20 resultados para Discrete time control systems
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
In this paper, a new scheduling algorithm for the flexible manufacturing cell is presented, which is a discrete time control method with fixed length control period combining with event interruption. At the flow control level we determine simultaneously the production mix and the proportion of parts to be processed through each route. The simulation results for a hypothetical manufacturing cell are presented.
Resumo:
A time-varying controllable fault-tolerant field associative memory model and the realization algorithms are proposed. On the one hand, this model simulates the time-dependent changeability character of the fault-tolerant field of human brain's associative memory. On the other hand, fault-tolerant fields of the memory samples of the model can be controlled, and we can design proper fault-tolerant fields for memory samples at different time according to the essentiality of memory samples. Moreover, the model has realized the nonlinear association of infinite value pattern from n dimension space to m dimension space. And the fault-tolerant fields of the memory samples are full of the whole real space R-n. The simulation shows that the model has the above characters and the speed of associative memory about the model is faster.
Resumo:
针对具有有界时延和数据包丢失的网络控制系统,提出了一种新的稳定性判据.基于Lyapunov方法和图论理论,给出非线性离散和连续网络控制系统渐近稳定的充分条件,获得保持这两类系统稳定的最大允许时延界,得到控制器设计方法.并且,利用区间矩阵的谱特征,给出网络控制系统区间稳定的充分条件.设计算法,获得比例积分反馈控制器增益.算例表明所提方法的有效性。
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本文将Smith预估技术与逆 Nyquist 阵列法结合对多时延多变量对象进行离散控制系统设计,采用这种方法设计出的控制器易用计算机实现,系统仿真结果也是令人满意的。
Resumo:
本文阐述了离散时间点过程理论,时变马尔科夫链及鞅差分序列在城市交通车队状态观测器中的应用。并在此基础上,改进了[5]中的估计算法。用本文提出的非线性最小方差估计算法,对提供的交通状态进行估计,所得结果比[5]中算法精度有明显提高。在大连市某交通干线计算机控制系统中初步应用,取得了令人满意的结果。
Resumo:
The wind error of the double-edge technique Doppler lidar due to the instability of injection-seeding solid laser and the drift of interferometer s spectrum was analyzed. Corresponding numerical simulation indicated that if the wind error of 1 m/s was achieved, the unsuccessful injection-seeding pulses should be less than 0.06% in integration time of 5 min. (30000 pulses). In the respect of spectrum drift of the interferometer, double temperature control systems were used and the accuracy of minus or plus 0.002°C was obtained, corresponding to the wind error of minus or plus 0.226 m/s. Monitoring of buildup time of the injection-seeding laser and temperature of the interferometer was significantly to improve the invertion accuracy of wind error by rejecting the data with frequency jumping and drifting. Researches of injection-seeding and spectrum stability of the interferometer were practical for the development of double-edge wind lidar.}
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In this paper, two models of coalition and income's distribution in FSCS (fuzzy supply chain systems) are proposed based on the fuzzy set theory and fuzzy cooperative game theory. The fuzzy dynamic coalition choice's recursive equations are constructed in terms of sup-t composition of fuzzy relations, where t is a triangular norm. The existence of the fuzzy relations in FSCS is also proved. On the other hand, the approaches to ascertain the fuzzy coalition through the choice's recursive equations and distribute the fuzzy income in FSCS by the fuzzy Shapley values are also given. These models are discussed in two parts: the fuzzy dynamic coalition choice of different units in FSCS; the fuzzy income's distribution model among different participators in the same coalition. Furthermore, numerical examples are given aiming at illustrating these models., and the results show that these models are feasible and validity in FSCS.
Resumo:
We investigate theoretically the interplay between Zeeman splitting, Rashba spin-orbit interaction (RSOI), and Dresselhaus spin-orbit interaction (DSOI) and its influence on the magnetotransport property of two-dimensional electron gas (2DEG) at low temperature. Our theoretical results show that the nodes of the beating patterns of the magnetoresistivity rho(xx) for 2DEG with RSOI or DSOI alone depend sensitively on the total spin splitting induced by these three spin splitting mechanisms. It is interesting to find that the eigenstates in the presence of RSOI alone are connected with those in the presence of DSOI alone but with opposite Zeeman splitting by a time-reversal transformation. Consequently, the magnetoresistivities exhibit exactly the same oscillation patterns for these two cases. For strong RSOI or DSOI alone, the magneto-oscillation of rho(xx) shows two distinct periods. For 2DEG with both RSOI and DSOI, the beating patterns vanish for equal RSOI and DSOI strengths and vanishing Zeeman splitting. They will appear again, however, when Zeeman splitting or the difference between RSOI and DSOI strengths increases.
Resumo:
Processing networks are a variant of the standard linear programming network model which are especially useful for optimizing industrial energy/environment systems. Modelling advantages include an intuitive diagrammatic representation and the ability to incorporate all forms of energy and pollutants in a single integrated linear network model. Added advantages include increased speed of solution and algorithms supporting formulation. The paper explores their use in modelling the energy and pollution control systems in large industrial plants. The pollution control options in an ethylene production plant are analyzed as an example. PROFLOW, a computer tool for the formulation, analysis, and solution of processing network models, is introduced.
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The properties of positively invariant sets are involved in many different problems in control theory, such as constrained control, robustness analysis, synthesis and optimization. In this paper we provide an overview of the literature concerning positively invariant sets and their application to the analysis and synthesis of control systems.
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在工控领域中,企业实时数据的管理和共享是企业在提高自动化程度过程中面临的重要课题。该文在着重分析了工控领域中实时数据库的应用需求之后,详细介绍了实时数据库系统Agilor开放式的系统结构及其数据处理中所采用的关键技术。
Resumo:
何首乌为常用中药,由何首乌及含何首乌的中成药制剂所引起的不良反应也时见报道,科学阐明不良反应的物质基础并提出解决方案对何首乌的使用十分重要。本论文研究了何首乌炮制前后KM小鼠肝脏毒性基因表达谱、生物活性及化学成分的变化。所获结果支持何首乌炮制的目的是减毒、改性(改变药效),何首乌生、熟异治的观点。制首乌对抑郁症的效果显著优于生首乌,这与本草所记载的何首乌炮制后补肝肾、益精血,归肝、肾经一致。 主要结果如下: 1、 生、制首乌的毒理基因芯片研究结果 何首乌的不良反应主要表现在肝损害方面。本研究建立了生何首乌和制何首乌不同剂量的肝毒性作用模型,体重指标统计发现生何首乌各剂量组平均体重显著下降,中剂量组(10 g/kg.d)体重下降20 %,高剂量组(20 g/kg.d)体重下降42%,50%动物死亡,提示动物机体能量代谢障碍;基因芯片研究结果表明何首乌是CYP450的抑制剂,生何首乌相对于制何首乌CYP3A4、CYP4A5显著下调,导致毒性成分在体内的吸收增加,服用大剂量的生何首乌后产生明显的肝毒性;主要对以下六条Pathway产生影响:①PPAR signaling pathway,主要毒性靶基因有RXRB CYP7a1、Acadl、Apoa2、Cyp4a、 FABP2 、MAPKKK5等基因。②Calcium signaling pathway,主要毒性靶基因有CAMK2B、CACNA1F、S100A1、 F2R、Ryr1、Slc8a2、Camk4 ③Neuroactive ligand-receptor interaction,主要毒性靶基因有Chrm4、 Ntsr2 、 GABRR1、 GRIK3、F2R等基因。④Wnt signaling pathway,主要毒性靶基因有Daam2、Rac1 等基因。⑤Complement and coagulation cascades,主要毒性靶基因有F2R、Serpina1b、Cfi 、FGA等基因。⑥Oxidative hosphorylation,主要毒性靶基因有Atp5e、NDUFA1等基因。生何首乌毒性明显强于制首乌,且生何首乌水煎液的毒性大于生何乌首丙酮提取物的毒性,这一结果表明,何首乌主要的毒性成分很可能并不仅仅是传统所认为的以大黄素为代表的蒽醌类化合物,而是何首乌中大量存在的有效组分二苯乙烯苷与大黄素相互作用的结果,这一研究结果与前述的何首乌对肝药酶的影响是一致的。后续生、制首乌的化学成分差异研究表明,炮制后二苯乙烯苷含量明显降低:生首乌为5.512 %、清蒸制首乌为3.811 %、豆制首乌为3.538 %,大黄素的含量炮制后显著升高,生首乌为0.094 %、清蒸制首乌为0.119 %、豆制首乌为0.126 %。 2 生、制首乌药效差异研究结果 本文采用慢性中等强度不可预知应激刺激模型(chronic unpredictable mild stress, CUMS)和动物行为绝望实验法,研究生、制首乌抗抑郁活性的差异,制首乌(5 g/kg.d)与模型组相比有显著差异(P< 0.01),生首乌制首乌(5g/kg.d)与模型组相比无显著差异,这一结果表明制首乌抗抑郁活性显著优于生首乌。 本文比较了生、制首乌对四氧嘧啶糖尿病模型小鼠血糖的影响的差异,生首乌(5 g/kg.d)与模型组相比有显著差异(P< 0.01),制首乌(5 g/kg.d)与模型组相比无显著差异,这一结果表明生首乌降糖活性优于制首乌。这一结果与历代中医古书中生首乌治疗消渴症(糖尿病)的记载一致。 3生、制首乌化学成分差异的研究结果 本文选用HPLC-DAD指纹图谱技术结合药效成分含量测定来研究生、制首乌化学成分的差异。炮制后,何首乌中的主要化学成分并未消失,只是其含量发生了改变。炮制后二苯乙烯苷含量明显降低:生首乌为5.512 %、清蒸制首乌为3.811 %、豆制首乌为3.538 %,大黄素的含量炮制后显著升高,生首乌为0.094 %、清蒸制首乌为0.119 %、豆制首乌为0.126 %。 综上所述,炮制前后何首乌中二苯乙烯苷和大黄素含量比的变化可能是何首乌炮制减毒、改性的物质基础。 根据上述结果我们建立了生、制首乌的质量控制新模式。 In recent years, some adverse drug reactions (ADR) about some traditional Chinese medicine were reported at times. As a Chinese medicine most in use, the ADRs of Radix Polygoni multiflori (RPM) and the medicines containing the RPM were also mentioned. The resolution of the problems caused by the ADRs is very important for the use of the RPM as a medicine. The process (or preparation) is a significant feature for the clinical use of the Chinese medicine and an important technology for the safe use and good effect of the Chinese medicine. By processing, the toxicity of the Chinese medicine can be reduced, its properties can be changed and curative effect can be enhanced at the same time. The changes of the gene expression profiles for KM mice hepatotoxic effects, and the change of the biological activity and the chemical composition after being processed of the RPm were studied in the present dissertation. The RPm heatotoxicity mechanism and the toxicity target genes were explained on the gene level for the first time. With the antidepressant activity, and the hypoglycemic effect as the target, the differences on the pharmacodynamics between the processed RPm and unprocessed RPm, for the first time, were investigated. The results obtained show that the antidepressant activity of the processed RPM is far higher than the ones of unprocessed RPm. As we know, the results were reported for the first time. The quality control systems (QCS) for the processed and the unprocessed RPm were founded. The HPLC-DAD was used in the systems founded on the basis of the toxicology and the pharmacodynamics experiments. As we know, the OCSs were reported for the first time. The above-mentioned experimental results confirm that the unique process theory of the traditional Chinese medicine (TCM) used for the process of the Radix Polygoni multiflori (RPm) is correct, i.e after being processed the toxicity of the RPm decreases and its Pharmacodynamic effects change. It is known to author that there have been no similar reports in the literatures up to now. The main experimental results are summarized as follows: 1 The results on the mice toxicology gene chip for the unprocessed and processed RPm The KM mice hepatotoxic model caused by the RPm at the different dosages was established in the present study. The results obtained show that the mouse average body weight obviously decreased in the groups at the different dosages of the unprocessed RPm: the 10 g/kg.d .group decreased 20%; 20 g/kg.d. group decreased 42%, and 50% mice died at 20 g/kg.d. group. The main experimental results on the mice toxicology gene chip The RPm is the CYP450 inhibitor. As compared with the processd RPm, the CYP3A4, CYP4A5 of the unprocessed RPm demonstrate the marked downregulation, which leads to the increase of the poison absorbtion into the body with the result that the unprocessed RPm yields the marked hepatotoxication. The hepatotoxication was produced because the following 6 pathways were affected: ①PPAR signaling pathway, the chief toxicity target genes are RXRB, CYP7a1, Acadl, Apoa2, Cyp4a, FABP2 and MAPKKK5 etc. ②Calcium signaling pathway, the chief toxicity target genes are CAMK2B, CACNA1F, S100A1, F2R, Ryr1,Slc8a2 and Camk4 etc. ③Neuroactive ligand-receptor interaction, the chief toxicity target genes are Chrm4, Ntsr2, GABRR1, GRIK3 and F2R etc. ④Wnt signaling pathway, the chief toxicity target genes are Daam2, Rac1 etc. ⑤Complement and coagulation cascades, the chief toxicity target genes are F2R, Serpina1b, Cfi and FGA etc. ⑥Oxidative phosphorylation, the chief toxicity target genes are Atp5e, NDUFA1 etc. The above experimental results, for the first time , demonstrate on the gene level that the unprocessed Rpm toxicity is far stronger than the processed RPm one, and the toxicity of the water decoction of the unprocessed RPm is greater than the one of its acetone extracts, which shows that the chief toxicity components of the RPm are probably not only the anthraquinones, for example, the emodin, but the complex compounds produced by the interaction between the emondin and the stilbene glucoside which is the largest component of the unprocessed RPm. The result is accordance with the above effect of the RPm on the hepatic drugenzyme. Aftter being processed, in fact, the content of the stibene glucoside in the RPm markedly decreases. 2. The results on the pharmacodynamic differences between the unprocessed and processed RPm The results obtained show that the effects of processing on RPm pharmacodynamic behaviour received in the Chinese Material Medica are correct. It is known to author that this is the first experimental result in the research materials now available. The chief results are as follows: For the treatment of the antidepressant, the curative effect of the processed RPm is far better than the one of the unprocessed RPm. By contrast with the above results, the hypoblycemic effect of the unprocessed RPm is better than the one of the processed RPm. 3. The results on the Chemical Composition The results obtained by using HPLC-DAD fingerprint and by the determination of effective component content show that the main chemical components in the RPm after being processed do not disappear, but their contents change. The contents of the stilbene glucoside (SG) and emodin in the different samples were determined as follows: SG contents 5.512 % for the unprocessed RPm 3.811 % for the processed RPm (Steamed) 3.588 % for the processed RPm (black soybean) Emodin contents 0.094 % for the unprocessed RPm 0.119 % for the processed RPm (Steamed) 0.126 % for the processed RPm (black soybean) The combination of above experimental results on the toxicity, the pharmacodynamics and the chemical composition indicates that the changes of the content ratio of SG/emodin may be the substance base of the toxicity decrease and pharmacodynamic changes of the RPM by the processing.
Resumo:
视觉伺服可以应用于机器人初始定位自动导引、自动避障、轨线跟踪和运动目标跟踪等控制系统中。传统的视觉伺服系统在运行时包括工作空间定位和动力学逆运算两个过程,需要实时计算视觉雅可比矩阵和机器人逆雅可比矩阵,计算量大,系统结构复杂。本文分析了基于图像的机器人视觉伺服的基本原理,使用BP神经网络来确定达到指定位姿所需要的关节角度,将视觉信息直接融入伺服过程,在保证伺服精度的情况下大大简化了控制算法。文中针对Puma560工业机器人的模型进行了仿真实验,结果验证了该方法的有效性。
Resumo:
论文设计研制了行为辅助机器人验证平台,以此平台为基础可以针对行为辅助机器人进行力控制研究。针对机器人力控制的实际要求,设计了行为辅助机器人柔性关节结构,辨识了系统参数。基于QNX实时操作系统设计了控制系统软件。机器人控制系统软件主要包括传感器数据采集和控制算法两部分,可以满足柔性关节控制需求。
Resumo:
针对一类具有单输入滞后不确定非线性系统 ,采用精确反馈线性化方法和 Lyapunov方法设计出一种使系统终极有界 ( UUB)的无记忆光滑状态反馈鲁棒控制器 .仿真算例表明了本文所采用方法的有效性 .