基于e-σ-modification混合自适应律的鲁棒级联式侧滑飞行控制研究

针对常规布局飞机舵面故障下的侧滑飞行控制问题,提出一种基于e-σ-modification混合自适应律的级联式侧滑飞行控制方法。在滚转角和偏航角速率响应时间远小于侧滑角响应的假设下,证明了侧滑角级联回路的稳定性并给出调节时间ts与PI参数的关系。在扰动或未建模舵动态下,针对相对阶等于1和大于1的滚转角和偏航角速率通道分别设计模型参考自适应控制器(model reference adaptive controller,MRAC)。利用李雅普诺夫方法证明了在e-σ-modification律下鲁棒自适应控制内环的有界稳定,并给出在e-modification律基础上能够进一步减小输出误差和控制参数误差界限的自适应增益选择方法。仿真验证表明在允许的舵偏范围内,该侧滑飞行控制方法不仅具有较满意的侧滑角保持和跟踪性能,而且能够有效减小上述误差界限,有效性得以验证。

FUZZY IDENTIFIER WITH EXPONENTIAL RATE OF CONVERGENCE FOR NONLINEAR DYNAMIC SYSTEMS

In this paper, fuzzy systems are used as identifiers for unknown nonlinear dynamic systems. The fuzzy identifier can incorporate linguistic knowledge of nonlinear dynamic systems with input-output pairs directly into the design. In the case where there is the modelling error, a new identification algorithm is proposed. It is proved that the fuzzy identifier is globally stable and the identification error converges to zero exponentially fast.

Uncommon and Impact-Suspicious Geologic Phenomena across Jordan and Adjacent Areas, Arabian Plate

For the discovery and analysis of Jebel Waqf as Suwwan (JWS) Impact Crater, Jordan pushed the authors to consequently focusing on other unusual geologic phenomena such as circular/oval structures (some of “crypto-volcanic” origin), disharmonic folding, horizontal stylolites, and a broad stripe of?Sanidine-Hornfels-Facies, all of them hosted in Upper Cretaceous/Paleogene carbonate rocks exposed across Jordan and adjacent areas. Shatter cones are the most useful tools during field work in the realm of circular structures. In addition to the impact-geologic data of JWS Impact Structure hitherto available, the cooling process of melted Lower Cretaceous Kurnub-Sandstone could be verified by microscopically identified SiO2-modifications between the melting point (1714°C) and low temperatures. In comparison with the Suffield 500 tons explosion tests [20] and with the Ries Impact Crater, Germany, excavation and vaporization processes of target rocks demand drilling between Central Uplift and Inner Ring of the JWS Impact Structure (“Chert-Carbonate-Impact-Chess Game”). In a scenario: “Impacting meets Plate Tectonics”, phenomena like disharmonic folding, horizontal stylolites, and an abundance of circular/oval structures of high diameter variation through northwest Jordan are discussed under aspects of gravitational gliding, effects of seismic surface waves (Love-), transpressional structures related to Jordan Rift-Tectonics, and possible impact processes of unknown number occurred on the Arabian Plate in southeastern direction with northwest-directed impulse. The so-called “Mottled Zone” of Jordan and Palestine owning a high number (~100) of mineral neoformations with formation temperatures up to ~1120°C(pseudo-wollastonite = β-CaSiO3), is to be interpreted as of “Sanidine-Hornfels-Impact Facies” under ricochet conditions along an “Avenue of Ricochet-Impact-Thermo-Cataclysm”. Marble-related travertines represent a low temperature facies of the impact event. The temporal projection of patterns like Rapid Climate Change (RCC), astrophysical data [Hoyle’s Comet: 47], acid events in ice-cores, tektite fall, Rise and Fall of Neolithic/Bronze Age Cultures, reveals an amazing “Ensemble” of coincidences among all of these parameters since the Middle/Upper Pleistocene boundary throughout Holocene. Ten short Interval Cases are discussed as being “Rare Event”- suspicious. Myths like the “Gilgamesch Epos” and “John’s Apocalypse” surprisingly provide realistic hints on impact events comparable with modern observations and experiments, which are: approach of extraterrestrial bodies, impact cratering, earthquakes and faulting, supercyclonic whirl-storms (wildfires), effects of hot ejecta, destruction of fauna, flora, and cities, long-lasting flooding, darkness caused by ashes and dust circulating in atmosphere and stratosphere (sintwinter), and environmental pollution. Such hints were handed down in myths of ~180 ethnic peoples around the globe. “High probability Cases” focus on impact events on ~9600 yr B.P and on ~6000 yr B.P. Other “Rare Events” may have possibly occurred about ~8000 yr B.P. and on ~3200 yr. B.P. (all radiocarbon yr.cal.). Core-drilling in the pull-apart basins of the Jordan Rift System (Dead Sea, Lake Tiberias) as traps having possibly preserved volcanic and impact ejecta would be a challenging international and interdisciplinary project.

Quasi-sure Product Variation of Two-parameter Smooth Martingales on the Wiener Space

In this paper, we prove that the process of product variation of a two-parameter smooth martingale admits an ∞ modification, which can be constructed as the quasi-sure limit of sum of the corresponding product variation.

Two Parameter Smooth Martingales on the Wiener Space

We prove that two parameter smooth continuous martingales have ∞-modification and establish a Doob’s inequality in terms of(p,r)-capacity for two parameter smooth martingales.

Observer-based Variable Universe Adaptive Fuzzy Controller Without Additional Dynamic Order

A high-precision fuzzy controller, based on a state observer, is developed for a class of nonlinear single-input-single-output(SISO) systems with system uncertainties and external disturbances. The state observer is introduced to resolve the problem of the unavailability of state variables. Assisted by the observer, a variable universe fuzzy system is designed to approximate the ideal control law. Being auxiliary components, a robust control term and a state feedback control term are designed to suppress the influence of the lumped uncertainties and remove the observation error, respectively. Different from the existing results, no additional dynamic order is required for the control design. All the adaptive laws and the control law are built based on the Lyapunov synthesis approach, and the signals involved in the closed-loop system are guaranteed to be uniformly ultimately bounded. Simulation results performed on Duffing forced oscillation demonstrate the advantages of the proposed control scheme.