基于稀疏表示的惯性传感器信号实时滤波方法

针对惯性传感器信号处理的特点,提出了基于稀疏表示的信号滤波处理系统模型和方法。通过 K-SVD算法对信号学习训练获得字典,为了减少计算量,满足实时性,尽量降低字典的大小,仿真结果表明,在满足一定精度的条件下,字典的大小最小为3×10。在该字典下对信号进行稀疏表示和重构,改变信号的输入方式,可以实现信号的实时滤波。仿真结果表明提出的滤波方法能有效地消除噪声,改善输出信号精度,可以提高信噪比最大为4．5 dB。该滤波方法与传统的滤波方法相比有较大的优势,为惯性传感器信号处理提供了一种新的方法。     

基于Allan方差改进阈值的惯性传感器动态信号小波去噪

惯性传感器信号的去噪效果通常都是用Allan方差来评价,针对这个特点,提出了一种基于Allan方差噪声系数的小波阈值改进算法。先用提升小波将信号分解到不同频段,再用Allan方差计算各频带上的噪声系数,根据各频带噪声系数的大小确定其滤波阈值,再结合参数可调的阈值函数对各尺度信号进行滤波去噪。改进算法以去噪效果评价参数来修正阈值,具有很强的针对性。通过同其它常用的惯性传感器去噪方法做比较,证明该算法可以有效的随机噪声,提取出更加准确真实的惯性传感器动态输出。     

一种盲自适应随机共振数字基带信号处理方法

随机共振能够明显提高输出信噪比,在信号处理领域得到了广泛关注。与传统噪声调节随机共振相比,参数调节随机共振增强了随机共振的鲁棒性,但面临如何选取最佳系统参数的问题。以峭度和负熵来度量非线性系统输出信号的概率分布情况,找出了输出信号的概率分布特性与最佳系统参数之间的对应关系。在此基础上,提出一种盲自适应随机共振方法,并将其应用于数字基带二进制信号处理之中。该方法利用输出信号的峭度或负熵数值引导非线性系统参数迭代,使之自适应达到随机共振状态。该方法可解决最佳系统参数的选取问题,能够增强随机共振的灵活性及鲁棒性。利用MATLAB软件搭建随机共振仿真平台对提出方法进行了实验验证,仿真结果表明,该方法能够迅速收敛到最佳系统参数值,进而明显提高输出信号的信噪比。     

改进的裂变自举粒子滤波算法在GPS导航系统中的应用

为了提高全球定位系统GPS的定位精度和可靠性,提出了一种基于裂变自举粒子滤波FBPF的GPS定位系统算法。根据GPS输出的参数之间的相互联系建立了系统的状态方程,并应用于对GPS接收数据进行滤波处理的改进FBPF算法中。GPS导航系统中采用DSP对GPS接收机的输出信号进行译码和滤波处理。     

基于参数优化的ICEEMDAN-MEMS陀螺信号处理研究

航空飞行器多维智能感知系统极端应用环境中,MEMS陀螺的输出信号中会含有各种噪声,进而影响系统后续的导航任务。为了改善MEMS陀螺输出信号的质量,提出了一种参数优化的改进的自适应噪声完全集成经验模态分解(ICEEMDAN)的MEMS陀螺信号滤波方法。首先通过灰狼优化算法(GWO)对ICEEMDAN的参数进行优化;对MEMS陀螺的输出信号进行分解,得到若干个本征模态函数(IMF),并根据排列熵对分量进行划分,并使用递归最小二乘算法(RLS)对混合分量进行滤波;最后将信号重构得到最终信号。对系统实测数据进行处理,分析结果表明：与原始信号相比,降噪后的MEMS陀螺输出信号均方根误差(RMSE)降低了78.6%,该算法可有效地去除输出信号中的噪声,具备一定的工程应用价值。     

基于饱和系统随机共振的图像去噪算法

利用随机共振（SR）机制，在传输相关信号的非线性系统中加入噪声，在输出端信号可被增强。本文提出一种基于动态饱和非线性系统随机共振的图像去噪算法，首先将图像重采样为一维信号，并调节动态饱和非线性系统的参数，使之达到最优，使动态饱和非线性系统能够产生随机共振。相比一维随机共振，二维随机共振的图像复原效果更接近于原图，输出图像的直方图和峰值信噪比(PSNR)，也明显优于一维随机共振。相比于传统滤波方法，饱和系统的去噪效果更好，同时对于噪声强度的变化具有较好的鲁棒性。     

基于随机共振的大件平板受力信号提取

针对大件受力检测中的直流输出电压信号淹没在噪声中,导致提取结果不准确,提出了一种周期性脉宽调制(PWM)波结合随机共振提取直流微弱信号的方法.通过PWM波将原始信号调制成待测信号,利用随机共振系统检测待测信号;通过低通滤波器对输出信号进行滤波;还原有用信号.经过仿真实验分析,对比传统直流微弱信号检测方法,提出的方法信号提取结果的误差较小,可达到检测的目的.     

HHT算法在压电陶瓷驱动器的微纳米位移传感器中的应用

针对信号虽然经过了模拟滤波,采集到的信号经过数据采集系统后不可避免的含有随机噪声,噪声限制了传感器的分辨率和系统的动态范围。提出利用HHT算法的经验模态分解对用于压电陶瓷的微纳米传感器采集到的数字信号进行数字滤波,将采集到的微弱信号进行进一步处理,以提高微纳米传感器在稳态输出时信号的信噪比从而提高传感器的性能。采用两种方法进行处理。其中一种方法是滤掉经过模态分解后信号中的最高频噪声,另一种方法是滤掉经过模态分解后信号中的前两阶噪声。最后对比实验结果证实了此算法的有效性,它能够改善传感器的线性度。     

基于部分惯性传感器信息的单目视觉同步定位与地图创建方法

传统的单目视觉同步定位与地图创建(MonoSLAM)方法很难处理累积误差问题,如何有效地利用惯性传感器输出的运动信息辅助SLAM系统抑制累积误差是MonoSLAM研究中的一项重要内容.由于惯性传感器输出的三轴方向角中横滚角和俯仰角的精度较高,而偏航角的精度相对较低,如果在SLAM系统中直接使用惯性传感器输出的偏航角信息不但无法有效地抑制该系统中的累积误差,反而会进一步增大系统误差、降低SLAM系统的稳定性.针对这种情况,提出一种基于惯性传感器横滚角和俯仰角的MonoSLAM方法.首先利用惯性传感器输出的横滚角和俯仰角进行系统标定;然后将惯性传感器自身的偏航角作为系统状态向量的一个分量,利用扩展卡尔曼滤波器实时地估计状态向量,进而实现实时鲁棒的同步定位和地图创建.实验结果表明,该方法可以有效地抑制SLAM系统运行过程中产生的累积误差,并降低惯性传感器测量误差对SLAM系统稳定性的影响.     

基于Kalman滤波算法的姿态传感器信号融合技术研究

针对应用三轴陀螺仪和三轴加速度传感器的四旋翼飞行器姿态角测量问题,提出了基于Kalman滤波算法的姿态传感器信号融合方法。该方法将陀螺仪输出的角速度误差作为时变误差处理,认为陀螺仪输出的角速度误差与其所测角速度及上一时刻的角速度输出误差相关,并据此建立陀螺仪测量线性方程,在此基础上,应用Kalman滤波算法,以加速度计输出的姿态角对陀螺仪测量的姿态角进行修正,从而达到姿态角准确测量的目的。实验结果表明：应用Kalman滤波算法对加速度传感器和陀螺仪信号融合后可有效消除姿态角测量累积误差并显著改善姿态角测量的动态特性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.