21 resultados para Control Methods
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
本文对模糊控制的理论方法目前在交流电机系统中的应用作了全面的分析和总结 .针对交流电机系统控制的特点 ,重点讨论了简单模糊控制、复合模糊控制以及仿生模糊控制等几种典型的模糊控制方法和技术 ,分析了它们各自的特点和存在的问题 ,并给出了模糊控制的实现方法和手段 .最后 ,对模糊控制在交流电机系统中应用的关键问题和未来发展方向进行了展望
Resumo:
提出了一种平面自由运动半物理仿真系统的设计,对系统仿真试验的初始条件形成过程进行了具体阐述。系统中应用了一种平面两自由度直角坐标运动装置,用于完成系统驱动及速度和位置控制,同时这种运动装置能够进行直角坐标跟随运动,并与其末端测量机构共同实现对平面自由运动物体的高精度大范围位姿测量。建立了系统的运动学模型,并设计相应的控制算法实现试验所需的运动过程,采用半闭环和闭环相结合的方法有效控制系统的末端累积误差;针对提出的复合测量方法,建立了测量原理的数学模型,并进行了精度分析和仿真计算。实验证明这种设计和相应的控制测量方法合理可行。
Resumo:
本文介绍了一个野外探查机器人监督式控制器的设计与实现,介绍了机器人控制器的三种传统控制方法并比较了其优缺点,论证了在具体的机器人上应用监督式控制的优点,分析和讨论了其软硬件结构和功能,最后对这个具体的项目的控制器设计实现进行了总结和展望。
Resumo:
仿人机器人是研究人类智能的高级平台,是综合多种学科的复杂智能机械,其研制和开发涉及到各学科、多方面问题,目前已成为机器人领域的研究热点问题之一.本文对仿人机器人目前的发展现状进行了综述,分析了多种仿人机器人的自由度分布,介绍了具有不同结构特点的腰机构,分析了腰关节在仿人机器人的稳定动态步行、全身协调运动及有情感步行等方面的重要作用.本文还指出了仿人机器人目前的主要研究方向.
Resumo:
拟人机器人的动力学具有高度非线性、高度耦合的特点,分析清楚各组成部分之间的交互作用力是实施高级控制方法的基础。文章在以往分析移动机械手的基础上,从整体建模的角度入手,对拟人机器人的交互作用力提出了一个新的模型,即神经网络模型。利用该模型对一个特殊的单一手臂运动的例子进行了拟合,其结果是收敛的。这说明提出的模型是有效的,此后,我们将陆续给出研究成果。
Resumo:
近十年来人们对专用爬壁机器人领域的研究越来越感兴趣。如清洗高层建筑、石油气罐的喷漆喷砂、核工业设施的检测维护、援助消防和营救工作以及危险环境的远程监控等都急需一种自动化设备。爬壁机器人, 因其可以吸附墙壁表面和携带适当的传感器或工具,是这些工作的最佳候选。 本文中设计了一种反恐侦察爬壁机器人系统。在反恐侦察中,将微小型爬壁机器人上安装无线摄像头、麦克风等装置,代替侦察人员探测狭小空间内部的敌情,不但能提高侦察的准确度,还能增强安全性,减小人员伤亡。针对这一应用背景,国家863 计划提供资金开展了反恐侦察爬壁机器人样机系统的研制项目。 这种侦察爬壁机器人样机采用了两足式结构和欠驱动机构设计,使得机器人具有灵活的运动能力和多种运动方式。该机器人可以壁面爬行、穿越管道和跨越交叉面。两个有力的吸盘足依靠真空泵抽取吸盘内气体来实现吸附墙面。欠驱动机构减少了电机数量,使得机器人尺寸、重量和功耗都较小,但却对控制增加了挑战。机器人运动学方程被求出,这有助于我们理解其运动机理。 机器人上有无线遥控和无线视频传输系统分别负责接收指令和采集图像信息。针对该爬壁机器人在体积,重量,功耗和速度上的要求,本文提出了以TI公司的TMS320F2812DSP 为控制芯片的嵌入式控制系统的设计方案, 控制器的主要功能是实现多电机实时控制,搭建高效可靠的人机通讯和机器人运动规划。层次较高的操作指令采用有限状态机理论实现跟踪机器人运动状态。 电机的伺服控制,是整个控制系统设计中最基本、最重要的部分。对此本文提出了梯形速度规划和PID 控制策略,经过参数优化,基本达到了控制精度的要求。 最后,通过实验验证了机器人高效的能力,表明侦察爬壁机器人样机系统具备了执行反恐侦察的基本功能。
Resumo:
蛇具有细长无肢的身体、独特的半球形关节,使其可在神经系统控制下完成与环境相适应的多种节律运动。模仿蛇的运动机理和行为方式而设计的蛇形机器人克服了轮腿式机器人的缺点,增加了机器人的运动方式,扩大了机器人的应用范围。但应用传统的控制策略实现蛇形机器人运动控制遇到了很难克服的问题。随着社会经济与科技的发展,研究人员把从蛇运动神经系统研究中得到的启示应用到蛇形机器人上,希望不仅可以解决其运动控制问题,更能在构型、步态及控制机制上皆可展示蛇的特征。 生物学家已经证明动物的节律运动是其低级神经中枢的自激行为,是由中枢模式发生器(Central Pattern Generator,CPG)控制的。中枢模式发生器是一种能够在缺乏有规律的感知和中枢控制输入的情况下,产生有节奏模式输出的神经网络。 本文以国家自然科学基金课题《基于CPG的蛇形机器人控制方法研究》和国家“863”高技术计划资助项目《具有环境适应能力的蛇形机器人的研究》为依托,突破以相互抑制机理研究CPG的传统观点,首次创新性地提出应用循环抑制(Cyclic Inhibition, CI)机理来研究蛇形机器人的CPG建模与实现问题。本研究涵概了神经元模型的特性分析、蛇形机器人关节循环抑制CPG建模理论、蛇形机器人循环抑制CPG神经网络稳定性分析以及典型步态的生成方法、循环抑制CPG神经网络控制蛇形机器人蜿蜒运动参数设定策略、应用动力学仿真和实验对该CPG控制方法有效性的验证。 首先,本文介绍了两个用于CPG建模研究的蛇形机器人“勘查者”和“勘查者-I”。给出各自机械系统、控制系统的构成和动力学仿真平台。 其次,详细分析了神经元以及传统的相互抑制(Mutual Inhibition, MI)CPG的特性。从工程角度首次创新性地应用循环抑制建模理论构建了蛇形机器人CPG模型,并对其稳定性进行了深入的分析。首次证明持续型神经元构成的单向循环抑制(Unilateral Cyclic Inhibition, UCI) CPG是能产生振荡输出CPG中微分方程数量最少的,而且其产生振荡输出的机理完全不同于传统的相互抑制CPG。其不需要具备调整功能,只需要神经元之间强的单向循环抑制连接。 第三,首次应用单向激励连接循环抑制CPG构成蛇形机器人神经网络系统。分析了其稳定性,给出其产生振荡输出的条件。通过仿真和实验验证了循环抑制CPG神经网络实现典型步态(蜿蜒运动、伸缩运动和侧向运动)的有效性。首次应用双向循环抑制(Bidirectional Cyclic Inhibition, BCI)CPG神经网络在不同高级控制神经元命令激活下的输出实现蛇形机器人典型运动步态之间的转换。为蛇节律运动生成机制建模提供了新方法。 最后,从实时性、控制方便性等工程应用的角度,对单向循环抑制CPG神经网络实现蛇形机器人蜿蜒运动控制进行了深入的分析。给出了S-波形、幅值、运动速度和运动轨迹曲率的参数设定策略。该系统应用首CPG自激励权重调解成功解决了传统CPG控制系统中CPG的个数比蛇形机器人关节数多一个的问题,并用其实现了一种独特的转弯控制策略。 综上,为蛇形机器人运动控制提供了全新的方法。
Resumo:
研究当前国内外变速箱试验系统的特点,基于现代汽车变速箱生产信息化、网络化和柔性化的要求,依托某变速箱装配线项目,针对其试验环线,提出一种具有并行结构的变速箱自动试验环线,并设计基于Device Net的控制系统,探究试验环线的智能控制。该系统已经进入实际应用,可较好地完成变速箱的性能检测以及试验后的数据分析。
Resumo:
In order to developing reservoir of Upper of Ng at high-speed and high-efficient in Chengdao oilfield which is located in the bally shallow sea, the paper builds up a series of theory and means predicting and descripting reservoir in earlier period of oilfield development. There are some conclusions as follows. 1. It is the first time to form a series of technique of fine geological modeling of the channel-sandy reservoir by means of mainly seismic methods. These technique include the logging restriction seismic inversion, the whole three dimension seismic interpretation, seismic properties analysis and so on which are used to the 3-dimension distributing prediction of sandy body, structure and properties of the channel reservoir by a lot of the seismic information and a small quantity of the drilling and the logging information in the earlier stage of the oil-field development. It is the first time that these methods applied to production and the high-speed development of the shallow sea oilfield. The prediction sandy body was modified by the data of new drilling, the new reservoir prediction thinking of traced inversion is built. The applied effect of the technique was very well, according to approximately 200 wells belonging to 30 well groups in Chengdao oilfield, the drilling succeeded rate of the predicting sandy body reached 100%, the error total thickness only was 8%. 2. The author advanced the thinking and methods of the forecasting residual-oil prediction at the earlier stage of production. Based on well data and seismic data, correlation of sediment units was correlated by cycle-correlation and classification control methods, and the normalization and finely interpretation of the well logging and sedimentation micro-facies were acquired. On the region of poor well, using the logging restriction inversion technique and regarding finished drilling production well as the new restriction condition, the sand body distributing and its property were predicted again and derived 3-dimension pool geologic model including structure, reservoir, fluid, reservoir engineering parameter and producing dynamic etc. According to the reservoir geologic model, the reservoir engineering design was optimized, the tracking simulation of the reservoir numerical simulation was done by means of the dynamic data (pressure, yield and water content) of development well, the production rule and oil-water distributing rule was traced, the distributing of the remaining oil was predicted and controlled. The dynamic reservoir modeling method in metaphase of development was taken out. Based on the new drilling data, the static reservoir geologic model was momentarily modified, the research of the flow units was brought up including identifying flow units, evaluating flow units capability and establishing the fine flow units model; according to the dynamic data of production and well testing data, the dynamic tracing reservoir description was realized through the constant modification of the reservoir geologic model restricted these dynamic data by the theory of well testing and the reservoir numerical simulation. It was built the dynamic tracing reservoir model, which was used to track survey of the remaining oil on earlier period. The reservoir engineering tracking analysis technique on shallow sea oilfield was founded. After renewing the structure history since tertiary in Chengdao area by the balance section technique and estimating the activity character of the Chengbei fault by the sealing fault analysis technique, the meandering stream sediment pattern of the Upper of Ng was founded in which the meandering border was the uppermost reservoir unit. Based on the specialty of the lower rock component maturity and the structure maturity, the author founded 3 kinds of pore structure pattern in the Guanshang member of Chengdao oil-field in which the storing space mainly was primary (genetic) inter-granular pore, little was secondary solution pore and the inter-crystal pore tiny pore, and the type of throat mainly distributed as the slice shape and the contract neck shape. The positive rhythmic was briefly type included the simple positive rhythm, the complex positive rhythm and the compound rhythm. Interbed mainly is mudstone widely, the physical properties and the calcite interbed distribute localized. 5. The author synthetically analyzed the influence action of the micro-heterogeneity, the macro-heterogeneity and the structure heterogeneity to the oilfield water flood development. The efficiency of water flood is well in tiny structure of convex type or even type at top and bottom in which the water breakthrough of oil well is soon at the high part of structure when inject at the low part of structure, and the efficiency of water flood is poor in tiny structure of concave type at top and bottom. The remaining oil was controlled by sedimentary facies; the water flooding efficiency is well in the border or channel bar and is bad in the floodplain or the levee. The separation and inter layer have a little influence to the non-obvious positive rhythm reservoir, in which the remaining oil commonly locate within the 1-3 meter of the lower part of the separation and inter layer with lower water flooding efficiency.
Resumo:
In this paper, several simplification methods are presented for shape control of repetitive structures such as symmetrical, rotational periodic, linear periodic, chain and axisymmetrical structures. Some special features in the differential equations governing these repetitive structures are examined by considering the whole structures. Based on the special properties of the governing equations, several methods are presented for simplifying their solution process. Finally, the static shape control of a cantilever symmetrical plate with piezoelectric actuator patches is demonstrated using the present simplification method. The result shows that present methods can effectively be used to find the optimal control voltage for shape control.
Resumo:
In this paper, available elimination techniques are assessed. OLGA2000 software is used to simulate severe slugging formation mechanism in certain offshore riser. The simulation results show that pressure fluctuations of riser base and riser top is very large and severe slugging easily forms. Sensibility analysis shows that the measures and methods which include properly reducing pipe riser diameter, reducing water cut increasing terminal pressure, decreasing the height and inclination of riser and increasing GOR can eliminate or control severe slugging in riser pipe.
Resumo:
A spectral-filter method is numerically demonstrated to obtain sub-5 fs pulses by using femtosecond filamentation in fused silica. Instead of employing spectral phase compensation, by properly employing a high-pass filter to select the broadened high-frequency spectra that are located almost in phase in the tailing edge of the self-compressed pulses owing to self-steepening, as short as single-cycle pulses can be obtained. For instance, for an input pulse with a duration of 50 fs and energy 2.2 mu J, the minimum pulse duration can reach to similar to 4 fs (about 1.5 cycles) by applying a proper spectral filter. (C) 2008 Optical Society of America
Resumo:
The green peach aphid, Myzus persicae, is a major pest of tobacco, Nicotiana tabacum, in Yunnan province, China, where its control still depends on the use of insecticides. In recent years, the local government and farmers have sought to improve the biological control of this tobacco pest. In this paper, we present methods for mass rearing Aphidius gifuensis, a dominant endoparasitoid of M. persicae on tobacco plants in this region. The tobacco cultivar K326 (N. tabacum) was used as the host plant and M. persicae as the host insect. In the greenhouse, we collected tobacco seedlings for about 35 days (i.e., until the six-true-leaf stage), transferred them to 7.5-cm diameter pots, and kept these plants in the greenhouse for another 18 days. These pots were then transferred to an insectary-greenhouse, where the tobacco seedlings were inoculated with five to seven wingless adult M. persicae per pot. After 3 days, the infested seedlings were moved to a second greenhouse to allow the aphid population to increase, and after an additional 4 +/- 1 days when 182 +/- 4.25 aphid adults and nymphs were produced per pot, they were inoculated with A. gifuensis. With this rearing system, we were able to produce 256 +/- 8.8 aphid mummies per pot, with an emergence rate of 95.6 +/- 2.45%; 69% were females. The daily cost of parasite production (recurring costs only) was US$ 0.06 per 1000 aphid mummies. With this technique, we released 109 800 parasitoids in 1998, 196 000 in 1999, 780 000 in 2000, and 5 600 000 in 2001 during a 2-month period each year This production method is discussed with respect to countrywide usage in biological control and integrated control of M. persicae.
Resumo:
It is widely accepted that mitochondrial DNA (mtDNA) control region evolves faster than protein encoding genes with few exceptions. In the present study, we sequenced the mitochondrial cytochrome b gene (cyt b) and control region (CR) and compared their rates in 93 specimens representing 67 species of loaches and some related taxa in the Cobitoidea (Order Cypriniformes). The results showed that sequence divergences of the CR were broadly higher than those of the cyt b (about 1.83 times). However, in considering only closely related species, CR sequence evolution was slower than that of cyt b gene (ratio of CR/cyt b is 0.78), a pattern that is found to be very common in Cypriniformes. Combined data of the cyt b and CR were used to estimate the phylogenetic relationship of the Cobitoidea by maximum parsimony, neighbor-joining, and Bayesian methods. With Cyprinus carpio and Danio rerio as outgroups, three analyses identified the same four lineages representing four subfamilies of loaches, with Botiinae on the basal-most clade. The phylogenctic relationship of the Cobitoidea was ((Catostomidae + Gyrinocheilidae) + (Botiinae + (Balitorinae + (Cobitinae + Nemacheilinae)))), which indicated that Sawada's Cobitidae (including Cobitinae and Botiinae) was not monophyletic. Our molecular phylogenetic analyses are in very close agreement with the phylogenetic results based on the morphological data proposed by Nalbant and Bianco, wherein these four subfamilies were elevated to the family level as Botiidae, Balitoridae, Cobitidae, and Nemacheilidae. (c) 2005 Elsevier Inc. All rights reserved.