空盒气压表实验室间比对测量结果不确定度评定

本文是对空盒气压表实验室间比对测量结果的不确定度分析.     

基于Proteus的气压报警系统设计

利用Proteus设计了一种数字气压报警系统。通过MPX4115气压传感器获得与大气压相对应的模拟电压值,经过V/F转换器将模拟电信号转换为数字脉冲信号输入到单片机,单片机接收脉冲信号,经计算处理得出实际的气压值,最后通过数码管显示电路显示出来,并在Proteus上成功完成了仿真调试。结果表明本系统具有携带方便,操作简单,精确度高,适合远距离传送,并可根据具体情况设置警戒值进行智能监测报警,可实现不同环境下的分布-集中监控的特点。     

Honeywell HPA200精密气压计测量异常现象分析

为了解决Honeywell HPA200精密气压计出现的严重超标的测量异常现象,通过分析对比相关的因素,查找验证HPA200精密气压计受到400 MHz无线对讲机的电磁干扰,依此设计硬件LC带阻滤波器,来滤除400 MHz左右的确定性干扰信号.最终通过实际测试和验证,LC带阻滤波器可以增强HPA200精密气压计抗干扰能...     

电容式石英膜盒压力传感器的研制

本文介绍了电容式石英膜盒压力传感器工作原理、石英膜盒结构设计和加工工艺。对配用的测试电路也做了说明,整体石英弹性膜盒的研制成功为脆性材料弹性化开拓了应用新途径并为大气压力无汞测量提供了新的敏感器件。     

CBSC: A Crowdsensing System for Automatic Calibrating of Barometers

The mobile crowdsensing software systems can complete large-scale and complex sensing tasks with the help of the collective intelligence from large numbers of ordinary users. In this paper, we build a typical crowdsensing system, which can efficiently calibrate large numbers of smartphone barometer sensors. The barometer sensor now becomes a very common sensor on smartphones. It is very useful in many applications, such as positioning, environment sensing and activity detection. Unfortunately, most smartphone barometers today are not accurate enough, and it is rather challenging to efficiently calibrate a large number of smartphone barometers. Here, we try to achieve this goal by designing a crowdsensingbased smartphone calibration system, which is called CBSC. It makes use of low-power barometers on smartphones and needs few reference points and little human assistant. We propose a hidden Markov model for peer-to-peer calibration, and calibrate all the barometers by solving a minimum dominating set problem. The field studies show that CBSC can get an accuracy of within 0.1 hPa in 84% cases. Compared with the traditional solutions, CBSC is more practical and the accuracy is satisfying. The experience gained when building this system can also help the development of other crowdsensing-based systems.     

变极性等离子电弧压力的影响因素分析

利用U形压力计测试了不同工艺参数条件下的变极性等离子焊接的电弧压力,利用正交试验测试了不同正极性电流、反极性电流、正反极性时间比和等离子气流量四种参数条件下的电弧压力.结果表明,电弧压力随着这些因素的增加而增加,而四种因素对电弧压力影响的大小依次为:等离子气流量>正极性电流>正反极性时间比>反极性电流.分析原因,等离子气流量是通过冷却压缩提高电弧压力,压缩了电弧尺寸,而焊接电流则通过电磁压缩,但也提高了电弧半径.由于正反极性阶段电弧压力的差异较为明显.因此正反极性时间比对电弧压力也有显著的作用.

Abstract：

VPPA pressure was measured at different welding parameters by U-tube barometer method. The effects of different welding conditions on arc force, including straight polarity current, reverse polarity current, time ratio, plasma gas flow rate were analyzed by the orthogonal experiment. The results indicates that VPPA pressure increased with these four parameters, and the influences of the welding parameters are in order of plasma gas flow rate, straight polarity current, time ratio, and reverse polarity current. Then the mechanisms were discussed. The plasma gas can cool and compress the arc column and compress the arc radius, which increases the VPPA pressure; while the welding current increases the arc radius by electromagnetic compression, which enhances the VPPA pressure. Moreover, due to the great difference of VPPA pressure between straight polarity phase and reverse polarity phase, time ratio is also one of key factors to VPPA pressure.     

基于加速度信息修正的四旋翼位置估计算法研究

针对单一的微传感器无法准确进行四旋翼无人机空间定位的问题,设计了一种多元信息融合的互补滤波算法用于无人机空间位置估计。该算法的核心思想为利用一类通用的辅助传感器如气压传感器,全球定位系统（GPS）以及微基站的测量信息对加速度传感器的测量信息进行实时修正,然后利用修正后的加速度信息积分估计四旋翼无人机的空间位置。本文在自主研制的飞行控制平台上验证了这种互补滤波算法的有效性。通过对比实验验证,利用本文设计的互补滤波算法可以使得无人机运动速度估计值以及空间位置估计值无偏差的收敛。飞行实验证明,将该互补滤波算法输出的速度以及位置估计信息应用于位置控制器中,可以实现无人机稳定的位置控制。     

基于SCP1000-D01的气压计的设计

SCP1000-D01是由芬兰VTI公司生产的一款高精度、高分辨率、低功耗的气压传感器,内置A/D转换器、ASIC结构以及EEPROM存储单元,并提供SPI接口与外部进行通讯.用户通过MCU与SCP1000-D01传感器组成的系统读取存储在EEPROM中的压力值和温度信息,并通过公式计算压力等值.介绍了SCP1000的性能特点、引脚功能、内部结构、工作原理及气压计的典型应用.     

Scalable floor localization using barometer on smartphone

Traditional fingerprint‐based localization techniques mainly rely on infrastructure support such as GSM and Wi‐Fi. They require war‐driving, which is both time‐consuming and labor‐intensive. With recent advances of smartphone sensors, sensor‐assisted localization techniques are emerging. However, they often need user‐specific training and more power intensive sensing, resulting in infeasible solutions for real deployment. In this paper, we present Barometer‐based floor Localization system (B‐Loc), a novel floor localization system to identify the floor level in a multi‐floor building on which a mobile user is located. It makes use of the barometer on smartphone. B‐Loc does not rely on any Wi‐Fi infrastructure and requires neither war‐driving nor prior knowledge of the buildings. Leveraging on crowdsourcing, B‐Loc builds the barometer fingerprint map, which contains the barometric pressure value for each floor level to locate users' floor levels. We conduct both simulation and field studies to demonstrate the accuracy, scalability, and robustness of B‐Loc. Our simulation shows that B‐Loc can locate the user fast and the field study in a 10‐floor building shows that B‐Loc achieves an accuracy of over 98%. Copyright © 2016 John Wiley & Sons, Ltd.     

基于单片机控制的数字气压计设计与实现

介绍了一种精密数字气压计的软硬件实现方法。该方法通过气压传感器获得与大气压相对应的模拟电压值，并经过V／F变换输入到单片机进行处理，从而实时显示相应的气压值。用本文所述的方法制成的气压计携带方便，操作简单，精确度高，完全符合设计要求。