Nonlinear optimized adaptive trajectory control of helicopter

This paper attempts to develop an optimized adaptive trajectory control system for helicopters based on the dynamic inversion method. This control algorithm is implemented by three time-scale separation architectures. Pseudo control hedging (PCH) is used to protect the adaptive element from actuator saturation nonlinearities and also from the inner-outer-loop interaction. In addition, to augment the attitude control system, two online adaptive architectures that employ a neural network are used. By tuning the neural network based on the system model, a better and faster learning will be achieved, but this is a frustrating and time consuming process. Due to complexity in accurate tuning of neural network, this paper introduces a non-dominated sorting genetic algorithm II (NSGA-II) for off-line optimization of the neural network. Thus, in the proposed method, the neural network can compensate model inversion error caused by the deficiency of full knowledge of helicopter dynamics more accurately. The effectiveness of proposed method is demonstrated by numerical simulations.     

On finite-time stability and stabilization of nonlinear port-controlled Hamiltonian systems

The finite-time stability and stabilization of nonlinear port-controlled Hamiltonian(PCH)systems are investigated in this paper,and a number of new results are proposed.Firstly,by exploiting the Hamiltonian structural properties,a proper form of the Hamiltonian function is obtained,based on which a finite-time stability criterion is then presented for a class of Hamiltonian systems.Secondly,using the obtained stability criterion and the so-called"energy shaping plus damping injection"technique,the continuous finite-time stabilization problem is studied for the PCH system,and several global stabilization results are provided.Finally,the continuous robust finite-time stabilization of the PCH system with external disturbances is investigated,and two results on designing global robust finite-time stabilizers are obtained.Study of several examples with numerical simulations shows that the control design approach developed in this paper works very well.     

A novel induction motor control scheme using IDA-PBC

A new control scheme for induction motors is proposed in the present paper, applying the interconnection and damping assignment-passivity based control （IDA-PBC） method. The scheme is based exclusively on passivity based control, without restricting the input frequency as it is done in field oriented control （FOC）. A port-controlled Hamiltonian （PCH） model of the induction motor is deduced to make the interconnection and damping of energy explicit on the scheme. The proposed controller is validated under computational simulations and experimental tests using an inverter prototype.     

M-CCCH应用与效果分析

随着GSM数据业务的迅猛发展,现网增加了大量的寻呼和立即指配,已对公共控制信道造成了一定的影响,进而引起网络质量问题.本文分析了M-CCCH原理并对M-CCCH配置提出了计算方法,并在实际网络中的应用效果进行了分析.     

开放式火电厂生产实时数据平台的建设和应用

目前,在广东省电厂中,３００ＭＷ以上的大型机组基本配备了分散控制系统（ＤＣＳ）。该ＤＣＳ采集了大量的机组生产实时数据,但它使用的是专用网络,是一个封闭运行的计算机系统。为实现数据共享,需要建立一个开放式的生产实时信息平台。为此,阐述了如何把ＤＣＳ与ＭＩＳ网络相连,以及从ＶＤＰＦ,ＩＮＦＩ－９０两种ＤＣＳ系统上采集数据的方法,并且指出,在计算机平台和实时应用系统之间采用“中件”,对于保证系统的开放性、实时性及可升级性具有重要的意义。     

GSM系统的业务量控制

通信网中的业务量控制是维持正常操作所必不可少的技术 ,本文介绍了当今使用较多的GSM数字移动通信系统在业务量控制上所采取的一些基本方法。     

GSM网络寻呼承载能力及突发应对策略分析

着重分析了GSM网络Um接口和Abis接口的寻呼承载能力,阐述了寻呼容量对位置区承载话务量的限制,以实例说明了寻呼量突发的特点,并提出了多种应对寻呼量突发的策略。     

非线性哈密顿控制系统输出反馈同时镇定(英文)

研究有限多个非线性哈密顿控制系统同时镇定问题,给出了若干输出反馈同时镇定控制器设计新结果.首先,利用哈密顿系统的结构特性和零状态可检测性,得到了一种新的设计方法.然后,研究哈密顿系统中含有外部干扰和结构不确定性的情形,设计了三种同时镇定控制器：一个是鲁棒同时镇定器,一个是自适应同时镇定器,最后一个是鲁棒自适应H∞同时镇定器.例子和仿真研究表明：本文提出的控制器设计方法是行之有效的.     

Synthesis and characterisation of organo-silica hydrophobic clay heterostructures for volatile organic compounds removal

Mesostructured materials belonging to a new class of solid acids known as porous clay heterostructures (PCHs) have been prepared by chemical modification of a natural clay, by using a cationic surfactant, a neutral amine, and an equimolar mixture of bis(triethoxysilyl)benzene (BTEB) and tetraethyl orthosilicate (TEOS). The effect of different polymerisation times of the silica sources and of the hydrocarbon chain length of the neutral amine was studied. The materials retained their layered structure after the formation of stable pillars by the polymerisation of hydrolysed TEOS and BTEB. All materials were characterised by low temperature nitrogen adsorption isotherms, ¹³C CP MAS, ²⁹Si MAS and CP MAS NMR spectroscopy, thermal analyses and infrared spectroscopy. The specific surface BET areas of the materials were in the range 550–800 m² g⁻¹ and the corresponding microporous volume were near 0.2–0.3 cm³ g⁻¹. The reduction of the reaction time from 12 to 4 h avoids the extra-gallery polymerisation, contributing for a larger specific surface area. The increase of two carbon atoms in the neutral amine chain does not show much effect on the available surface area.

These materials were very effective as adsorbents of volatile organic compounds (VOCs), according to tests on methanol, methyl ethyl ketone, toluene and trichloroethylene. The water adsorption isotherms proved the hydrophobicity of the materials, suggesting their capabilities for VOC adsorption in the presence of water.     

Simultaneous stabilization of a set of nonlinear port-controlled Hamiltonian systems

This paper investigates simultaneous stabilization of a set of nonlinear port-controlled Hamiltonian (PCH) systems and proposes a number of results on the design of simultaneous stabilization controllers for the PCH systems. Firstly, the case of two PCH systems is studied. Using the dissipative Hamiltonian structural properties, the two systems are combined to generate an augmented PCH system, with which some results on the control design are then obtained. For the case that there exist parametric uncertainties in the two systems’ Hamiltonian structures, an adaptive simultaneous stabilization controller is proposed. When there are external disturbances and parametric uncertainties in the two systems, two simultaneous stabilization controllers are designed for the systems: one is a robust controller and the other is a robust adaptive one. Secondly, the case of more than two PCH systems is investigated, and a new result is proposed for the simultaneous stabilization of the systems. Finally, two illustrative examples are studied by using the results proposed in this paper. Simulations show that the simultaneous stabilization controllers obtained in this paper work very well.