Stationary inventory control policies in supply systems under inflation conditions

This paper considers the feasibility of using the optimal parameters of stationary inventory control policies to design inventory control rules in supply systems operating on a real market. The efficiency of the long-sighted and myopic inventory control policies is compared. Different approaches to design the optimal stationary policies are investigated. A comparative evaluation of these approaches is given and the specifics of their application are discussed. The optimal parameters of the stationary inventory control policies as functions of the market state and, in particular, of the inflation rate are estimated via simulation experiments.     

基于遗传算法的模糊控制器的综合优化设计

该文简要叙述了模糊控制器的优化设计原理,提出了一种采用遗传算法对模糊控制器的量化因子、比例因子、隶属函数的参数和模糊控制规则进行综合优化的设计方法,并采用VisualC++6.0编制了相应的软件,该软件已成功地应用于工程中。此外,该软件也可作为遗传优化和模糊控制器设计的辅助教学软件。     

Stable and optimal fuzzy control of linear systems

A number of stable and optimal fuzzy controllers are developed for linear systems. Based on some classical results in control theory, we design the structure and parameters of fuzzy controllers such that the closed-loop fuzzy control systems are stable, provided that the process under control is linear and satisfies certain conditions. It turns out that if stability is the only requirement, there is much freedom in choosing the fuzzy controller parameters. Therefore, a performance criterion is set to optimalize the parameters. Using the Pontryagin minimum principle, we design an optimal fuzzy controller for linear systems with quadratic cost function. Finally, the optimal fuzzy controller is applied to a ball-and-beam system     

基于鲁棒可靠性的不确定时滞系统最优H∞控制器设计

用区间变量描述控制系统参数的不确定性,提出了不确定时滞系统鲁棒H_∞控制的鲁棒可靠性方法,基于鲁棒可靠性的不确定时滞系统最优状态反馈H_∞控制器设计方法,将系统的最优控制器设计归结为基于线性矩阵不等式(LMI)的优化问题．所设计的控制器可以在满足对所有不确定性鲁棒可靠的前提条件下,具有最优的H_∞鲁棒性能,并能在控制系统的设计中综合考虑控制性能、控制代价和鲁棒可靠性．数值算例说明了所提方法的有效性和可行性．     

PID数字控制器多指标优化模拟设计方法研究

建立PID数字控制器多指标统一优化模拟设计方法;用SIMULINK仿真研究数字PID控制对模拟PID控制的复现能力和PID计算机控制系统的阶跃响应,用MATLAB仿真筛选PID参数的优化组合值;提出并建立了一种新的PID数字控制器多指标优化模拟设计方法,包括:PID初值确定方法、模拟PID优化参数MATLAB筛选方案和软件流程图、模拟PID参数转换数字PID参数的方法、SIMULINK仿真验证设计结果的有效性的方法等;研究表明,该方法可用于1～5ms采样周期的PID数字控制器多指标优化模拟设计,且能独立使用、无需PID经验数据和其它设计/整定方法;提供了4个代表性的实例设计,验证了该方法的有效性。     

Optimal damping of forced oscillations in discrete-time systems

In this paper we consider a linear discrete-time control system affected by an additive sinusoidal disturbance with known frequencies but unknown amplitudes and phases. The problem is to damp this forced oscillation in an optimal fashion. We show that the natural solution from the point of view of optimal control is neither robust with respect to errors in the frequencies, and thus not optimal in practice, nor independent of the unknown amplitudes and phases. The main result of this paper concerns the existence and design of a realizable, robust optimal regulator, which is universal in the sense that it does not depend on the unknown amplitudes and phases and is optimal for all choices of such parameters. The regulator allows for a considerable degree of design freedom to satisfy other design specifications. Finally, it is shown that this regulator is optimal also for a wide class of stochastic control problems     

基于控制参数化的注塑工业过程最优反馈控制方法

本文针对一类典型的注塑工业过程系统, 研究了注塑填充过程中产生的熔体流动速度最优跟踪控制问题, 提出了一种基于控制参数化的计算最优反馈控制器设计方法以实现注塑过程中熔融聚合物流动前沿位移的最优跟 踪控制, 进而达到改善注塑零件性能的高效生产目标. 首先, 面向注塑工艺复杂生产过程建立了动态过程系统数学 模型, 提出了注塑机内部熔融聚合物流动前沿位置的动态最优跟踪控制问题; 其次, 设计了一种多级反馈控制律, 通 过控制参数化方法将控制反馈核进行了参数化表示, 将控制器设计问题转化为一序列最优参数决策问题; 然后, 通 过状态灵敏度方程分析方法, 求解出了目标函数及约束条件关于决策变量参数梯度信息的显式表达式, 并基于所提 供的梯度信息结合序列二次规划算法进行了高效优化迭代求解; 最后, 通过实验仿真验证了本文所提出的最优反 馈控制器设计方法的可行性和有效性.     

Quadratic optimization of motion coordination and control

Algorithms for continuous-time quadratic optimization of motion control are presented. Explicit solutions to the Hamilton-Jacobi equation for optimal control of rigid-body motion are found by solving an algebraic matrix equation. The system stability is investigated according to Lyapunov function theory and it is shown that global asymptotic stability holds. How optimal control and adaptive control may act in concert in the case of unknown or uncertain system parameters is shown. The solution results in natural design parameters in the form of square weighting matrices, as known from linear quadratic optimal control. The proposed optimal control is useful both for motion control, trajectory planning, and motion analysis     

Optimal Compensation by Linear Robust Control for Uncertain Systems

Linear control design of nonlinear discrete-time uncertain systems with (possibly fast) uncertain parameters is considered. The possible uncertainty bound needs to be within a threshold. The threshold in turn is dependent on a design parameter. To achieve the maximum threshold by an optimal choice of the design parameter, a constrained optimization problem is proposed. The optimal compensation of the uncertainty is in general a partial compensation.     

Optimal control of nonlinear systems: a predictive control approach

A new nonlinear predictive control law for a class of multivariable nonlinear systems is presented in this paper. It is shown that the closed-loop dynamics under this nonlinear predictive controller explicitly depend on design parameters (prediction time and control order). The main features of this result are that an explicitly analytical form of the optimal predictive controller is given, on-line optimisation is not required, stability of the closed-loop system is guaranteed, the whole design procedure is transparent to designers and the resultant controller is easy to implement. By establishing the relationship between the design parameters and time-domain transient, it is shown that the design of an optimal generalised predictive controller to achieve desired time-domain specifications for nonlinear systems can be performed by looking up tables. The design procedure is illustrated by designing an autopilot for a missile.     

反馈线性化最优滑模变结构励磁控制

将滑模变结构控制具有对摄动的完全自适应性与反馈线性化理论和最优控制理论结合起来,针对励磁系统,提出了一种基于反馈线性化最优的滑模变结构控制方法,给出了控制器的设计过程,避免了通常设计滑模变结构控制器时参数选取的盲目性,保证系统运行在较佳状态,且按指数趋近律设计的滑模变结构控制器不易产生抖动。仿真结果表明,这种方法能够充分发挥滑模变结构控制的鲁棒性优点,对电力系统具有较好的稳定作用。     

基于ALQ方法的飞行姿态控制系统设计

研究飞机稳定性控制优化问题,由于飞行高度和环境的变化,系统控制器性能不能满足系统的要求。为了克服常规最优控制中模型参数和外界干扰对控制器性能的影响,提出了一种应用自适应线性二次型(Adaptive Linear Quadratic,ALQ)方法的飞机纵向控制律设计技术,首先通过自适应机制实时辨识控制系统参数,辨识的参数应用于最优线性二次型的建模设计控制中,通过在线自适应的调整控制律参数,达到了理想的控制效果,仿真验证表明在存在外部扰动和建模误差时,改进算法比传统的LQ方法具有更好的鲁棒性和稳定性,可为优化设计提供参考。     

一种简易的多回路控制系统优化设计方法研究

给出了一种简易的控制系统设计方法——标准特征多项式设计方法,多回路控制系统采用这种方法将使控制系统设计的工作量大为简化。在此基础上,采用NCD工具箱,用标准特征多项式方法得到的参数值作为NCD（nonlinear control design）模块的初始化值对控制系统的参数进一步进行优化,并与任意选择的6组参数值作为NCD模块初始化值而得到的优化效果进行了比较。还对飞行控制的多回路控制系统的鲁棒性进行了研究。结果证明,用标准特征多项式和NCD优化方法,设计方便,并且系统有很好的鲁棒性。     

An iterative approach to the optimal co-design of linear control systems

This paper investigates the optimal co-design of both physical plants and control policies for a class of continuous-time linear control systems. The optimal co-design of a specific linear control system is commonly formulated as a nonlinear non-convex optimisation problem (NNOP), and solved by using iterative techniques, where the plant parameters and the control policy are updated iteratively and alternately. This paper proposes a novel iterative approach to solve the NNOP, where the plant parameters are updated by solving a standard semi-definite programming problem, with non-convexity no longer involved. The proposed system design is generally less conservative in terms of the system performance compared to the conventional system-equivalence-based design, albeit the range of applicability is slightly reduced. A practical optimisation algorithm is proposed to compute a sub-optimal solution ensuring the system stability, and the convergence of the algorithm is established. The effectiveness of the proposed algorithm is illustrated by its application to the optimal co-design of a physical load positioning system.     

Robust maximum principle for multi-model LQ-problem

This paper presents the version of the robust maximum principle in the context of multi-model control formulated as the minimax Bolza problem. The cost function contains a terminal term as well as an integral one. A fixed horizon and terminal set are considered. The necessary conditions of the optimality are derived for the class of uncertain systems given by an ordinary differential equation with parameters from a given finite set. This problem consists in the control design providing a good behaviour for a given class of multi-model system. It is shown that the design of the minimax optimal controller is reduced to a finite-dimensional optimization problem given at the corresponding simplex set containing the weight parameters to be found. The robust optimal control may be interpreted as a mixture (with the optimal weights) of the controls which are optimal for each fixed parameter value. The proof is based on the recent results obtained for minimax Mayer problem (Boltyanski and Poznyak 1999a). The minimax linear quadratic control problem is considered in detail and the illustrative examples dealing with finite as well as infinite horizons conclude this paper.     

线性采样系统二次型最优控制器的MATLAB实现

当被控对象具有较大滞后特性时通常运用采样控制方式进行控制，而线性二次型最优控制又以其综合性、灵活性和实用性受到重视和发展。MATLAB软件的Simulink模块可以快速方便地对控制系统进行建模和仿真。文中通过实例给出了完整的线性采样系统二次型最优控制器的设计过程，简述了连续系统离散化以及线性二次型最优控制器的基本原理、设计方法，并提出了一个Simulink环境下的仿真模型，通过得到的闭环系统的阶跃响应分析了参数变化对最优控制系统的影响。整个设计表明了运用Smulink对采样系统进行设计和分析是完全可行的。     

燃气机热泵流量控制策略研究

针对燃气机热泵控制系统适应环境温度和系统负荷的变化,需要合适的控制策略改变电子膨胀阀的开度来调节制冷剂的流量。通过对电子膨胀阀的工作原理和控制策略的分析,利用MATLAB比较不同控制策略的控制效果得到最优的控制器参数从而确定控制系统的最优传递函数;利用西门子S7-200给出温度、过热度检测和热物理参数实时监控的PLC监控设计方案和通过触摸屏显示温度、压力、过热度等相关数据及历史变化曲线,实现燃气机热泵控制系统中蒸发器过热度的自动检测、PID控制、监控和存储;通过仿真对比了几种策略控制效果,并通过实际试验数据的采集和图像显示,表明了基于遗传算法最优PID参数整定方法确定的控制器参数的控制效果最优。     

变速控制力矩陀螺的飞轮参数与构型倾侧角优化设计

为了在保证姿控和储能功能条件下设计出变速控制力矩陀螺(VSCMG) 簇参数, 在已有动量包络分析的基础之上, 给出了考虑飞轮调速范围存在上限和下限约束条件下的动量包络空间和储能特性分析, 提出了VSCMG簇的飞轮参数和构型倾侧角的优化设计方法. 将VSCMG簇的参数优化设计问题描述为非线性、多约束、强耦合的 单目标静态优化问题, 采用序列二次规划算法求解优化问题, 获得优化的单元参数, 并计算出动量包络面, 验证了所提出优化方法的有效性.

     

Higher Order Sliding Mode Controllers With Optimal Reaching

Higher order sliding mode (HOSM) control design is considered for systems with a known permanent relative degree. In this paper, we introduce the robust Fuller's problem that is a robust generalization of the Fuller's problem, a standard optimal control problem for a chain of integrators with bounded control. By solving the robust Fuller's problem it is possible to obtain feedback laws that are HOSM algorithms of generic order and, in addition, provide optimal finite-time reaching of the sliding manifold. A common difficulty in the use of existing HOSM algorithms is the tuning of design parameters: our methodology proves useful for the tuning of HOSM controller parameters in order to assure desired performances and prevent instabilities. The convergence and stability properties of the proposed family of controllers are theoretically analyzed. Simulation evidence demonstrates their effectiveness.     

A Novel Robust Constraint Force Servo Control for Under‐actuated Manipulator Systems: Fuzzy and Optimal

We consider the control design for under‐actuated manipulator systems. The task is to drive the system to be close to a prescribed constraint. The system contains uncertainty. It is bounded where the bounding information is prescribed by a fuzzy set (e.g., the bound is close to 1). The initial condition is also prescribed by a fuzzy set. A class of robust control is proposed, which guarantees a deterministic performance. On top of that, the choice of a control design parameter is cast into a fuzzy‐theoretic setting. A performance index, consisting of accumulated fuzzy‐based system performance and control cost, is proposed. The optimal control design parameters, which minimize the performance index, can be obtained by solving two algebraic quartic (fourth‐order) equations. As a result, the control design problem, which addresses both fuzzy and optimal characteristics, is completely solved.