Adaptive sampling for corrugated plate digitization using a laser displacement sensor

The surface quality of a corrugated plate directly determines the heat transfer property of the thermal power mechanical apparatus.Traditional detection methods are impractical for real-world production,being slow and destructive.In contrast,the point laser displacement sensor,employing the optical triangle method,emerges as a promising device for assessing parts with variable curvature and highly reflective surfaces.Despite its benefits,high-density sampling by an innate frequency introduces challenges such as data redundancy and a poor signal-to-noise ratio,potentially affecting the efficiency and precision of subsequent data processing.To address these challenges,adjustable frequency data sampling has been developed for this sensor,allowing adaptive sampling for corrugated plate digitization.The process begins with surface digitization to extract discrete points,which are transformed into intersection curves using the B-spline fitting technique.Subsequently,dominant points are identified,considering multigeometric constraints for curvature and arch height.Finally,the sampling signal is adjusted based on the distribution information of dominant points.Comparative results indicate that the proposed method effectively minimizes redundant sampling without compromising the accurate capture of essential geometric features.

Approximate Continuous Aggregation via Time Window Based Compression and Sampling in WSNs

In many applications continuous aggregation of sensed data is usually required. The existing aggregation schemes usually compute every aggregation result in a continuous aggregation either by a complete aggregation procedure or by partial data update at each epoch. To further reduce the energy cost, we propose a sampling-based approach with time window based linear regression for approximate continuous aggregation. We analyze the approximation error of the aggregation results and discuss the determinations of parameters in our approach. Simulation results verify the effectiveness of our approach.

Self-calibration and algorithm of sample set of piezoresistive pressure sensors

Aiming at piezoresistive pressure sensors, this paper studies simulation of standard pressure by using benchmark current source and self-calibration of the sampling data characteristics. A data fusion algorithm for sample set is presented which transforms a surface problem into a curve fitting and interpolation problem. The simulation result shows that benchmark current source simulating pressure is successful and data fusion algorithm is effective. The maximum measurement error is only 0.098 kPa and maximum relative error is 0.92% at 0-45 kPa and -10-45~C.

Development of Optical Chemical Sensor Based on Pararosaniline in Sol-Gel Matrix for Detection of Formaldehyde in Food Samples

Optical chemical sensor based on immobilesed pararosaniline into sol-gel matrix tetraethyl orthosilicate (TEOS) is a simple tool that can be used to detect the presence of formalin (formaldehide) in food. Pararosaline in sol-gel matrix was developed when contacted with food sample that contains formalin. The optical signal was produced by changing color from purple to yellow, that can be used to detect quantitative formaldehide in sample. The results, chemo sensor optic, have characteristic, maximum wave length 576.42 nm, with linier range 0-100 ppm, linearity coefficient R2 = 0.999, limit detection (LOD) 0.504 ppm, limit of quantification (LOQ) 1.680 ppm, sensitivity 0.087, disturbed matrix selectivity 1.716 %. The optimum is operational at pH 4, and response time at 150 seconds of 2 ppm. This sensor can be used to detect formalin in food sample in a simple mode and reusable for 4 times application. In addition, the sensor can be regenerated using

All-Solid-State Screen-Printed Sensors for Potentiometric Calcium(II) Determinations in Environmental Samples

This paper describes preparation, characterization and electrochemical performance of novel planar miniaturized all-solid-state (ASS) screen-printed potentiometric sensors for the detection of Ca2+ ions in environmental samples. Screen-printed graphite-based ion-selective electrodes (ISEs) and screen-printed reference electrodes based on silver-containing pastes have been applied in a space saving manner on common ceramic substrates with small dimensions. Applications to environmental samples are shown by direct potentiometry and potentiometric titrations in real water samples. Conducting polymers (CPs) have been used as solid-contact materials and as intermediate layer between the polyvinyl chloride (PVC)-containing ion-selective membrane and the graphite-containing substrate. Different diamides have been incorporated into the PVC membrane. In the range from 10-4 mol/L to 10-1 mol/L, the ISEs show linear slopes of 27 mV/decade, which is close to the Nernstian response. Moreover, the ISEs have response times of 6 months. The novel potentiometric ASS sensors enable simple and exact Ca2+ determinations in real samples.

Sensor Fault Diagnosis Observer Design for Linear Sampled-Data Descriptor System with Time-Vary Delay

In this paper, a robust sensor fault diagnosis observer with non-singular structure is proposed for a class of linear sampled-data descriptor system with state time-vary delay. Firstly, a sampled-data descriptor model with time-vary delay is proposed and transformed into a discrete-time non-singular one. Then, a robust sensor fault diagnosis observer is proposed based on the state estimation error and the measurement residual, this observer can guarantee the robustness of the residual against the augmented disturbance and the sensor fault, which means the H∞ performance index is satisfied. As the confining matrix of the designed observer parameters does not meet the Linear Matrix Inequality (LMI), a cone complementary linearization (CCL) algorithm is proposed to solve this problem. The decision logic of the residual is obtained by the residual evaluation function. Simulation results show the effectiveness of the method.

基于线结构光扫描的烟支表面缺陷检测方法研究

在烟支表面缺陷检测时,为解决传统二维图像方法无法获得深度信息的问题,提出一种基于线结构光传感器旋转扫描的检测方法。烟支在两同向辊轮的旋转带动下实现自转,通过线结构光视觉传感器获取物体轴向轮廓线,使用随机采样一致性拟合轮廓线,通过计算原始点到拟合轮廓的距离判断缺陷点。选取某品牌烟支在检测过程中得到的原始数据,其中多组样本的Kappa值均达到0.97,重复性达到99.3%。研究为烟支缺陷检测提供参考。

分子印迹材料在手性拆分中的应用研究进展

拆分手性化合物、提纯有利生物活性的对映异构体在食品、制药、生命科学等领域具有重要意义。分子印迹聚合物(MIP)是一种人工合成的具有对目标物质定向亲和性的聚合物,基于MIP制造的手性选择剂具有更高的亲和力和选择性,同时更易于制备和更为稳定,因此在手性拆分领域得到了广泛应用。综述了MIP材料在手性拆分中用于样品前处理、手性固定相(CSP)、传感器的研究进展,并介绍了提高手性选择能力的新策略,包括手性树状大分子、表面印迹载体、金属离子、纳米MIP、手性功能单体、协同辅助材料等,展望了MIP手性拆分未来的发展方向。

异步测量系统的分布式序贯椭球相交融合估计

针对具有测量缺失现象的多源异步测量系统的状态估计,提出一种基于条件Kalman滤波的分布式序贯椭球相交(DSEI)融合算法。对系统测量缺失现象通过一组服从伯努利分布的随机变量进行建模描述;同步化状态空间模块利用状态迭代方法将异步测量系统在测量更新时刻进行同步;局部滤波模块采用条件Kalman滤波算法实现,保证滤波结果的完整性;融合估计模块在不考虑多传感器间相关性信息的前提下,设计DSEI融合算法对各个传感器提供的滤波结果进行融合。仿真实例验证了所提算法具有精度提高35%、迭代时间小于3 ms的优越性能。

基于单电流传感器的改进相电流重构技术

在电机闭环控制过程中,电流传感器故障、不同电流传感器的不一致性等因素可能导致系统失稳。为提高系统的容错能力,减小故障对控制系统稳定性的影响,提出一种基于单电流传感器的改进相电流重构技术。通过移动脉宽调制的脉冲矢量来消除母线电流采样盲区,进而通过母线电流重构获得三相电流。相比于传统电流重构方法,所提改进方法重构的电流更接近真实电流值,能够减小电流总谐波,降低电磁转矩脉动,提升系统的稳态性能。通过仿真和实验对比2种重构方法,证明了所提改进方法的优势。结果表明所提改进方法能有效实现电流重构,提升系统稳态性能。

高阻值传感器采样在医疗检测中的应用

与电压型或者电流型传感器不同,纯阻型传感器作为无源器件,在采集时需要避免偏置电压和偏置电流对其产生的影响。一些特定医疗传感器的阻值变化往往是微弱且高阻态的,因此,设计了合适的采样电路,以确保采样范围和可采集度。

穿梭油轮气体探测系统的设计与安装

为保证穿梭油轮在海上航行和船员作业时的安全,相关海事规范和公约通常要求船上配备气体探测系统,对挥发到空气中的可燃气体、有毒气体或氧气的浓度实现本地和远程监测。文章通过实船应用,根据气体探测系统的原理、传感器的形式以及规范要求,介绍了穿梭油轮气体探测系统的设计要求和安装要领,为穿梭油轮气体探测系统的设计、选型和安装提供了技术支持,以实现穿梭油轮海上安全作业的目的。

Stabilization of a high-order harmonic generation seeded extreme ultraviolet free electron laser by time-synchronization control with electro-optic sampling

A fully coherent free electron laser(FEL) seeded with a higher-order harmonic(HH) pulse from high-order harmonic generation(HHG) is successfully operated for a sufficiently prolonged time in pilot user experiments by using a timing drift feedback. For HHG-seeded FELs, the seeding laser pulses have to be synchronized with electron bunches. Despite seeded FELs being non-chaotic light sources in principle, external laser-seeded FELs are often unstable in practice because of a timing jitter and a drift between the seeding laser pulses and the accelerated electron bunches. Accordingly,we constructed a relative arrival-timing monitor based on non-invasive electro-optic sampling(EOS). The EOS monitor made uninterrupted shot-to-shot monitoring possible even during the seeded FEL operation. The EOS system was then used for arrival-timing feedback with an adjustability of 100 fs for continual operation of the HHG-seeded FEL. Using the EOS-based beam drift controlling system, the HHG-seeded FEL was operated over half a day with an effective hit rate of 20%–30%. The output pulse energy was 20 μJ at the 61.2 nm wavelength. Towards seeded FELs in the water window region, we investigated our upgrade plan to seed high-power FELs with HH photon energy of 30–100 e V and lase at shorter wavelengths of up to 2 nm through high-gain harmonic generation(HGHG) at the energy-upgraded SPring-8Compact SASE Source(SCSS) accelerator. We studied a benefit as well as the feasibility of the next HHG-seeded FEL machine with single-stage HGHG with tunability of a lasing wavelength.

Electro-optical sampling non-synchronous delay scanning measurement of electron beam bunch length at BFEL

The Electro-optical sampling delay scanning technique can be used for electron beam bunch length measurement. A novel non-synchronous delay scanning technique based on the electro-optical sampling measurements is presented. Based on Beijing Free Electron Laser （BFEL）, the electron beam bunch length was measured with the electro-optical sampling technique for the first time in China. The result shows that the electron beam bunch length at BFEL is about 5.6±1.2 ps.

Pixel and Column Fixed Pattern Noise Suppression Mechanism in CMOS Image Sensor

A double sampling circuit to eliminating fixed pattern noise(FPN) in CMOS image sensor (CIS) is presented. Double sampling is implemented by column switch capacitor amplifier directly, and offset compensation is added to the amplifier to suppress column FPN. The amplifier is embedded in a 64×64 CIS and successfully fabricated with chartered 0.35 μm process. Theory analysis and circuit simulation indicate that FPN can be suppressed from millivolt to microvolt. Test results show that FPN is smaller than one least-significant bit of 8 bit ADC. FPN is reduced to an acceptable level with double sampling technique implemented with switch capacitor amplifier.

Adaptive Soft-sensor Modeling Algorithm Based on FCMISVM and Its Application in PX Adsorption Separation Process

为了克服软传感器模型不能与这个过程被更新的问题，变化，基于算法和增长支持向量用机器制造的混合模糊 c 工具(FCM )(ISVM ) 为算法建模的一个软传感器被建议。这混合算法 FCMISVM 包括三部分：取样基于 FCM 算法聚类，学习基于 ISVM，和启发式的样品排水量方法的算法。在训练过程，训练样品被与 SVM 算法聚类的 FCM 算法，然后 by training 各个首先聚类，一个亚模型被造到每个聚类。在预言的进程，当表示新操作信息的一件增长样品在模型被介绍时，到每个聚类的样品的模糊会员函数是首先由 FCM 算法计算了。然后，与最大的模糊会员功能聚类的一个相应 SVM 亚模型被用来预言并且表现增长学习因此模型能被更新联机。启发式的样品排水量方法选择的一件旧样品然后从亚模型被丢弃控制工作集合的尺寸。建议方法被使用在吸附分离过程预言 p 二甲苯(PX ) 纯净。模拟结果显示建议方法实际上增加模型的适应能力到各种各样的操作条件并且改进它的归纳能力。

Carbon Dots as“On–Off–On”Fluorescence Sensors for Selective and Consecutive Detection of 4-Nitrophenol and Cerium(IV)in Water Samples

An“on–off–on”fluorescence sensor was designed for rapidly and consecutively detecting 4-nitrophenol and cerium(IV)without the use of any labeling materials.The yellow carbon dots were synthesized by a simple one-step hydrothermal approach,and various techniques were applied to investigate the morphology,structure,and optical properties of the carbon dots.Under the optimal experimental conditions,4-nitrophenol rapidly quenched the fluorescence of carbon dots as a result of the inner filter eff ect(IFE).The fluorescence intensity of carbon dots was linear with the concentration of 4-nitrophenol(1–150μmol/L)and the limit of detection was 0.32μmol/L.The fluorescence was gradually recovered as the cerium(IV)concentration(0.5–100μmol/L)increased in CDs/4-NP,and the limit of detection was 0.16μmol/L.The sensor showed good selectivity and demonstrated high accuracy for the analysis of 4-nitrophenol and cerium(IV)in actual water samples.

Chemically modified carbon-based electrodes for the determination of paracetamol in drugs and biological samples

Paracetamol is a non-steroidal, anti-inflammatory drug widely used in pharmaceutical applications for its sturdy, antipyretic and analgesic action. However, an overdose of paracetamol can cause fulminant hepatic necrosis and other toxic effects. Thus, the development of advantageous analytical tools to detect and determine paracetamol is required. Due to simplicity, higher sensitivity and selectivity as well as costefficiency, electrochemical sensors were fully investigated in last decades. This review describes the advancements made in the development of electrochemical sensors for the paracetamol detection and quantification in pharmaceutical and biological samples. The progress made in electrochemical sensors for the selective detection of paracetamol in the last 10 years was examined, with a special focus on highly innovative features introduced by nanotechnology. As the literature is rather extensive, we tried to simplify this work by summarizing and grouping electrochemical sensors according to the by which manner their substrates were chemically modified and the analytical performances obtained.

A Novel Current Sensor Technique for Brushless DC Motor Drives

The torque output in a permanent magnet brushless DC motor (BLDCM) is usually controlled by regulating the motor phase currents. In this paper, three kinds of PWM strategies together with some critical review on traditional current measurements in a BLDCM drive system are discussed. A novel method for assessing the PWM information and measuring the motor phase currents by a dc link current sensor is proposed. An attractive feature of the proposed method is the simplicity with the current sample processing because there is no need to incorporate the conduction information of the power switches or diodes. Only the single sided PWM or the double sided complementary PWM is needed with the proposed technique.

MIXED-GRAINED CMOS FIELD PROGRAMMABLE ANALOG ARRAY FOR SMART SENSORY APPLICATIONS

The drive towards shorter design cycles for analog integrated circuits has given impetus to the development of Field Programmable Analog Arrays(FPAAs),which are the analogue counterparts of Field Programmable Gate Arrays(FPGAs).In this paper,we present a new design methodology which using FPAA as a powerful analog front-end processing platform in the smart sensory microsystem.The proposed FPAA contains 16 homogeneous mixed-grained Configurable Analog Blocks(CABs) which house a variety of processing elements especially the proposed fine-grained Core Configurable Amplifiers(CCAs).The high flexible CABs allow the FPAA operating in both continuous-time and discrete-time approaches suitable to support variety of sensors.To reduce the nonideal parasitic effects and save area,the fat-tree interconnection network is adopted in this FPAA.The functionality of this FPAA is demonstrated through embedding of voltage and capacitive sensor signal readout circuits and a configurable band pass filter.The minimal detectable voltage and capacitor achieves 38 uV and 8.3 aF respectively within 100 Hz sensor bandwidth.The power consumption comparison of CCA in three applications shows that the FPAA has high power efficiency.And the simulation results also show that the FPAA has good tolerance with wide PVT variations.