基于信息融合估计的离散系统最优跟踪控制

针对期望输出和未来干扰无预见的离散线性系统最优跟踪问题,提出一种基于信息融合最优估计的控制方法.若将当前给定值和可测干扰值分别看作系统未来输出和干扰的预见值,则跟踪控制问题可转化为具有无限预见步数的预见控制问题,并将无限预见信息融合成一步等效预见信息,进而获得近似最优融合控制律.对线性直流电机系统和宏观经济系统的仿真结果均验证了该控制器在提高系统跟踪精度和抑制干扰等方面的有效性.

     

基于误差系统的信息融合最优预见跟踪控制

针对期望轨迹和干扰可预见的最优跟踪问题, 提出了一种基于误差系统的信息融合最优控制方法. 将线性伺服系统转化为误差系统; 利用信息融合估计方法, 通过融合期望轨迹、干扰输入、误差系统状态等信息, 获得误差系统协状态以及控制增量的最优估计. 构建了由积分项、状态反馈控制项和预见前馈补偿项组成的最优预见控制系统. 线性直流电机系统的控制仿真结果表明, 信息融合最优预见控制下的位置跟踪精度比传统最优预见控制下的要高.     

基于信息融合估计的离散线性系统预见控制

针对期望轨迹和干扰可预见的离散线性最优跟踪问题, 提出了一种基于信息融合估计的预见控制方法. 推导了最优预见控制律的融合估计过程和最优预见性能指标. 建立了包含状态反馈项、目标和干扰前馈补偿项的信息融合预见控制系统, 并分析了其渐近特性和稳态跟踪误差问题. 直流电机系统的仿真结果表明, 信息融合预见控制下的系统跟踪性能随着预见步数的增加而迅速提高并趋于稳定, 且综合考虑跟踪误差与能量消耗时要优于传统预见控制.     

基于信息融合的离散系统最优预见重复控制

针对现有控制器中预见补偿器和重复控制器相对独立作用的最优跟踪问题,提出从信息融合的角度构造线性离散系统的最优预见重复控制器的设计方法.首先,在离散系统中引入L阶差分算子,将预见重复控制设计问题转化为调节稳定性问题;然后,使用协状态和信息量的概念获得控制软约束信息来描述最优融合的过程,得到控制增量信息和增广误差系统协状态的最优估计滤波;最后,将有关预见重复控制器控制律所有信息融合,得到由状态反馈、重复控制和预见补偿构成的最优预见重复控制器.数字仿真结果表明,与独立的最优预见重复控制器相比,基于信息融合的最优预见重复控制器在更少的周期内达到稳定,且在有限的步数下,更能有效利用系统的未来有效信息,从而大幅提高跟踪精度.     

时变参数不确定离散时间系统的预见控制

基于具有参数依赖的Lyapunov函数方法及LMI技巧,研究一类时变参数不确定离散时间系统的预见跟踪控制问题.首先,采用预见控制理论中误差系统的方法,引入两个与状态变量和输入变量有关的辅助信号,构造出包含未来目标值信号和干扰信号的信息的扩大误差系统,将原系统的预见跟踪问题转化为扩大误差系统的镇定问题;然后,针对扩大误差系统,考虑输出反馈时,通过改造输出方程融合可预见信号的未来信息.研究表明,通过求解LMI,即可确定静态输出反馈预见控制器增益矩阵的参数矩阵.数值仿真表明了结果的有效性.     

非线性离散系统的信息融合最优预见控制

将信息融合思想引入非线性离散系统的预见控制,提出了信息融合最优预见控制,将对控制系统的所有性能要求和系统动力学转化为可融合信息;然后从信息融合估计的角度,使原问题转化为求控制量的"融合估计"问题.推导了基于卡尔曼滤波器的最优预见控制算法,讨论了预见步数的选取问题,并通过对机械手的转移控制仿真研究说明了信息融合最优预见控制算法的有效性.     

时滞多变量过程信息融合解耦控制

针对工业过程中时滞多变量线性系统各回路问存在的强耦合问题,提出一种基于信息融合估计的解耦控制方法.通过融合主通道和相应耦合通道的期望输出软约束信息和控制能量软约束信息,估计出二次性能指标下的最优自适应解耦控制律.进一步对无限预见期望输出信息进行一步预见等效处理,获得计算更简单的近似最优解耦控制律.实例仿真结果表明了该解耦控制器具有计算量小、解耦程度可调以及控制品质好等优点.     

人机系统最优预见补偿跟踪控制研究

1　引　言预见控制理论是最优跟踪控制问题的新的出发点 ,其有效性在机器人、数字机床等路径控制中得到证实[1 ] .本文将预见控制应用到人机控制系统 .人具有“先前看”的能力 ,尤其是训练有素的驾驶员具有积极利用未来目标信号提高跟踪品质的预见操纵行为 .以驾驶员 -飞机目标跟踪控制系统为例 ,在人的最优控制模型( OCM)基础上 ,通过目标信息的预见显示 ,建立人的最优预见控制模型 ( OPCM) .应用数字最优预见控制理论 [2 ] ,对信号发生器产生的目标信号进行预见跟踪控制 .2　驾驶员最优预见控制模型 ( OPCM)2 .1　数字最优预见控制最…     

一般型最优有限预见控制及其在地形跟踪中的应用研究

提出一种新的预见控制方法——一般型最优有限预见控制方法,并将其应用于巡航导弹地形跟踪控制系统的设计.将参考信号和干扰信号考虑成更一般的形式,在其自相关函数值已知的条件下,得到了一般型有限预见伺服系统设计问题的最优解.通过仿真证实,采用该方法设计地形跟踪系统,可以明显地改善巡航导弹的地形跟踪性能.     

参数不确定离散时间系统的有限时间输出反馈预见控制器设计

基于参数依赖的Lyapunov函数方法及LMI技巧,研究一类参数不确定离散时间系统的有限时间输出反馈预见控制问题.首先,采用预见控制理论中误差系统的方法,引入差分算子和离散提升技术,构造出包含未来目标值信号和干扰信号的信息的扩大误差系统,将有限时间预见控制问题转化为扩大误差系统的有限时间稳定性问题;然后,针对所推导出的扩大误差系统设计输出反馈预见控制器,通过改造输出方程以充分利用可预见信号的未来信息,并通过LMI技巧给出闭环系统有限时间稳定的条件及预见控制器的设计方法.研究结果表明,通过求解LMI,可确定静态输出反馈预见控制器增益矩阵.数值仿真表明了所提出方法的有效性.     

On the finite preview problem in manual control

An optimal control formulation of the preview control problem is presented and optimal tracking results reviewed. An information weighting pattern for previewed input information is developed and used to obtain a control realizable with finite preview which closely approximates the optimal control which requires infinite preview, The information weighting pattern is also used to establish bounds on the preview requirements for the class of systems considered.     

Output feedback preview tracking control for discrete-time polytopic time-varying systems

This paper focuses on the problem of static output feedback preview tracking control for discrete-time systems with time-varying parameters subject to a previewable reference signal. We develop a design method of a robust controller with integral and preview actions achieving robust tracking performance. First, an augmented error system including future information on reference signal is constructed by introducing two new related auxiliary variables to the original system state and input. This leads to a tracking problem being transformed into a regulator problem. Then, a previewable reference signal is fully utilised through reformulation of the output equation for the augmented error system while considering a static output feedback. Meanwhile, the static output preview control gains are solved explicitly by the proposed conditions. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.     

Inversion-based optimal output tracking–transition switching with preview for nonminimum-phase linear systems

In this article, the problem of nonperiodic tracking–transition switching with preview is considered. Such a control problem exists in applications including nanoscale material property mapping, robot manipulation, and probe-based nanofabrication, where the output needs to track the desired trajectory during the tracking sections, and rapidly transit to another point during the transition sections with no post-transition oscillations. Due to the coupling between the control of the tracking sections and that of the transition ones, and the potential mismatch of the boundary system state at the tracking–transition switching instants, these control objectives become challenging for nonminimum-phase systems. In the proposed approach, the optimal desired output trajectory for the transition sections is designed through a direct minimization of the output energy, and the needed control input that maintains the smoothness of both the output and the system state across all tracking–transition switching is obtained through a preview-based stable-inversion approach. The needed preview time is quantified by the characteristics of the system dynamics, and can be minimized via the recently developed optimal preview-based inversion technique. The proposed approach is illustrated through a nanomanipulation example in simulation.     

Optimal preview control for a linear continuous-time stochastic control system in finite-time horizon

This paper discusses the design of the optimal preview controller for a linear continuous-time stochastic control system in finite-time horizon, using the method of augmented error system. First, an assistant system is introduced for state shifting. Then, in order to overcome the difficulty of the state equation of the stochastic control system being unable to be differentiated because of Brownian motion, the integrator is introduced. Thus, the augmented error system which contains the integrator vector, control input, reference signal, error vector and state of the system is reconstructed. This leads to the tracking problem of the optimal preview control of the linear stochastic control system being transformed into the optimal output tracking problem of the augmented error system. With the method of dynamic programming in the theory of stochastic control, the optimal controller with previewable signals of the augmented error system being equal to the controller of the original system is obtained. Finally, numerical simulations show the effectiveness of the controller.     

Preview control for a class of linear stochastic systems with multiplicative noise

ABSTRACT

In this paper, the preview control problem for a class of linear continuous time stochastic systems with multiplicative noise is studied based on the augmented error system method. First, a deterministic assistant system is introduced, and the original system is translated to the assistant system. Then, the integrator is employed to ensure the output of the closed-loop system tracking the reference signal accurately. Second, the augmented error system, which includes integrator vector, control vector and reference signal, is constructed based on the system after translation. As a result, the tracking problem is transformed into the optimal control problem of the augmented error system, and the optimal control input is obtained by the dynamic programming method. This control input is regarded as the preview controller of the original system. For a linear stochastic system with multiplicative noise, the difficulty being unable to construct an augmented error system by the derivation method is solved in this paper. And, the existence and uniqueness solution of the Riccati equation corresponding to the stochastic augmented error system is discussed. The numerical simulations show that the preview controller designed in this paper is very effective.     

Preview control of polytopic time-varying systems subject to actuator saturation

In this study, a novel method is proposed to track a previewable reference signal in the polytopic time-varying system with input saturation. Firstly, an augmented model containing future information is constructed using a new formal variable. This leads to the tracking control problem of polytopic time-varying system with input saturation is transformed into a stability problem of augmented error system. Next, the state and static output feedback preview controls are introduced, and the corresponding controller gains are produced by the proposed conditions. Two examples are presented to validate the effectiveness of the proposed preview controller.     

Output feedback preview control for polytopic uncertain discrete‐time systems with time‐varying delay

This paper considers the preview tracking control problem of polytopic uncertain discrete‐time systems with a time‐varying delay subject to a previewable reference signal. First, a model transformation is employed and a discrete‐time system with a time‐invariant delay and an external disturbance is obtained. The difference operator method can be extended to derive an augmented error system that includes future information on the reference signal. Then, a previewable reference signal is fully utilized through reformulation of the output equation while considering the output feedback. Based on the small gain theorem, a static output feedback controller with preview actions is designed such that the output can asymptotically track the reference signal. Finally, numerical simulation examples also illustrate the superiority of the desired preview controller for the uncertain system in the paper.