A robust algorithm for a class of optimal control problems subject to regional stability constraints and disturbances

A robust globally convergent algorithm for solving the optimization control problem (OCP) in both state feedback controller and observation control system is investigated. Finding the OCP adjoint parameter for computing the optimal observer gain and feedback gain vectors are desired. First, the optimal control problem considering stability of degree constrains and disturbance that affects the dynamics of system is converted into a two-point boundary value problem (TPBVP). Then, we apply the He’s polynomials based on homotopy perturbation method (HPM) as an efficient method to find both optimal gains. The algorithm will be modified do decrease the number of iterations required to attain a desired control problem cost function. As a result lower computational complexity is required when compared with other state of the art methods. Applying the HPM makes the solution procedure become easier, simpler and more straightforward. In the proposed method the control problem can be solved with lower amplitudes of the input signal (control effort), comparing with analytical method. Lower control efforts may also help to avoid saturation effects, and to restrain the system to work within linear operating areas of the state space. On the other hand, there is a tradeoff between control effort and the degree of optimality obtained. For demonstrating the simplicity and efficiency of the proposed optimal control method, the algorithm is compared with a control architecture using the Kalman filter estimator and a controller gain designed by the Lyapunov’s second method.     

氚型TR管微波击穿特性的实验研究

介绍了雷达接收机用氚型TR管的结构和工作机理,给出X波段某氚型TR管在不同峰值功率、脉冲宽度和重复频率X波段微波信号作用下微波击穿特性的测试方法,研究其对大功率微波信号的压缩作用;从实验角度获取其透过功率、脉冲宽度与入射功率、脉宽和重复频率的关系,重点分析其对高峰值功率、低重复频率微波短脉冲信号的击穿特性,得出其对大动态微波短脉冲接收装置的击穿保护性能,为氚型TR管改型设计、高功率微波短脉冲雷达体制的技术可行性论证和当前雷达设备抗电磁辐射能力验证研究提供参考数据。     

高功率射频武器技术发展综述

在简要叙述高功率射频武器的基本概念、基本组成、性能特点及其在现代战争中的潜在应用的基础上，重点归纳了最新研究成果。     

国产化聚酯分散型控制系统的设计

介绍了江苏仪征化纤股份有限公司涤纶一厂国产化聚酯生产中分散型控制系统的组成结构，软硬件的设计和实施。重点介绍了DCS的全局操作站、局域控制网、高性能过程控制器、网络接口模件的组成结构。     

同轴插板式模式转换器频率特性研究

通过分析同轴插板式模式转换器的模式耦合过程,推导了模式转换器转换效率与频率的关系式,进而研究了其频带宽度与转换器同轴波导内外径参数之间的关系.通过数值计算,给出了可获得最大带宽的模式转换器设计条件:同轴波导的内、外半径之和约为波长的0.824倍,外半径小于波长的0.525倍.     

高功率微波在大气击穿时的传输特性研究

讨论了高功率微波大气击穿的微观机理，研究了电磁波在其中的传播特性，并进行了数值模拟。结果表明，在低密度等离子体中，场的反射很小，电磁波几乎没有能量损耗；在高密度等离子体，反射和传输同时存在，反射强度将逐渐增强，透射强度将逐渐减弱。     

Couple stress fluid flow in a rotating channel with peristalsis

This article describes a new model for obtaining closed-form semi-analytical solutions of peristaltic flow induced by sinusoidal wave trains propagating with constant speed on the walls of a two-dimensional rotating infinite channel. The channel rotates with a constant angular speed about the z-axis and is filled with couple stress fluid. The governing equations of the channel deformation and the flow rate inside the channel are derived using the lubrication theory approach. The resulting equations are solved, using the homotopy perturbation method(HPM), for exact solutions to the longitudinal velocity distribution, pressure gradient, flow rate due to secondary velocity, and pressure rise per wavelength. The effect of various values of physical parameters, such as, Taylor's number and couple stress parameter, together with some interesting features of peristaltic flow are discussed through graphs. The trapping phenomenon is investigated for different values of parameters under consideration. It is shown that Taylor's number and the couple stress parameter have an increasing effect on the longitudinal velocity distribution till half of the channel, on the flow rate due to secondary velocity, and on the number of closed streamlines circulating the bolus.     

Mathematical modelling of hydrothermal performance for Kenics type static mixer using power law obeying fluids

In this study, analytical, numerical, and experimental works are presented to demonstrate hydrothermal characteristics of a flow choosing non-Newtonian behaviour through a Kenics type static mixer. Experiments are conducted by varying the superficial fluid velocities of the heterogeneous mixture oil with Sudan dye and water, as well as for the homogeneous aqueous system, consisting of CMC (2 wt%) in water. Six static mixing elements are placed in series, and the corresponding wall temperatures of the inline pipe are varied over a range of 293–363 K. In the context of hydrodynamic study, analytical models are solved using the Bessel function and Laguerre function and validated with the in-house experimental results and numerical results. In the thermal performance study, mathematical models are formulated based on differential transformation method (DTM) and homotopy perturbation method (HPM), and have been validated with the numerical results. The deviation among the experimentally measured average pressure drops estimated from our experiment and that predicted by analytical models is found to be as low as ±8.1%. The deviation between the analytical results obtained from the HPM and DTM method and numerical results based on the finite volume method solution of the same equation is observed as low as ±4%. Additionally, both proposed analytical methods used are compared with each other to evaluate the dimensionless swirl flow velocity and temperature gradient of the inline Kenics Static mixer. In the thermal performance study, we observe that the DTM is in good agreement with the numerical method as compared to HPM.     

Investigation of heat transfer in a geometry with variable cross section

In this paper, the thermal conductivity that plays an important role in heat transfer efficiency is investigated. He's homotopy perturbation method (HPM) and Adomian decomposition method (ADM) are applied to the nonlinear heat transfer equations and the comparison between results is illustrated within several plots. Here, thermal conductivity has been considered as a function of temperature. Also the variable heat generation has been taken into account. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20266 Copyright © 2009 Wiley Periodicals, Inc.     

在TPS系统中实现温度串级调节

针对汽提塔温度自动化控制的特点，以Honeywell TPS为例，利用专用模块和TPS丰富的功能，完成汽提塔温度与蒸汽流量的串级调节。