Eigenstructure Assignment in a Class of Second-order Descriptor Linear Systems: A Complete Parametric Approach

In this paper eigenstructure assignment via proportional-plus-derivative feedback is investigated for a class of second-order descriptor linear systems. Under certain conditions, simple, general and complete parametric solutions of both finite closed-loop eigenvector matrices and feedback gain matrices are derived. The parametric approach utilizes directly original system data, involves manipulations only on n-dimensional matrices, and reveals all the design degrees of freedom which can be further utilized to achieve certain additional system specifications. A numerical example shows the effect of the proposed approach.

Two parametric approaches for eigenstructure assignment in second-order linear systems

This paper considers eigenstructure assignment in second-order linear systems via proportional plus derivative feedback. It is shown that the problem is closely related to a type of so-called second-order Sylvester matrix equations. Through establishing two general parametric solutions to this type of matrix equations, two complete parametric methods for the proposed eigenstructure assignment problem are presented. Both methods give simple complete parametric expressions for the feedback gains and the closed-loop eigenvector matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the right factorization of the system, and allows the closed-loop eigenvalues to be set undetermined and sought via certain optimization procedures. An example shows the effectiveness of the proposed approaches. Keywords Second-order linear systems - Eigenstructure assignment - Proportional plus derivative feedback - Parametric solution - Singular value decompoition - Right factorization This work was supported in part by the Chinese Outstanding Youth Foundation (No.69504002).

Eigenstructure assignment of lower-order dynamical compensatorsfor linear systems with unknown inputs

Presents a systematic design method of reduced order dynamical compensator via the parametric representations of eigenstructure assignment for linear system, which provides maximum degree of freedom, and can be easily used for the design of a linear system with unknown inputs under some conditions. Even when these conditions are not satisfied, the lower order dynamical compensator can also be designed under some relaxed conditions. Some examples illustrate that the method is neat, simple and effective.

Eigenstructure assignment in a class of second-order dynamic systems

Eigenstructure assignment using the proportional-plus-derivative feedback controller in a class of secondorder dynamic system is investigated. Simple, general, complete parametric expressions for both the closed-loop eigenvector matrix and the feedback gains are established based on two simple Smith form reductions. The approach utilizes directly the original system data and involves manipulations only on n-dimensional matrices. Furthermore, it reveals all the degrees of freedom which can be further utilized to achieve additional system specifications. An example shows the effect of the proposed approach.

An explicit solution to right factorization with applicationin eigenstructure assignment

Based on the well-known Leverrier algorithm, a simple explicit solution to right factorization of a linear system is established. This solution is expressed by the controllability matrix of the given system and a symmetric operator matrix. Applications of this solution to a type of generalized Sylvester matrix equatiorls and the problem of parametric eigenstructure assignment by state feedback are investigated,and general complete parametric solutions to these two problems are deduced. These new solutions are simple, and possess desirable structural properties which render the solutions readily implementable. An example demonstrates the effect of the proposed results.

An explicit solution to polynomial matrix right coprime factorization with application in eigenstructure assignment

在这篇论文，输入状态转移功能的多项式矩阵权利 coprimefactorization 的一个明确的答案以 Krylov 矩阵和系数矩阵的对的 thePseudo 可控制性索引被获得。建议途径仅仅需要解决一系列线性方程。generalizedSylvester 矩阵方程和由州的反馈的参量的 eigenstructure 赋值的问题的一种类型的这个答案的应用程序被调查。这些新答案简单，他们拥有更好结构的性质和方便的空想使用。一个例子显示出建议结果的效果。

基于特征结构配置的电磁轴承-刚性转子系统动态补偿器的设计

由于电磁轴承-转子系统的动力学特性与控制器的结构和参数密切相关,若要使系统安全、稳定及可靠地运行,控制器的设计尤为重要。针对电磁轴承-刚性转子系统,提出一种基于特征结构配置的动态补偿器的设计方法。首先,通过模态解耦,将平动和锥动运动相互耦合的四自由度电磁轴承-刚性转子系统解耦为2个单自由度平动子系统和2个单自由度锥动子系统。然后,基于特征结构配置,建立引入动态补偿器后的闭环系统的特征值和特征向量与补偿器参数之间的关系。之后,限定特征值的变化范围,以使系统具备稳定性和良好的动态性能,构造优化目标函数,以同时抑制转子系统的不平衡位移和不平衡控制电流,从而使系统具备所需的动力特性。最后,通过数值仿真和试验,验证所设计的动态补偿器的有效性。

EIGENSTRUCTURE ASSIGNMENT FOR TIME-VARYING LINEAR SYSTEMS

The problem of eigenstructure assignment via output feedback for time-varying linearsystems is treated, and the sufficient and necessary condition and two simple effective algorithmsare presented. Two forms of parametric representations of the set of closed loop eigenvectormatrices and the set of feedback gains with respect to the closed loop eigenvalues and twogroups of parameter vectors are established. Without any constraint to the closed loop poles,the obtained results have generalized many previous results even in the constant case, andhave also overcome their defects.

某型飞机侧向通道EA/QFT鲁棒控制

提出了一种M IM O定量反馈理论与特征值配置相结合的鲁棒解耦控制方法,该方法首先利用特征值配置使系统达到性能指标要求,通过对特征向量的限制实现M IM O系统解耦,然后利用QFT方法使其具备鲁棒性。通过对某型飞机侧向通道的仿真表明:该方法不仅解耦效果良好,而且具有较强的鲁棒性。

基于改进PEA的日地L2平动点编队飞行高精度位置保持

针对日地L2平动点相对运动拟线性变参数(QLPV)动力学模型,提出一种改进的多项式特征结构配置(PEA)方法实现日地L2平动点编队飞行高精度相对位置保持。建立日地L2平动点编队飞行相对运动QLPV动力学模型,将基于线性时不变系统(LTI)的PEA方法进行改进,设计参数/状态变化的控制方法来获取闭环系统设计传递函数,与期望传递函数进行类似于线性系统的条件匹配,获得含时变参数和状态的多项式控制器,确保系统在参数和状态变化时能保持控制系统性能不变。在进行多输入多输出(MIMO)系统的算法设计时,将系统期望传递函数设为解耦形式,实现飞行器三轴位置间的解耦控制,以确保系统的控制精度。考虑到拟线性变参数系统与传统线性系统的不同,对拟线性变参数闭环系统的稳定性进行分析。最后进行了相应的数学仿真验证算法的可行性和有效性。

基于EA、LMI与ANN的平流层飞艇纵向智能增稳控制系统设计

文中描述分析了平流层飞艇的特点,建立了飞艇的六自由度数学模型,并对其进行了线性化,获得了状态空间表达式,对得到的线性系统进行了特性分析,并将纵向运动划分为三个模态。为了改善飞艇的稳定性,在空域中选定若干设计点,利用基于LMI的EA对其进行了控制器设计,然后利用神经网络形成了神经网络控制器,达到了控制器全空域泛化的目的。结合实际数据对加入控制器后的飞艇模型进行仿真,仿真结果表明了这种设计方法的有效性。

基于PEA的椭圆轨道航天器编队飞行高精度位置保持

针对航天器编队飞行时相对位置保持精度要求高的特点,采用基于线性变参数模型的多项式特征结构配置方法设计椭圆轨道航天器间相对位置控制算法。对于线性变参数控制系统,本文将基于线性定常系统的多项式特征结构配置方法推广以确保系统性能与变化参数间的独立性。在特征结构配置时,先设计带参数变化的控制器结构后计算出带未知控制器增益的设计闭环传递函数,接着将其与含有闭环系统性能的期望传递函数在三个条件下进行匹配,进而获得未知控制器增益的表达式。在设计实际控制椭圆轨道编队飞行MIMO相对位置保持算法时,将系统期望传递函数设为解耦形式来实现三轴位置控制间的解耦控制,达到提高系统控制性能的目的。最后进行相应的数学仿真,其结果表明该算法能够保证系统的高精度位置保持要求。

基于特征结构配置的奇异振动系统鲁棒镇定

奇异振动系统由于存在无穷远特征结构,导致系统的动态性能较差,这给实际应用带来了困难。目的 为了改善奇异振动系统的稳定性,方法 采用加速度-速度主动控制策略,提出基于特征结构配置的奇异振动系统鲁棒镇定。基于特征结构配置及奇异值分解方法讨论奇异振动系统的镇定问题,提出镇定控制器的参数化设计方法。在随机扰动环境下,讨论奇异振动系统受参数扰动时的鲁棒特征值镇定问题和镇定控制器设计方案。通过引入拉格朗日乘子,构造基于扰动位移的多元函数,将鲁棒镇定问题转化为广义系统特征结构优化问题。利用构造的扰动函数及Rayleigh定理,提出奇异振动系统鲁棒镇定控制器设计的新方法。结果 通过两个算法制定了相应控制器设计步骤,仿真验证了算法的可行性。数值结果表明,本文方法能快速镇定奇异振动系统,且使闭环系统具有很好的稳态性能。结论 提出的新方法改善了奇异振动系统动态性能的同时,也增强了闭环系统的抗干扰能力,从而提高了系统的鲁棒性。

基于H_∞鲁棒控制和EA的平流层验证飞艇姿态控制器设计

H∞鲁棒控制理论在设计控制系统时,对系统的时域性能未加以考虑,不能保证设计的反馈系统满足期望的时域性能指标;特征结构配置可以依据实际系统的需要配置闭环系统的极点及对应的特征向量,可以满足系统设计对时域指标的要求;为此,基于H∞鲁棒控制和特征结构配置理论,进行了混合优化控制器的设计。将特征结构配置的输出反馈作为内环,将H∞鲁棒控制理论设计的跟踪控制器作为外环,同时兼顾时域与频域性能指标,满足系统对鲁棒性和对指定信号精确跟踪的要求;通过对某平流层飞艇的验证艇的纵向姿态跟踪控制的仿真,结果表明,当选取状态变量v,α,q,θ,eδ,T,eθs,eδ0,T0对应的性能指标系数为c1=0.001,c2=0.001,c3=0.001,c4=0.002,c5=0.002,c6=0.001,c7=0.003,c8=0.01,c9=0.001时,飞艇在有风干扰下仍然能够很好的跟踪输入指令,无稳态误差,调节时间短,仿真效果良好。

Global stabilizing controller design for linear time-varying systems and its application on BTT missiles

A parametric method for the gain-scheduled controller design of a linear time-varying system is given. According to the proposed scheduling method, the performance between adjacent characteristic points is preserved by the invariant eigenvalues and the gradually varying eigenvectors. A sufficient stability criterion is given by constructing a series of Lyapunov functions based on the selected discrete characteristic points. An important contribution is that it provides a simple and feasible approach for the design of gain-scheduled controllers for linear time-varying systems, which can guarantee both the global stability and the desired closed-loop performance of the resulted system. The method is applied to the design of a BTT missile autopilot and the simulation results show that the method is superior to the traditional one in sense of either global stability or system performance.

Design of Luenberger function observer with disturbance decoupling for matrix second-order linear systems-a parametric approach

A simple method for disturbance decoupling for matrix second-order linear systems is proposed directly in matrix second-order framework via Luenberger function observers based on complete parametric eigenstructure assignment. By introducing the H2 norm of the transfer function from disturbance to estimation error, sufficient and necessary conditions for disturbance decoupling in matrix second-order linear systems are established and are arranged into constraints on the design parameters via Luenberger function observers in terms of the closed-loop eigenvalues and the group of design parameters provided by the eigenstructure assignment approach. Therefore, the disturbance decoupling problem is converted into an eigenstructure assignment problem with extra parameter constraints. A simple example is investigated to show the effect and simplicity of the approach.

Three-axis coupled flight control law design forflying wing aircraft using eigenstructure assignment method

Due to elimination of horizontal and vertical tails,flying wing aircraft has poor longitudinal and directional dynamic characteristics.In addition,flying wing aircraft uses drag rudders for yaw control,which tends to generate strong three-axis control coupling.To overcome these problems,a flight control law design method that couples the longitudinal axis with the lateraldirectional axes is proposed.First,the three-axis coupled control augmentation structure is specified.In the structure,a‘‘soft/hard"cross-connection method is developed for three-axis dynamic decoupling and longitudinal control response decoupling from the drag rudders;maneuvering turn angular rate estimation and subtraction are used in the yaw axis to improve the directional damping.Besides,feedforward control is adopted to improve the maneuverability and control decoupling performance.Then,detailed design methods for feedback and feedforward control parameters are established using eigenstructure assignment and model following technique.Finally,the proposed design method is evaluated and compared with conventional method by numeric simulations.The influences of control derivatives variation of drag rudders on the method are also analyzed.It is demonstrated that the method can effectively improve the dynamic characteristics of flying wing aircraft,especially the directional damping characteristics,and decouple the longitudinal responses from the drag rudders.

EIGENSTRUCTURE ASSIGNMENT VIA DYNAMICOUTPUT FEEDBACK

In this papers the problem of eigenstructure assignment via dynamic output feedback is studied. First, the necessary and sufficient assignability conditions via dynamic output feedback are given. Then, an approach to determine the structure and the minimal order of the dynamic output feedback based on the assigned eigenstructure is proposed.Finally, the controllability and the observability of the compensated system are analyzed.

EIGENSTRUCTURE ASSIGNMENT PROBLEM

There have been many discussions about the eigenstructure assignment problem of linear multivariable time-invariant system in the past years. In [1], we studied the problem by polynomial matrix theory for state feedback case and gave two ways to find the state feedback matrix K. But there was a presumption that the given eigenstructure is assignable.