一类带随机跳跃的完全耦合的线性二次随机控制问题

研究一类带随机跳跃的完全耦合的线性二次随机控制问题. 得到了最优控制的显式解, 并可以证明最优控制是唯一的. 引入了一类推广的黎卡提方程并讨论了其可解性. 利用这一类推广的黎卡提方程的解, 得到了上述带随机跳跃的最优控制问题的线性状态反馈调节器.     

基于I&I与Hamiltonian理论的机器人速度观测器设计

近期, Astolfi和Stamnes等对一类机械系统设计了速度观测器. 采用了分步设计Lyapunov 函数的方法, 这导致观测误差系统结构复杂、 证明繁琐. 而且设计的偏微分方程(Partial differential equation, PDE) 不合理, 导致计算量大、不易求解. 本文在Astolfi和Stamnes等的基础上, 对一类机械(机器人) 系统设计了速度观测器. 通过对观测误差系统的Hamiltonian 实现, 克服了Astolfi和Stamnes等方法中的上述缺点. 并设计了一类偏微分方程, 避免了繁琐计算. 最后, 将所设计的速度观测器应用到一类关节机器人中, 仿真结果验证了设计方法的有效性.     

滑模控制一类非线性分布式时滞系统

针对一类状态不可测的非线性不确定分布式时滞系统, 给出了系统滑动模态鲁棒渐近稳定的充分条件. 设计了一类滑模观测器, 同时采用线性矩阵不等式的处理方法给出了该观测器存在的充分条件. 再应用滑模控制的趋近率方法和基于观测器所得到的估计状态, 综合了一类滑模控制器. 该控制器同时保证了估计状态下的滑模面和估计误差状态下的滑模面的渐近可达性.     

一类非线性微分-代数系统的L2-增益分析及状态反馈H∞控制

分析了一类非线性微分-代数系统的L2-增益,并讨论了一类状态反馈H∞控制问题.在一定条件下给出了控制器的设计,并保证了闭环指数为1且零解渐近稳定.     

一类定量微分对策理论中最优策略的算法及其收敛性

本文利用不动点原理讨论了一类定量微分对策理论中最优策略的计算方法问题.首先构 造出了一种迭代方法,然后利用不动点原理分析了该迭代法的收敛性.本文给出的方法还可 用于一类Nash微分对策的Nash策略的分散计算方法.     

基于输入输出线性化方法的一类多输入多输出非线性系统的观测器设计

研究一类多输入多输出仿射非线性系统的状态观测器设计问题. 基于输入输出线性化方法提出了一类多输入多输出仿射非线性系统的状态观测器设计的新方法, 并给出保证状态估计误差渐近趋于零的充分条件. 算例表明了所得结果的有效性.     

一类Hash函数的注记

研究了一类Hash函数的Hash冲突问题.利用数论中关于整除的相关定理,完整地给出了一类Hash函数已经解决了Hash冲突的理论证明,为该函数的应用提供了可靠的理论基础.算例演示结果表明了该类Hash函数在寻找频繁项目集时的方便性和有效性.     

实际输入饱和的一类非完整运动学系统的镇定

对一类非完整移动机器人提出了实际输入饱和下镇定控制器的设计方案.这种设计不是基于链式系统而是基于原始系统的.控制器的设计使用了滑模控制和多步控制策略,并用Lyapunov的思想证明了闭环系统的收敛性.最后,用设计的控制器对一类机器人进行了仿真,验证了方法的有效性.     

一类非线性系统的故障诊断

讨论了一类非线性系统执行器故障的诊断问题.首先应用已有的状态和输出变换, 将一类非线性系统转化为两个低维子系统,然后利用滑模观测器设计理论和等价控制的概念 重构执行器故障.     

不确定时滞线性系统的鲁棒容错控制研究

研究了线性时滞不确定系统的一类鲁棒容错控制问题.基于Lyapunov方法,证明了当一类不确定系统采用一种带时滞的状态反馈控制律时,该系统对于传感器和执行器故障具有完整性.仿真实例说明了该方法的有效性.     

模型跟踪广义预测鲁棒自适应控制器

本文采用滤波CARMA模型,基于内模原理,提出了一种新的广义预测鲁棒自适应控制器,并分析了闭环系统性能,在新的控制器中,引入适当的前馈作用,使得跟踪和调节问题解耦,利用部分状态跟踪、模型参考以及极点配置方法解决跟踪问题,利用多步预测滚动优化方法解决调节问题;适当选择滤波器可以保证对平稳随机扰动有满意的响应,减少可调参数对闭环系统响应的影响,增强系统对未建模动态的鲁棒性,仿真结果表明:该控制器对确定性和非平稳随机扰动具有不变性,对系统时延和阶次变化具有鲁棒性,适用于非最小相位和开环不稳定系统。     

A three-loop model-following control structure: theory and implementation

This article presents a novel three-loop control system, which supplements control structures known from the literature as model following control (MFC). The major advantage of the proposed system is its high robustness to process parameter variations; it is much higher than that offered by single-loop or two-loop control systems. Features of the new structure are revealed by a theoretical analysis that has been carried out from the viewpoint of requirements for a force/pose controller of a Stäubli RX60 manipulator. This article shows how the proposed control structure responds to such strong process parameter variations and makes a comparison to results yielded by single-loop control structures.     

鲁棒低增益变结构模型参考自适应控制

就对象含未建模动态且其建模部分相对阶大于1时的变结构模型参考自适应控制 (VS-MRAC)系统,提出了一种鲁棒低增益变结构控制方案,特点是系统变结构律在低增益状态 下仍可保证所有辅助误差均在有限时间内收敛到零,从而提高了系统跟踪精度.此外,还研究了 平均值滤波器对系统稳定性的影响.     

Optimal control during feedback failure

The problem of controlling a perturbed open loop system so as to keep its performance errors within bounds is considered. The objective is to maximise the time during which performance errors remain below a prescribed ceiling, while the controlled system's parameters are within a specified neighbourhood of their nominal values. It is shown that there is an optimal open loop controller that achieves this objective. Conditions under which the optimal controller generates a bang-bang control input signal are characterised. In general, it is shown that the performance of the optimal controller can always be approximated by a bang-bang signal.     

Generalized terminal state constraint for model predictive control

A terminal state equality constraint for Model Predictive Control (MPC) laws is investigated, where the terminal state/input pair is not fixed a priori but it is a free variable in the optimization. The approach, named “generalized” terminal state constraint, can be used for both tracking MPC (i.e. when the objective is to track a given steady state) and economic MPC (i.e. when the objective is to minimize a cost function which does not necessarily attains its minimum at a steady state). It is shown that the proposed technique provides, in general, a larger feasibility set with respect to the existing approaches, given the same prediction horizon. Moreover, a new receding horizon strategy is introduced, exploiting the generalized terminal state constraint. Under mild assumptions, the new strategy is guaranteed to converge in finite time, with arbitrarily good accuracy, to an MPC law with an optimally-chosen terminal state constraint, while still enjoying a larger feasibility set. The features of the new technique are illustrated by an inverted pendulum example in both the tracking and the economic contexts.     

Stabilization of robot motion and contact force interaction for third-order motor dynamics

An approach to the synthesis of control laws stabilizing motion and force in contact tasks, based on the exponential stability of the closed-loop control system, is described. When using the synthesized control laws, simultaneous stabilization of both motion and force is achieved with a preset quality of the transient responses. The task is solved in a most general form, taking into account the constraints on robot control, its position and the force of interaction of the robot and the environment, and the external perturbations and inaccuracies of the measuring sensors, when the environment dynamics is being described by nonlinear second-order differential equation, and the robot dynamics includes the third-order equations of the robot actuators dynamics.     

高频增益符号未知时的变结构模型参考自适应控制:任意相对阶的控制律设计

讨论被控对象相对阶大于1且高频增益符号未知时的变结构模型参考自适应控制问题,从而将相对阶为1时的结果推广到任意相对阶.首先对关键信号构造监控函数,并在此基础上提出了一种控制信号切换律.进而证明,当被控对象相对阶大于1、高频增益符号未知时,在监控函数的监测下,相关控制信号经至多有限次切换后将停止切换,跟踪误差将收敛到一个残集内,且该残集可通过减小某些设计参数而变得任意小.特别,本文证明,与相对阶为1时相同,当对象相对阶大于1时,若系统的某些初始条件为零,则至多只需要一次切换.     

Multivariable PID control by decoupling

This paper presents a new methodology to design multivariable proportional-integral-derivative (PID) controllers based on decoupling control. The method is presented for general n × n processes. In the design procedure, an ideal decoupling control with integral action is designed to minimise interactions. It depends on the desired open-loop processes that are specified according to realisability conditions and desired closed-loop performance specifications. These realisability conditions are stated and three common cases to define the open-loop processes are studied and proposed. Then, controller elements are approximated to PID structure. From a practical point of view, the wind-up problem is also considered and a new anti-wind-up scheme for multivariable PID controller is proposed. Comparisons with other works demonstrate the effectiveness of the methodology through the use of several simulation examples and an experimental lab process.     

Feedforward output-feedback control for continuous exothermic reactors with isotonic kinetics

The robust feedforward (FF) output-feedback (OF) control problem of (possibly open-loop unstable) continuous exothermic jacketed reactors with isotonic kinetics with respect to reactant concentration is considered. The volume, temperature, and concentration must be regulated by manipulating the feed, exit and coolant flowrates on the basis of volume and temperature measurements. The problem is addressed as an interlaced controller-observer design within a constructive control framework. The result is a quasi linear-decentralized (qLD) FF-OF dynamic controller which: (i) recovers (up to observer convergence) the behavior of a robust nonlinear FF-SF controller, (ii) has closed-loop stability conditions coupled with conventional-like tuning guidelines, and (iii) constitutes an add-on to the PI control scheme commonly employed in industrial reactors. The approach is tested with an open-loop unstable reactor example through simulations.     

Least-restrictive robust periodic model predictive control applied to room temperature regulation

State-feedback model predictive control (MPC) of constrained discrete-time periodic affine systems is considered. The periodic systems’ states and inputs are subject to periodically time-dependent, hard, polyhedral constraints. Disturbances are additive, bounded and subject to periodically time-dependent bounds. The objective is to design MPC laws that robustly enforce constraint satisfaction in a manner that is least-restrictive, i.e., have the largest possible domain. The proposed design method is demonstrated on a building climate control example. The proposed method is directly applicable to time-invariant MPC.