A novel communication law for bilateral force-reflecting subsystem of teleoperators with time delay

This paper presents a novel communication law for teleoperators in the presence of substantial time delay. This new communication law can guarantee the stability of teleoperators in any time delay. The performance of teleoperators which use this new communication law is improved greatly.     

带遥控和自动温控功能的PWM控制器

介绍一种实用的带有遥控控制功能、自动温控功能、以PWM方式输出控制信号的多功能控制器模块,其特点是充分应用了Z8单片机的内部硬件资源以同时实现多种功能。阐明了最大限度开发单片机听基本思路和方法,可应用到其它单片它系统中。     

On the gain scheduling for networked PI controller over IP network

The potential use of networks for real-time high-performance control and automation is enormous and appealing. Replacing a widely used proportional-integral (PI) controller by a new networked controller for networked control capability can be costly and time-consuming. This paper proposes a methodology based on gain scheduling with respect to real-time IP traffic conditions to enhance the existing PI controller so it can be used over IP networks with a general network protocol like Ethernet. This paper first describes the gain scheduling approach based on constant network delays using a rational function approach. The formulation is extended to random IP network round-trip time (RTT) delays by using the generalized exponential distribution model. Simulation results show that the PI controller with gain scheduling provides significantly better networked control system performance.     

基于FPGA的红外遥控彩灯控制器的设计

设计一种基于现场可编程逻辑器件FPGA的红外遥控彩灯多模式显示控制系统。具有成本低、性能可靠、扩展性好等优点。详细介绍了系统的电路结构,提出一种由SC9148B红外发射芯片及外围电路作为发送器,HS0038B红外一体化芯片作为接收器,FPGA作为核心控制器的红外遥控系统的构建方法。该系统通过时序仿真与FPGA逻辑验证,结果表明,该设计能很好地实现彩灯红外遥控信号的解码控制、键值信号存储及译码、彩灯多模式显示等功能。     

Nonlinear filtering for state delayed systems with Markovian switching

This paper deals with the filtering problem for a general class of nonlinear time-delay systems with Markovian jumping parameters. The nonlinear time-delay stochastic systems may switch from one to the others according to the behavior of a Markov chain. The purpose of the problem addressed is to design a nonlinear full-order filter such that the dynamics of the estimation error is guaranteed to be stochastically exponentially stable in the mean square. Both filter analysis and synthesis problems are investigated. Sufficient conditions are established for the existence of the desired exponential filters, which are expressed in terms of the solutions to a set of linear matrix inequalities (LMIs). The explicit expression of the desired filters is also provided. A simulation example is given to illustrate the design procedures and performances of the proposed method.     

延迟效应重构网络算法研究

大量调控网络重构的模型和方法被研究,但是数据大小对算法精度的影响问题涉及很少。通过研究数据尺寸大小对延迟信息论方法构建基因调控网络精度的影响,表明基因调控网络构建的精度会在一定数据尺寸规模下达到一个稳态。为了克服互信息的一些缺点,引入了多时延互信息值计算两个基因之间的调控关系,构建的基因调控网络取得了很好的查全率和查准率。并用真实的生物分子网络进行测试,实验表明,基于多时延的策略在构建基因调控网络中扮演了一个重要角色。     

Efficient signal transmission algorithms for remote sensing gamma radiation over developed mobil WiMax network

This paper overcomes two key issues within radiation monitoring networks. Secure and accurate transmission of detected gamma radiation in remote areas is the first challenge. The second one is related to the robustness of transmitted signal under different fading scenarios. These issues are handled during signal transmission over worldwide interoperability for microwave access (WiMax) networks. The signals are experimentally captured using a ¹³⁷Cs point source, a NaI (TI) detector, and an analog-to-digital converter with 16 MS/s. For the first issue, several algorithms are implemented for secure and efficient transmission of gamma-based signals. These algorithms include encoding of captured signal, decoding, interleaving, and frequency transformation of modulated signal. Encoding and decoding of target signals are conducted using the Reed Solomon technique and convolutional encoding with a Viterbi decoder. A superior algorithm for channel interleaver using the combinational interleaving method is introduced. Fast lifting transform (FLT) is applied for transforming modulated signal into frequency domain. The results declare that CC = 1/2 with BPSK-1/2 coding rate introduces a better BER of 0.00068. A higher SNR of 1.5 dB is accomplished by the combinational interleaving algorithm. For the second issue, several models are suggested for overcoming channel degradations under gamma, exponential, Poisson, and geometric fading. Closed-form expressions that describe outage probability, bit error rate (BER), and symbol error rate (SER) are suggested. Geometric and gamma fading achieve respectively a lower BER of 0.18 and 0.48. These channels demonstrate similar channel performances at 3.6 dB. The proposed models are validated through comparison with published work. Finally, the proposed algorithms enable higher data rate transmission of detected ¹³⁷Cs signals under higher robustness using WiMax networks.     

网络遥操作机器人系统模糊变结构控制研究

针对网络遥操作机器人系统在实际应用中存在时延可能导致系统不稳定且难以控制的问题,通过对系统动力学建模和时延下系统理想性能分析,设计了一种新型的模糊滑模控制方案,在该方案中主机械手采用阻抗控制而从机械手采用模糊变结构控制。仿真结果表明,该控制方案能有效地抑制变结构控制中的抖振,系统能较好地实现位置比例跟踪和力比例跟踪。     

一种可远程网管的光纤收发器的设计

针对目前网管光纤收发器网管模式比较单一,且网络管理功能不完善,存在稳定性较差、价格偏高等问题,提出了一种以LPC2210嵌入式处理器和IP113S光电介质转换芯片为核心,以嵌入式多任务操作系统μCLinux为操作平台的新型可网管机架式光纤收发器。该系统硬件主要包括光电转换、网管控制和电源等三大部分,而系统软件支持多种网络管理模式。实验结果表明,该系统设计达到预期目标,与传统产品相比,该系统的稳定性得到明显地提高,管理功能能够实时监控系统,适用于电信级业务应用。     

基于nRF24L的带鼠标功能的电视遥控器

本文介绍一种用于TV上的基于nRF24L芯片设计的带有鼠标功能的新型电视遥控器,阐述硬件系统的工作原理和实际电路设计,同时介绍软件设计的部分要点。该遥控器利用磁感应导航键实现鼠标功能,通过nRF24L芯片的2.4GHz无线模块传送和接收遥控信号,实现对TV的遥控。     

Nonlinear dynamics of a semiconductor laser with delayed negative optoelectronic feedback

Nonlinear dynamics of a semiconductor laser with delayed negative optoelectronic feedback are studied both numerically and experimentally. Mappings of the dynamic states and bifurcation diagrams are compared between a delayed negative optoelectronic feedback system and a delayed positive optoelectronic feedback system. Both systems follow a quasiperiodic route to chaos, where regular pulsing, quasiperiodic pulsing, and chaotic pulsing states are observed. Frequency-locked pulsing states are also found in a delayed negative optoelectronic feedback system, but not in a delayed positive optoelectronic feedback system. These frequency-locked pulsing states are experimentally observed to exhibit a harmonic frequency-locking phenomenon, where the pulsing frequency is locked to a harmonic of the delay loop frequency instead of the delay loop frequency itself. The rotation numbers of these frequency-locked pulsing states show a Devil's staircase structure.     

Stochastic stabilization for bilateral teleoperation over networks with probabilistic delays

This paper studies the bilateral teleoperation over communication networks. Specifically, the network-induced random delays are modeled as being from a finite set, each delay in the set having a probability of occurrence. To fully utilize the stochastic information inherent with the delays, a novel design scheme combining the probability information and pole placement is proposed to achieve better tracking performance. The teleoperation problem is first formulated as the stabilization of an error dynamic system where the error is the difference between the states of the master and slave. Then, by constructing a Lyapunov function, a sufficient condition to guarantee the input-to-state stability is established in terms of linear matrix inequalities. The simulation results and comparison show a decrease in tracking error with the new design method.     

Communication over a wireless network with random connections

A network of nodes in which pairs communicate over a shared wireless medium is analyzed. We consider the maximum total aggregate traffic flow possible as given by the number of users multiplied by their data rate. The model in this paper differs substantially from the many existing approaches in that the channel connections in this network are entirely random: rather than being governed by geometry and a decay-versus-distance law, the strengths of the connections between nodes are drawn independently from a common distribution. Such a model is appropriate for environments where the first-order effect that governs the signal strength at a receiving node is a random event (such as the existence of an obstacle), rather than the distance from the transmitter. It is shown that the aggregate traffic flow as a function of the number of nodes n is a strong function of the channel distribution. In particular, for certain distributions the aggregate traffic flow is at least n/(logn)/sup d/ for some d>0, which is significantly larger than the O(/spl radic/n) results obtained for many geometric models. The results provide guidelines for the connectivity that is needed for large aggregate traffic. The relation between the proposed model and existing distance-based models is shown in some cases.     

Nonlinear adaptive prediction of speech with a pipelined recurrentneural network

New learning algorithms for an adaptive nonlinear forward predictor that is based on a pipelined recurrent neural network (PRNN) are presented. A computationally efficient gradient descent (GD) learning algorithm, together with a novel extended recursive least squares (ERLS) learning algorithm, are proposed. Simulation studies based on three speech signals that have been made public and are available on the World Wide Web (WWW) are used to test the nonlinear predictor. The gradient descent algorithm is shown to yield poor performance in terms of prediction error gain, whereas consistently improved results are achieved with the ERLS algorithm. The merit of the nonlinear predictor structure is confirmed by yielding approximately 2 dB higher prediction gain than a linear structure predictor that employs the conventional recursive least squares (RLS) algorithm     

延迟神经网络滞后同步双周期间歇控制

文中提出了一个使用李雅普诺夫函数理论和两种不同周期研究延迟网络的滞后同步。在间歇控制系统基础上,建立合适的函数和Halanay微分不等式得到指数稳定性。最后,通过数值仿真验证了理论结果的正确性。     

Nonlinear multi-input-multi-output neural network control of DCmotor drive with field weakening

A new multi-input-multi-output nonlinear control system, based on a simple and straightforward modification of the internal model control, is proposed. The nonlinear modified internal model control structure is completely defined by the inverse process model and guarantees the offset-free control. A feedforward neural network (NN) inverse model with one hidden layer and a small number of hidden neurons is successfully applied in a real-time control of the nonlinear process considered     

多偏移遥感图像的BP神经网络亚像元定位

提出了一种借助多偏移遥感图像来改进基于BP神经网络(BPNN)的亚像元定位新方法.不同于原BPNN方法使用单幅低空间分辨率观测图像,新方法利用多幅带有亚像元偏移的低空间分辨图像来确定亚像元属于各类的概率,然后根据概率值和地物覆盖比例确定亚像元类别,以降低BPNN定位模型中的不确定性和误差.实验表明,提出方法在视觉和定量评价上,均能获得更高精度的亚像元定位结果,验证了提出方法的有效性.     

Performance Comparison of Uncoded OFDM Systems with Trellis Shaping over Nonlinear Channels

Orthogonal frequency-division multiplexing (OFDM) can achieve remarkable performance in terms of spectral efficiency, but its power amplifier efficiency becomes poor because of its high peak-to-average power ratio (PAPR) nature of transmitted signals. Trellis shaping is an effective method to reduce peak and average power without signal distortion at the cost of transmitter complexity and its performance depends on the metric used for the trellis decoder. Several metrics, defined in either time or frequency domain, have been proposed in the literature. In many practical OFDM systems, however, slight nonlinearity is tolerable as long as the resulting distortion meets the system requirements such as bit error rate (BER) and spurious level of transmitted signals. In this paper, we make a thorough performance comparison of trellis-shaped uncoded OFDM systems with different metrics in terms of complexity, achievable PAPR, and resulting BER as well as power spectrum in a practical channel where the signal envelope is distorted by a power amplifier (PA). Our study shows that the metric designed in frequency domain is mostly favorable in such a scenario.     

基于云计算的矿井无线传感网络火情远程监控系统

针对矿井实际需求情况,提出了一种基于云计算的无线传感网络火情远程监控系统,此系统包括通讯基站、无线传感器网络和云计算平台,其中,无线传感器网络通过通讯基站与云计算平台相连接。它包括用于采集煤矿安全数据的无线传感器、执行器和用于传输煤矿安全数据的无线网关。该系统具备低成本、自组织、低功耗、信息交互方便的特点,具有很好的应用前景。     

A novel IP with MPLS over WDM-based broad-band wavelength switchedIP network

This paper presents a new technology for constructing IP over photonic systems. An IP with multiprotocol label switching (MPLS) over wavelength division multiplexing (WDM)-based broad-band IP network architecture and protocol is proposed and analyzed in this paper, which supports variable-length IP-like optical packet label switching and optical virtual path routing. This system tries to merge into one layer the functionalities of the wavelength switching, SONET mux/demux, and IP routing, and is sometimes known as the concept of optical MPLS. The label banding, forwarding/switching process, and node architecture of the proposed network are discussed and studied. A unique as well as important function of a lambda/label edge router (LER) is a flow assembly device that can encompass MPLS' forward equivalence classes, label stacking, and label switching path aggregation function. At the same time, a particular function of the core label switching router is wavelength merging. A fiber delay line is used to delay the data stream in order to process the label information and resolve contention. Transmission bit error rate measurements of the baseband data stream and back-to-back is also demonstrated to show its feasibility