基于定性趋势分析的空调系统传感器故障检测

提出了基于定性趋势分析的空调系统传感器故障检测方法。该方法将空调系统中信号相似的传感器分成一组,利用组中信号间的趋势相似性进行故障检测。采集了空调系统的传感器数据,对传感器偏置故障和漂移故障进行仿真实验,结果表明,该方法能检测传感器的偏置故障和漂移故障。     

电子鼻在食品工业中的应用研究进展

电子鼻是一种新颖的模拟人的嗅觉来分析、识别和检测复杂嗅味和挥发性成分的仪器。电子鼻由气体传感器、信号处理和模式识别系统等组成。介绍了电子鼻的组成和工作原理,综述了电子鼻在食品原料、加工、质量监测、成份检验以及农产品贮藏中的应用研究进展,并指出了电子鼻目前存在的主要问题。     

Olfactory coordinated area coverage

This paper proposes an olfaction based methodology to automatically cover an unknown area enabling the decoupled cooperation of a group of floor cleaning mobile robots. This method is based on the utilisation of low cost chemical sensors in cleaning mobile robots, in order to differentiate clean from dirty areas. The experimental results show that the use of olfactory capabilities allows to efficiently cover and clean a certain area, and demonstrate the possibility of coordinating several mobile robots without the need of expensive sensing capabilities, map building or complex algorithms for task scheduling.     

主动嗅觉研究现状

对主动嗅觉（或称移动机器人气味/气体定位）问题的研究现状进行了较为详细的介绍．分析了当前此研究所使用的具有代表性的气味/气体和风向传感器原理．总结了主动嗅觉所包含的三个步骤,即气味/气体烟羽的发现、跟踪和气味/气体源确认,及每一步所采取的主要策略．最后,指出了当前主动嗅觉研究的主要难点．     

Robust static output feedback controller synthesis using Kharitonov’s theorem and evolutionary algorithms

This paper presents a simple but effective tuning strategy for robust static output feedback (SOF) controllers with minimal quadratic cost in the context of multiple parametric uncertainties. Finding this type of controller is known to be computationally intractable using conventional techniques. This is mainly due to the non-convexity of the resulting control problem, which has a fixed structure. To solve this kind of control problem easily and directly, without using any complicated mathematical manipulations, we utilize Kharitonov’s theorem and an evolutionary algorithm (EA) for the resolution of the underlying constrained optimization problem. Using Kharitonov’s theorem, a family of bounded, robustly stable static output feedback controllers can be defined and EA is used to select the controller that ensures a minimal quadratic cost within this family. The resulting tuning strategy is applicable to both stable and unstable systems, without any limitations on the order of the process to be controlled. A numerical study was conducted to demonstrate the validity of the proposed tuning procedure.     

关于漂移分析的注记

进化算法成功应用于求解各种复杂优化问题,其理论研究尚处于初级阶段。时间复杂性分析可以估计算法的平均运行时间,是进化算法理论研究中的重要方向和有力工具。讨论了漂移分析和进化算法时间复杂性的关系,利用吸收马尔科夫链给出漂移定理的一个新的证明;用一步平均漂移估计算法计算时间,得到了线性函数进化算法时间复杂度的一个一般性的结果。这些结果有助于更好地理解进化算法的工作原理和性能。     

基于广义回归神经网络的传感器故障诊断研究

针对诊断传感器偏置故障与漂移故障的难点问题,提出了一种基于广义回归神经网络(GRNN)的传感器故障诊断方法。该方法充分利用控制系统闭环回路测控信息,建立一组多输入单输出GRNN观测器,通过将观测器输出与传感器实际输出相比较获取残差序列,获得基于残差序列的传感器偏置故障和漂移故障的辨识策略,实现控制系统传感器故障在线诊断。仿真结果表明:该方法可以快速准确地检测和分离传感器故障,辨识传感器故障类型、故障大小以及故障发生的时间。     

Recognizing multi-modal sensor signals using evolutionary learning of dynamic Bayesian networks

Multi-modal context-aware systems can provide user-adaptive services, but it requires complicated recognition models with larger resources. The limitations to build optimal models and infer the context efficiently make it difficult to develop practical context-aware systems. We developed a multi-modal context-aware system with various wearable sensors including accelerometers, gyroscopes, physiological sensors, and data gloves. The system used probabilistic models to handle the uncertain and noisy time-series sensor data. In order to construct the efficient probabilistic models, this paper uses an evolutionary algorithm to model structure and EM algorithm to determine parameters. The trained models are selectively inferred based on a semantic network which describes the semantic relations of the contexts and sensors. Experiments with the real data collected show the usefulness of the proposed method.     

Drift-correcting template update strategy for precision feature point tracking

In this paper we present a drift-correcting template update strategy for precisely tracking a feature point in 2D image sequences. The proposed strategy greatly complements one of the latest published template update strategies by incorporating a robust non-rigid image registration step. Previous strategies use the first template to correct drifts in the current template; however, the drift still builds up when the first template becomes different from the current one particularly in a long image sequence. In our strategy the first template is updated timely when it is revealed to be quite different from the current template and henceforth the updated first template is used to correct template drifts in subsequent frames. Our method runs fast on a 3.0 GHz desktop PC, using about 0.03 s on average to track a feature point in a frame (under the assumption of a general affine transformation model, 61 × 61 pixels in template size) and less than 0.1 s to update the first template. The proposed template update strategy can be implemented either serially or in parallel. Quantitative evaluation results show the proposed method in precision tracking of a distinctive feature point whose appearance is constantly changing. Qualitative evaluation results show that the proposed method has a more sustained ability to track a feature point than two previous template update strategies. We also revealed the limitations of the proposed template update strategy by tracking feature points on a human’s face.     

Functional testing and characterisation of (bio-)chemical sensors on wafer level

An automated computer-assisted system for the functional testing and characterisation of (bio-)chemical sensors on wafer level is developed and integrated into a commercial prober station. The system enables the identification and selection of “good” sensors on wafer level and thus, allows to avoid further expensive bonding, encapsulation and packaging processes for defective or non-functioning sensor structures. Moreover, a specifically designed flow-through electrochemical microcell offers the possibility of wafer-level characterisation of (bio-)chemical sensors in terms of sensitivity, drift, hysteresis and response time at an early process stage. The system has been exemplarily tested using wafers combining pH-sensitive capacitive electrolyte-insulator-semiconductor structures as well as ion-sensitive field-effect transistors with different geometrical sizes and gate layouts.     

一类活动边界分布参数系统的移动控制策略

针对一类具有活动边界的分布参数系统,考虑移动传感器/执行器的动力学行为,研究其移动控制问题.考虑并列的传感器/执行器,通过传感器对系统的状态进行测量并将测量值传递给执行装置中的控制器.根据传感器之间不同的信息传递方式分别设计相应的控制器,基于无穷维抽象发展方程理论和Lyapunov方法得到相应的移动控制策略,并证明所提出的移动控制策略与系统的活动边界之间的关系.最后通过仿真结果验证所提出策略的有效性.     

State and input observability recovering by additional sensor implementation: A graph-theoretic approach

This paper deals with the problem of additional sensor location in order to recover the state and input observability for structured linear systems. The proposed method is based on a graph-theoretic approach and assumes only the knowledge of the system’s structure. It allows one to provide the minimal number of the required sensors and either their pertinent location or a necessary and sufficient condition which allows one to check if a sensor location is adequate or not. We obtain a sensor placement procedure based on classical and well-known graph theory algorithms, which have polynomial complexity orders.     

Mixed self-assembled lipopolymers with spacer lipids enhancing sensitivity of lipid-derivative QCMs for odor sensors

An odor sensing system using a quartz crystal microbalance (QCM) sensor array and pattern recognition technique has been for years a main research topic in our group. For the general field of artificial olfaction using acoustic-wave based sensors such as QCMs it is vital to search for novel sensing materials. Here we present recent results of our ongoing study on application of pegylated lipids as coatings for QCM odor-sensors. The method presented herein is based on self-assembling of lipids and lipid-derivatives on the QCM surfaces. The disulphide-terminated lipids and lipopolymers are co-chemisorbed onto gold electrodes of QCM sensors by simple immersion in ethanolic solutions. This creates porous supports onto which additional layers of lipopolymers are physisorbed. The method allows for fabrication of lipopolymeric QCM odor-sensors with enhanced sensitivity to odorants, capable of very good discrimination among odorant samples—according to the functional group of an odorant.     

Facing drift: a comparison of three methods

Drift is a common phenomenon in active sensors and, if left untreated, is generally the limiting factor in their performance. It is shown that drift and spread in sensor characteristics are tightly interwoven due to finite sensitivity to biasing parameters. Modern treatments of drift are dynamical under operating conditions, notably so chopping, the sensitivity variation method and the recently introduced van Putten-method. These methods differ in regards to drift-dependence on biasing. In their application to silicon flow sensors, the first two reduce but do not eliminate drift. The geometric van Putten-method leaves biasing invariant, which eliminates drift and obtains uniform sensor-characteristics leaving drift-free operation.     

DigitalBeing - using the environment as an expressive medium for dance

Dancers express their feelings and moods through gestures and body movements. We seek to extend this mode of expression by dynamically and automatically adjusting music and lighting in the dance environment to reflect the dancer’s arousal state. Our intention is to offer a space that performance artists can use as a creative tool that extends the grammar of dance. To enable the dynamic manipulation of lighting and music, the performance space will be augmented with several sensors: physiological sensors worn by a dancer to measure her arousal state, as well as pressure sensors installed in a floor mat to track the dancers’ locations and movements. Data from these sensors will be passed to a three layered architecture. Layer 1 is composed of a sensor analysis system that analyzes and synthesizes physiological and pressure sensor signals. Layer 2 is composed of intelligent systems that adapt lighting and music to portray the dancer’s arousal state. The intelligent on-stage lighting system dynamically adjusts on-stage lighting direction and color. The intelligent virtual lighting system dynamically adapts virtual lighting in the projected imagery. The intelligent music system dynamically and unobtrusively adjusts the music. Layer 3 translates the high-level adjustments made by the intelligent systems in layer 2 to appropriate lighting board, image rendering, and audio box commands. Furthermore the resulting artifact is the DigitalBeing - a personal signature of the dancer in digital space. In this paper, we will describe this architecture in detail as well as the equipment and control systems used.     

Artificial neural networks capable of learning spatiotemporal chemical diffusion in the cortical brain

Neurochemical and pharmacological studies of the central nervous system are important in understanding normal brain function and discovering effective treatments for brain diseases. Imaging systems are capable of providing large spatiotemporal chemical information, but they require the subject to remain still during recording. Implantable chemical sensors can be used in freely behaving animals and are able to provide higher resolution than imaging systems, but only in close proximity to the sensor.The aim of this research was to design and evaluate an artificial neural network capable of generating 3D chemical information over time using data acquired from a limited number of chemical sensors that could eventually be recorded from a freely behaving animal. The results show that the spatiotemporal neural network is capable of learning ion diffusion in a model of the cortical brain, in ideal or noisy conditions, and that network simulations of sensor data are as accurate as mathematical simulations.     

基于强化学习的适应性微粒群算法

惯性权重足微粒群算法(PSO)的重要参数,它可以甲衡算法的全局和局部搜索能力的关系,改善算法的性能.对此,提出一种基于强化学习的适应性微粒群算法(RPSO).首先将不同惯性权重调整策略视为粒子的行动集合;然后通过计算Q函数值.考察粒子多步进化的效果;进而选择粒_了最优进化策略,动态调整惯性权重,以增强算法寻找全局最优的...     

Combined evolution strategies for dynamic calibration ofvideo-based measurement systems

Calibration is a crucial step to obtaining 3D measurement using video camera-based stereo systems. All the parameters can be determined except for the pair of principal points, which poses a considerable drawback. Whereas in low-accuracy systems such points can be assumed to lie at the image center without degrading the overall 3D accuracy; in high-accuracy systems their true position must be computed accurately. In this case, all the calibration parameters can still be estimated through epipolar geometry, but it is necessary to minimize a highly nonlinear cost function. It is shown here that by combining two evolutionary optimization strategies this minimization can be carried out, both efficiently and reliably. The resulting strategy, which we call enhanced evolutionary search (EES), allows the full calibration of a stereo system using only a rigid bar. Moreover, EES can be applied to a wide range of applications where the cost function contains complex nonlinear relationships among the optimization variables     

气体传感器阵列温度漂移抑制的研究

半导体气体传感器存在漂移问题,温度变化对漂移的影响尤为明显.在气体传感器阵列中,可以加入温度、湿度等传感器,监测其工作环境.实验系统采用恒温箱设定一组温度,制备气体样本20例(两种浓度样本各10例),采集传感器对样本的响应;通过人工神经网络来识别样本;当有误判发生时,在原网络中引入温度传感器的响应值,消除了误判,在一定程度上抑制了漂移,改善了网络性能,验证了该温度漂移抑制方法的可行性.     

Time-varying feedback control of nonaffine nonlinear systems without drift

Sufficient conditions are presented under which a general nonlinear system without drift is globally asymptotically stabilizable by time-varying state feedback. A novel approach is developed for the design of a time-varying smooth state feedback controller. The controller is explicitly constructed by using the bounded state feedback strategy (Lin, 1995, 1996) combined with Lyapunov technique as well as lossless systems theory. This work incorporates earlier global stabilization results (Coron, 1992; Pomet, 1992) for controllable affine systems without drift, which are known not to be smoothly stabilizable via any time-invariant state feedback.