A methodology to select optimal system components for computer integrated manufacturing by evaluating synergy

The enormous growth in manufacturing automation has produced a plethora of advanced manufacturing technologies (AMTs) with diverse features. These AMTs could consist of semi- and fully automated systems or equipment. Manufacturing companies are seeking ways to gain a competitive edge over their competitors by investing in AMTs, where the ability to make rational choices among these AMTs is important for success. Integration of AMTs in an enterprise brings many islands of automation into a single database-shared entity. Effective integration by efficient communication links among these AMTs will generate significant benefits across many traditional functional units, eliminate many functional barriers, and provide opportunities to achieve the competitive goals. The effect of synergy caused by the integration of AMTs will have an impact on various functional units of the enterprise. This paper provides a methodology, firstly to identify appropriate technologies for a company based on their strategic focus, and secondly to estimate the functional interrelationships within the framework of a unified approach for the justification of computer integrated manufacturing (CIM). These derived functional interrelationships are utilised to assess the effect of synergy in an integrated enterprise and identify the optimal capital investments in AMTs as system components of CIM.     

基于PLC/SCAD A结构的计算机综合控制系统

以工厂流程控制为应用背景，阐述基于PLC（控制）/PC-SCADA（监控）/MIS（管理）的三级分布式控制系统的设计方法，讨论了采用PLC实现过程控制，冗余热备，PC工控机SCADA实时监控和功能扩展以及管理控制一体化系统开发应用等关键技术。     

An integrated methodology for operations analysis of computer integrated manufacturing systems: Application to an FMS for manufacture of medical instruments

This paper contributes a novel methodology for operations analysis of computer integrated manufacturing systems. The methodology employs an integrated set of personal computer-based manufacturing systems modelling software, and is conducted in three stages. The methodology is illustrated in detail for analysis of materials flow and staffing for a flexible manufacturing system (FMS) installed at a medical instruments manufacturing plant. First, a rough-cut capacity and materials flow analysis was performed using a queueing model. Second, a detailed analysis of FMS system characteristics was conducted by creating and analysing a discrete-event simulation model. Finally, a graphical animation package was used to verify previous results and provide visual feedback on FMS system performance. Analysis results were obtained rapidly and conveniently, and were used to advise manufacturing managers regarding FMS operating policy. This analysis methodology can be applied to a wide range of computer integrated manufacturing systems and manufacturing cells.     

初态学习下时滞非线性系统的迭代学习控制

针对在有限时间区间上重复运行的一类状态时滞非线性系统,研究了一种带有初态学习的迭代学习控制算法。基于算子谱理论证明了系统在任意初态条件下经过迭代学习后,其输出能够完全跟踪期望轨迹,得到了该算法谱半径形式的收敛条件,比范数形式的收敛条件放宽了。并通过对系统初态的迭代学习,放松了迭代学习控制算法对初始状态函数的要求。仿真结果验证了所提算法的有效性。最后,将该算法应用到含有状态时滞的非线性间歇过程,结果也表明了该算法的有效性和可靠性。     

一种面向用户的计算机集成热工测控系统的研制

良好的测控手段和用户友好的测试软件是高精度的空调器性能测量装置的重要保证.本文分析了影响空调器测量精度的影响因素,设计了一套用于空调器性能测量的测控系统.测控系统以面向用户为设计原则,在保证测量精度的前提下,采用了高性能的测量传感器、自动控制器、人机对话的触摸屏等,编制了关键的控制采集软件,具有控制精度高、使用灵活、界面友好、性能稳定可靠等特点,在多套空调器性能测量装置上成功应用.     

A model-based methodology for on-line quality control

An on-line model development and quality control methodology is presented for manufacturers in the process industries with the goal of enabling automated quality assurance. Given appropriate process instrumentation, the methodology starts with the characterization of statistical variation for the process while operating in steady state. Significant process conditions are then perturbed by six standard deviations to bound the expected long-term process variation including lot-to-lot variability of feedstock materials. If the process is found to be robust, acquired process data is used to model the process behavior using principle components analysis (PCA). The PCA model is then used to accept and reject manufactured parts given real-time process data. This methodology is applied to an instrumented injection molding process that is subjected to 12 common process faults. The results indicate that the methodology was able to detect every one of 33 defective molding cycles caused by eight of the imposed faults as well as two additional faults that did not result in observable defective products. The quality controller did not detect the two remaining imposed process faults that did not produce defects and also rejected three molding cycles (2% of the total) that appeared to produce acceptable products.     

Robust partial integrated guidance and control for missiles via extended state observer

A novel extended state observer (ESO) based control is proposed for a class of nonlinear systems subject to multiple uncertainties, and then applied to partial integrated guidance and control (PIGC) design for a missile. The proposed control strategy incorporates both an ESO and an adaptive sliding mode control law. The multiple uncertainties are treated as an extended state of the plant, and then estimate them using the ESO and compensate for them in the control action, in real time. Based on the output of the ESO, the resulting adaptive sliding mode control law is inherently continuous and differentiable. Strict proof is given to show that the estimation error of the ESO can be arbitrarily small in a finite time. In addition, the adaptive sliding mode control law can achieve finite time convergence to a neighborhood of the origin, and the accurate expression of the convergent region is given. Finally, simulations are conducted on the planar missile–target engagement geometry. The effectiveness of the proposed control strategy in enhanced interception performance and improved robustness against multiple uncertainties are demonstrated.     

一种步进电机的自适应控制算法

本文先论述了“自动装料机料斗门自动控制”的设计。要在满足高速装料（150—250袋／b）的情况下,为了保证装袋的计量精度为正负2％。提出了一种步进电机的自适应控制算法。具体思想是：将整个装料时间划分成几个阶段,按照流量——时闻曲线分别建立不同的数学模型。采用不同的控制算法,并根据每次实际的控制效果来判断下一次的控制量。     

Dynamic availability-oriented control of the automated storage/retrieval system. A computer integrated manufacturing perspective

Dynamic scheduling of the storage/retrieval (S/R) requests and increasing the utilization of the storage spaces, are the two common approaches to improve the efficiency of the automated storage/retrieval systems (AS/RS) in industry practice. However, the actual improvement of the AS/RS has to be justified from the perspective of computer integrated manufacturing system (CIMS) because the ultimate objective of the AS/RS is to assist the CIMS in enhancing its material handling efficiency as well as synchronizing the production. Targeting on this crucial requirement, a dynamic availability-oriented controller (DAOC) is developed in this paper to minimize the mean request fulfilment time of the AS/RS. Firstly, while considering the three types of critical dynamic constraints from the CIMS’ shop floor: the availabilities for both machines and the AS/RS, the process plan of the product, and the production schedule, DAOC is capable of determining the optimal execution sequence of the S/R requests issued from the CIMS and activating dynamic storage space consolidation commands of the AS/RS. Secondly, simulation experiments are conducted and the results show that DAOC successfully improves the S/R request control scheme of the traditional class-based assignment method and significantly outperforms four comparable approaches under various CIMS configurations.     

Hierarchical adaptive control of self-stabilizing electromechanical systems using artificial-immune self-tuning mechanism for state weighting-factors

Journal of Mechanical Science and Technology - This article presents a novel self-adaptive linear-quadratic-regulator (LQR) architecture to improve the robustness of self-stabilizing...     

A robust adaptive load frequency control for micro-grids

The goal of this study is to introduce a novel robust load frequency control (LFC) strategy for micro-grid(s) (MG(s)) in islanded mode operation. Admittedly, power generators in MG(s) cannot supply steady electric power output and sometimes cause unbalance between supply and demand. Battery energy storage system (BESS) is one of the effective solutions to these problems. Due to the high cost of the BESS, a new idea of Vehicle-to-Grid (V2G) is that a battery of Electric-Vehicle (EV) can be applied as a tantamount large-scale BESS in MG(s). As a result, a new robust control strategy for an islanded micro-grid (MG) is introduced that can consider electric vehicles׳ (EV(s)) effect. Moreover, in this paper, a new combination of the General Type II Fuzzy Logic Sets (GT2FLS) and the Modified Harmony Search Algorithm (MHSA) technique is applied for adaptive tuning of proportional-integral (PI) controller. Implementing General Type II Fuzzy Systems is computationally expensive. However, using a recently introduced α-plane representation, GT2FLS can be seen as a composition of several Interval Type II Fuzzy Logic Systems (IT2FLS) with a corresponding level of α for each. Real-data from an offshore wind farm in Sweden and solar radiation data in Aberdeen (United Kingdom) was used in order to examine the performance of the proposed novel controller. A comparison is made between the achieved results of Optimal Fuzzy-PI (OFPI) controller and those of Optimal Interval Type II Fuzzy-PI (IT2FPI) controller, which are of most recent advances in the area at hand. The Simulation results prove the successfulness and effectiveness of the proposed controller.     

塑料挤出机计算机控制系统

本文介绍变结构预测控制技术,触摸屏彩色图形界面,模块化结构在塑料挤出机中的应用。     

复杂仿真器的计算机控制系统研究

本文在深入剖析某工程仿真器主要功能和工作原理的基础上,将现代计算机控制与气压控制及动力学系统相结合,研究并解决了该仿真器的自动控制系统的关键技术问题。该系统的设计与实现对计算机控制技术的研究和应用有重要参考价值。     

A flexure-based mechanism and control methodology for ultra-precision turning operation

This paper presents the methodology for modeling and control of a high precision flexure-based mechanism for ultra-precision turning operation. A high performance piezoelectric actuator is used to driven the flexure-based mechanism. A parallel flexure hinge mechanism is utilized to guide the moving platform and to preload the piezoelectric actuator. A high resolution capacitive sensor is used to measure the displacement of the flexure-based mechanism for closed-loop control. With consideration of the driving circuit, the dynamic model of the flexure-based mechanism has been established. The effect of the driving circuit on the dynamic response of the precision mechanism is investigated. Experimental tests have been carried out to verify the established model and the performance of the flexure-based mechanism.     

计算机辅助产品创新集成工具的框架

通过对产品设计过程的分析，介绍了在产品设计过程中质量功能配置、发明问题解决理论和稳健设计的理论，阐述了这些理论在产品设计中的应用，提出了计算机辅助创新集成工具的框架，并以汽车车门的设计为实例，对该工具的使用作了进一步说明。     

转台速率波动自适应抑制方案的设计

提出了一种能够有效地抑制转台速率波动的自适应补偿方法,阐述了该方法的原理、结构配置,开发了自适应控制律,进行了系统稳定性分析,并进行了仿真和试验研究。结果表明:该方法能够有效地抑制位置反馈元件周期性误差导致的速率波动,提高转台的速率平稳性。采用该方案,对转台输入200°/s的速率指令,在经过大约6 s的自适应调节时间后其速率波动由原来的5°/s降低到0.4°/s,波动量减少到自适应前的1/12;试验结果与仿真结果是一致的,验证了该方法的有效性和可行性。     

基于LonWorks技术的动车组计算机网络控制系统

介绍了动车组控制系统的构成和功能，阐述了基于LonWorks技术的动车组列车通信网络。该系统已经受了长期运行的考核。     

A multi-target tracking algorithm for application to adaptive cruise control

This paper presents a Multiple Target Tracking (MTT) Adaptive Cruise Control (ACC) system which consists of three parts; a multi-model-based multi-target state estimator, a primary vehicular target determination algorithm, and a single-target adaptive cruise control algorithm. Three motion models, which are validated using simulated and experimental data, are adopted to distinguish large lateral motions from longitudinally excited motions. The improvement in the state estimation performance when using three models is verified in target tracking simulations. However, the performance and safety benefits of a multi-model-based MTT-ACC system is investigated via simulations using real driving radar sensor data. The MTT-ACC system is tested under lane changing situations to examine how much the system performance is improved when multiple models are incorporated. Simulation results show system response that is more realistic and reflective of actual human driving behavior.