Intelligent control of a nonlinear tank reactor

In this paper, intelligent control of a particular Catalytic Continuous Stirred Tank Reactor (CSTR) is addressed. Control command is the sum of two components: steady state and transient commands. A fuzzy controller generates a transient control command that pushes the system towards the setpoint. A steady state control command is generated to maintain the steady state situation at the setpoint (based on the concept of ‘control equilibrium point’). For comparison, a case study was also controlled by the neuro‐predictive algorithm. The studied CSTR is known as a good example of a neuro‐predictive control application; however, the newly proposed hybrid intelligent method leads to much better setpoint tracking as well as less change in control command (which is very important in implementation of the control system).     

基于LoRa技术的低压集抄系统运行可靠性分析

传统的低压集抄系统运行的可靠性评估方法,缺少具体的可靠性评估指标框架,无法准确地判定系统的运行状态,造成评估准确率、评估效率、评估可靠度及评估完整度较低的问题。提出基于LoRa技术的低压集抄系统运行可靠性评估方法。在LoRa的框架协议内设定系统运行可靠性的评估指标,判定该低压集抄系统的状态转移率、平稳状态概率以及元件的瞬时状态,以此判定系统的运行状态是否可靠。在此基础上,分别计算系统各个运行状态当中各个节点的负荷承载能力,以及电压崩溃风险。由此完成低压集抄系统运行可靠性评估。经实验验证：所提出的系统运行可靠性分析方法比传统方法的平均评估准确率提高了25%,且所提方法的评估效率、评估可靠度和评估完整度均高于传统方法。     

Tracking periodic signals for a class of uncertain nonlinear systems

In this paper, a conditional learning control (CLC) is proposed to track periodic signals for a class of nonlinear systems with unknown dynamics. The main advantage of the CLC over the conventional iterative learning control is that monotonic convergence of the control sequence in the iteration domain is achieved, as the CLC ensures the learning is based on the steady‐state output, and hence the effect of the vanishing and unknown transient output is minimized. Following this result, the convergence of the tracking errors is obtained. Further, the optimal setting of the learning gains can be obtained in a min–max sense. A simulation example is presented to illustrate the performance and implementation of the CLC. Copyright © 2009 John Wiley & Sons, Ltd.     

Optimized design for anti-reflection coating process in roll-to-roll slot-die coating system

This study investigated the application of the anti-reflection (AR) coating technology by using the roll-to-roll (R2R) slot-die coating process. To simulate the coating phenomenon, we investigated governing parameters in the slot-die coating process by using a viscocapillary model. Results of using this model revealed that the coating speed and solid content are two dominant factors affecting transmittance, which is an important parameter for the AR coating process. As the design of experiment methodology, response surface design was used to observe parameter interactions and establish a meta model for obtaining optimum process conditions. Further, to enhance the accuracy of analysis of the coating performance, the light wavelength was divided into visible and IR wavelength regions. In addition, the average and standard deviation values of transmittance were determined by a statistical correlation. An improvement of approximately 5% of the transmittance was observed in comparison to that of an uncoated (bare) substrate. The optimum conditions of process parameters for the AR coating process were determined through the established meta model and guidelines for performing the AR slot-die coating process were suggested.     

铜材连续挤压生产设备的监测、控制系统研制

铜材连续挤压生产线控制采用计算机监控系统,以工控机作为上位机对PLC及整套生产设备线的状态进行监控,以INTOUCH软件作为用户可以定制功能的软件平台,开发出良好的人机界面、监控画面以及数据存储、等功能。PLC作为下位机通过通信线缆与上位计算机相连,执行上位机指令,通过梯形图编程完成逻辑控制、顺序控制及实时控制等功能。铜材挤压生产设备结合现代电子技术和计算机构成的控制系统,实现模糊控制,全线自动,其性能稳定可靠、操作简单,完全满足生产工艺的要求。     

Performance analysis for queueing systems with close down periods and server under maintenance

A single server queue subject to maintenance of the server and the close down period is considered. We obtain explicit expressions for the transient probabilities of the system size, the server under maintenance state and the close down period. The time-dependent performance measures of the system and the probability density function of the first-passage-time to reach the maintenance state are discussed. The corresponding steady state analysis and key performance measures of the system are also presented. Finally, the effect of various parameters on system performance measures is demonstrated by a numerical example.     

小型弹用发动机建模及控制研究

为了有效对某型航空发动机进行控制,首先对其过渡态的各状态段的实验数据,基于系统辨识的理论,按照预处理、辨识、验证的步骤求取其传递函数;考虑到发动机过渡态状态变化大,故利用鲁棒性强、能克服对象参数变化的H∞控制方法来进行控制系统的设计,并引入前馈比例控制器对控制结构进行变形,以克服H∞回路成形控制超调量大的缺陷;仿真结果表明辨识数据与原始数据的拟合度能够达到82.99%,鲁棒控制器在发动机状态大范围变化时仍能拥有不错的控制效果,调节时间1秒左右。     

高流量呼吸湿化治疗仪的机理分析与数据建模

绝对湿度是高流量呼吸湿化治疗仪的重要控制参数,控制不当会影响治疗效果,建立准确稳态模型是控制绝对湿度的基础。通过对湿化仪的系统结构和工作原理进行研究,建立湿化仪稳态过程的机理模型。此模型具有多元、高阶次和非线性且缺少部分可测参数,难以实现模型的精确辨识。采用多元线性拟合方法,建立以湿化罐出气口温度为控制目标的稳态模型,仪器测试结果表明通过对湿化罐出气口温度进行控制,实现了对湿化罐出气口绝对湿度的间接控制,验证了数据模型的有效性和实用性。     

一种基于粘滑运动原理的微小型机器人建模与实验

为实现微小型机器人的精密运动定位,提出一种基于粘滑运动原理的足式微小型机器人.机器人足由双压电膜驱动,本身为空间不等截面的弹性梁结构.首先建立了柔性足的有限自由度模型和机器人系统的动力学模型.然后根据粘滑驱动中的粘滞和滑移过程的不同特点,分别对粘滞过程的静力学与滑移过程的瞬态动力学进行了分析,得到了机器人运动位移、分辨力与驱动电压之间的关系,并分析了粘滞-滑移过程中摩擦力的变化以及足尖的状态切换过程.分析结果表明,在粘滞阶段,基体的静态位移与驱动电压近似呈线性关系,且随驱动电压的增高而增大;在滑移阶段,由于柔性足的振动及振动与摩擦力的耦合关系,足端的滑移距离及基体位移与驱动电压之间存在非线性关系.建立了机器人样机,对机器人的运动分辨力和位移响应进行了测试,实验数据显示,基于粘滑运动原理,机器人可以实现0.88μm的高运动分辨力.     

Modeling of service agents for simulation in cloud manufacturing

Cloud Manufacturing is a paradigm of intelligent manufacturing system with information opening, resource sharing, and diversified services. In order to research the issues in cloud manufacturing, such as behaviors of a service provider and service consumer, matching of service, dynamic change of resource, verification of business model, scheduling of service and evolution of service network, cloud manufacturing simulation platform is widely applied. However, the method of simulation-based on agent or rule lacks to represent the characteristics of service in cloud manufacturing. This paper presents a method of integrating the service and agent to form a service agent. The service agent integrates intelligence to the service in cloud manufacturing so that it can trade autonomously and adapt itself to the environment. A simulation case of production takt is presented in the rear of the paper. It shows that the conceptual model of the service agent and the communication architecture of the service agent can build the service agent model, which can support the cloud manufacturing simulation platform.     

Approach to the analysis of the dynamics of industrial FCC units

Although it is known that FCC units are operated at a controllable steady state, it is commonly assumed that this state is pseudostable. An ignited steady state, theoretically stable, outside the operable domain has also been reported for the same set of operating parameters. The aim of this work is to introduce a theoretical method for the preliminary analysis of the controllability of an industrial FCC unit, at any set of conditions, using a nonlinear model directly. An approach for the analysis of the stability of the system zero dynamics is used to investigate the dynamic behaviour of two common operating policies when the unit is operating either in the standard or in the ignited steady state. It is used to predict some particular characteristics of the process, such as the presence of inverse response after the change in catalyst circulation rate, a common control action. The results derived from the analysis developed are discussed in terms of physical responses and verified by performing open loop dynamic simulations of an industrial FCC unit. The operation of the unit is simulated for both the standard and the ignited steady states.     

Modeling and control of time-pressure dispensing for semiconductor manufacturing

To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manu- facturing,a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amount dispensed in each cycle. Taking account of gas compressibility,an intelligent model-based control strategy is proposed to compensate the deviation of adhesive amount dispensed from the desired one.Both simulations and experiments show that the dispensing consistency is greatly improved by using the model-based control strategy developed in this paper.     

The Qualitative Properties of Symmetric Open‐Loop Nash Equilibria in the State‐Control Dynamic System in Differential Games

The local stability, steady state comparative statics, and local comparative dynamics of symmetric open‐loop Nash equilibria in the state‐control dynamic system for a seemingly ubiquitous class of discounted infinite horizon differential games are investigated. It is shown that most of the useful qualitative results occur because the same small number of assumptions is being made about the mathematical structure of the integrand and/or state equations. Applications of the results to exhaustible resource extraction and capital accumulation differential games are provided.     

The general architecture of adaptive robotic systems for manufacturing applications

Adaptive system often refers to the adaptive control system. In this paper, we discuss the adaptive system concept from an architectural perspective of the system. We use the robotic system as an example to illustrate the adaptive system concept, because the robotic system is a generic system underlying many manufacturing systems. Specifically, the paper presents our work on the development of a general architecture of the adaptive robotic system for manufacturing applications. The contribution of this paper includes: (i) elaboration of the concept of adaptive system and classification of means to make the system adaptive and (ii) formulation of a general architecture of the adaptive robotic system based on the criterion that the more system variants out of the architecture implies the more generality of the architecture. Throughout this paper, we use an industrial robotic system for illustration.     

矿用PCB板组件三防漆涂覆工艺改进

针对传统三防漆工艺受技术因素及环境因素影响存在可控度不高、涂覆一致性差等问题,提出了一种改进的矿用PCB板组件三防漆涂覆工艺;介绍了三防漆涂覆方式和材料的选择,研究了矿用PCB板组件三防漆涂覆工艺方法和内容。测试结果表明,选择双组份聚氨酯漆、采用选择性喷涂法的涂覆效果一致性好,提高了生产效率。     

MATLAB在稳态与动态导热过程分析中的应用

在传热过程分析研究中需要求解微分方程,而这些描述传热过程的微分方程在多数情况下无法获得解析解,只能利用数值方法求解。通过MatLab在若干导热过程实例中的应用,探讨稳态与动态传热过程中温度分布、传热量、热通量等参数的求解与分析方法。结果表明MatLab工具能够十分有效、快速、准确地求解稳态与动态传热微分方程,为传热过程的数值分析研究提供了一个强有力的工具。     

区间速率连续Petri网可达稳态必要性分析

文章就区间速率连续Petri网可达稳态的必要性问题进行研究,在介绍区间速率连续Petri网及其使能、引发语义的基础上首先给出区间速率连续Petri网在指定标识下具有稳态的条件;其次通过提出区间速率连续Petri网一种标识向量等价类划分方法从而给出分析区间速率连续Petri网可达稳态必要性的有效方法;最后给出一个应用例子,考察区间速率连续Petri网的可达稳态问题。     

Dynamic coating for protein separation in cyclic olefin copolymer microfluidic devices

We report our study on using hydroxyethyl cellulose (HEC) as a dynamic coating for protein separation in microfluidic devices made from cyclic olefin copolymer (COC). The coating significantly enhances hydrophilicity of COC surface, evident from the decrease in contact angle of water in a COC channel. Surface treatment of COC channels with HEC also results in a 72% drop in electroosmotic (EO) mobility and a significant reduction in protein adsorption on the channel wall. Using bovine serum albumin as a model protein, the number of theoretical plates of 1.1 × 10⁴ was achieved in a separation distance of 3.3 cm using free solution electrophoresis. Hydroxyethyl cellulose dynamic coating is also found to have an effect on isoelectric focusing (IEF) of proteins. It not only prevents proteins from adsorption, but also reduces EO flow, both of which help achieve IEF of proteins with a difference of 0.1 pH values in isoelectric points (pI).     

Soft computing applications in dynamic model identification of polymer extrusion process

This paper proposes the applications of soft computing to deal with the constraints in conventional modelling techniques of the dynamic extrusion process. The proposed technique increases the efficiency in utilising the available information during the model identification. The resultant model can be classified as a ‘grey-box model’ or has been termed as a ‘semi-physical model’ in the context. The extrusion process contains a number of parameters that are sensitive to the operating environment. Fuzzy rule-based system (FRBS) is introduced into the analytical model of extrusion by means of sub-models to approximate those operational-sensitive parameters. In drawing an optimal structure for each sub-model, a hybrid algorithm of genetic algorithm with fuzzy system (GA-fuzzy) has been implemented. The sub-models obtained show advantages such as linguistic interpretability, simpler rule-base and less membership functions (MFs). The developed model is adaptive with its learning ability through the steepest decent error back-propagation algorithm. This ability might help to minimise the deviation of the model prediction when the operational-sensitive parameters adapt to the changing operating environment in the real situation. The model is first evaluated through simulations on the consistency of model prediction with the theoretical analysis. Then, the usefulness of adaptive sub-models during the operation is further explored in existence of prediction error.     

Graph-theoretic characterisations of the steady states for containment control

Containment control is a consensus-like protocol whose objective is to drive all the followers into the convex hull formed by the leaders. The steady states of the followers have great effect on system performance. Two kinds of cell partitions from graph theory are employed to investigate the reflections of the information topology on the steady states of the followers. It is proved that agents that belong to the same cell have the same steady states.