Fabrication of micro-capacitive inclination sensor by resin molding

Capacitive inclination sensors have the advantage that they can easily provide a linear analog output with respect to inclination. Although inclination sensors featuring this advantages are already commercially available, they are generally too large. We fabricated a micro-capacitive inclination sensor by a combination of a resin forming method and a mold. Electrodes of the sensor are 40 μm in a gap and 12 mm² in area. The sensor detects difference of capacitance, which varies with movement of silicone oil accompanying with inclination of the sensor. Since the dimensions of the sensing region are 5 × 5 × 3 mm³ this inclination sensor is expected to be widely used in fields where efficient and reliable position control is a primary factor to be considered. The use of resins is also expected to contribute to a reduction in the costs of materials. We successfully fabricated a micro inclination sensor as a molded product. In future, we will wire up the device to complete this inclination sensor, and will then conduct performance evaluations. If techniques using resin-molded parts are introduced to the low-cost mass-production of Micro Electro Mechanical Systems devices, the range of applications will further expand to new areas of technology and industry.     

应变式传感器的信号隔离及数据重构

采用较高频率的周期性方波信号作为载波及解调信号,通过调制与同步解调技术对应变式传感器的输出模拟信号进行变压器式隔离.将隔离后的模拟信号及传感器使用环境温度对应的数字量作为输入变量,传感器的实际负载作为输出变量,利用移动最小二乘回归(MLSR)重构传感器所受负载与使用温度及隔离信号之间的数据模型.试验结果表明,采用调制及同步解调技术的模拟信号变压器式隔离电路具有良好的温度稳定性,利用MLSR建立的传感器数据重构模型拥有比传统最小二乘回归(LSR)更高的精度,在试验条件下的温度变化范围内,采用变压器式隔离电路得到的模拟信号隔离相对误差低于±0.2%,基于MLSR的传感器数据重构模型的负载检测相对误差低于±0.07%.     

Characterization of miniaturized one-side-electrode-type fluid-based inclinometer

In this study, electrical double-layer theory is applied to realize a one-side-electrode-type fluid-based inclinometer combined with complementary metal oxide semiconductor (CMOS) circuitry. Substrate penetration lithography was applied in the fabrication of high-aspect-ratio SU-8 container molds, and molds with heights 1.0 mm were fabricated. Polydimethylsiloxane (PDMS) was used as the container material, and electrodes were fabricated on a ceramic substrate. Considering the electrical double-layer property, low surface tension, the dielectric constant and the problem of volatilization, methanol and propylene carbonate were tested as electrolytes. A charge-balanced capacitance–voltage (C–V) conversion circuit was designed as a detection circuit for this sensor and it was fabricated using 0.35 μm CMOS technology. The sensor part and detection circuit were integrated in one ceramic packaging for realize a miniaturization of inclination sensor system. To overcome the surface tension of the PDMS surface, silicone oil was injected in the container to cover the entire inner surface so that the movement of solution in the container became smooth. The linearity of the analog output of ±60° inclination for container dimensions of Ø 4.0 mm × 1.0 mm (diameter × thickness) was less than 6%/F.S. The minimum moving angle and response time were 0.4° and 0.9 s, respectively, when propylene carbonate was used as the electrolyte. The change in temperature did not affect the output voltage of the sensor between 0 and 50 °C. The effect of vibration was demonstrated in this paper.     

动作传感器AMI602在步态特征提取中的应用

针对步态特征提取系统中采用模拟输出的传感器时,易受外界干扰,需外接RC滤波电路、A/D转换器、外接数据存储器,采集的数据量有限的缺陷,提出了一种基于数字输出的AMI602动作传感器的步态特征提取系统。实验中,AMI602输出的加速度数据通过CC1110微处理器进行无线发送和接收。接收到的数据通过串口发送到PC机上进行处理。通过分析人体步态信号中三轴向的加速度波形和俯仰角及倾斜角的变化来提取步态特征。经测试表明:该系统能够清晰地反映人体步态时的特征信号,且抗干扰性强,精确度高,易操作,灵活性强。     

Z-温度传感器的非线性补偿

为实现Z-温度传感器的线性输出,在对Z-温度传感器的特性进行实际测试和研究的基础上,设计了Z-温度传感器的工作电路,给出了温度数字传感器输出标准值。采用分段线性化的方法进行非线性补偿,通过单片机软件编程加以实现。实验结果表明:设计的Z-温度传感器的输出与期望的线性输出的最大误差小于±1℃,满足一般测温要求。     

Design,analysis and simulation of a novel linear capacitive tilt micro-sensor

A new capacitive structure for tilt sensor based on the MEMS technology is designed, analyzed and simulated. With a detailed analysis, we achieve to a precise relation between capacitance and inclination angle. Taking advantage of cylindrical structure in our design, we reach to a linear relationship between capacitance and tilt angle. In three designs of our capacitive tilt micro-sensor, there are 1, 2 and 4 micro capacitors. These capacitors have a common plate of mercury which is movable. Another plate is fixed. Displacement of mercury according to the deflection tends to the variations of capacitors and subsequently total capacitance of the tilt micro-sensor changes. In each of three designs for this micro-sensor, output capacitance (C_out) is introduced with a special equation for obtaining a linear and continues relationship between C_out and tilt angle. The last proposed micro-sensor structure with 4 micro capacitors, shows linear relationship for C_out over tilt measurement range of ?180° to +180° on one axis besides proper sensitivity.     

Two-dimensional orientation sensor

The development of a two-dimensional noncontact electrooptical orientation sensor is addressed in this article. The sensor is based on the intensity measurement of modulated light signals reflected from the surface of an object. The transducer of the proposed sensor was designed based on the optimal mechanical-design parameters obtained in the first stage of our research, where results were reported for one-dimensional inclination angle measurements. Experiments undertaken in the second stage of our research, and reported herein, verify the operational principle of the two-dimensional sensor, which yielded acceptable performance characteristics. An important characteristic of this orientation sensor is the distance-independent inclination-angle measurements (i.e., output signals utilized to estimate the two inclination angles are independent of the sensor's distance to the object's surface).     

A high-performance MEMS capacitive strain sensing system

This paper describes the design of a functional strain sensing module with large dynamic range (80 dB), DC to 10 kHz response, high resolution, and mini size for industrial applications, such as the rolling-element bearings research. The design of the MEMS capacitive strain sensor employs mechanical amplifications of package design and buckle beams as well as the linear differential comb capacitor. The sensor is interfaced with a low noise charge amplifier, mixer, and filter circuits to provide an analog output that demonstrated a resolution of 0.09 microstrains with a maximum range of ±1000 microstrains. The sensor and the electronic circuits, including a temperature sensor, can be integrated on a chip, and packaged as a small functional unit. Additional electronics were integrated with the interface circuit on the chip that provide A/D conversion, radio frequency power supply, and digital signal telemetry to a near-by control unit. Preliminary test results are compared with the design simulation.     

具有温度自补偿功能的高分辨力倾角传感器的设计

基于微加速度倾角测量原理,研制了一种高分辨力数字式倾角传感器。针对温度漂移现象,采用MSP430微处理器和DS18B20温度传感器进行了温度补偿智能化设计。针对嵌入式单片机编写了实时IIR数字滤波算法,有效抑制高频振动噪声干扰。通过分段线性化标定的方法,对传感器进行零位设置和倾角标定。实测结果表明:传感器倾角测量精度可达0.001°。     

Towards red‐edge positions less sensitive to canopy biophysical parameters for leaf chlorophyll estimation using properties optique spectrales des feuilles (PROSPECT) and scattering by arbitrarily inclined leaves (SAILH) simulated data

Several methods for extracting the chlorophyll sensitive red‐edge position (REP) from hyperspectral data are reported in literature. This study is a continuation of a recent paper published as ‘A new technique for extracting the red edge position from hyperspectral data: the linear extrapolation method’. The method was validated experimentally for estimation of foliar nitrogen concentrations of rye, maize and mixed grass/herb. The objective of this study was to test the utility of the linear extrapolation method under different conditions including variable canopy biophysical parameters, solar zenith angle, sensor noise and spectral bandwidth. REPs were extracted from synthetic canopy spectra that were simulated using properties optique spectrales des feuilles (PROSPECT) and scattering by arbitrarily inclined leaves (SAILH) radiative transfer models. REPs extracted by the linear extrapolation method involving wavebands at 680, 694, 724 and 760 nm produced the highest correlation (R ² = 0.75) with leaf chlorophyll content with minimal effects of leaf and canopy biophysical confounders (leaf area index, leaf inclination distribution and leaf dry matter content) compared to traditional techniques including the linear interpolation, inverted Gaussian modelling and polynomial fitting techniques. In addition, the new technique is insensitive to changes in solar zenith angle. However, the advantage of using the linear extrapolation method compared to the various alternative methods diminishes with increasing sensor noise and decreasing spectral resolution. In summary, the linear extrapolation technique confirms its high potential for leaf chlorophyll estimation. The efficacy of the technique under field conditions needs to be established.     

基于光纤传感技术的金属线胀系数非接触测量

针对传统金属线胀系数测试方法存在的缺陷,介绍一种新颖的金属线胀系数实时非接触测量方法。该方法是利用反射式光纤位移传感器输出特性曲线的线性区实现微位移测量的原理,从而实现对金属线胀系数的测量,实验给出了测试结果:黄铜棒的线胀系数为 18. 81×10-6 /℃,铁棒的线胀系数为11. 69×10-6 /℃。该方法无论是操作过程还是测量精度都优于传统测量方法。     

Development of thin film based flexible current clamp sensor using screen-printed coil

This paper reports a novel flexible current clamp sensor with 480 turns silver paste coil (line/space = 50/50 μm) formed by through-holes and screen-printing technologies. Using screen-printing techniques, fine stripe patterns could be formed on a 50-mm-long and 10-mm-wide polyimide film in few seconds. Coil resistance between their contact pads is about 2.3 kΩ. When the value of a primary current was 20 A, the output voltage was 22.6 mV. Furthermore, the output voltage changed linearly with the changing of the primary current in the 0–20 A range. The sensor is developed using only coating, through-holes laser drilling, and screen-printing technologies. Therefore it can be fabricated by a reel-to-reel continuous film processing system.     

电化学式葡萄糖传感器阳极的研究

制备了一种石墨粉含量高的混合物导电材料,研究了该材料的导电性能及水中贮存稳定性,并将其作为电化学式葡萄糖传感器的阳极,以此电极作为固定化酶载体得到的葡萄糖氧化酶电极对葡萄糖的响应时间为２０ ～３０ ｓ、灵敏度为６０ ｎＡ／（ｍｍｏｌ·Ｌ－１） 、线性响应范围为０ ．０２ ～７ ．０ ｍ ｍｏｌ／Ｌ,在水溶液中储存２０ 天,传感器的响应值基本保持不变。     

太阳敏感器电模拟器设计

针对小卫星半实物仿真系统的技术需求,提出了一种太阳敏感器电模拟器设计实现方法;模拟器以FPGA作为控制核心,采用压控电流源实现了0-1式太阳敏感器、模拟式太阳敏感器的输出电流模拟;通过专用电流源芯片REF200实现了数字式太阳敏感器输出电流模拟;模拟器由计算机通过RS-485接口控制,既能模拟太阳敏感器正常工作时的电信号输出,也能模拟太阳敏感器出现故障时的电信号输出;该太阳敏感器电模拟器已应用于小卫星的半实物仿真,其电流精度可达±1μA。     

基于差动电容的高精度倾角测量系统设计

介绍了一种新型的高精度倾角测量系统。采用差动电容式倾角传感器与温度特性好的精密电阻器构成阻容电桥,用文氏振荡电桥作为激励源,用差动放大电路组成阻抗变换和前置放大电路,采用低功耗18位A／D转换器MAX132对模拟电路调理后的直流模拟电压信号进行转换。提出通过在A／D转换器参考电压的电路中接入热敏电阻器的方法实现温度补偿。经过试验验证,该倾角测量系统达到了高分辨率、高稳定性和低功耗的设计要求。     

基于T-S模糊神经网络的齿槽效应补偿方法研究*

针对齿槽效应带来的齿槽误差问题,提出在传感器探头内布设齿槽位置检测线圈,建立传感器齿槽特性模型和基于T-S模糊神经网络的齿槽补偿系统模型,依据齿槽位置信号对传感器进行齿槽误差补偿。利用附加动量的BP学习方法对网络进行学习和测试。仿真结果表明补偿模型的输出不再随齿槽位置波动,最大误差为依0.2mm,该种方法可以有效地消除齿槽效应并提高传感器的检测精度,满足高速磁浮车悬浮控制系统要求。     

A 0.6 V 117 nW high performance energy efficient system-on-chip (SoC) CMOS temperature sensor in 0.18 µm CMOS for aerospace applications

This research article presents and describes a novel design with improved performance low power consumption threshold voltage based CMOS thermal sensor for aerospace applications. The proposed temperature sensor utilizes the change in behavior of threshold voltage of MOSFET with variation in temperature. The challenge while designing the temperature sensor was to achieve the linearize output voltage with respect to change in temperature. Process corner analysis has been done to check the robustness of the circuit while performance analysis and sensitivity of the temperature sensor have been verified in the occurrence of parasitic. The proposed temperature sensor is featured with low power consumption, less power supply voltage utilization, high performance and sensitivity with inaccuracy as low as possible. The presented temperature sensor utilizes an active area of 18 µm × 9.85 µm with 117 nW power consumption. An improved linear performance with an inaccuracy of merely − 0.01 to + 0.47 °C over a wide temperature range of − 20 to + 120 °C is presented here. The sensitivity of proposed temperature sensor is found to be as high as 0.77 mV/°C. The proposed temperature sensor is realized and tested in Cadence virtuoso mixed signal design atmosphere using 0.18 µm CMOS technology and further investigated with support of tool from Mentor graphics. The engaged area of pad-limited chip is measured to be 0.96 mm².

     

胶囊内窥镜倾角传感式磁跟踪系统的设计

为了提高胶囊内窥镜的跟踪精度,增强实时性,提出了倾角传感与磁场传感相结合的无线跟踪方法。推导了倾角传感模块在跟踪系统中的角度测量原理,基于坐标旋转和空间磁场理论,建立了倾角传感式磁跟踪数学模型,获得了胶囊方位与磁场信号的数学关系式。根据倾角传感的磁跟踪方案,设计开发了系统样机,包括:磁场发生装置、倾角式无线磁传感模块、无线数据接收装置、数据处理平台。跟踪实验表明,角度跟踪平均误差为4.2°、4.5°,标准偏差为2.2°、2.4°;x分量、y分量、z分量的平均位置误差为0.011 3 m、0.012 1 m、0.010 4 m,标准偏差为0.008 2 m、0.007 5 m、0.006 8 m。倾角传感器的引入减少了励磁源的个数,减小了每轮跟踪的采样数据量和采样时间,简化了非线性方程组的求解,进一步提高了跟踪精度。     

Viewing direction measurements on flat and curved flexible E‐paper displays

The viewing direction characterization of reflective displays is more demanding than for emissive displays because defined illumination–detection geometries must be maintained for each viewing direction. In addition, the geometry should mimic the behavior of viewers who tend to exclude the reflection of light sources from a handheld reflective display. Viewing direction data was extracted from measured Bidirectional Reflectance Distribution Functions, showing that a source inclination of 45° sufficiently excludes the specular and haze components of source reflection from the measurement. Applying this so‐called 45/θ geometry to curved flexible displays is not straightforward since viewing direction, display curvature, and alignment each affect the measured reflectance. The viewing direction geometry proposed for convex cylindrical displays uses a ring light to deliver viewing‐direction independent illuminance, and maps the range of viewing directions onto the pixels of an image sensor. The illumination can also be applied to flat displays, allowing direct comparisons of flat and cylindrical display states. First results on e‐paper show good agreement with Bidirectional Reflectance Distribution Function data.     

电感式对中传感系统设计与实现

针对实际生产中金属带材的跑偏问题,介绍了一种电感式检测装置—电感式对中传感系统。一般电感式传感器测量转换模块输出的都是模拟信号,且需要外加交流电源,使用不便。设计的电感式对中传感系统从电感式传感器的基本原理出发,设计系统结构。实验表明:该系统能够得到优于±0.2 mm的精度。