基于RST的包装机混合式定量称重控制模型设计

目的提高包装机混合式定量的称重精度。方法针对包装机混合式定量称重系统具有非线性和时滞性的特点,构造三支路结构的双自由度数字控制器(RST控制器),等效为前向预测控制器和无延时控制器,以消除系统扰动和滞后的影响,设计基于RST的包装机定量称重控制系统。运用Simulink工具与传统PID控制器和PID-Smith控制器进行仿真对比。结果 RST控制器相较于PID控制器和PID-Smith控制器超调量小、调节时间短、跟踪能力好、鲁棒性强,能够有效地提高包装机称重控制系统的稳定性和控制精度。结论 RST控制器能够提高包装机混合式定量称重精度,从而提高包装机的包装精度。     

卷筒料印刷装备收卷张力系统解耦控制研究

目的 为了保证卷筒料印刷装备收卷张力系统的性能,提出一种适用于收卷张力系统的自抗扰（ADRC）解耦控制器。方法 在收卷张力系统数学模型基础上,结合卷筒料收卷系统的工作原理,基于ADRC控制技术设计收卷张力系统的ADRC解耦控制器,并利用Simulink软件对所提出的控制策略进行仿真研究。结果 在相同的阶跃输入下,研究结果表明,PID控制器调整时间为2.4 s,而ADRC解耦控制器调整时间为0.7 s;在PID控制下,收卷基材张力出现超调和震荡,而在ADRC解耦控制下,基材张力无超调和震荡现象;采用PID控制器,收卷牵引跨度张力变化引起收卷跨度张力波动,而采用ADRC控制器则没有波动。结论 提出的卷筒料印刷装备收卷张力系统ADRC解耦控制器实现了高精度张力控制,具有比传统PID控制器更好的控制性能。     

光电平台伺服系统自抗扰滑模控制

提出一种基于参考模型的自抗扰滑模控制器,它包括一个自抗扰控制器和一个全局滑模控制器.根据参考模型,利用跟踪微分器设计自抗扰控制器,控制参考模型的输出精确跟踪指令输入信号.全局滑模控制器控制伺服系统被控对象的输出高精度跟踪参考模型的输出.光电平台伺服系统的实验结果证明该新型控制器能有效补偿系统的参数不确定性和非线性扰动,提高了伺服系统的跟踪精度.系统具有全局鲁棒性.     

基于双模糊PID的药品包装贴标张力控制系统设计

目的 为提高药品包装的贴标精度,设计一种基于双模糊PID控制器的贴标机张力控制系统。方法 简要论述药品包装生产线结构及其工艺流程。针对标签纸带收卷过程具有时变性、非线性和动态干扰等特点,设计一种双模糊PID张力控制器。利用副模糊控制器实现主模糊控制器的变量论域系数整定,而主模糊控制器可实现PID控制器参数整定。通过实验验证所述控制系统的有效性。结果 实验结果表明,与PID控制器相比,双模糊PID控制可使系统超调量减小50%,系统调节时间减小65%;贴标位置准确、标签贴附平整。结论 所述控制系统具有较好的抗干扰性能,贴标效果良好,具有一定使用价值。     

基于滑模控制的可拓控制器设计

根据滑模控制概念, 提出一种新的可拓控制器。在控制策略设计上分为两个部分,第一个部分是根据系统已知部分设计滑模控制的等效控制, 另一部分为鲁棒控制以解决系统的不确定性因素及外部干扰问题。首先,构造一基本可拓控制器,用所定可拓集的关联函数作为系统状态信息的评价指针, 并在其中植入一组待调增益参数,经参数修正来综合滑模可拓控制的鲁棒控制(滑模的撞击控制),以保证系统的稳定性。最后以一个非线性控制系统的仿真为例来说明所设计的可拓控制器的控制性能。     

Cell control research— current status and development trends

A critical literature review on cell controller research is presented in this paper. Different definitions of a flexible manufacturing cell and cell controller are analysed, and comprehensive cell and cell controller definitions are given. Based on the requirements for a cell control system suggested by practitioners, users and researchers, a new set of general requirements for the development of a cell control system is proposed. After many well-known cell control systems are reviewed, a general structure of a cell controller and the general architecture of the cell control system, which includes a cell controller and a sub-system for the generation and configuration of a cell controller, are suggested. The scheduling approaches used in cell control are also discussed. The tools employed for modelling the cell control logic are examined. The trends and potential research directions in cell controller development are addressed.     

Hybrid controller with recurrent neural network for magnetic levitation system

We propose a hybrid controller using a recurrent neural network (RNN) to control a levitated object in a magnetic levitation system. We describe a nonlinear dynamic model of the system and propose a computed force controller, based on feedback linearization, to control the position of the levitated object. To relax the requirement of the lumped uncertainty in the design of the computed force controller, an RNN functions as an uncertainty observer to adapt the lumped uncertainty on line. The computed force controller, the RNN uncertainty observer, and a compensated controller are embodied in a hybrid controller, which is based on Lyapunov stability. The computed force controller, with the RNN uncertainty observer, is the main tracking controller, and the compensated controller compensates the minimum approximation error of the RNN uncertainty observer. To ensure the convergence of the RNN, the adaptation law of the RNN is modified by using a projection algorithm. Experimental results illustrate the validity of the proposed control design for the magnetic levitation system.     

空调系统神经模糊控制器-仿真和优化

以恒温空调系统为控制对象，对神经模糊控制器、常规模糊控制器和PID控制器进行了数字仿真，并用单纯形法对控制比例因子进行了参数寻优，获得了最优参数和动态响应曲线；通过对神经模糊控制器的优化学习，大大提高了神经模糊控制器的控制精度和稳定性，其性能优于最优化的PID控制器和最优化的常规模糊控制器，能有效地满足温度控制要求，并具有较好的鲁棒性；由于神经模糊控制器具有模糊控制和神经网络的智能，经过优化学习后，它具有艮好的控制性能和自适应能力。     

凹版印刷机自动套色系统的控制方法与实现

针对凹版印刷机的工作特点,提出了一种新颖的凹版印刷机自动套色控制系统的控制与实现方法,并采用多片８０Ｃ１９６ＫＣ单片机与一台ＰＣ机实现该控制系统。该控制系统在实际应用中证明,其能大大提高各类凹版印刷机的套印精度和印刷速度,因而具有广泛的应用前景。     

Adaptive disturbance rejection in an optical trap

This article presents a method for characterizing the system dynamics of a trapped particle in real-time and designing a controller to minimize disturbances to the particle's position. Specifically, adaptive system identification is used to determine the trap characteristics and the actuator transfer function describing the mirror voltage to trap position path. Using an internal model control scheme combined with a filtered-x least-mean-square algorithm, adaptive control was used to create a controller that minimizes a frequency weighted mean-squared-error. The dynamics associated with multiple particle sizes and materials were experimentally determined under different power levels, each case resulting in different system dynamics and demonstrating positive control results. The adaptive system identification and the controller presented automate the process of system identification and control design, enabling the automation of optical trap controller design.     

ROBUSTNESS OF OPTIMALLY ROBUST CONTROLLERS——Dedicated to the Sixtieth Birthday of Prof. You Zhao-yong

The largest robust stability radius r(P0) of a system P0 is defined as the radius of the largest ball Bmax in the gap metric centered at P0 which can be stabilized by one single controller. Any controller which stabilizes Bmax is called an optimally robust controller of P0. Any controller, regarded as a system, should have its own largest robust stability radius also. In this paper it is shown that the largest robust stability radius of any optimally robust controller of P0 is larger than or equal to r(Po). Moreover, the variation of the closed-loop transfer matrix caused by the perturbation of the system is estimated.     

新混沌系统分析及其同步控制

提出了一个新混沌系统,通过Matlab对该系统进行了分岔图、Lyapunov指数、相图等仿真分析,证实了在选定特定参数下,该系统为混沌系统。随着参数的改变,该系统会出现周期–倍周期–混沌–周期–倍周期–混沌交替现象,具有较复杂的动力学特性及对初值的敏感性,通过Multisim电路仿真证实了该系统的物理可实现性。针对提出的新混沌系统,设计了错位投影同步控制器,从理论上证实了在同步控制器的作用下该系统与Chen混沌系统达到了同步,通过Matlab仿真证实了同步控制器的有效性。最后,在同步控制器作用下实现了新混沌系统和Chen混沌系统的数字加密传输。     

伴随型非线性系统的自适应RBF神经网络补偿控制

为了抵消伴随型非线性系统中的非线性项,可以设计控制器对非线性系统精确线性化.通常由于系统中存在外界不确定性因素导致系统模型的不确定,而不能直接设计控制器.利用"RBF神经网络能以任意精度逼近连续函数"的原理,对系统模型中的不确定项进行自适应辨识,并将辨识结果提供给控制器,从而实现伴随型非线性系统的神经网络自适应补偿控制.将控制器应用于起重机吊重摆角子系统,对摆角进行控制.实验结果表明:吊重摆角及其角速度约在5s后,得到了很好的控制,并且控制器对系统模型的不确定项的逼近误差约在5s时达到0;控制器对系统的不确定性因素和系统参数变化均具有很强的鲁棒性.     

非线性系统的自适应可拓控制器设计

探讨可拓控制器的设计方法,利用自适应控制的设计策略来修正可拓控制器的增益参数,以近似获得所期望的最佳控制。所提出的控制器结构仅需调整单一参数,故易于实现。另外,引入最大值控制以保证所设计的可拓控制系统的稳定性,并将该控制器应用在非线性系统的控制上,以验证它的有效性及控制能力。     

Studies on the heating capacity control of a multi-type heat pump system applying a multi-input multi-output (MIMO) method

This paper describes a method to control capacity of a multi-type heat pump system. Because indoor units are interconnected, alteration of the heating or cooling setting of one indoor unit can influence the performance of the other indoor units. Proportional-integral (PI) controllers were used to assess system performance, and the PI controllers’ gain values were optimized by using a genetic algorithm. A system model was established following a system identification optimization process, and a pseudo random binary sequence was selected as the system identification input signal. A multi-input multi-output (MIMO) controller was more effective in reducing such cross-coupling effects than a single-input single-output (SISO) controller. The temperature at the secondary fluid outlet in the condenser and the saturation pressure at the evaporator were selected as the control variables in the MIMO controller. The experimental results showed that an optimized MIMO controller could reduce overshoot by up to 40% compared with the results using a SISO controller.     

Performance optimization of a transcritical CO2 refrigeration system using a controlled ejector

An on-line optimal quasi cascade controller for an ejector with variable nozzle throat area is proposed to improve the operating performance of the transcritical CO₂ ejector refrigeration system. The optimal gas cooler pressure is tracked in real time by the controller including a tracker and a predictor. Using the system dynamic model, the dynamic responses of the system performance and ejector efficiency under variable nozzle throat area are first analyzed. Then the parameters of the tracker and predictor are determined by simulation respectively which exhibits a good dynamic characteristic with an acceptable settling time. Besides, the controller presents a good robustness under variable compressor speeds and mass flow rate of cooling water. Furthermore, the system performance is actually increased to the maximal value by the controller even at the variable operating conditions. Finally, the optimal controller is verified by experiments to be an effective way to improve the system performance automatically.     

PID模糊控制器在软胶囊生产过程中对温度控制系统的调节

本文阐述了模糊控制的方法,模糊控制器PID的结构和工作原理。介绍了利用PID模糊控制器运用模糊控制原理对软胶囊生产中温度控制系统的在线最佳调整,使其具有较好的静动态特性,提高系统的鲁棒性。利用MATLAB软件进行了仿真,证明其控制性能好于常规控制器。     

变频空调多变量模糊控制

家用变频空调蒸发压缩循环各反馈回路存在强耦合,使得传统的基于模型的控制器和解耦模糊控制器控制性能受到限制.提出一种非模型多变量模糊控制器,调节蒸发压缩循环的蒸发温度和过热度以改善其控制性能. 实验结果表明所提出的MFC能有效提高系统性能和改善能效,且该控制器设计和实现简单方便.     

模糊自适应PID控制在张力控制中的应用

针对凹版印刷机张力控制系统是一个非线性、强藕合、时变的复杂系统,用普通的PID难以达到理想的控制效果,设计出一种基于模糊控制原理的自适应PID控制器,根据偏差和偏差变化率来实时调整KP、KI、KD的参数.仿真结果表明,这种模糊自适应PID比常规PID控制器在张力控制中具有更好的控制性能.     

Decoherence and the conditions for the classical control of quantum systems

We find the conditions for one quantum system to function as a classical controller of another quantum system: the controller must be an open system and rapidly diagonalized in the diagonal basis of the controller variable that is coupled to the controlled system. This causes decoherence in the controlled system that can be made small if the rate of diagonalization is fast. We give a detailed example based on the quantum optomechanical control of a mechanical resonator. The resulting equations are structurally similar to recently proposed models for consistently combining quantum and classical stochastic dynamics.