高应变率的要求。     

Development of in-wheel sensor system for accurate measurement of wheel terrain interaction characteristics

Planetary rovers need high mobility on a rough terrain such as sandy soil, because such a terrain often impedes the rover mobility and causes significant wheel slip. Therefore, the accurate estimation of wheel soil interaction characteristics is an important issue. Recent studies related to wheel soil interaction mechanics have revealed that the classical wheel model has not adequately addressed the actual interaction characteristics observed through experiments. This article proposes an in-wheel sensor system equipped with two sensory devices on the wheel surface: force sensors that directly measure the force distribution between the wheel and soil and light sensors that accurately detect the wheel soil surface boundary line. This sensor design enables the accurate measurement of wheel terrain interaction characteristics such as wheel force distribution, wheel–soil contact angles, and wheel sinkage when the powered wheel runs on loose sand. In this article, the development of the in-wheel sensor system is introduced along with its system diagram and sensor modules. The usefulness of the in-wheel sensor system is then experimentally evaluated via a single wheel test bench. The experimental results confirm that explicit differences can be observed between the classical wheel model and practical data measured by the in-wheel sensor system.     

Combined-load testing of the space-shuttle insulation at 1100°C

The Space Shuttle's insulation coating has been mechanically characterized at temperatures to 1100°C. A creep/combined-load test machine was fabricated, and a capacitive sensor system was devised to assist in the alignment and installation of fragile, thin-walled cylindrical specimens in the test frame. A biaxial strain sensor is described which features low cross-talk, excellent long-term stability and high resolution. Ceramic fixtures and silicate-coated refractory metals are used where temperatures exceed 600°C, and specimen heating is simplified by attaching the transducer to the inside of test cylinders.     

Inherent problems in force measurement

A force sensor is ordinarily used as a part of a larger system such as a testing machine, test stand, weighing system or process-control system. When a force sensor is calibrated in a standards laboratory and then installed and used in a different system, there may be a significant shift in sensor response due to differences in many factors such as machine-sensor mechanical interaction, loading sequence, loading rate and environmental conditions. NBS research is directed toward establishing the magnitude of the errors due to these factors and developing methods for controlling these errors. Some initial results in the study of machinesensor interaction, hysteresis, thermoelastic effect and creep are discussed here. A long range objective is to enable users to make informed judgments about the adequacy of their own force measurements, based on an understanding of their own measurement process rather than a routine calibration at a standards laboratory.     

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针对机载武器发射产生的废气对发动机工作参数的影响，自行研制了微压差压力传感器来测 量发动机压气机后压力的突降信号，及时打开防喘系统来防止发动机喘振或停车. 论述了传 感器的结构、工作原理和设计思路以及主要组件参数的设计方法，并得出符合设计要求的试 验结果.     

螺栓松动边界下纤维增强复合薄板的振动测试方法

提出了基于预埋压力传感器的量化测试方法,研究了螺栓松动边界对纤维增强复合薄板振动特性的影响。首先,自主设计并开发了带有预埋压力传感器的螺栓松动边界下复合薄板的振动测试系统,并详细介绍了系统各个部件的组成和功能;然后,归纳出一套合理、规范的松动边界下复合薄板的振动测试流程,并对HF10碳纤维/树脂复合薄板进行了实际测试。结果表明:随着螺栓松动程度的不断增加,复合薄板的固有频率逐渐降低,模态振型的节线位置也发生了不同程度的变化,但其阻尼结果呈现先增大后减小的趋势;而共振和非共振响应呈现先减小后增大的趋势。     

FAE云雾爆轰冲击波压力测试技术研究

对数年来FAE外场试验中冲击波压力测量方法和测量技术进行了分析总结 ,着重分析了爆轰理论模型的具体应用和不规则反射对冲击波测量的影响 ,提出了传感器装置安装的有效改进方法并在试验中得到了验证 ,提高了系统测量精度。     

Development and Application of a Novel Technique for Direct Heat Flux Measurements in Turbomachinery Flows

The high performance and efficiency of modern gas turbines are only possible with temperatures inside the engine exceeding the allowed material temperatures in some areas by several hundred degrees. Therefore effective cooling methods are one of the key factors for the success of these engines. In order to achieve reliable predictions of the heat load of rotor or stator blades numerous research activities were performed to understand the nature of heat transfer in complex unsteady flows. Even numerical methods have made significant progress in recent years detailed experimental data are still necessary for validation and further development of the engines and the design tools. Here a new method to directly measure the heat flux at the material surface and accurately determine the heat transfer coefficienth is presented. The new sensor is based on the anisotropic characteristics of single crystals and allows the determination of the time varying heat flux on the surface of a model turbine airfoil. This feature is of special interest to study the influence of periodically disturbed flow conditions on the heat transfer characteristics of cooled turbine blades. The working principle of an anisotropic heat flux (AHF) sensor is briefly described together with the design of the actual sensor used in this study. Prior to the application of the sensor in a cascade test rig, comprehensive test of the sensor, the electronics and the data acquisition system were performed using a pulsed laser beam as heat source. To test the sensor under realistic conditions a large number of sensor was installed in a test blade and heat transfer measurements were performed in a cascade test rig equipped with a spoke-wheel wake generator. The results showed good agreement in the time mean results compared with standard techniques. Additionally time resolved data could be extracted from the sensor signals providing detailed information on the unsteady heat transfer characteristics and boundary layer development. This revised version was published online in July 2006 with corrections to the Cover Date.     

高g值加速度计的设计与冲击特性分析

针对特殊场合的测试需求,设计了四端全固支的高过载梁岛结构加速度计;利用Hopkinson杆冲击校准装置对该加速度计的动态特性进行了测试。测试结果表明,传感器的灵敏度为1.2V/g,线性度5%左右;结构受到2105g冲击后完好且输出信号正常,能有效满足高冲击、强烈振动场合的特殊测试要求,可以应用于侵彻系统。 更多还原     

单轴旋转惯导系统旋转性误差分析及补偿

对单轴旋转惯导系统因旋转而引入的各项误差进行分析,研究其误差特性及补偿方法。针对单轴正反连续旋转方案,在假定惯性测试组件的器件误差和其他非旋转性的误差在精确标定的情况下,推导了因旋转轴安装不正交引起的涡动、轴系间隙引起的晃动、测角器件误差、旋转控制引起的换向超调误差、角位置、角速度不准确等因素而引起的误差的表现形式,定性和定量地分析了各误差对于系统精度的影响。针对对系统影响显著的旋转轴不正交误差,提出了一种基于系统自身旋转轴正反旋转的误差标定及补偿方法并进行了仿真实验。在给定条件下的仿真结果表明,该方法能够准确标定出旋转轴的不正交误差,标定精度达到角秒级。     

A simple automated hot-wire positioning technique for near-wall measurements

4 Summary A simple hot-wire sensor positioning technique is presented. The technique is easily integrated with a personal computer to achieve a completely automated system. A single initial calibration of the system outside of the test section is all that is necessary and no subsequent manual re-positioning is required during experimentation. This gives the capability of performing multiple measurements of near-wall velocity at different locations on a wall surface without the need of cumbersome and extensive alignment of the traverse system with respect to the wall surface. Preliminary tests indicate that the technique is viable for near-wall velocity measurements.