42 resultados para Network-based positioning
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
In order to effectively improve the classification performance of neural network, first architecture of fuzzy neural network with fuzzy input was proposed. Next a cost function of fuzzy outputs and non-fuzzy targets was defined. Then a learning algorithm from the cost function for adjusting weights was derived. And then the fuzzy neural network was inversed and fuzzified inversion algorithm was proposed. Finally, computer simulations on real-world pattern classification problems examine the effectives of the proposed approach. The experiment results show that the proposed approach has the merits of high learning efficiency, high classification accuracy and high generalization capability.
Resumo:
Two highly connected cobalt(II) and zinc(II) coordination polymers with tetranuclear metal clusters as the nodes of network have been prepared, being the first example of an 8-connected self-penetrating net based on a cross-linked alpha-Po subnet.
Resumo:
Lake Dianchi is a shallow and turbid lake, located in Southwest China. Since 1985, Lake Dianchi has experienced severe cyanabacterial blooms (dominated by Microcystis spp.). In extreme cases, the algal cell densities have exceeded three billion cells per liter. To predict and elucidate the population dynamics ofMicrocystis spp. in Lake Dianchi, a neural network based model was developed. The correlation coefficient (R 2) between the predicted algal concentrations by the model and the observed values was 0.911. Sensitivity analysis was performed to clarify the algal dynamics to the changes of environmental factors. The results of a sensitivity analysis of the neural network model suggested that small increases in pH could cause significantly reduced algal abundance. Further investigations on raw data showed that the response of Microcystis spp. concentration to pH increase was dependent on algal biomass and pH level. When Microcystis spp. population and pH were moderate or low, the response of Microcystis spp. population would be more likely to be positive in Lake Dianchi; contrarily, Microcystis spp. population in Lake Dianchi would be more likely to show negative response to pH increase when Microcystis spp. population and pH were high. The paper concluded that the extremely high concentration of algal population and high pH could explain the distinctive response of Microcystis spp. population to +1 SD (standard deviation) pH increase in Lake Dianchi. And the paper also elucidated the algal dynamics to changes of other environmental factors. One SD increase of water temperature (WT) had strongest positive relationship with Microcystis spp. biomass. Chemical oxygen demand (COD) and total phosphorus (TP) had strong positive effect on Microcystis spp. abundance while total nitrogen (TN), biological oxygen demand in five days (BOD5), and dissolved oxygen had only weak relationship with Microcystis spp. concentration. And transparency (Tr) had moderate positive relationship with Microcystis spp. concentration.
Resumo:
A novel approach for multi-dimension signals processing, that is multi-weight neural network based on high dimensional geometry theory, is proposed. With this theory, the geometry algorithm for building the multi-weight neuron is mentioned. To illustrate the advantage of the novel approach, a Chinese speech emotion recognition experiment has been done. From this experiment, the human emotions are classified into 6 archetypal classes: fear, anger, happiness, sadness, surprise and disgust. And the amplitude, pitch frequency and formant are used as the feature parameters for speech emotion recognition. Compared with traditional GSVM model, the new method has its superiority. It is noted that this method has significant values for researches and applications henceforth.
Resumo:
A neural network-based process model is proposed to optimize the semiconductor manufacturing process. Being different from some works in several research groups which developed neural network-based models to predict process quality with a set of process variables of only single manufacturing step, we applied this model to wafer fabrication parameters control and wafer lot yield optimization. The original data are collected from a wafer fabrication line, including technological parameters and wafer test results. The wafer lot yield is taken as the optimization target. Learning from historical technological records and wafer test results, the model can predict the wafer yield. To eliminate the "bad" or noisy samples from the sample set, an experimental method was used to determine the number of hidden units so that both good learning ability and prediction capability can be obtained.
Resumo:
提出一种移动对象数据库模型——Dynamic Transportation Network Based Moving Objects Database(简称DTNMOD),并给出了DTNMOD中基于移动对象时空轨迹的网络实时动态交通流分析方法.在DTNMOD中,交通网络被表示成动态的时空网络,可以描述交通状态、拓扑结构以及交通参数随时间的变化过程;网络受限的移动对象则用网络移动点表示.DTNMOD模型包含了完整的数据类型和查询操作的定义,因此可以在任何可扩充数据库(如PostgreSQL或SECONDO)中实现,从而得到完整的数据库模型和查询语言.为了对相关模型的性能进行比较与分析,基于PostgreSQL实现了一个原型系统并进行了一系列的实验.实验结果表明,DTNMOD提供了良好的区域查询及连接查询性能.
Resumo:
本文根据国内工业机器人技术开发和应用现状及其技术发展趋势 ,进行了基于现场总线的工业机器人联网技术的研究和开发 ,并将机器人作为生产线底层设备 ,实现了工业机器人网络的互联 .本文介绍了这个系统的硬件结构、上位监控机软件实现、控制器软件实现以及系统完成的功能 .
Resumo:
本文在分析了网络环境下机器人遥操作系统的结构的基础上,介绍了一套基于网络的移动机器人遥操作实验系统的设备组成及硬软件结构的设计和实现。系统设计简洁有效,网络虚拟机的设计和使用则极大地方便了遥操作研究的开展。
Resumo:
针对基于网络的智能机器人遥操作系统中人机交互的主要难点和现有方法的不足,结合基于网络的多机器人遥操作系统的特点,应用多模式控制的方法丰富了操作者与机器人系统的交互途径,提高了操作效率.在此基础上,为解决网络时延给多机器人遥操作系统中的人机交互带来的问题,提出了一种带有时间标记的基于事件的方法,在保证系统稳定运行的同时提高了系统的效率和性能.实验证明了所提方法的有效性和优越性.
Resumo:
为了实现定位抓取任务,提出基于网络的直角坐标机器人视觉控制系统。针对机器人运动控制的非线性与强耦合特性,采用神经网络控制器,构建了图像偏差与运动控制量之间的对应关系。通过对图像增强、边缘提取、特征提取等图像处理方法的综合分析,提出了一套优化组合图像处理法。在计算机网络环境下,采用自定义协议实现图像处理器与运动控制器协调控制,并将远程监控应用到机器人控制中。实验结果表明,该系统能够在视野范围内自动实现定位抓取动作。
Resumo:
基于多智能体系统理论,研讨在非结构,不确定环境下面向复杂任务的多机器人分布式协调系统的实现原理,方法和技术。提出的递阶混合式协调结构,基于网络的通讯模式和基于有限状态机的规划与控制集成方法,充分考虑了复杂任务和真实自然环境的特点,通过构建一个全实物的多移动机器人实验平台,对规划,控制,传感,通讯,协调与合作的各关键技术进行了开发和集成,使多机器人分布式协调技术的研究直接面向实际应用,编队和物料搬运的演示实验结果展示了多机器人协调技术的广阔应用前景。
Resumo:
研究一种正交轮式移动车为载体的类人形机器人的建模与控制问题.首先基于分体建模的思想,采用机理建模和神经网络技术相结合的方法建立了动力学模型;然后依据该模型,提出一种新的基于 NN 的自适应 H_∞位置跟踪控制器,使鲁棒非线性 H_∞控制方法自然地与模型的直接自适应神经网络技术集成为一体,并证明了其鲁棒稳定性.最后,仿真研究验证了该方法的正确性和有效性.
Resumo:
基于网络的机器人遥操作系统是互联网技术与机器人技术相结合的产物,其基本特点是操作者的决策能力与远端机器人系统精确、快速运动能力的有机结合,这种结合通过互联网这种廉价的通讯媒介得以实现。这类系统较之于传统机器人系统的优点主要体现在两个方面:一方面延伸了操作者的感知和操作能力,使操作者可以置身于安全的环境中而完成危险环境中的作业任务;另一方面提高了机器人对工作环境的适应能力,辅之以操作者的决策,机器人可以工作于非结构化的工作环境中。随着互联网技术的飞速发展,基于网络的机器人遥操作技术在远程医疗、远程服务、远程制造等领域得到了广泛的应用。 互联网技术为机器人遥操作技术的应用开辟了广阔的应用前景,但同时也带来了新的挑战,互联网数据传输的特征——有限带宽、随机时延、丢包和乱序等——降低了遥操作系统的性能,甚至造成系统的不稳定。传统的主从式控制策略增加了操作者的工作负担,而且需要占用大量网络带宽,造成网络资源的浪费;而协作式控制策略虽然可以减少通信量,但操作者对机器人系统的影响降低,而且只能依据经验设计。另外,传统的控制策略并没有考虑机器人遥操作系统的混杂本质特征。一个理想的机器人网络遥操作系统应该能够实现系统计算、通信等功能的合理划分。合理划分的原则是:把操作者从控制闭环中解放出来,适当减轻操作者的工作压力;充分利用机器人系统的计算能力和运动能力,降低系统对网络带宽的需求;适当保留操作者对机器人系统的决策能力,从端机器人系统要有一定的自主能力。基于以上基本原则,本文提出了基于运动描述语言(Motion Description Language, MDL)的机器人网络遥操作系统设计方法,针对该方法在以下几个方面进行了深入研究: 1. 针对现有的机器人网络遥操作系统结构存在的问题,提出了基于运动描述语言的机器人网络遥操作系统控制结构。该控制结构充分考虑了机器人网络遥操作系统的构成特点,实现了系统计算、通信等功能的合理划分,为系统设计奠定了基础。 2. 结合基于事件的规划与控制理论,提出了新的运动描述语言模型,并以轮式移动机器人的镇定问题为例说明了基于运动描述语言的机器人系统控制方法。为了分析运动描述语言的网络环境特征,我们对基于运动描述语言的机器人网络遥操作系统进行了仿真研究,并与传统的遥操作方法进行了对比分析,仿真结果表明,基于运动描述语言的控制方法对网络随机延迟具有鲁棒性。 3. 在基于网络的机器人遥操作系统中,操作者依据系统运行过程中特定的事件进行决策,据此提出了遥操作系统中的信息变换和运动描述语言框架中的增强信息反馈方法。在信息变换方法中,针对各种媒体信息的特点以及操作者的感知特征,把视频信息转换为力信息,引导操作者提供和系统状态对应的控制命令。运动描述语言框架中的增强信息反馈方法反映了操作者感知离散事件的本质特征,对操作者感兴趣的离散事件进行了凸显,增强了操作者的感知能力。实验结果验证了两种方法的有效性。 4. 针对具体的遥操作目标抓取任务,建立了基于运动描述语言的机器人网络遥操作原型系统,定义了一致可操作性的概念,并探讨了运动描述语言框架中的优化问题。通过实验对传统的控制方法与基于运动描述语言的控制方法进行了对比分析,实验结果说明,基于运动描述语言的机器人网络遥操作系统在降低操作者工作负担以及减少对通信网络带宽需求方面具有很大的优势。 基于运动描述语言的机器人网络遥操作系统克服了传统控制方法的缺点,通过抽象实现了数据的压缩,这种特点较之于传统的控制方法在降低通信量以及操作者的工作负担方面具有很大的优势,对于提高机器人网络遥操作系统的性能具有现实意义。