ANN based CMOS ASIC design for improved temperature-drift compensation of piezoresistive micro-machined high resolution pressure sensor

The paper investigates the temperature-drift compensation of a high resolution piezoresistive pressure sensor using ANN based on conventional neuron model as also the inverse delayed function model of neuron. Using the delayed neuron model, an improvement in temperature-drift compensation has been obtained compared to the conventional neuron model. The CMOS analog ASIC design of a feed forward neural network using the inverse delayed function model of self connectionless neuron for the precise temperature-drift compensation has been presented. The inverse tan-sigmoid function is realized in CMOS implementation by Gilbert multiplier, differential adder and a cubing circuit. The entire design of the circuit has been done using AMS 0.35 μm CMOS model and simulated using Mentor Graphics ELDO simulator. Using the inverse delayed function model of neuron a mean square error of the order of 10⁻⁷ of the neural network has been obtained against a mean square error of the order of 10⁻³ using conventional neuron model for the same architecture of ANN. This brings down the error from 9% for uncompensated sensor to 0.1% only for compensated sensor using the delayed model of neuron in the temperature range of 0-70 °C. Using conventional neuron based ANN compensation, the error is reduced to 1% error.     

Temperature compensation of piezoresistive micro-machined porous silicon pressure sensor by ANN

Porous silicon based micro-machined peizoresistive pressure sensors are fabricated and tested in the range of 0–1 bar and temperature range of 25–80 °C. The dependence of pressure sensitivity on the variation of ambient temperature is investigated. An intelligent online temperature compensation scheme using ANN technique has been described. The proposed scheme leads to an error reduction of approximately 98% from temperature uncompensated value. A hardware implementation of the proposed scheme using micro-controller is also described.     

压力传感器高精度温度补偿的软件实现

克服传统的通过硬件电路来对压力传感器进行温度误差补偿的缺点,介绍利用单片机进行压力传感器温度补偿的基本方法,论述如何利用软件进行温度误差补偿的方法,详细描述高精度温度补偿的软件算法原理,为实现通过软件进行温度补偿提供了理论依据。通过实验测试证明了采用高精度温度补偿算法的传感器输出精度有了显著的提高。     

Novel silicon high sensitive photonic sensor

Light depended resistors (LDR) or photoresistors are semiconductor devices that are changing resistance under illumination. These devices have many applications in industrial controls: item counters, presence and proximity sensors, flame detectors, photometric devices, etc. If the light falling on the device has energy which is greater than the bandgap of the semiconductor, photons absorbed by the semiconductor excite electron-hole pairs which result in lowering the resistance of the semiconductor. Generally, these devices are made of semiconductors such as CdS or CdSe using a thin film technology, since they have traps and misfits in their atomic structure, leading to high dark current and noise.In this work, we describe a novel approach for a novel family of high sensitive light detectors made of single-crystalline silicon. Basic sensor was built in a flat shape providing lateral electrical transport of excited charged carriers. Simple laboratory methods were used to diffuse impurities on both sides of the sensor. The sample shows high sensitivity due to light intensity variation from dark to strong light (∼96,000 lx). A 30 times variation in the sample resistance was obtained.     

压力传感器温度补偿的一种新方法

针对温度对硅压阻式压力传感器输出影响的问题,提出将主成分分析(PCA)与改进的反向传播(BP)神经网络相结合,用于压力传感器的温度补偿的新方法.利用PCA提取温度补偿的主要信息使多维问题得以简化,同时剔除了数据的噪声误差,且对BP神经网络进行了改进,以充分发挥其强大的泛化功能和容错能力.研究结果表明,该方法有效抑制了温...     

压阻式硅基传感器的温度补偿方法研究

介绍了压阻式传感器的温度补偿原理及补偿方法 ,详细阐述了硅压阻式加速度传感器 30 2 8的补偿方法 ,给出了实验数据。该补偿方法使用元器件少 ,补偿简单 ,具有很强的实用性     

压阻式硅基传感器的温度补偿方法研究

介绍了压阻式传感器的温度补偿原理及补偿方法，详细阐述了硅压阻式加速度传感器3028的补偿方法，给出了实验数据。该补偿方法使用元器件少，补偿简单，具有很强的实用性。     

一种SOI高温压力传感器

SOI高温压力传感器是一种新型的高性能,高品质的压力传感器。本文提出了一种SOI高温压力传感器的结构,并从掺杂浓度和功率等关键因素进行了高温分析。设计了敏感芯片 的工艺流程以及关键工艺参数。通过在室温和高温下的测量,结果表明非线性误差小于0.1%,迟滞性小于0.5%,敏感芯片可以在350℃高温下工作。本文为高温压力传感器的研究提供了参考。     

A low noise, high resolution silicon temperature sensor

High resolution temperature measurement is essential for determination of blood perfusion in biomaterials. A compact, low noise, high resolution temperature sensor designed for use in an invasive tissue property measurement probe is presented. The circuit is based on traditional proportional-to-absolute-temperature (PTAT) principles. A feedback technique is used to improve linearity and reduce noise. Data from test chips shows temperature resolution of 3 m°C. The chips were fabricated using a 1.75 μm double poly, single metal modified CMOS process designed for this project     

低温漂高PSRR的二阶补偿带隙基准源设计

设计了一种线性补偿低温漂高电源抑制比带隙基准电压源电路。带隙基准核心电路采用三支路共源共栅电流镜结构,提高电路电源抑制比。补偿电路采用分段补偿原理,在低温阶段,加入一段负温度系数电流,在高温阶段,加入一段正温度系数电流,通过补偿,使带隙基准输出电压的精确度大大提高,达到降低温度系数的目的;同时电流镜采用共源共栅结构,不仅提高电路的电源抑制比,而且可以抑制负载对镜像晶体管电压的影响。基于0.5 μm CMOS工艺,使用Cadence Spectre对电路仿真,结果表明,在-50~+125℃温度范围内,基准输出电压的温度系数为2.62×10-6/℃,低频时的电源抑制比(PSRR)高达88 dB。     

一种硅压阻式压力传感器温度补偿算法及软件实现

硅压阻式压力传感器的零点温度漂移和灵敏度温度漂移是影响传感器性能的主要因素之一,如何能使该类误差得到有效补偿对于提高其性能很有意义。通过对硅压阻式压力传感器建立高阶温度补偿模型进行温度误差补偿是一种有效的方法,并在该模型基础上给出了拟合系数计算方法,并用Matlab GUI软件来实现温度补偿系数计算,进而实现传感器输出的动态温补,达到了很好的输出线性性。实验结果表明,补偿后传感器输出的非线性误差小于0.5% F.S。     

Micromachined chromium nitride thin-film pressure sensor for high temperature applications

The fabrication and characteristics of a micromachined chromium nitride (Cr-N) thin-film pressure sensor with high overpressure tolerance for high temperature applications are presented. The proposed pressure sensor consists of a Cr-N thin-film, patterned after a Wheatstone bridge configuration, and then sputter-deposited onto thermally oxidised Si membranes with a buried cavity for overpressure tolerance and an Al interconnection layer. This device is very suitable for high temperature integrated pressure sensors.     

一种应力迟滞和温度自动补偿型FBG压力传感器

基于波登管与悬臂梁的组合设计,将2个相同波长的光纤布拉格光栅(FBG)分别与悬臂梁的上、下表面对称粘贴组成差动式FBG传感系统,实现了外压力调谐双FBG布拉格波长差的调谐方法。理论分析和实验研究结果表明,该系统不仅能自动补偿FBG压力传感系统中弹性衬底元件在加压和减压过程中的弹性迟滞,而且能同时自动补偿温度,改善传感系统的线性响应特性;在0～20MPa的压力范围内,双峰波长差的调谐范围为0.0～5.6nm,压力调谐双峰波长差的灵敏度可达0.28nm/MPa,是压力调谐单峰波长灵敏度的2倍,标准误差可由单峰的0.066nm降低到0.0084nm。     

Modeling, simulation and temperature compensation of porous polysilicon capacitive humidity sensor using ANN technique

The porous polysilicon capacitive sensor used for measuring relative humidity has the advantages of low cost, ease of fabrication and CMOS compatibility. However, the capacitance of the sensor, which is a function of concentration of water vapour, also depends on ambient temperature. Thus, variation of ambient temperature causes error in the performance of sensor outputs. In this paper, two ANN models have been developed. The first model is used to simulate the behavior of the capacitive humidity sensor (CHS). This model can also be used for on line monitoring of the fault of the sensor. The second model is based on inverse modeling, which can be used to compensate the effect of ambient temperature error. It is found from the simulation studies that the error of the direct model is within ±2% of full scale and for the inverse model the error is within ±0.5% of full scale over a temperature range from 20 to 70 °C. A hardware implementation scheme for realization of the CHS model is also proposed.     

曲率补偿低温漂带隙基准电压源设计

设计了一种曲率补偿低温漂带隙基准电压源。采用放大器钳位的传统实现方式,在电路中加入两种不同的分段曲率补偿电路,低温阶段,设计节点电流相减产生一段负温度系数补偿电流,高温阶段,控制晶体三极管导通产生一段正温度系数补偿电流,实现了对基准电压曲率补偿,同时采用共源共栅结构以提高电路的电源抑制比。在0.18μm的TSMC工艺下,使用Cadence Spectre对电路进行仿真,仿真结果表明,在3.3 V的电源电压下,基准输出电压为1.241 V,在–40~+125℃范围内,基准电压的温度系数为3.02×10–6/℃,低频时电源抑制比(PSRR)低于–57 d B。     

Nonlinear analysis of a CMOS integrated silicon pressure sensor

This paper reports theoretical and experimental results of analysis on the nonlinear characteristics of a CMOS integrated pressure sensor with a square silicon diaphragm. It is shown that nonlinearity is caused by both the large diaphragm deflection and the nonlinear piezoresistance of the resistors. The optimum layout for the piezoresistors to minimize their nonlinearity is also shown. The measured nonlinearity for the fabricated device agrees well quantitatively with the numerically analyzed nonlinearity.     

姿态传感器温度补偿方法研究

针对电子产品可能会出现随着环境温度的变化而产生测量误差的现象,在此选用姿态传感器在检测过程中出现这种误差的情况,提出了一种在软件方面利用最小二乘法进行温度补偿的方法。该方法计算简单,补偿精度高。通过实验数据验证表明,经过最小二乘法进行温度补偿后的检测精度,相比补偿前有了很大的提高。因此在高精度技术要求的检测中,利用这种方法进行温度补偿后可精确地检测出载体的姿态角度。     

压力传感器的非线性校正和迟滞补偿

针对压力传感器在桥梁支座压剪机应用中的非线性和迟滞现象,对其进行了分析,并采用最小二乘法对传感器输出信号进行非线性校正,然后利用函数校正法进行迟滞补偿。实验表明,该方法可以有效实现压力传感器的非线性校正和迟滞补偿。     

高动态电涡流位移传感器温度实时补偿算法

电涡流位移传感器在测量不同位移时有不同的温度灵敏度系数。单一的曲线拟合方法无法实现全量程的温度补偿。在温箱中收集多个指定位移处线圈电压的温飘数据,并拟合成曲线,根据这些曲线和传感器内线圈的温度可得到指定位移处线圈电压。用最小二乘法拟合指定位移和线圈电压得到一个多项式方程。把线圈电压值代入该方程可得到与温度无关的位移量,实现温度补偿。采用DMA中断和后台程序相结合的方法,使得传感器具有高动态响应。     

光纤光栅应变传感器温度补偿系统研究

提出了采用BP神经网络算法来实现FBG应变传感器的温度补偿系统,用以改善FBG应变传感器的温度交叉敏感现象。通过计算机程序和实验表明,此方法实现了FBG应变传感器对应变量和温度量的精确分离,较好地改善了温度对传感器造成的非线性干扰,使传感器对应变的测量误差达到10-3数量级。同时,有效地抑制了FBG应变传感器非线性特性的影响。