Optimal choice of weighting factors in adaptive linear quadratic control

Most of the processes in the industry have nonlinear behavior. Control of such processes with conventional control methods could lead to unstable, suboptimal, etc., results. On the other hand, the adaptive control is a technique widely used for controlling of nonlinear systems. The approach here is based on the recursive identification of the external linear model as a linear representation of the originally nonlinear system. The controller then reacts to the change of the working point or disturbances which could occur by the change of the parameters, structure, etc. The polynomial synthesis together with the linear quadratic(LQ) approach is employed here for the controller synthesis. These techniques satisfy basic control requirements such as the stability, the reference signal tracking and the disturbance attenuation. Resulted controller could be tuned with the choice of weighting factors in LQ approach. This work investigates the effect of these factors on control results. Proposed methods are tested on the mathematical model of the isothermal continuous stirred-tank reactor and simulated results are also verified on the real model of the continuous stirred tank reactor.     

Robust output feedback stabilization of a class of time-varying non-linear systems

This paper deals with the problem of robust output feedback stabilization of a class of time-varying non-linear systems. This class of systems involves two kinds of time-varying uncertainties: those norm-bounded and those bounded by a smooth non-linear function of the output. Under the assumption that the zero dynamics of the system are uniformly asymptotically stable and some additional mild conditions, we show via a Lyapunov function approach that the uncertain system can be robustly stabilized by a time-varying non-linear output feedback controller. The order of this controller turns out to be one less than the relative degree of the uncertain system. A systematic design procedure is given for constructing the controller. Illustrative examples are given. Note that the results generalize several previous results on robust output feedback stabilization.     

基于H2与H∞的\"动中通\"伺服系统控制器设计

本文以\"动中通\"伺服系统为对象, 研究了一种基于H_2和H_{/infty}指标的控制器设计方案. 在反馈控制器方面, 将满足LQ最优准则的扩展状态反馈与状态观测设计整合成一个H_2设计问题, 给出理论推导与设计方法; 在前馈控制器方面, 将扰动抑制H_{/infty}指标设计转换为模型匹配设计, 并给出有效求解方法. 在控制器参数整定过程中, 考虑主谐振模态、不确定性等对系统的∞影响, 给出了一种兼顾动态性能和鲁棒稳定性的整定方法. 该设计方案从反馈到前馈均着重考虑扰动抑制能力, 并且在实际系统上取得了较好的效果, 对扰动抑制能力要求较高的控制器设计有一定指导作用.     

复合钎焊铝箔LQ3-1的成品包覆率与原始包覆率的关系

结合工厂实际生产,研究了复合钎焊箔ＬＱ３－１的原始包覆率δ与成品包覆率δｉ的关系,得出δｉ＝０．９４δ。探讨了包覆层厚度不均匀性产生的原因以及不均匀性的危害性。     

简化测量通道的优化励磁控制

该文将常规最优励磁控制方式与PID励磁控制和PSS的特点相结合，提出了使用系统部分可测量及其微分量以构成一组状态反馈量的优化励磁控制的设计方法，简化了控制器的测量通道。文中建立了该控制系统的动态方程，计算了输电系统在该控制方式下的静态稳定性、暂态稳定性和动态特性，并与对应的常规最优励磁控制方式进行了比较。结果表明，所提出的简化测量通道优化励磁控制方式较常规最优励磁控制方式的性能更为优越，并由于简化了测量通道，实现起来更加容易。     

具有指定极点的最优控制系统之参数化设计

本文提出了一种以LQ逆问题为基础的最优控制系统之参数化设计方法。推导出加权矩阵与开环、最优闭环特征多项式系数之间的解析关系式。只要给定一组期望的闭环极点,即可确定与之对应的加权矩阵和最优反馈增益矩阵,而不必求解复杂的代数Riccati方程。     

Solution to a class of stochastic LQ problems with bounded control

A new approach for finding an exact analytical solution to the modified Hamilton-Jacobi-Bellman equation is proposed. Together with the recently developed hybrid solution method, the proposed strategy allows to find a solution to a whole class of stochastic optimal control problems with bounded in magnitude control force.     

Employing the algebraic Riccati equation for a parametrization of the solutions of the finite-horizon LQ problem: the discrete-time case

In this paper, a new methodology is developed for the closed-form solution of a generalized version of the finite-horizon linear-quadratic regulator problem for LTI discrete-time systems. The problem considered herein encompasses the classical version of the LQ problem with assigned initial state and weighted terminal state, as well as the so-called fixed-end point version, in which both the initial and the terminal states are sharply assigned. The present approach is based on a parametrization of all the solutions of the extended symplectic system. In this way, closed-form expressions for the optimal state trajectory and control law may be determined in terms of the boundary conditions. By taking advantage of standard software routines for the solution of the algebraic Riccati and Stein equations, our results lead to a simple and computationally attractive approach for the solution of the considered optimal control problem without the need of iterating the Riccati difference equation.     

多变量离散时间系统的自适应LQ控制

考虑了多变量离散系统的自适应ＬＱ（线性二次）控制问题,利用ＬＳ（最小二乘）算法和ＷＬＳ（加权最小二乘）算法的自收敛性和随机正则化的思想「１」,证明了修改的估计模型是几乎处处自收敛的、一致可控和一致可观的,基于上面的估计,提出了两种自适应ＬＱ控制律,证明了闭环系统是稳定的和最优的。