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41.
This paper addresses the problem of semi‐global stabilization by output feedback for a class of nonlinear systems whose output gains are unknown. For each subsystem, we first design a state compensator and use the compensator states to construct a control law to stabilize the nominal linear system without the perturbing nonlinearities. Then, combining the output feedback domination approach with block‐backstepping scheme, a series of homogeneous output feedback controllers are constructed recursively for each subsystem and the closed‐loop system is rendered semi‐globally asymptotically stable. 相似文献
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In this paper, a feedback model predictive control method is presented to tackle control problems with constrained multivariables for uncertain discrete‐time nonlinear Markovian jump systems. An uncertain Markovian jump fuzzy system (MJFS) is obtained by employing the Takagi‐Sugeno (T‐S) fuzzy model to represent a discrete‐time nonlinear system with norm bounded uncertainties and Markovain jump parameters. To achieve more generality, the transition probabilities of the Markov chain are assumed to be partly unknown and partly accessible. The predictive formulation adopts an on‐line optimization paradigm that utilizes the closed‐loop state feedback controller and is solved using the standard semi‐definite programming (SDP). To reduce the on‐line computational burden, a mode independent control move is calculated at every sampling time based on a stochastic fuzzy Lyapunov function (FLF) and a parallel distributed compensation (PDC) scheme. The robust mean square stability, performance minimization and constraint satisfaction properties are guaranteed under the control move for all admissible uncertainties. A numerical example is given to show the efficiency of the developed approach. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
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Dihua Zhai Yu Kang Ping Zhao Yun-Bo Zhao 《International Journal of Control, Automation and Systems》2012,10(6):1182-1192
The stability of a class of switched stochastic nonlinear retarded systems with asynchronous switching controller is investigated. By constructing a virtual switching signal and using the average dwell time approach incorporated with Razumikhin-type theorem, the sufficient criteria for pth moment exponential stability and global asymptotic stability in probability are given. It is shown that the stability of the asynchronous stochastic systems can be guaranteed provided that the average dwell time is sufficiently large and the mismatched time between the controller and the systems is sufficiently small. This result is then applied to a class of switched stochastic nonlinear delay systems where the controller is designed with both state and switching delays. A numerical example illustrates the effectiveness of the obtained results. 相似文献
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Pengtao Zhai Mingyang Liu Wenying Zhou Liugang Chen Dafei Ding Guotian Ye 《International Journal of Applied Ceramic Technology》2021,18(3):1017-1024
Refractory materials such as mullite, andalusite, forsterite, and cordierite are generally used to prepare saggers for the calcination of Li-ion battery Li(NixCoyMnz)O2 (LNCM) cathode material. However, these compounds are prone to be attacked by the LNCM materials, thereby leading to short life spans and contamination of the Li-ion battery cathode materials. To improve the corrosion resistance of refractory sagger materials, the most clear cut-way is enhancing the corrosion resistance of matrix using a new refractory component. Potassium aluminate (K2O·11Al2O3, KA11) with an excellent corrosion resistance against alkaline oxide was synthesized via solid-state method using potassium carbonate (K2CO3) and industrial alumina powder (Al2O3). Interactions between KA11 and LNCM cathode materials at 800°C–1100°C were characterized by refractory-LNCM precursor laboratory-scale tests to understand the corrosion behavior of KA11. The microstructure and phase composition of synthesized KA11 and the calcined KA11-LNCM mixture cylinders were analyzed with SEM and XRD. The observations reveal that KA11 shows a better corrosion resistance to LNCM materials compared with mullite, cordierite, and forsterite. The addition of synthesized KA11 also favors the thermal shock resistances of mullite-based sagger materials. 相似文献
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界面性能对复合驱提高采收率有重大的影响,界面张力越低,洗油效率越高;Zeta电位越高,油水乳状液越稳定。研究了各类无机盐对新疆油田复合驱界面性能的影响。结果显示,Zeta电位的绝对值随着无机盐浓度的增高而增大;无机碱中,碳酸根离子降低界面张力效果最好,氢氧根次之,碳酸氢根最差;阳离子中,钾离子降低界面张力效果最好,其次是钠离子,镁离子会略微提高界面张力,钙离子则会大幅度提高界面张力;阴离子中,与硫酸根相比,氯离子能更好地降低界面张力。通过以上研究,确定了Q站污水处理站外排水更适合三元复合驱配液。 相似文献
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针对某黄金生产企业含砷氰化尾矿污染特征,开展了搅拌洗涤法、臭氧氧化法、酸化溶砷法、铁盐固砷法等多种无害化方法联合处理试验研究,旨在将该含砷氰化尾矿处理至满足氰渣规范回填利用污染控制要求。结果表明:该含砷氰化尾矿回填利用污染控制技术工艺为压滤调浆搅拌洗涤+臭氧氧化+酸化溶砷+铁盐固砷,最佳参数为原矿浆压滤后加水调浆,矿浆浓度40%,臭氧投加量0.66 g/L,酸化溶砷pH值3、曝气量0.1 m3/h、反应时间2 h,铁盐固砷七水合硫酸亚铁投加量20.0 g/L、反应时间1 h。研究结果为该黄金生产企业含砷氰化尾矿回填利用提供了技术支撑。 相似文献
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选择“钛酸丁酯-水-乙醇-盐酸”的溶胶.凝胶反应体系,考察反应物水的用量变化对反应过程、溶胶结构和光催化性能的影响,并获得了含有锐钛矿晶体、具有光催化性能的氧化钛溶胶。钛酸丁酯与水的摩尔比为1:2、1:4、1:8时,会逐渐形成凝胶,溶胶常温干燥后的粉体呈无定型结构,透射电镜中只能观察到细小的成膜粒子,溶胶不能使罗丹明B溶液分解褪色。钛酸丁酯与水的摩尔比为1:40、1:100、1:200时,钛酸丁酯发生充分水解,有可能形成稳定的溶胶;溶胶常温干燥后的粉体呈锐钛矿晶型,且结晶强度随水的用量的增加而增强;透射电镜中可观察到松散的团聚体、初显正方形较为紧密的结晶体和致密规则的正方形锐钛矿晶体;各溶胶均可催化降解罗丹明B使其褪色。 相似文献