基于MFA与PID控制器的串级控制系统的实验比较

通过实时控制试验,对比了MFA与常规PID分别作为外环控制器的串级控制系统以及单闭环MFA与常规PID控制器的抗干扰能力,试验表明,MFA的控制效果要比PID好,调整参数也比较简单.     

雷达稳定平台模糊PID串级控制设计与仿真

机载雷达稳定平台是根据陀螺仪采集到载机角速度信息,驱动直流伺服电机采用反向运动补偿原理工作,以保证机载雷达成像稳定,清晰。为了提高机载雷达稳定平台的响应性能和抗干扰能力,提出一种模糊PID串级控制方案,根据陀螺仪所采集的角速度信息和编码器反馈的角度位置信息,采用速度模糊PID控制和位置模糊PID控制串联的形式对直流伺服电机进行控制。经MATLAB仿真实验证明,模糊PID串级控制比传统单级PID控制以及传统PID串级控制具有更优秀的响应性能以及抗干扰能力,更加适合复杂环境下机载雷达稳定平台的稳定要求。     

LQG Optimization of PID Structured Multi-Model Process Control Systems: One DOF Tracking and Feedforward Control

The solution of an optimal control problem is discussed where the single degree of freedom structure of the controller is chosen to have a very simple form. The controller may be chosen to be of reduced order, lead/lag, or PID forms, and the controller is required to minimize an LQG cost-index. The optimization is based upon a cost-function which allows separate costing of the terms due to the feedback and feedforward controllers. The system model can be uncertain and can be represented by a set of linear models over which the optimization is performed. This provides a form of robust optimal control that might even be applied to nonlinear systems that are approximated adequately by a set of linearized models. The aim is to find a single controller that has a simple form and stabilises the full set of models.     

漂白过程温度建模与控制

文章介绍了阶跃响应建模法的思想并利用该方法建立了漂白过程温度的数学模型。针对温度控制的大时滞性,采用改进的继电反馈辨识法来自整定PID控制器的参数,获得了良好的实时控制效果。     

径向磁悬浮电主轴系统设计研究

本文主要从工业实际应用的角度出发,提供了一种从径向磁悬浮电主轴的结构设计开始到控制系统的整个系统的完整新颖的设计方法,其中在结构设计中提出了两个对结构起决定意义的参数——X（每极的圆周宽度／（每极的圆周宽度＋每槽的圆周宽度））和Y（槽的径向厚度／每个槽的圆周宽度）,并对它们的科学取值进行了深入的探讨,还给出了由机械特性——刚度和阻尼出发迅速设计出PID控制器的计算公式,最后进行了功率损耗分析和发热量校验．本文在上述理论分析的基础上,设计了样机,安装在机床厂磨床上进行实地磨削实验,性能稳定、良好,其精度达到1μm．     

数字化陆用武器系统中的建模、优化与控制

从复杂一体化武器系统的体系结构设计与优化、一体化指挥控制中的优化与决策、 高速多维度运动体的参数辨识与状态估计、多智能平台的协同控制、 非线性随动系统建模与控制五个方面阐述了数字化陆用武器系统中涉及的的建模、优化与控制问题, 涵盖了陆用武器系统中的指挥控制、 火力控制和武器平台的控制. 在对五个方面的国内外研究现状进行论述与分析的基础上, 指出需要进一步研究的问题和未来研究展望.     

The challenge of equality constraints in robust design optimization: examination and new approach

In recent years, robust design optimization (RDO) has emerged as a significant area of research. The focus of RDO is to obtain a design that minimizes the effects of uncertainty on product reliability and performance. The effectiveness of the resulting solution in RDO highly depends on how the objective function and the constraints are formulated to account for uncertainties. Inequality constraint and objective function formulations under uncertainty have been studied extensively in the literature. However, the approaches for formulating equality constraints in the RDO literature are in a state of disharmony. Moreover, we observe that these approaches are generally applicable only to certain special cases of equality constraints. There is a need for a systematic approach for handling equality constraints in RDO, which is the motivation for this research. In this paper, we examine critical issues pertinent to formulating equality constraints in RDO. Equality constraints in RDO can be classified as belonging to two classes: (1) those that cannot be satisfied, because of the uncertainty inherently present in the RDO problem, and (2) those that must be satisfied, regardless of the uncertainty present in the problem. In this paper, we propose a linearization- based approach to classify equality constraints into the above two classes, and propose respective formulation methods. The theoretical developments presented in this paper are illustrated with the help of two numerical examples.     

Nonlinear tracking control in the presence of state and control constraints: a generalized reference governor

This paper proposes a new approach to reference governor design. As in prior literature, the governor accepts input commands and modifies their evolution so that specified pointwise-in-time constraints on state and control variables are satisfied. The new approach applies to general discrete-time and continuous-time nonlinear systems with uncertainties. It relies on safety properties provided by sublevel sets of equilibria-parameterized functions. These functions need not be Lyapunov functions, and the corresponding sublevel sets need not be positively invariant. Technical conditions that capture the bare essentials of what is needed are identified and the usual desirable properties of reference governors are established. The new approach significantly broadens the class of methods available for constructing the nonlinear function that is required in the implementation of the reference governors. This advantage is illustrated in a nonlinear control problem where off-line, computer-based simulation is the basis for constructing the nonlinear function.     

PID与模糊控制算法的比较及其改进

分析比较了PID控制和模糊控制算法，针对一般PID控制容易产生超调，模糊控制的稳态精度不高的缺陷，提出了相应的改进算法－复合PID算法和带动态补偿的模糊控制算法，并通过水温控制仿真实验，比较了这几种控制算法的控制效果，实验结果证明，这两种改进算法不仅系统超调小，而且具有较高的稳态控制精度，可广泛应用于精确控制领域。     

汽油调合累积过程在线控制与优化

汽油调合具有非连续批次性的特点,并且调合头产品在罐中存在累积过程。已有汽油调合在线配方优化针对的是瞬时调合头产品而非罐中产品,无法解决罐底补偿问题,造成罐产品性质与实际目标性质存在偏差,调合生产经济效益进一步提高受到限制。为解决这一问题,文中采用具有收缩时域的模型预测全局滚动优化方式,兼顾质量过剩最小与经济效益最大化两方面要求,提出累积调合过程在线控制与优化算法。在瞬时产品配方优化层的基础上,通过增加瞬时产品目标值计算层,形成二级递阶结构。应用案例结果:证明该算法能用于累积调合过程,能兼顾罐产品质量和调合经济效益最大化,能够有效地解决罐底补偿问题。     

On IQC approach to the analysis and design of linear systems subject to actuator saturation

This paper establishes IQC-based (Integral Quadratic Constraints) conditions under which an ellipsoid is contractively invariant for a single input linear system under a saturated linear feedback law. Based on these set invariance conditions, the determination of the largest such ellipsoid, for use as an estimate of the domain of attraction, can be formulated and solved as an LMI optimization problem. Such an LMI problem can also be readily adapted for the design of the feedback gain that achieves the largest contractively invariant ellipsoid. While the advantages of the proposed IQC approach remain to be explored, it is shown in this paper that the largest contractively invariant ellipsoid determined by this approach is the same as the one determined by the existing approach based on expressing the saturated linear feedback as a linear differential inclusion (LDI), which is known to lead to non-conservative result in determining the largest contractively invariant ellipsoid for single input systems.     

Comparative performance analysis of various binary coded PSO algorithms in multivariable PID controller design

In this paper, comparative performance analysis of various binary coded PSO algorithms on optimal PI and PID controller design for multiple inputs multiple outputs (MIMO) process is stated. Four algorithms such as modified particle swarm optimization (MPSO), discrete binary PSO (DBPSO), modified discrete binary PSO (MBPSO) and probability based binary PSO (PBPSO) are independently realized using MATLAB. The MIMO process of binary distillation column plant, described by Wood and Berry, with and without a decoupler having two inputs and two outputs is considered. Simulations are carried out to minimize two objective functions, that is, time integral of absolute error (ITAE) and integral of absolute error (IAE) with single stopping criterion for each algorithm called maximum number of fitness evaluations. The simulation experiments are repeated 20 times with each algorithm in each case. The performance measures for comparison of various algorithms such as mean fitness, variance of fitness, and best fitness are computed. The transient performance indicators and computation time are also recorded. The inferences are made based on analysis of statistical data obtained from 20 trials of each algorithm and after having comparison with some recently reported results about same MIMO controller design employing real coded genetic algorithm (RGA) with SBX and multi-crossover approaches, covariance matrix adaptation evolution strategy (CMAES), differential evolution (DE), modified continuous PSO (MPSO) and biggest log modulus tuning (BLT). On the basis of simulation results PBPSO is identified as a comparatively better method in terms of its simplicity, consistency, search and computational efficiency.     

Isolation and handling of actuator faults in nonlinear systems

This work considers the problem of control actuator fault detection and isolation and fault-tolerant control for a multi-input multi-output nonlinear system subject to constraints on the manipulated inputs and proposes a fault detection and isolation filter and controller reconfiguration design. The implementation of the fault detection and isolation filters and reconfiguration strategy are demonstrated via a chemical process example.     

Frequency analysis and compensation of valve stiction in cascade control loops

Valve stiction is often a common problem in control loops and stiction induced oscillation is the main cause of poor performance in control systems. Cascade control is extensively applied in process industry as an effective strategy to restrain disturbances and compensate process nonlinearities. In recent years many studies have been performed on the detection and quantification of valve stiction in single feedback control loops. However, there is a lack in developing a mechanism which can analyze stiction induced oscillation in cascade control loops. This work focuses on the frequency analysis of stiction induced oscillations in cascade control loops and proposes a mechanism of oscillation compensation through outer and inner controller tuning. The effect of oscillation compensation by changing control strategies is also discussed. The theoretical analysis is evaluated through simulation examples and a pilot-scale flow-level cascade control experiment.     

网络化控制系统的研究现状与展望

随着网络技术的发展,网络化控制系统日益成为人们关注的课题,特别是目前工业以太网所取得的进展引起人们广泛兴趣。介绍了网络化控制系统的发展过程,在综述网络化控制系统研究现状的基础上,对网络化控制系统的建模、状态估计、信息时延、调度算法、通信约束等方面进行了深入分析,并对其中的建模、网络信息调度的最优化、网络环境下控制理论研究、应用研究等方面的未来发展作了展望。     

基于控制量补偿的过热汽温混合型模糊自调整PID控制研究

本文针对惰性区具有多个参数及迟延摄动的电厂锅炉过热汽温控制问题及其对汽温响应和抗扰动特性的特殊要求，提出一种基于控制量补偿的混合型模糊自调整PD控制策略。仿真结果表明，这种混合模糊控制方法和利用自适应遗传算法优化获得的固定参数PID控制方式相比，显著的改善了汽温响应特性，同时较好的解决了采用常规PID控制器的过热汽温系统中，控制器的参数整定无法同时兼顾设定值跟踪响应特性和干扰抑制特性的问题。     

On the two-degree-of-freedom Wiener–Hopf optimal design with tracking and disturbance rejection constraints

In this paper, the design of the two-degree-of-freedom optimal Wiener–Hopf controller with asymptotic tracking and disturbance rejection constraints is studied. Based on the solvability conditions and the solution parameterization of Diophantine equations over the stable rational fractional ring M(s), the disturbance rejection problem in the general case is solved. A simple cost function is defined to reflect the transient performance of control signal caused by deterministic signals. Finally, the design of the two-degree-of-freedom optimal Wiener–Hopf controller is presented.     

网络控制系统的时延仿真研究与控制器设计

针对网络控制系统(NCS)中的随机时延问题,根据实际网络时延的分布情况,提出了一种新的具有随机时延的网络控制系统的建模方法-离散T-S模型,并用并行分布补偿原理(PDC)设计模糊控制器.同时提出一种新的模糊控制系统隶属函数的确定方法,利用Lyapunov定理和线性矩阵不等式(LMI)研究了系统的稳定性问题,给出基于LMI的模糊控制器的设计方法.最后通过仿真实例证明控制方法能够使具有时延的网络控制系统稳定.     

Semi‐global containment control for linear systems in the presence of actuator position and rate saturation

This paper studies the semi‐global containment control problem for a group of general linear systems in the presence of actuator position and rate saturation. Both a state feedback containment control algorithm and an output feedback containment algorithm are constructed for each follower agent in the system by using low gain approach. We show that the states of all follower agents will converge to the convex hull formed by the leader agents asymptotically under these control algorithms when the communication topology among follower agents is a connected undirected graph and each leader agent is a neighbor of at least one follower agent. Simulation results illustrate the theoretical results.