非自衡时滞对象的改进内模控制

针对化工生产中常见的具有积分和时滞特性的过程对象，采用一种改进的两自由度内模控制方案．其中一个新增的控制器用于设定值跟踪响应的期望极点配置，利用直接合成法设计设定值跟踪控制器；另一个新增的控制器用于稳定对象和抑制扰动，并采用期望闭环余灵敏度法确定控制器．设定值跟踪控制器和扰动抑制控制器可通过性能参数独立调节，并保证系统具有较好的鲁棒稳定性．最后，通过仿真实例验证了控制方案的有效性．     

非自衡时滞对象的改进内模控制

针对化工生产中常见的具有积分和时滞特性的过程对象,采用一种改进的两自由度内模控制方案．其中一个新增的控制器用于设定值跟踪响应的期望极点配置,利用直接合成法设计设定值跟踪控制器;另一个新增的控制器用于稳定对象和抑制扰动,并采用期望闭环余灵敏度法确定控制器．设定值跟踪控制器和扰动抑制控制器可通过性能参数独立调节,并保证系统具有较好的鲁棒稳定性．最后,通过仿真实例验证了控制方案的有效性．

     

控制大时滞积分过程

提出了一种包含三个控制器的大时滞积分过程控制方案,给出了简单的设计和整定方法,该方案能分离闭环设定值响应和扰动响应,从而能独立优化这些响应,仿真表明,所提出的控制方案具有快速的设定值跟踪和良好的抗扰动功能,同时系统鲁棒性也比现有的控制方案大为增强。     

基于改进Smith预估控制结构的二自由度PID控制

针对工业过程中的二阶不稳定时滞过程, 基于改进史密斯预估控制结构提出了一种简单的两自由度控制方案.设定值跟踪控制器和扰动抑制控制器采用同一设计程序, 并基于内模控制原理提出了控制器解析设计方案.设定值跟踪控制器和抗扰动控制器可分别通过单性能参数独立调节和优化, 每个控制器都具有PID形式, 给出了控制器调整参数的选择范围和扰动抑制闭环保证鲁棒稳定性的条件.仿真实例验证了提出方法对于近期其他方法的优越性.     

用比例控制器实现对扰动的全补偿

为了获得用比例控制器实现对可测量扰动的全补偿和将扰动响应与设定值响应分别处理，本文提出了一种多控制器策略。它由四个控制器，即：一个设定值控制器、两个扰动控制器和一个比例前馈控制器。这四个控制器可以分别独立设计获得好的设定值跟踪和抗扰动性能，特别是其前馈控制器是比例型的，可实现对可测量扰动的全补偿并保证了前馈控制器的可实现性。最后将该控制策略应用于压力槽的实时控制中，获得了良好的控制性能。     

化工不稳定时滞对象的改进内模控制

针对化工过程中典型不稳定时滞对象,基于传统内模控制提出了两自由度控制方案,新增两个控制器分别用于稳定控制对象和抑制扰动,在镇定不稳定过程的基础上,设定值跟踪控制器和扰动抑制控制器可独立调节而无需再取折衷,同时保证系统具有较好的鲁棒稳定性.最后通过仿真实例验证了该控制方案的有效性.     

不稳定时滞对象的二自由度控制器设计

在工业生产过程中,特别是化工领域,许多单元属于开环不稳定过程,特别还存在时滞特性;针对此情况,提出了一种二自由度响应控制结构,该结构优点是设定值跟踪与扰动响应完全解耦,分别对设定值跟踪控制器和扰动控制器两个参数进行独立调节,而无需进行折中,保证了系统的稳定性和鲁棒性;最后对一阶二阶不稳定时滞系统的仿真结果表明,所提出的二自由度控制结构能够有效地解决系统的稳定鲁棒性和扰动抑制作用。     

基于抗干扰的Smith预估控制改进方法研究

针对工业过程控制系统设计的核心之一抗干扰问题,就自平衡对象,对Smith预估控制提出了三种循序渐进的改进方案,分别从不同角度讨论了如何提高系统的抗干扰性能和模型失配时的稳定性问题。针对干扰进入系统的位置不同,主要找到Smith预估器在定值系统中调节效果不明显的原因,对其结构进行改进并选取一阶典型环节加上纯滞后环节进行研究和Simulink仿真。改进方案实现了将设定值和扰动响应分离,使得跟踪控制器和扰动器可以独立设计,从而可同时获得良好的设定值跟踪和抑制扰动的能力。     

基于有界扰动分区的多模型自适应控制

对于含有界扰动的离散时间系统,将有界扰动变化范围分割成若干小区间,针对这些区间建立多个自适应模型,并针对每一个自适应模型建立相应的控制器.给定一个指标切换函数,基于多个自适应模型控制器和给定的指标切换函数构成多模型自适应控制器.可以证明多模型自适应控制器能够保证闭环系统是输入输出有界稳定的.仿真实例表明,当被控对象的有界扰动随时间变化的时候,采用单一模型自适应控制,系统输出很难跟踪设定值,而多模型自适应控制器却极大地改善了控制品质.     

金氰化浸出过程的自优化控制

针对湿法冶金金氰化浸出过程的实时优化问题,提出一个自优化控制方案.基于系统的参数不确定模型,选择并求解输出变量的线性组合为被控变量,在反馈控制器作用下跟踪其恒定设定值,实现浸出过程在不确定性扰动下的自优化控制.仿真结果验证了该控制方案的有效性:扰动产生时,系统的经济指标在常规控制作用下得到改善,并最终运行于真实的最优点附近,提高了浸出过程的生产效益.     

积分时滞过程的数字P I D 控制

对积分时滞过程提出一种数字PID控制结构，通过一个内部反馈回路对积分时滞过程进行预稳定控制，并给出数字PI控制器的设计算法，仿真结果显示该控制结构具有良好的设定值跟踪特性，并且对时滞偏差具有很强的鲁棒性能，最后简要讨论了抗负载干扰的控制结构。     

Automatic controller tuning via unfalsified control

In this paper, we present a new algorithm for the automatic adaptation of linear single-loop controllers. The algorithm is based on the idea of unfalsified control, where a set of controllers is defined and using measured data, the controller from the set is chosen online which provides the best performance. This scheme is extended here by an adaptation of the set of controllers after a change of the operating point of the plant. The original concept of unfalsified control relies on the computation of the performance of controllers that are not in the loop using so-called fictitious signals. However, the proposed cost function leads to erroneous results, in particular, it is not possible to detect closed-loop instability that may result from inserting a controller. Therefore a different cost function and a new method for online evaluation of controllers that are not in the loop without an explicit plant model are proposed. With this new cost function, the set of controllers can be adapted as well which is performed using an evolutionary algorithm. The method is demonstrated for a well-known example, the nonlinear non-minimum phase CSTR model with van der Vusse reaction scheme and PID controllers.     

Design of optimized fuzzy cascade controllers by means of Hierarchical Fair Competition-based Genetic Algorithms

In this study, we present a design of an optimized fuzzy cascade controller based on Hierarchical Fair Competition-based Genetic Algorithms (HFCGA) for a rotary inverted pendulum system. In this system, one controls the movement of a pendulum through the adjustment of a rotating arm. The objective is to control the position of the rotating arm and to make the pendulum maintain the unstable equilibrium point at vertical position. To control the system, we design a fuzzy cascade controller scheme which consists of two fuzzy controllers arrange in a cascaded topology. The parameters of the controller are optimized by means of the HFCGA algorithm. The fuzzy cascade scheme comprises two controllers located in two loops. An inner loop controller governs the position of the rotating arm while an outer controller modifies a set point of the inner controller implied by the changes of the angle of pendulum. The HFCGA being a computationally effective scheme of the Parallel Genetic Algorithm (PGA) has been developed to eliminate an effect of premature convergence encountered in Serial Genetic Algorithms (SGA). It has emerged as an effective optimization vehicle to deal with very large search spaces. A comparative analysis involving computing simulations and practical experiment demonstrates that the proposed HFCGA based fuzzy cascade controller comes with superb performance in comparison with the conventional Linear Quadratic Regulator (LQR) controller as well as HFCGA-based PD cascade controller.     

Control based on double neural networks-PI for parallel mechanism

In this paper, a control system based on double neural networks-PI for 3-RPS parallel mechanism is presented to aim for the nonlinear modeling and controlling. The control system is composed of three linear controllers, one neural network controller (NNC) for compensating the nonlinear modeling and one neural network identification (NNI) for the controlling model. Simulation results have shown that the response time, movement accuracy and resistance to load disturbance of the 3-RPS parallel mechanism system can be improved using the double neural networks-PI.     

Disturbance Observer Based Speed Control of PMSM Using Fractional Order PI Controller

In this paper, fractional order PI (FOPI) control is developed for speed control of permanent magnet synchronous motor (PMSM). Designing the parameters for FOPI controller is a challenging task, especially for nonlinear systems like PMSM. All three PI controllers in the conventional vector controlled speed drive are replaced by FOPI controllers. Design of these FOPI controllers is based on the locally linearized model of PMSM around an operating point. This operating point changes with the load torque. The novelty of the work reported here is in use of Non Linear Disturbance Observer (NLDO) to estimate load torque to obtain this new operating point. All three FOPI controllers are then designed adaptively using this new operating point. The scheme is tested on simulation using MATLAB/SIMULINK and results are presented.      

面向智慧医疗云的SDN动态负载均衡方法

文中 引入软件定义网络(Software Defined Network,SDN)对智慧医疗云进行网络管理,并且针对传统SDN控制器存在单点失效和负载均衡的问题,设计了智慧医疗分布式SDN控制器系统。SDN控制系统分为SDN控制器集群、数据转发平面和智慧医疗云服务系统3层。在此基础上,提出一种实时负载动态自调节的快速负载均衡算法DAF(Dynamic Adaptive and Fast Load Balancing)。在该算法中,负载信息感知组件周期性地采集自己的负载信息,自动地进行控制器间的负载信息交互;控制器的负载值超过阈值时,会触发交换机迁移动作,以动态配置交换机与控制器之间的映射关系。实验结果表明,面向智慧医疗云的分布式SDN控制系统的性能良好,且DAF算法能够快速地实现SDN控制器间的负载均衡,提升了智慧医疗云的网络吞吐量。     

直流调速系统的新型二自由度控制器

针对直流调速系统提出了一种新的二自由度内模控制器设计方法,所设计的控制器结构简单,容易实现,而且参数调整方便,它可以使系统同时具有良好的跟随性能和抗扰性能,仿真研究结果表明了它的有效性。     

Multi-loop design of multi-scale controllers for multivariable processes

Based on the recently proposed (SISO) multi-scale control scheme, a new approach is introduced to design multi-loop controllers for multivariable processes. The basic feature of the multi-scale control scheme is to decompose a given plant into a sum of basic modes. To achieve good nominal control performance and performance robustness, a set of sub-controllers are designed based on the plant modes in such a way that they are mutually enhanced with each other so as to optimize the overall control objective. It is shown that the designed multi-scale controller is equivalent to a conventional PID controller augmented with a filter. The multi-scale control scheme offers a systematic approach to designing multi-loop PID controllers augmented with filters. Numerical studies show that the proposed multi-loop multi-scale controllers provide improved nominal performance and performance robustness over some well-established multi-loop PID controller schemes.