简易室内定高四旋翼飞行器设计

本文设计一款可在低空区间(对地高度0.3~5 m)保持指定高度飞行的简易四旋翼飞行器。控制器采用STM32F103RCT6单片机,通过惯性测量单元集成的数字传感器MPU6050和超声波测距模块分别测量得到飞行器的姿态角信息和飞行器对地高度,从而实现近地定高飞行目的。该四旋翼飞行器体积小、飞行灵活、有一定的运载能力,且成本低廉易于实现,该设计为室内等狭小空间的探测提供了理想平台。     

提高微型高度计分辨率的一种设计方法

介绍一种适用于微型飞行器的新型微型高度计的设计技术。利用标准气压高度公式推导得到了简化的气压高度微分式。系统包括微型气压计、微处理器、差压放大器、模数转换器和数模转换器。微处理器负责气压信号的采样、基准电压的调整和温度补偿,并最终计算输出高度值。设计的微型高度计样机质量小、功耗低,经测定,在标准大气压环境中其相对高度测量的分辨率为0.1m,精度为0.6m。现已应用于微型飞行器的自主飞行控制系统。     

测大楼高度的N种方法

每一个问题,都有一个现成而漂亮的答案。而每一个创造者,都是自己动脑筋思考,在现成答案之外,找到另一个新答案。许多人在中学时代,被问过这样一个物理问题“:如何利用气压计测算一栋大楼的高度?”而几乎每个用功学生的回答都是“:用气压计测量地面与楼顶的大气压力,然后用这个大气压力差即可计算出大楼的高度。”答案非常漂亮,也是参考书里的现成标准答案。物理学界流传这样一则故事:某年,有一个学生对上述问题的回答居然是“:带着气压计到大楼顶,气压计上绑着一条长绳,然后缓缓垂下,等气压计触及地面时,再拉上来,绳子的长度即是大楼的高度…     

双参数三维无源测距方法

为了提高飞行器对地面目标测距方法的有效性,提出了一种双参数三维测距方法.计算并分析了测距方法的定位误差几何分布,仿真结果验证了该方法的正确性.     

四旋翼飞行器串级PID控制设计与实现

针对四旋翼飞行器姿态与高度控制问题进行了分析,设计了串级PID姿态和高度控制器。以功能强大的STM32F407芯片作处理器,由MPU6050测量模块、磁力计、气压计和超声波模块进行姿态角度的检测与高度测量,结合四元数姿态表示方法,以多种传感器数据进行姿态解算,提高了测量精度;姿态与高度控制都使用串级控制算法,由于增加了内环角速度和高度速度的控制,提高了系统的抗干扰能力。最后根据MATLAB仿真对比实验和飞行实验平台验证,结果表明,所设计的控制器不仅提高了系统的抗干扰能力而且提高了系统的控制精度,具有较好的飞行控制效果。     

基于多传感器的微型四旋翼室内自主悬停研究

针对微型四旋翼在室内环境下不能通过外部定位系统实现自主悬停的问题,给出一种基于多传感器的微型四旋翼自主悬停控制方法。采用四旋翼分布式多传感器构建环境信息检测系统,实时获取四旋翼飞行器姿态和相对位置信息;通过设计控制装置对飞行器姿态进行控制,实现自稳飞行;通过室内基站定位平台与光流传感器的速度反馈,实现水平方向位置控制;通过超声波、气压计融合,实现飞行高度控制,最终完成对四旋翼飞行器的室内空间位置控制,使飞行器能够在室内空间中的任何一点悬停,并仅在小范围内波动。通过自主悬停仿真研究验证了方法的有效性。     

卡尔曼滤波微机故障测距装置的研制

本文介绍了一种运用卡尔曼滤波进行故障测距的装置，通过在５００ＫＶ，３７６．４ＫＭ的某高压输电线上的实验表明，该装置测距结果精确高度，测距结果可靠。     

用于移动机器人导航的多超声测距系统软硬件设计

本文给出了移动机器人导航系统中超声测距系统软硬件设计，包括测距数据的获得及通讯等，经在ＴＩＴ－１型移动机器人上实验验证，测距距离（０．３～５）米，精度±４厘米，可以满足移动机器人室内环境导航的要求．     

基于超声测距的随钻井径测量系统设计

 传统电缆测井的机械多臂井径仪在高速旋转的随钻条件下难以完成测量,而基于超声测距的随钻井径测量系统,具有利用超声测距的非接触、速度快、信息处理简单、抗干扰能力强等优点,通过采用3个换能器等角距圆周分布,在存在“偏心”时可有效测量井径以及井筒轴心到仪器轴心的距离矢量。本文借鉴国内外现有超声波随钻井径测量系统及技术经验,设计了以单片机为核心的模块化超声随钻井径测量系统。从超声换能器特性、硬件电路以及程序控制3个方面入手进行协同设计,精度高、具偏心修正功能。根据理论计算和超声换能器产品参数特点,采用1MHz的超声换能器进行测距。采用增益可编程的反射波信号检测电路,通过多次增益校正,使得首个反射波信号前沿被比较器捕捉到,把超声波传输时间检测精度提高到一个换能器振荡周期以内,有效提高了测距精度,实现高速高精度测量与井径计算,其测量精度达到毫米量级。     

基于贝叶斯估计的超声红外复合测距系统

针对单一传感器在复杂环境中测量数据可靠性差以及同一类型多传感器测距盲区无法补偿的问题,提出了一种基于贝叶斯估计的不同类型多传感器复合测距方法。该方法综合了超声与红外2种传感器的优点,利用红外传感器对超声传感器的测距盲区进行补偿,解决了单一类型传感器存在的测距盲区问题。对同一类型多个传感器同时获取的数据动态建立置信距离矩阵,应用椭圆曲线表示的支持程度关系矩阵确定各传感器测量结果中的有效值,并对其应用贝叶斯估计的方法进行数据融合,使测距准确度进一步提高。基于超声红外复合测距移动机器人的仿真实验表明,采用贝叶斯估计方法在保证实时性的前提下提高了测距的准确度,误差为±1 mm,达到了设计要求,为移动机器人的研究提供了参考。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with