一种基于天空光的新型成像式仿生偏振导航传感装置

模仿昆虫偏振导航机理,设计了成像式仿生偏振导航传感装置样机。研究了天空光偏振分布模型,分析了成像式仿生偏振导航传感装置工作原理。解决了一般探测装置解算偏振参数需要上位机辅助的问题,使用CMOS图像传感器和数字信号处理器,实时输出导航角度。进行了室内、室外装置性能测试,获得了3个方向偏振分量标准化强度曲线。实验结果表明:传感装置室内外角度测量误差分别为-0.8°~0.3°,-1.2°~1.4°,能够较高精度地输出导航角度,可以满足实时导航定位的需要。     

磁流变阻尼器内部流体动能的能量采集

为了构建自供能式磁流变阻尼器内部实时状态监测传感系统,本文介绍了一种针对磁流变阻尼器内部流体能的能量采集装置。该装置被安装于磁流变阻尼器活塞顶端并为检测阻尼器内部工作参数的无线传感模块1供电。根据能量守恒定律,推导出磁流变阻尼器中磁流变液流动能的理论模型。通过实验测试分析了在不同的外界激励下能量采集装置的工作情况,证明了采集的电能随着活塞的运动频率增加而增加,而与磁流变阻尼器的磁流变特性没有明显的关系。测试表明利用此装置能较好的采集到来自于磁流变阻尼器内部流体流动产生的能量,为无线传感模块供电。     

螺栓孔裂纹的漏磁检测

介绍了飞机机翼大梁螺栓孔漏磁检测方法,提出对工件进行脉冲式磁化,增强漏磁检测信号;对Hall检测传感装置进行优化设计,提高漏磁检测的灵敏度;采用圆光栅与驱动装置联动,消除探头运动速度不均匀对采样的影响,实现空域等距采样,并据此研制了螺栓孔裂纹漏磁检测系统,该系统能够在不解体或少量简单拆装条件下,对螺栓孔裂纹进行无损裂纹定量检测,取得了满意的效果。     

一种无线传感网与现场总线通信网关的设计与实现

设计了一种无线传感网与CAN总线、Modbus总线的通信网关。该装置以嵌入式微处理器STM32F207ZG为核心,采用无线通信模块CC2530作为无线传感网汇聚节点。在RS485通信的基础上实现了Modbus协议。STM32F207ZG内部CAN总线控制器配合CAN总线收发模块使网关可以接入CAN总线。试验表明:该网关分别接入Modbus总线、CAN总线均可实现总线监控网络与无线传感网的数据传输,且可以作为新型无线传感网监控系统扩充现场总线数据采集设备的接入点。     

基于无线传感器网络的管道检测精确定位

为了对大范围的工业管道检测装置进行精确定位,采用无线传感器网络,在工业管道外布置磁传感器模块来测量管道检测装置的磁信号.每个磁传感器模块由磁传感单元、处理单元、收发单元、电源单元等功能模块组成.磁传感器模块的测量数据由无线传感器网络传送到处理中心.处理中心依据无线传感器网络发回的磁信号数据,由磁定位算法计算得到管道检测装置所处的精确位置,从而实现管道检测位置的精确定位.     

基于无线传感网络的高层建筑在线监测系统设计

设计一种基于Zigbee无线传感网络的高层建筑在线监测系统,实现对高层建筑震动、晃动等在线监测。检测终端功耗低、体积小、便于安装,实验表明该系统能有效检测精度为0.01075g的三分量加速度,并估算检测点的位移。     

谐振式无线供电技术在无线传感网中的应用研究

为了研究无线传感网的磁耦合谐振式无线供电技术,根据电路理论,建立了单线圈发射3个线圈接收的电路模型,同时推导和研究了负载电压、传输效率等传输特性与谐振频率、负载电阻、各线圈间的互感系数的关系。利用传输特性公式,通过Matlab仿真,确定了各线圈的电感值,分析了线圈电感值、传输距离和负载电阻值对传输特性的影响。最后通过无线传感网的无线供电实验验证了理论推导和仿真分析的正确性,为电网的无线传感网的谐振式无线供电技术提供了一定依据。     

一种针对大跨径桥梁承压风险检测的智能系统设计与实现

提出一种针对大跨径桥梁承压风险检测的智能系统设计方案。系统包括数据采集模块,以无线传感网络为基础采集桥梁承重结构稳定压力信息。设计承压信息处理模块,根据得到桥梁不同区域承重信息,计算桥梁结构的稳定性,对大面积的桥梁承重结构情况进行检测,设计无线传感网络通信模块,配合良好的软件通信协议算法,保证信息的及时准确传递。后期的实验证明,在桥梁塌方风险检测过程中,系统的有效性较高,决策精度达到88%,拥有较好的实时性和良好的应用性。     

脉冲漏磁检测技术中新型传感器设计及实验验证

漏磁检测法广泛应用于铁磁性材料的缺陷检测.应用有限元法对一新型脉冲漏磁传感装置下钢管缺陷产生的漏磁场进行了仿真分析,仿真结果表明提取缺陷漏磁场三维分量进行缺陷识别,相比较传统的提取一维或二维缺陷漏磁场分量而言,可获取更多有关缺陷尺寸、位置等信息,提高对缺陷的识别能力.采用所设计的新型脉冲漏磁传感器,对脉冲漏磁三维检测分量信号进行了分析,由三维检测信号峰值扫描波形可有效识别缺陷,并评估缺陷长度、深度等信息;实验结果与仿真分析有较好的一致性.     

无线传感网络基本演示系统

本文设计并实现了结合GPRS和无线传感网络技术的基本演示系统。本系统由三部分组成,包括MCU方软件、PC方监听软件和PC方监控软件。MCU方软件可分为无线传感网节点程序、网关节点程序和GPRS主控器程序。无线传感节点和网关节点采用飞思卡尔公司推出的一款Zigbee模块MC13213,实现动态编址和路由功能。GPRS主控器收集本网段内无线节点采集的数据并且通过GPRS模块发给远程服务器。PC方监听软件处于MCU方软件与监控软件之间。它是一个基于Socket的程序。PC方监控软件作为一个Web系统,为用户提供了友好的图形化界面。     

Effect of surface wind speed and sensor view zenith angle dependence of emissivity on SST retrieval from thermal infrared data: ATSR

The Along Track Scanning Radiometer (ATSR) data are currently being processed at various places within the European community including the Rutherford Appleton Laboratory (RAL) in the U.K. In generating an atmospherically corrected sea-surface temperature (SST) field, the emissivity of the sea surface is assumed to be independent of the sensor view zenith angle, sea state and wavelength (Ian Barton, RAL, personal communication). The sensor view zenith angle dependence of the emissivity is generally not known because of the complications introduced by the surface wind speed. This paper attempts to evaluate the uncertainties introduced in the SST due to the variation of emissivity with the sensor view zenith angle and surface roughness generated by the wind speed.

Using the Cox and Munk formulation, Takashima and Takayama have simulated the sea water emissivities as a function of wind speed of up to 15ms^-1 and a range of the sensor view zenith angles. Their emissivity data for 11 and 12μm channels corresponding to the viewing geometry of the ATSR have been used in this work. It is shown that, depending on the value of the SST, there can be significant errors due to the sensor view zenith angle and sea surface roughness dependence of the emissivity. For example, if the SST is 10°C and the wind speed is 0ms^-1, then the errors due to the sensor view zenith angle dependence of the emissivity are shown to be 0·77°C and 0·55°C in 11 and 12μm channels, respectively, and at 15 ms^-l the respective errors reach about 1·ldeg K and 0·86 deg K. The errors due to the deviations of the emissivities from unity for nadir view in calm conditions are about 2·1°C and 3·5°C, respectively, in the 11 and 12μm channels. All of these errors are additive, indicating the importance of the calibration and validation.     

On the accuracy of the global positioning system—A test using a hand-held receiver

Abstract

This study aims to evaluate the accuracy of location (x, y and z) using a Magellan GPS NAV 1000 receiver. The position of a known reference point was compared with 50 fix points measured in two-dimensional (2D) mode (x, y) and with 50 fix points measured in three-dimensional (3D) mode (x, y and z).

The mean errors and the root mean square errors (RMSE) in the Euclidian distances between the reference point and the measured fix points were 17·9?m and 20·0?m respectively for the 2D measurements, and 25·7?m and 34·8?m respectively for the 3D measurements. The mean error in elevation was 0·2?m and the corresponding RMSE was 39·1?m. The study indicates a significant difference in the total error (Euclidian distance) between points obtained with different signal qualities and different geometric qualities. The error in the Euclidian distance never exceeded 44·0?m using 2D mode, which suggests that the Magellan GPS NAV 1000 receiver should be a useful supportive tool for many remote sensing applications.     

Vehicle sideslip estimator using load sensing bearings

This paper investigates the potential of load based vehicle sideslip estimation. Different techniques to measure tyre forces have been presented over the years; so far no technique has made it to the market. This paper considers a new technology based on load sensing bearings, which provides tyre force measurements. Based on the features of the sensor, a vehicle sideslip angle estimator is designed, analyzed and tested. The paper shows that direct tyre force sensing has mainly two advantages over traditional model-based estimators: primarily, it avoids the use of tyre models, which are heavily affected by uncertainties and modeling errors and secondarily, providing measurements on the road plane, it is less prone to errors introduced by roll and pitch dynamics. Extensive simulation tests along with a detailed analysis of experimental tests performed on an instrumented vehicle prove that the load based estimation outperforms the kinematic model-based benchmark yielding a root mean square error of 0.15°.     

基于光电和倾角检测的全天候太阳跟踪传感器设计

为提高双轴太阳跟踪系统的跟踪精度,设计了一种全天候太阳跟踪传感器。该传感器主要由外壳、接口电缆、9个光电探头、倾角传感器SCA100T—D02及相应电路组成。晴天时通过光电探头检测太阳的位置,阴雨天气时通过SCA100T—D02实时反馈太阳能电池板转动后的倾角,以修正和消除太阳跟踪系统进行视日运动轨迹跟踪时的机械误差。通过理论分析计算,确定了光敏电阻器在探头中的安装位置,传感器可感知高度角在-88.83°~88.83°范围内的太阳入射光线。经试验测试,传感器的倾角检测的最大相对误差为3.8%,能满足实际应用要求。     

Evaluation of the Kinect™ sensor for 3-D kinematic measurement in the workplace

Recording posture and movement is important for determining risk of musculoskeletal injury in the workplace, but existing motion capture systems are not suited for field work. Estimates of the 3-D relative positions of four 0.10 m cubes from the Kinect were compared to estimates from a Vicon motion capture system to determine whether the hardware sensing components were sensitive enough to be used as a portable 3-D motion capture system for workplace ergonomic assessments. The root-mean-squared errors (SD) were 0.0065 m (0.0048 m), 0.0109 m (0.0059 m), 0.0057 m (0.0042 m) in the x, y and z directions (with x axis to the right, y axis away from the sensor and z axis upwards). These data were collected over a range of 1.0-3.0m from the device covering a field of view of 54.0 degrees horizontally and 39.1 degrees vertically. Requirements for software, hardware and subject preparation were also considered to determine the usability of the Kinect in the field.     

用于生态环境微传感节点的光电能量转换系统设计

设计了一种用于森林生态环境传感节点的光电转换系统,以MSP430作为主要控制器件,设计双轴跟踪实现位置控制,并通过GPS模块进行辅助控制;采用遮光技术,提高传感器的量程;通过遮光板,采用阴影法增大传感器的测量差值,提高控制精度;采用最大功率点跟踪方法对锂电池充电,并通过电源管理模块对电能进行合理分配,提高利用率。实验结果表明：设计的控制系统能够实现光自动跟踪,提高了光伏的转换率,实现传感节点的无间断工作,具有较高的应用价值。     

Sitting comfort in an aircraft seat with different seat inclination angles

Passengers' comfort experience during flights is important in choosing their flights. The focus of this study is passengers’ perceived comfort in different climbing angles during ascent. Twenty-six participants were invited to experience three inclination angles including 3°, 14° and 18° in a Boeing 737 cabin. The angle of 3° was used to simulate cruising stage and the other two were used to simulate different climbing angles. Participants experienced each setting for 20 min where the perceived comfort, their heart rate variability(HRV), and their body contact pressure values on the backrest and seat pan were recorded with questionnaires, HRV bands and pressure mats respectively. The results indicate a preference of 14° inclination angle resembling the cruising angle (3°) and having the slowest moving speed of the center of pressure (COP) on both the backrest and seat pan.     

激光三角法在物面倾斜时的测量误差研究

相比传统的触针式测量,激光位移传感器因其高精度和非接触式测量的优点,在机械工程中已广泛使用。鉴于激光三角法的设计原理,当工件产生倾斜角时,激光位移传感器会产生误差。通过激光位移传感器、精密电移台、精密旋转台构建了实验测量系统,对测量数据使用Matlab进行分析,所用电移台的重复精度小于5μm,测得了不同倾斜角度下激光传感器的误差,用最小二乘法拟合进行了误差补偿。实验证明：误差标定后,激光传感器在测量倾斜物面时仍能保证高精度。     

Fabrication of high precision microstructure using ICP etching for capacitive inclination sensor

Capacitive inclination sensors have the advantage because it could easily provide a linear analog output with respect to inclination. Since the dimensions of the sensing region are very small, then this sensor is expected to be widely used in fields where efficient and reliable position control is a primary factor to be considered if this sensor could be mass produced at low cost. Therefore, we proposed fabrication process based on transfer to resin using mold. We successfully fabricated a micro capacitive inclination sensor by a combination of a resin forming method and a mold. The sensor consists of a gap distance of 80 μm between its electrodes. The sensor detects difference of capacitance, which varied with movement of silicone oil accompanying with inclination. When the sensor was inclined, linear analog output was obtained within the range of ?45 to +45°     

阵面安装误差对相控阵雷达测角精度的影响

分析阵面安装误差对相控阵雷达测角精度的影响,对研究和设计高精度相控阵雷达非常重要。建立了相控阵雷达阵面安装误差测角精度误差模型,分别仿真分析了阵面倾角安装误差、阵面方位法向误差和阵面不水平度对相控阵雷达测角误差的影响。与理论公式相比,推导出的简约式用于计算阵面安装误差引起的测角误差分析时精度达0.001°量级,可以为相控阵雷达测角系统精度误差指标分配及测角精度超差问题分析定位提供快速、精确的理论依据和工程指导。