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1.
现有的满意容错控制成果难以处理非凸非线性约束,无法用于在线重构容错控制器设计,针对一类离散系统的传感器故障,研究容错系统具有上述特性的闭环区域极点指标、二次型保性能指标和控制输入等约束的满意容错控制问题.借鉴预测控制对多种约束的软化处理策略,利用被控输出反馈控制结构和在线非线性优化技术,给出一种根据故障估计信息进行递推控制的主动满意容错控制器的数值化设计算法,并分析闭环容错系统的稳定性.据此设计的满意容错控制器可使闭环容错系统在保证稳定性和控制输入约束条件下具有满意的优化性能.仿真算例验证文中设计算法的有效性.  相似文献   

2.
非线性系统时变时滞和参数的在线联合估计   总被引:3,自引:0,他引:3  
为了解决非线性系统的时滞和参数的在线联合估计这一问题 ,提出了一种基于遗传算法的非线性系统时变时滞和参数的在线联合估计方法。将遗传算法的二进制编码改进为十进制编码。对于系统输入带有纯时滞的非线性系统 ,采用改进的遗传算法对系统时滞和参数进行在线联合估计。此方法能够有效地在线联合估计非线性系统的时变时滞和参数 ,并具有一定的抗噪声能力。仿真实验结果验证了此方法的有效性  相似文献   

3.
研究了一类非线性动态系统的执行器故障估计问题.采用Takagi-Sugeno(T-S)模糊模型对非线性动态系统建模,克服了以往研究需对非线性动态系统作Lipschitz条件假设的局限性.为避免传统滑模观测器在实现故障估计时的抖振问题,设计二阶滑模观测器实现了故障估计.为方便观测器设计,通过坐标变换分离出系统的可测状态;采用Lyapunov泛函与线性矩阵不等式设计观测器,并证明了观测误差动态系统的稳定性,进而得到了执行器故障的渐近估计.所提方法只需观测器与系统的输出信息,实现了故障的在线估计.通过一个液压传动系统的仿真分析验证了所提方法的有效性.  相似文献   

4.
提出了一种非线性系统的执行器多时滞鲁棒故障诊断方案,非线性与系统输入和输出有关,不确定性包括系统输入和状态等环节;通过构造观测器对状态和输出进行估计,得到具有鲁棒性的阈值;若系统的实际输出与估计输出之差(即残差)超出阈值,说明有故障发生,同时用自适应跟踪器对故障进行跟踪;在理论上证明了该方案的鲁棒性、灵敏度和稳定性,通过M atlab软件仿真验证了该方法的有效性.  相似文献   

5.
针对具有全局利普希茨非线性的广义马尔可夫跳变系统,研究了当执行器故障和传感器故障并存时系统的故障估计问题.首先,将原系统的状态向量和传感器故障向量扩展为辅助状态变量,得到增广系统.然后通过引入一个中间变量,提出了一种基于中间变量的估计器设计方法,用于估计原系统的状态、执行器故障以及传感器故障.通过构建输入到状态稳定李雅普诺夫函数,证明了广义误差系统对于故障函数的导函数是输入到状态稳定的,这意味着当故障函数的导函数随着时间收敛于0,误差系统也是渐近收敛的.最后通过一个数值算例验证了方法的有效性.  相似文献   

6.
针对一类线性部分严格正定且非线性部分可逆的Wiener模型,提出了基于神经网络参数估计的系统线性部分故障检测方法.引入卡尔曼滤波器滤除系统未知干扰和噪声,并将Wiener模型转化为ARMA模型,计算得到线性部分参数;神经网络在线估计系统线性部分的参数,通过参数估计值与实际值的比较检测系统故障.仿真实例证明了该方法的正确性和有效性.  相似文献   

7.
针对一类含有未知输入和非线性摄动的状态时滞系统,采用基于自适应观测器的故障诊断系统的设计方法,以线性矩阵不等式的形式给出此问题解的存在条件及求解算法,并论证了系统的鲁棒稳定性,给出了对故障检测具有高灵敏度、零误报率的阚值判断公式.设计的自适应观测器具有双重功能:首先作为故障检测观测器能够检测出故障的发生,然后作为故障诊断观测器能够理想地估计出故障随时间的变化曲线.此算法既能诊断突变故障,又能诊断缓变故障.仿真结果表明算法具有良好的诊断性能.  相似文献   

8.
提出了一种带有多时滞不确定非线性系统的鲁棒故障诊断方案,非线性与系统输入和输出有关,不确定性包括系统输入和状态等环节;通过构造观测器对状态和输出进行估计,得到具有鲁棒性的阈值;若系统的实际输出与估计输出之差(即残差)超出阈值,说明有故障发生,同时用自适应跟踪器对故障进行跟踪;在理论上证明了该方案的鲁棒性、灵敏度和稳定性。  相似文献   

9.
多变量未知非线性系统容错逆控制方法   总被引:1,自引:0,他引:1  
针对传统的逆系统在设计上需要精确数学模型和逆模型的解析解的限制,提出一种新的逆系统容错设计方法.该方法仅对非线性不确定系统的可逆部分求逆,通过引入鲁棒滑模观测器,对不可逆部分及执行器故障进行在线估计,从而以补偿方式在线修正逆模型并调节故障,使其在数值上精确地逼近非线性不确定受控对象的逆模型.仿真结果表明:该方法不仅对无显式的多变量未知非线性不确定系统具有良好的控制效果,对执行器故障也有较好的容错效果.  相似文献   

10.
针对仿射非线性系统,提出了一种新型的基于动态递归模糊神经网络(DRFNN)的间接自适应控制器.该控制器采用DRFNN对系统的动态非线性映射进行在线估计,并依据李亚普诺夫稳定性理论推导出DRFNN参数在线调整的自适应算法,同时运用投影算法确保参数向量处于约束集合内.应用自适应DRFNN对动态非线性映射进行在线估计时,仅采用被控系统的1个状态变量作为其输入,避免了因增加输入个数而导致网络结构膨胀的问题,从而加快了收敛速度.仿真结果表明:由自适应DRFNN构成的控制器可使系统具有满意的跟踪性能.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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