A parameter estimation based adaptive actuator failure compensation control scheme

An adaptive actuator failure compensation control scheme is developed using an indirect adaptive control method,by calculating the controller parameters from adaptive estimates of system parameters and actuator failure parameters.A key technical issue is how to deal with the actuator failure uncertainties such as failure pattern,time and values.A complete parametrization covering all possible failures is used to solve this issue for adaptive parameter estimation.A simultaneous mapping from the estimated system/failure parameters to the controller parameters is employed to make the control system capable of ensuring the desired system performance under failures,which is verified by simulation results.     

Solution of the HJI equations for nonlinear H∞ control design by state-dependent Riccati equations approach

The relationship between the technique by statedependent Riccati equations (SDRE) and Hamilton-Jacobi-Isaacs (HJI) equations for nonlinear H ∞ control design is investigated.By establishing the Lyapunov matrix equations for partial derivates of the solution of the SDREs and introducing symmetry measure for some related matrices,a method is proposed for examining whether the SDRE method admits a global optimal control equivalent to that solved by the HJI equation method.Two examples with simulation are given to illustrate the method is effective.     

Consensus problem of second-order multi-agent systems with time-varying communication delay and switching topology

Leader-following stationary consensus problem is investigated for the second-order multi-agent systems with timevarying communication delay and switching topology.Based on Lyapunov-Krasovskii functional and Lyapunov-Razumikhin functions respectively,consensus criterions in the form of linear matrix inequality (LMI) are obtained for the system with time-varying communication delays under static interconnection topology converging to the leader’s states.Moreover,the delay-dependent consensus criterion in the form of LMI is also obtained for the system with time-invariant communication delay and switching topologies by constructing Lyapunov-Krasovskii functional.Numerical simulations present the correctness of the results.     

Novel approach to GPS/SINS integration for IMU alignment

Strapdown inertial navigation system(SINS) requires an initialization process that establishes the relationship between the body frame and the local geographic reference.This process,called alignment,is generally used to estimate the initial attitude angles.This is possible because an accurate determination of the inertial measurement unit(IMU) motion is available based on the measurement obtained from global position system(GPS).But the update frequency of GPS is much lower than SINS.Due to the non-synchronous data streams from GPS and SINS,the initial attitude angles may not be computed accurately enough.In addition,the estimated initial attitude angles may have relatively large uncertainties that can affect the accuracy of other navigation parameters.This paper presents an effective approach of matching the velocities which are provided by GPS and SINS.In this approach,a digital high-pass filter,which implements a pre-filtering scheme of the measured signal,is used to filter the Schuler cycle of discrete velocity difference between the SINS and GPS.Simulation results show that this approach improves the accuracy greatly and makes the convergence time satisfy the required accuracy.     

基于DM6467的视频处理软件设计与优化

针对视频处理系统的实时性要求及视频压缩编码算法的现状,本文给出了基于TIDM6467的嵌入式视频处理软件及关键算法的优化实现.TMS320DM6467 ARM+DSP的ARM核进行实时采集与传输视频数据,DSP内核进行视频处理;软件基于嵌入式Linux操作系统,采用达芬奇软件框架实现视频采集和编码服务器的设计.为了提高压缩效率,本文提出一种快速半像素运动估计算法,在最佳整像素点周围通过计算直接推导出最佳半像素点的位置,避免全搜索的大运算处理,快速半像素运动估计算法所用时间为标准全搜索算法所用时间的41％～57％.本文所设计的视频处理软件能达到实时进行高清视频的采集与压缩处理,并将处理的结果存入U盘,同时能通过扩展实现多路视频的处理.实现系统控制与存储等功能.     

基于IOWHA算子和倒数灰关联度的组合预测模型及其应用

将诱导有序加权调和平均(IOWHA)算子和倒数灰关联度相结合,提出了基于IOWHA算子和倒数灰关联度的组合预测模型,同时定义了优性组合预测和非劣性组合预测的概念,并将该组合预测模型应用到税收收入预测中,验证了组合预测模型的合理性和有效性,并说明了优性组合预测的存在性.     

Nuclear Power Plant Life Extension - How Aging Affects Performance of Containments Other Structures

This paper focuses on how aging can affect performance of safety-related structures in nuclear power plants (NPPs). Knowledge and assessment of impacts of aging on structures is essential to Plant Life Extension analysis, especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large, aging fleet of NPPs. Seismic issues are of heightened interest to the worldwide nuclear community in the wake of the 2011 Tohoku Earthquake and Tsunami. This paper addresses the overlap and relationship of structure aging to severe loading performance, with particular emphasis on containment structures.     

随机级数的T-可和性与本性收敛

研究了Banach空间中向量级数的收敛性与T-可和性的关系,得出了结果:一般的复级数都存在一个求和阵T,使之为T-可和,并在此基础上,研究了随机级数的T-可和性与本性收敛的关系,得到了随机级数本性收敛的充要条件.     

数字校园平台考试管理子系统

本课题基于.NET以及SQL Server 2005数据库技术,使用C#.NET编成、实现。数字校园平台使用Remoting技术实现三层C/S架构,可以满足现在高校数字化、自动化完成信息管理的要求。该系统从灵活、通用、标准的设计思想出发,给高校办公人员提供集成、安全、可靠的的工作环境,具有友好的操作界面以及灵活的可扩展性。考试管理子系统可以实现高效教师题库维护自动组卷以及高校考试计划的信息收集和自动化计划安排。考试计划安排系统中的考试计划安排算法基于遗传算法来设计并实现。     

Combining sum-difference and auxiliary beams for adaptive monopulse in jamming

Only in the presence of sidelobe jamming(SLJ),can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously.While mainlobe jamming(MLJ) exists,the mainlobe of adaptive pattern will subject to serious distortion,which results in a failure of detecting and tracking targets by monopulse technique.Therefore,a monopulse angle estimation algorithm based on combining sum-difference beam and auxiliary beam is presented.This algorithm utilizes both high gain difference beams and high gain auxiliary beams for cancelling the mainlobe jammer and multiple sidelobe jammers(SLJs) while keeping an adaptive monopulse ratio.Theoretical analysis and simulation results indicate that the serious invalidation of monopulse technique in MLJ and SLJs scenarios is resolved well,which improves the monopulse angle accuracy greatly.Furthermore,the proposed algorithm is of simple implementation and low computational complexity.