Discrete event control system design using automation Petri nets and their ladder diagram implementation

As automated manufacturing systems become more complex, the need for an effective design tool to produce both high-level discrete event control systems (DECS) and low-level implementations becomes more important. Petri nets represent the most effective method for both the design and implementation of DECSs. In this paper, automation Petri nets (APN) are introduced to provide a new method for the design and implementation of DECSs. The APN is particularly well suited to multiproduct systems and provides a more effective solution than Grafcet in this context. Since ordinary Petri nets do not deal with sensors and actuators of DECSs, the Petri net concepts are extended, by including actions and sensor readings as formal structures within the APN. Moreover, enabling and inhibitor arcs, which can enable or disable transitions through the use of leading-edge, falling-edge and level of markings, are also introduced. In this paper, the methodology is explained by considering a fundamental APN structure. The conversion of APNs into the IEC1131-3 ladder diagrams (LD) for implementation on a PLC is also explained by using the token passing logic (TPL) concept. Finally, an illustrative example of how APNs can be applied to a discrete manufacturing problem is described in detail.     

铁矿石破碎机电流模糊控制的设计与应用

本文介绍了模糊控制在铁矿选矿厂矿石破碎机电流调节中的应用,采用具有多相可调整因子的模糊控制算法,对破碎机进碎皮带进行变频调速,以改变进矿量,使主机电流保持稳定。该控制方案已成功运用于上海梅山集团矿选矿厂细碎及中碎车间的石破碎机中。     

基于Adams/Car和Matlab/Simulink的汽车半主动悬架模糊控制研究

基于Adams/Car软件创建汽车半主动悬架系统多体模型,利用改进遗传算法优化模糊规则的策略,实现汽车半主动悬架系统模糊控制器的设计,为了证明模糊控制器的控制效果和遗传算法的优化性能,在Matlab/Simulink环境中对汽车半主动悬架系统多体模型实现联合仿真分析。与被动悬架系统的分析对比说明,基于Adams/Car和Matlab/Simulink软件创建的汽车半主动悬架系统模糊控制器在很大程度上降低了人身加速度、改善车辆的乘坐舒适性和驾驶平顺性,同时也证明了采取联合仿真方法的有效性和准确性。     

Robust decentralized hybrid adaptive output feedback fuzzy control for a class of large-scale MIMO nonlinear systems and its application to AHS

This paper presents a novel observer-based decentralized hybrid adaptive fuzzy control scheme for a class of large-scale continuous-time multiple-input multiple-output (MIMO) uncertain nonlinear systems whose state variables are unmeasurable. The scheme integrates fuzzy logic systems, state observers, and strictly positive real conditions to deal with three issues in the control of a large-scale MIMO uncertain nonlinear system: algorithm design, controller singularity, and transient response. Then, the design of the hybrid adaptive fuzzy controller is extended to address a general large-scale uncertain nonlinear system. It is shown that the resultant closed-loop large-scale system keeps asymptotically stable and the tracking error converges to zero. The better characteristics of our scheme are demonstrated by simulations.     

基于模糊控制和无线宽带通信的水利灌溉控制系统的设计与应用

为了合理地调配农业灌溉水资源,文中提出了一种基于模糊控制、PLC和无线宽带通信的水利灌溉控制系统设计方案.详细论述了系统组成、工作原理和模糊控制策略及其应用.该系统较好的克服了传统PID控制中稳定性差、参数整定难的问题,并利用PLC和无线宽带通信设备实现了对灌溉水资源的集中管理和分散控制,提高了农业灌溉水资源的利用率,为建设节水型社会提供了技术保证,有广泛的应用前景.