Receding horizon H∞ control for constrained time-delay systems

A receding horizon H∞ control algorithm is presented for linear discrete time-delay system in the presence of constrained input and disturbances. Disturbance attenuation level is optimized at each time instant, and the receding optimization problem includes several linear matrix inequality constraints. When the convex hull is applied to denote the saturating input, the algorithm has better performance. The numerical example can verify this result.     

Constrained predictive control of nonlinear stochastic systems

The receding horizon control (RHC) problem is considered for nonlinear Markov jump systems which can be represented by Takagi-Sugeno fuzzy models subject to constraints both on control inputs and on observe outputs. In the given receding horizon, for each mode sequence of the T-S modeled nonlinear system with Markov jump parameter, the cost function is optimized by constraints on state trajectories, so that the optimization control input sequences are obtained in order to make the state into a terminal invariant set. Out of the receding horizon, the stability is guaranteed by searching a state feedback control law. Based on such stability analysis, a linear matrix inequality approach for designing receding horizon predictive controller for nonlinear systems subject to constraints both on the inputs and on the outputs is developed. The simulation shows the validity of this method.         

Robust predictive control of polytopic uncertain systems with both state and input delays

A robust model predictive control algorithm for discrete linear systems with both state and input delays subjected to constrained input control is presented,where the polytopic uncertainties exist in both state matrices and input matrices.The algorithm optimizes an upper bound with respect to a state feedback control law.The feedback control law is presented based on the construction of a parameter-dependent Lyapunov function.The above optimization problem can be formulated as a LMI-based optimization.The feasibility of the optimization problem guarantees that the algorithm is robustly stable.The simulation results verify the effectiveness of the proposed algorithm.     

Markov跳变系统的单步约束预测控制

针对离散Markov跳变系统,研究带输出约束的单步预测控制问题。首先设计基于模态的单步预测控制器,驱动系统状态到达相应的终端不变集内,以此保证约束预测控制系统的稳定性,接着进一步讨论了系统存在峰值有界噪声输入情形。其中终端不变集是通过在预测时域外寻求一个虚拟的带约束的状态反馈控制器以保证系统的随机稳定性来获得,为计算方便,控制器的优化问题转化为SDP问题,并得到以LMI描述的优化问题。最后对Markov跳变系统描述的经济学动力系统的仿真结果说明了本控制器设计方法能够在峰值有界噪声输入下保证系统的稳定性,并且使控制变量满足给定的约束条件。     

基于神经网络的实时滚动追逃博弈导弹制导律

针对导弹实时滚动追逃博弈对抗双方制导律求解问题,设置了若干组对抗双方初始状态,采用分解正交配置法分别离线求解双边开环最优控制,并组成神经网络训练数据集。基于数据集将所有短周期初始和终止时刻对抗双方的状态和控制变量作为输入和输出,采用反向传播(back propagation,BP)算法训练神经网络。然后分别在简单、复杂和不确定环境下,基于滚动时域优化框架使用BP神经网络估计短优化周期内双边开环最优控制,反馈更新对抗双方状态并重复上述过程,进而实时滚动求解导弹追逃博弈双边闭环最优控制。最后将上述方法和直接法得到的优化结果进行比较,捕捉点位置和博弈时间最大误差分别为0.554%和0.097%,两种方法的优化结果吻合较好。同时本文方法计算耗时明显下降,有效提高了导弹滚动追逃博弈制导律求解的实时性。     

Fault-tolerant control of linear uncertain systems using H∞ robust predictive control

The robust fault-tolerant control problem of linear uncertain systems is studied. It is shown that a solution for this problem can be obtained from a H∞ robust predictive controller (RMPC) by the method of linear matrix inequality (LMI). This approach has the advantages of both H∞ control and MPC: the robustness and ability to handle constraints explicitly. The robust closed-loop stability of the linear uncertain system with input and output constraints is proven under an actuator and sensor faults condition. Finally, satisfactory results of simulation experiments verify the validity of this algorithm.     

Constrained predictive control based on T-S fuzzy model for nonlinear systems

A constrained generalized predictive control （GPC） algorithm based on the T-S fuzzy model is presented for the nonlinear system. First, a Takagi-Sugeno （T-S） fuzzy model based on the fuzzy cluster algorithm and the orthogonalleast square method is constructed to approach the nonlinear system. Since its consequence is linear, it can divide the nonlinear system into a number of linear or nearly linear subsystems. For this T-S fuzzy model, a GPC algorithm with input constraints is presented. This strategy takes into account all the constraints of the control signal and its increment, and does not require the calculation of the Diophantine equations. So it needs only a small computer memory and the computational speed is high. The simulation results show a good performance for the nonlinear systems.     

Fault-tolerant control of linear uncertain systems using H∞ robust predictive control

The robust fault-tolerant control problem of linear uncertain systems is studied. It is shown that a solution for this problem can be obtained from a H∞ robust predictive controller （RMPC） by the method of linear matrix inequality （LMI）. This approach has the advantages of both H∞ control and MPC： the robustness and ability to handle constraints explicitly. The robust closed-loop stability of the linear uncertain system with input and output constraints is proven under an actuator and sensor faults condition. Finally, satisfactory results of simulation experiments verify the validity of this algorithm.     

基于局部信息的滚动优化与机器人路径规划

文献[4]中提出了模糊优化的方法并应用于基于滚动机理的机器人路径规划。但在遇到某些特殊情况时会出现振荡问题而导致机器人不能到达终点。本文中提出了基于系统局部信息的滚动模糊优化算法，在模糊优化过程中引入了历史信息，通过增加新的和历史信息相关的约束，保证了所选择的局部子目标与全局目标的一致性，解决了上述振荡问题。并在MATLAB平台上进行了仿真，仿真结果证明了本算法的有效性。     

基于模糊专家系统与IDE算法的UCAV逃逸机动决策

针对现有研究中无人作战飞机(unmanned combat air vehicle, UCAV)近距逃逸机动的自适应性不足和战术性匮乏问题,提出一种将模糊专家系统与双策略竞争的可选外部存档差分进化算法(external archiving differential evolution algorithm with dual strategy competition, DSC-JADE)相结合的逃逸机动决策算法。通过对战术知识的学习,建立模糊专家系统,将逃逸决策过程通过滚动时域划分为离散片段,根据模糊专家系统决策得到机动动作,在其控制量对应的可行域内,采用改进差分进化算法(improved differential evolution, IDE)进行寻优得到最优控制量,完成逃逸机动决策。在UCAV处于劣势的初始条件下进行仿真验证,证明DSC-JADE算法相较原始差分进化以及其他传统群智能算法搜索能力更强,采用专家系统相较不采用专家系统逃逸决策能力更优。     

基于组合非线性反馈机器人控制吸引域评估

在机器人的关节空间轨迹控制跟踪控制中,全局渐近的控制方法在存在驱动器饱和与摩擦扰动时,很难得到理想的控制效果.针对组合非线性反馈与计算力矩相结合的控制方法,研究了机器人驱动器存在输入限制时的吸引域评估方法.用Ricatti方程迭代法设计线性增益,以获得尽量大的吸引域,仿真结果证明了所提方法的有效性.     

Design of unknown input observer with H∞ performance for linear time-delay systems

A unknown input observer (UIO) design for a class of linear time-delay systems when the observer error can't completely decouple from unknown input is dealt with. A sufficient condition to its existence is presented based on Lyapunov stability method Design problem of the proposed observer is formulated in term of linear matrix inequalities. Two design problems of the observer with internal delay and without internal delay are formulated Based on H_∞ control theory in time-delay systems, the proposed observer is designed in term of linear matrix inequalities (LMI). A design algorithm is proposed The effective of the proposed approach is illustrated by a numerical example     

无模型控制方法在直线电机控制中的仿真研究

将基于偏格式线性化的非线性系统无模型学习自适应控制方法应用在直线电机的速度和位置控制中．控制器的设计是直接基于称为伪偏导数的向量，伪偏导数是通过新型参数估计算法，根据给出的永磁直流直线电机非线性系统模型的输入输出信息在线导出的。利用Matlab软件进行仿真实验证明了该方法对电机这种具有不确知动态的非线性系统的有效性和稳定性。     

RHC-Based Consensus of Multi-Agent Systems with Simultaneous Packet Dropout and Input Delay

This paper is concerned with the multi-agent systems with both packet dropout and input delay. A novel receding horizon control (RHC) based consensus protocol is proposed by solving a distributed RHC based optimization problem. The novelty of the optimization problem lines in the involvement of the neighbours’ predictor information in the cost functions. Based on the derived RHC based consensus protocol, the necessary and sufficient condition for the mean-square consensus is obtained. In addition, the authors give a specific sufficient condition to guarantee the mean-square consensus.

     

多变量非线性系统的有约束模糊预测解耦控制

针对多变量非线性系统提出了一种带约束输入的广义预测解耦控制算法:首先对多变量非线性系统建立T-S模糊模型,然后在每个采样点对系统进行局部动态线性化,将得到的系统线性化模型进行对角解耦,然后对其设计带输入约束的GPC算法.该算法充分考虑了控制输入及其增量受约束的情况,而且不必求Dio-phantine方程,减小了计算量,且削弱了变量之间的耦合程度.最后的仿真结果说明了该算法对多变量非线性系统的有效性.     

New adaptive quasi-sliding mode control for nonlinear discrete-time systems

A new adaptive quasi-sliding mode control algorithm is developed for a class of nonlinear discrete-time systems, which is especially useful for nonlinear systems with vaguely known dynamics. This design is model-free, and is based directly on pseudo-partial-derivatives derived on-line from the input and output information of the system using an improved recursive projection type of identification algorithm. The theoretical analysis and simulation results show that the adaptive quasi-sliding mode control system is stable and convergent.     

Zero phase error control based on neural compensation for flight simulator servo system

1. INTRODUCTION In high precision tracking applications of mechanical systems, feedforward controllers are often used to enhance tracking performance, and they are generally prefilter for the desired trajectory to compensate for the dynamic lag of the closed loop and to extend the tracking bandwidth. Because of the rapid growth of computer technology, digital motion control system has become more and more popular, and feedforward controller design in discrete time domain attracts much atte…     

约束条件下滚动区间预测控制器鲁棒性能分析

分析了带约束条件的滚动区间预测控制器鲁棒性能．将控制受到的扰动分成两类——增益扰动和附加扰动,针对这两种扰动提出判断受约束流动区间预测控制器的鲁棒稳定性能的两个指数δｇ和δａ,并和静态线性二次型最优控制器鲁棒稳定性能进行了比较,指出了二者之间的关系．     

一类基于神经网络的非线性模型预测控制

在研究非线性对象输入/输出数据的基础上，将对象输出的Taylor级数展开式取线性项作为预测模型，提出一种非线性系统模型预测控制算法，为了保证预测模型的准确性，以神经网络做辩识器估计系统建模误差，对非线性对象进行单频预测控制，理论上已证明三层BP网能任意逼近L2上的非线性函数，本文通过仿真研究也表明了当神经网络逼近系统建模误差时，所提出的预测控制算法对复杂非线性对象能达到良好的控制效果。     

A self-similar local neuro-fuzzy model for short-term demand forecasting

This paper proposes a selfsimilar local neurofuzzy （SSLNF） model with mutual informati onbased input selection algorithm for the shortterm electricity demand forecasting. The proposed self similar model is composed of a number of local models, each being a local linear neurofuzzy （LLNF） model, and their associated validity functions and can be interpreted itself as an LLNF model. The proposed model is trained by a nested local liner model tree （NLOLIMOT） learning algorithm which partitions the input space into axisorthogonal subdomains and then fits an LLNF model and its associated validity function on each subdomain. Furthermore, the proposed approach allows different input spaces for rule premises （validity functions） and consequents （local models）. This appealing property is employed to assign the candidate input variables （i.e., previous load and temperature） which influence shortterm electricity demand in linear and nonlinear ways to local models and validity functions, respectively. Numerical results from shortterm load forecasting in the New England in 2002 demonstrated the accuracy of the SSLNF model for the STLF applications.