A fault isolation filter design using left eigenstructure assignment scheme

This paper presents a novel fault isolation filter design method using left eigenstructure assignment scheme proposed by the first author et al. The proposed method shows good performance of fault isolation with an exact eigenstructure assignment and guarantees that the corrupted γ faults can be isolated simultaneously when the number of available output measurements are equal to or larger than (γ+l). A numerical example for the fault isolation filter is also included.     

Eigenstructure assignment by the differential Sylvester equation for linear time-varying systems

This work is concerned with the assignment of the desired eigenstructure for linear time-varying systems such as missiles, rockets, fighters, etc. Despite its well-known limitations, gain scheduling control continues to be a major focus of research efforts. Scheduling of frozen-time, frozen-state controllers for fast time-varying dynamics is known to be mathematically fallacious and practically hazardous. Therefore, recent research efforts are being directed towards applying time-varying controllers. In this paper, we i) introduce a differential algebraic eigenvalue theory for linear time-varying systems, and ii) propose an eigenstructure assignment scheme for linear time-varying systems via the differential Sylvester equation based upon newly developed notions. The whole design procedure of the proposed eigenstructure assignment scheme is very systematic. The scheme can be used to determine the stability of linear time-varying systems easily as well as to provide a new horizon of designing controllers for linear time-varying systems. The presented method is illustrated by a numerical example.     

综合定量反馈理论与特征结构配置的飞行控制系统优化设计

定量反馈理论(QFT)是一种新颖的频率域鲁棒控制技术,在N ichols图上开展分析与设计。针对大包线范围内系统模型变化大的特点,可采用QFT设计横航向控制器。由于QFT主要针对单输入单输出(SISO)系统进行分析,因此首先应采用特征结构配置(EA)理论将无人机的横航向模态进行近似解耦,将多输入多输出(M IMO)系统转化为SISO系统,再采用QFT进行控制系统设计。本文将两种控制方法结合起来,构成综合优化飞行控制方法,针对某型无人机包线范围内选取的18个状态点组成的控制对象模板进行控制设计,并进行非线性仿真。仿真结果表明设计的控制器使得无人机在全包线范围内具有较好的性能和鲁棒稳定性。     

Frequency domain properties of EALQR with indefinite weighting matrix

EALQR (Linear Quadratic Regulator design with Eigenstructure Assignment capability) has the capability of exact assignment of eigenstructure with the guaranteed margins of the LQR for MIMO (Multi-Input Multi-Output) systems. However, EALQR undergoes a restriction on the state-weighting matrixQ in LQR to be indefinite with respect to the region of allowable closed-loop eigenvalues. The definiteness of the weighting matrix is closely related to the robustness property of a given system. In this paper, we derive a relation between the indefinite weighting matrix Q and the robustness property for EALQR. The modified frequency domain inequality, that could be guaranteed by EQLQR with an indefinite weighting matrix, is presented.     

FINITE-ELEMENT MODEL UPDATING,EIGENSTRUCTURE ASSIGNMENT AND EIGENVALUE EMBEDDING TECHNIQUES FOR VIBRATING SYSTEMS

This paper presents a brief overview of the existing direct methods for the finite-element model (FEM) updating problem and reviews the recently developed ‘direct and partial modal’ approach for the partial eigenstructure assignment problem and the ‘eigenvalue embedding’ techniques for vibrating systems, in the context of the solution of this problem.     

A new SSI algorithm for LPTV systems: Application to a hinged-bladed helicopter

Many systems such as turbo-generators, wind turbines and helicopters show intrinsic time-periodic behaviors. Usually, these structures are considered to be faithfully modeled as linear time-invariant (LTI). In some cases where the rotor is anisotropic, this modeling does not hold and the equations of motion lead necessarily to a linear periodically time-varying (referred to as LPTV in the control and digital signal field or LTP in the mechanical and nonlinear dynamics world) model. Classical modal analysis methodologies based on the classical time-invariant eigenstructure (frequencies and damping ratios) of the system no more apply. This is the case in particular for subspace methods. For such time-periodic systems, the modal analysis can be described by characteristic exponents called Floquet multipliers. The aim of this paper is to suggest a new subspace-based algorithm that is able to extract these multipliers and the corresponding frequencies and damping ratios. The algorithm is then tested on a numerical model of a hinged-bladed helicopter on the ground.     

300 MW汽轮发电机组转子轴系弯振鲁棒控制研究

针对300 MW汽轮机组转子轴承系统,在建立其8支承9节点集总模型的基础上,对轴系最左端面和发电机右端面的弯曲振动响应进行研究.为避免运行过程中受到的各种激励形式造成的扰动,设计了一种鲁棒轨迹控制器,保证了跟踪误差的一致终值有界.最后,通过模拟仿真对所提出的鲁棒控制方案与开环控制方案进行了比较,结果表明鲁棒轨迹控制具有更高的控制精度和稳定性.     

基于鲁棒预白化的机械噪声信号盲分离

机械噪声故障诊断的难度在于实际检测的噪声是多个设备或零部件噪声信号的混合,信噪比低,基于二阶统计量盲源分离算法的故障噪声诊断技术,利用二阶协方差矩阵的联合对角化,从测量噪声中分离出感兴趣故障噪声进而提取特征,但该算法抗干扰噪声性能差。本文利用多个协方差矩阵平滑滤波后的矩阵进行白化,进一步提高了抗干扰噪声能力,在样本数据较少时仍能实现较好的盲源分离效果,仿真实验证实了该算法的有效性。     

Gain-scheduling multivariable LPV control of an irrigation canal system

The purpose of this paper is to present a multivariable linear parameter varying (LPV) controller with a gain scheduling Smith Predictor (SP) scheme applicable to open-flow canal systems. This LPV controller based on SP is designed taking into account the uncertainty in the estimation of delay and the variation of plant parameters according to the operating point. This new methodology can be applied to a class of delay systems that can be represented by a set of models that can be factorized into a rational multivariable model in series with left/right diagonal (multiple) delays, such as, the case of irrigation canals. A multiple pool canal system is used to test and validate the proposed control approach.     

一种摆线齿轮齿形设计方案

通过对渐开线齿轮与摆线齿轮的齿形进行对比分析 ,提出一种新的摆线齿轮齿形设计方案 :将摆线齿轮左、右齿面的设计齿形取为理论摆线齿形 ,同时使摆线齿轮具有所需的齿厚减薄量。认为采用该方案可提高摆线针轮传动的承载能力和运动精度。给出了采用成形法和展成法获得该齿形的方法和措施     

基于Prodave的设备参数设定及监控系统

介绍了一种基于PLC的快速锻压机控制系统,该系统以S7-400 PLC为控制和数据处理核心,采用2个S7-300 PLC控制左操作机和右操作机,2个工控机分别实现参数设定和过程监控。系统采用了工业以太网实现S7-400 PLC与工控机之间通信的方法,采用基于Prodave IE动态链接库调用方法实现数据通信。重点研究了基于VB的参数设定及监控系统的不同类型数据处理方法,解决了S7 PLC和工控机不同环境的数据类型转换,为大型机械设备控制系统的设计开发提供了参考。     

新型船用导航雷达结构总体设计

新型船用导航雷达采用连续波与脉冲双体制兼容的设计方案,对设备的体积、重量和散热提出了较高的要求。为了减小天线座的体积和重量,将天线座底座腔体分隔成主腔体、左右副腔体共3个腔体,以此增加设备的安装面,从而减小天线座的体积和重量。为了能够有效散发天线座内设备产生的热量,在主腔体和副腔体之间做散热风道,内部器件的热量通过热传导散发到风道内。通过天线座散热仿真,证明天线座散热效果较好。该雷达结构满足各项结构设计指标要求。     

Generalized inverse beamforming with optimized regularization strategy

A promising recent development on acoustic source localization and source strength estimation is the generalized inverse beamforming, which is based on the microphone array cross-spectral matrix eigenstructure. This method presents several advantages over the conventional beamforming, including a higher accuracy on the source center localization and strength estimation even with distributed coherent sources. This paper aims to improve the strength estimation of the generalized inverse beamforming method with an automated regularization factor definition. Also in this work, a virtual target grid is introduced, and source mapping and strength estimation are obtained disregarding, as much as possible, the reflections influence. Two simple problems are used to compare the generalized inverse performance with fixed regularization factor to performance obtained using the optimized regularization strategy. Numerical and experimental data are used, and two other strength estimation methods are also evaluated for reference.     

电液伺服系统的非线性控制

针对电液伺服系统非线性、参数时变的特点,为提高系统的性能,首先讨论了系统的非线性数学模型,利用逆系统解耦控制方法,将非线性系统转化成伪线性系统,进行线性控制;在此基础上,提出了一种模糊PID自适应非线性控制设计方案,与逆系统控制方法进行了仿真比较;结果表明,采用模糊PID控制,在系统参数变化、外界扰动的影响下,具有较好的自适应性和动态鲁棒性能。     

黏性流体环境中压电宏纤维致动柔性结构的流固耦合振动特性及试验

柔性结构与周围流体的耦合作用机制广泛应用于仿生机器人、水下航行器、精密仪器及生命医疗等领域。具有驱动变形大、防水性好且柔韧性好的压电宏纤维（Macro fiber composite,MFC）致动器是水下柔性结构变形控制的首选。建立MFC内部致动弯矩和水动力载荷共同作用下柔性结构的流固耦合动力学模型。对粘贴MFC致动器的柔性结构特征截面进行计算流体动力学（Computational fluid dynamics,CFD）分析,得到不同振动特征频率下柔性结构周围流场、压力分布及所受水动力载荷,分别拟合得到MFC致动柔性结构水动力函数的实部和虚部表达式。结果表明柔性结构水动力载荷的附加质量和阻尼效应都随着振动频率的增加而减小。在等振动特征频率下,MFC致动梁结构水动力函数的实部大于匀质等截面梁的实部;在高振动频率下其水动力函数虚部同样大于匀质等截面梁。试验测试了MFC致动柔性结构的水下振动特性,试验所得MFC激励下柔性结构末端稳定振动的幅频特性和相频特性与建立的耦合动力模型相吻合,证实了所建立MFC致动柔性结构的水动力函数及流固耦合振动模型的有效性。     

用于压铸机改造的变频调速系统

本文介绍了压铸机变频调速系统,着重分析了压铸机采用变频器调速后存在的问题及应采取的措施。给出了压铸机变频调速系统选型方案。     

Pressure control of hydraulic servo system using proportional control valve

The purpose of this study is to develope a control scheme for the hydraulic servo system which can rapidly control the pressure in a hydraulic cylinder with very short stroke. Compared with the negligible stroke of the cylinder in the system, the flow gain of the proportional pressure control valve constituting the hydraulic servo system is relatively large and the time delay on the response of the valve is quite long. Therefore, the pressure control system, in this study tends to get unstable during operations. Considering the above mentioned characteristics of the system, a two-degree-of-freedom control scheme, composed of the I-PDD²… feedback compensator and the feedforward controller, is proposed. The reference model scheme is used in deciding the parameters of the controllers. The validity of the proposed control scheme is confirmed through the experiments.     

Lateral vehicle control based on active flight control technology

In this paper, a lateral vehicle control using the concept of control configured vehicle (CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to follow a chosen variable without significant motion change in other specified variables. The analysis techniques for decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling (i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver’s command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.     

基于德尔菲法和FAHP的特种车辆设计评价体系研究

针对特种车辆概念设计方案中的诸多模糊因素,利用AHP方法构建了概念设计方案的多目标、多层次评价指标体系,根据德尔菲法由专家打分的方式并结合FAHP法确定各评价因素的权重,并建立了特种车辆设计方案模糊综合评价模型。通过对广东某特种车辆制造公司的罐式运输车设计方案评价,实例验证了该评价体系在特种车辆设计方案评价中的应用。     

An Intelligent Integrated System Scheme for Machine Tool Diagnostics

The technology of neural networks and expert systems are finding increasing applications in the field of machine tool diagnostics. In this paper, the advantages and disadvantages of these methods are analysed and compared. An intelligent integrated diagnosis system based on a combination of the two methods is presented. This scheme aims to exploit the advantages and avoid the disadvantages of neural networks and expert systems. The implementation of the intelligent integrated diagnosis system scheme is also presented. A diagnosis system based on the scheme is introduced, and is applied to the process diagnosis of an existing machining centre. The experimental results show that the integrated system scheme is feasible and effective for machine tool diagnosis tasks.