VPP虚拟仪器元件库的实现框架

 可视化编程平台(VPP)是快速组建虚拟仪器系统的集成可视化环境,而虚拟仪器元件库是其组建系统的
基本构造块的集合,是VPP体系结构的基础．但是,当前版本VPP虚拟仪器元件库的设计与实现存在复用性和扩
展性差等问题． 通过对虚拟仪器元件的概念模型分析和形式化描述,不仅提出了虚拟仪器元件的对象模型和动态
模型,而且运用设计模式给出了虚拟仪器元件的核心框架,并使用UML对它们进行了描述,从而形成了VPP虚拟
仪器元件库的一个可复用、可扩展的面向对象框架． 基于该框架可以快速地实现虚拟仪器元件库的开发．     

两种导引车在汽车底盘装配中的应用

本文以自动导引车（AGV）和轨道导引车（RGV）在汽车底盘装配过程中的应用为基础,对它们各自的特点进行了对比分析,阐明了AGV和RGV发展趋势。     

求一般6-SPS并联机器人机构的全部位置 正解的混沌迭代方法

 采用简单的牛顿迭代法迭代，并将非线性方程视为非线性的动力学系统，利用使系统产生混沌的Julia集
的点求解方程的全部实数解，而Julia集的点在Jocobi矩阵行列式的值为零的解集的邻域内，给定矩阵的行列式的
值的表达式的一些变量为已知，仅有一个变量未知，把它转化为一元非线性方程，进而求出一元非线性方程全部
解． 再在给定变量的邻域内取定给定变量，根据一元非线性方程的全部解以确定该变量的搜索范围，运用粗、精迭
代法求解全部位置解．运用该算法编写了MATLAB程序，对一般机器人6-SPS机构的全部位置正解问题进行了
研究，得出了Jocobi矩阵的通用表达式，从而得到了其全部位置正解，为实际的6-SPS机构的位置正解问题提供了
全新的方法．     

汽车金属带式无级变速传动技术

 无级变速器是汽车传动技术的重要发展领域之一．介绍了金属带式无级变速传动技术的发展概况，阐述了
金属带式无级变速器的基本结构、传动原理，比较分析了其性能、可靠性、寿命与成本等一些技术特性．对金属带式
无级变速传动中的电液控制技术进行了分析，指出具有电液控制技术的无级变速综合控制系统才能满足现代汽车
发展的要求．     

考虑冲突避免的多AGV路径规划研究

目的 提高物流企业“货到人”拣选系统在实际生产中的工作效率，避免自动导引小车(AGV)间的冲突死锁，研究大规模多AGV的无冲突路径规划和协同避障问题。方法 首先考虑AGV空载、负载情况和路径扩展成本，改进A^*算法，动态调整代价函数，优化路径扩展方式。其次，提出冲突检测及避免算法，对可能产生局部冲突的路径交叉点进行避障调度，通过预约锁格，实现局部冲突的检测，制定优先级避障策略，解决AGV动态行驶路径上产生的局部冲突和死锁，进而实现全局无冲突路径规划。结果 对多组不同任务量和不同AGV规模的场景进行仿真，实验结果表明，考虑冲突避免的改进A^*算法能有效实现100个任务、90个货架单位和7个拣选站场景下的多AGV动态路径规划，相较于传统A^*算法，其平均拣选时长缩短了52.61%。结论 该方法可实现大规模场景下的多AGV动态路径规划，在付出较小转弯代价的同时有效避免局部动态冲突，该方法可为相关企业实现多AGV协同调度提供新的思路和理论依据。     

自由曲面的自适应跟踪测量方法研究

 激光传感器在测量自由曲面中有着非接触、精度高等优点，其应用越来越广泛． 但是激光测头的线性测量
范围较小，难以测量起伏变化较大的曲面． 针对这一问题，提出了激光测头的跟踪测量方法，使激光测头随曲面的
高度变化作上下调整，从而可以测量任一表面起伏的曲面，且能根据当前曲面的曲率大小自适应选择跟踪方式，实
现测点的自适应分布．最后，对一个工件分别进行了等间距测量和自适应跟踪测量，并对两种方法的测量结果做了
比较，证明了自适应跟踪测量方法的可行性和有效性，为自由曲面的测量提供了一种新的方法．     

一种用于自动导引车(AGV)的超声波导航系统

设计了一种用于自动导引车（AGV）的超声波导航系统，介绍了系统的工作原理及结构，并进行了各项导航功能的样车实验，实验数据表明：系统可适应AGV的工作特点，可用于CIMS中固定及自由路径模式的AGV。     

嵌入式网络化变电所电能量管理系统

 电能量管理系统是变电所自动化系统的重要组成部分．提出并研究设计了嵌入式网络化电能量管理系统,
以高性能嵌入式处理器和嵌入式实时操作系统为核心进行系统设计． 系统通过以太网口或嵌入式MODEM ,基于
TCP/IP协议进行网络通信,具有高可靠性、高实时性的特点．详细论述了系统设计、硬件设计和软件设计,并给出
实际运行结果．     

设计与计算的双向集成

 在CAD系统与计算程序协同工作中发生的数据交换，应理想地沿两个方向进行，以支持产品开发过程，
这通常称为“双向数据交换”．然而，如何对此概念准确理解，学术界在表述上都不尽相同．原本意义上的单向数据
交换，可以按序反向地进行，而被说成是“双向”的．这样，在一种事实上每时每刻都沿双向进行的数据交换之外，还
存在一个相同的提法． 然而，这两种方案有根本区别的． 由此，对概念进行区分，并指出其差别．     

机构设计在大型柱面网壳结构施工中的应用

 将机械行业中的机构运动概念应用到大型柱面网壳结构的施工，提出一种“折叠展开式”整体提升施工技
术． 详细阐述了该项施工方法的基本思想，并推导机构运动过程的运动学和动力学公式． 通过一个工程算例的分
析，总结机构运动和动力特性．计算结果证明机构运动过程中产生的动力效应不明显，处于“折叠”状态的网壳能够
承受施工荷载．该项新技术在亚洲最大跨度的柱面网壳结构的施工中得到了成功应用，证明了它的实用性和优越性．     

自动导引输送车系统

在工厂综合自动化中，担负输送任务的自动导引输送车（ＡＧＶ）及其系统（ＡＯＶＳ）近几年内非常引人注目．本文着重论述了自动导引输送车系统的组成、制导方式、行驶机构、控制方式以及它的末来的趋势．     

A max-algebra approach to the robust distributed control of repetitive AGV systems

This paper presents a new approach for distributed control of automatic guided vehicle systems (AGVS) that uses max-algebra formalism to model system operation. The proposed method differs from previous works on performance analysis and control of such systems in that it constructs a feasible schedule by exploiting the repetitive character of the flow of automated guided vehicles. The AGVS is treated as a distributed system composed of autonomous and repetitive processes of AGV flows. Its periodic behaviour follows from the type of operation characterizing the job shops considered. The proposed approach employs a concept of asynchronous traffic semaphores that provide the local mechanism for vehicle flow synchronization. Setting the timing of particular semaphores results in distributed control of vehicle flows possessing self-synchronization capabilities.     

A model for the design of zone control automated guided vehicle systems

An analytical modelling strategy is proposed as a screening device for use prior to the simulation phase in the design of zone control automated guided vehicle systems (AGVS). The proposed model predicts the effects of the major AGVS design variables on system-performance measures including maximum throughput capacity and risk factors associated with shop locking. This is done through a process which specifically evaluates the system operating dynamics associated with vehicle fleet size, guidepath layout, workstation storage capacity, routeing, and, to a less precise extent, vehicle dispatching. Operating dynamics are defined to include vehicle blocking resulting from guidepath contention and variation of in-process storage levels. The objective of the analytical model is to reduce the extent of simulation modelling necessary to design a zone-control AGVS for a given materials-handling workload. The model is illustrated for a sample AGVS with variation in the fleet size, workstation storage capacity and dispatching rule demonstrated.     

Modelling of an automated guided vehicle system (AG VS) in a just-in-time (JIT) environment

Like other production systems, just-in-time (JIT) systems need to address the issue of material transport between workstations such as those served by automated guided vehicles (AGVs). Unlike other production systems, however, the JIT philosophy imposes strict requirements on inventory levels and supply-demand protocols which render conventional AGV delivery strategies ineffective and counter-productive. This paper describes the modelling of an AGV system (AGVS) in a JIT environment in a way that is consistent with JIT principles. The influence of a ‘JIT perspective’ is emphasized throughout the model by introducing threshold values for both input and output queues, performance measures that emphasize lower inventories in addition to transport efficiency, and a new dispatching rule that implements better inventory and transport control. The dispatching rule is shown to perform better in a JIT environment than previously developed AGV dispatching rules in both transport and logistic criteria.     

面向“货到人”拣选系统的一种随机调度策略

通过“货到人”拣选系统作业流程分析,提出了在分批下发订单任务的情况下的一种随机调度策略。以AGV (automated guided vehicle)完成所有任务的总时间最短为目标函数,以任务分配为决策变量,考虑进行调度时AGV所处的状态以及在完成任务过程中AGV在拣选台的排队等待时间,建立随机调度策略的数学规划模型。利用遗传算法进行求解,通过实例仿真,验证了随机调度策略较调度空闲AGV策略具有更高的拣选效率,同时解决了AGV调度与拣选序列问题,对AGV数量配置具有指导作用。     

Modelling empty vehicle traffic in AGVS design

Empty vehicle traffic plays a critical role in the operating performance of automated guided vehicle systems (AGVSs). While significant research has been conducted on intelligent AGVS dispatching-which, in essence, is the management of empty vehicle traffic-research in AGVS design has sometimes ignored or simplified the role of empty vehicle traffic. In this paper, we show how empty vehicle traffic strongly influences several important AGVS design problems, such as flowpath design and vehicle requirements. We present analytical models to predict empty vehicle travel under two popular vehicle dispatching rules for systems facing stochastic trip demand. We show that using our models' estimates of empty vehicle traffic in the AGVS design process can dramatically improve the resulting system performance. We also analyse shop-floor transfer patters and find that empty traffic has a larger impact on systems with discernible trends in job movement.     

Coloured timed Petri net model for real-time control of automated guided vehicle systems

Automated guided vehicle systems (AGVS) are material-handling devices representing an efficient and flexible option for products management in automated manufacturing systems. In AGVS, vehicles follow a guide-path while controlled by a computer that assigns the route, tasks, velocity, etc. Moreover, the design of AGVS has to take into account some management problems such as collisions and deadlocks. The paper presents a novel control strategy to avoid deadlock and collisions in zone-controlled AGVS. In particular, the control scheme manages the assignments of new paths to vehicles and their acquisition of the next zone. Moreover, the use of coloured Petri nets is proposed to model the dynamics of AGVS and implement the control strategy stemming from the knowledge of the system state. Additionally, extending the coloured Petri net model with a time concept allows investigation of system performance. Several simulations of an AGVS with varying fleet size while measuring appropriate performance indices show the effectiveness of the proposed control strategy compared with an alternative policy previously presented.     

Decentralized autonomous AGV system for material handling

Decentralized control of an autonomous automated guided vehicle system (AGVS) used for material handling is expected to lead to high system flexibility and robustness. A complete control methodology for decentralized autonomous AGVS control was developed and implemented in a computer-integrated manufacturing environment. The methodology addresses all aspects of AGVS functionality: system management, navigation and load transfer. Hierarchical fuzzy behaviour-based control, a reactive navigation scheme, was expanded to multirobot control in semistructured environments by incorporating a priori path optimization and right-of-the-way determination.     

Potentials for bi-directional guide-path for automated guided vehicle based systems

Most current applications of automated guided vehicle systems (AGVS) in manufacturing shop environments employ uni-directional guide-paths for vehicle routing despite the fact that bi-directional vehicles exist. In this paper comparisons and issues regarding unidirectional and bi-directional flows are presented. Also presented is a model of a bi-directional traffic flow guide-path. The effect of the traffic flow pattern on the shop throughput is demonstrated and compared to that of a uni-directional flow system of an equivalent facility. The model is implemented using computer simulation.     

Performance evaluation of tandem and conventional AGV systems using generalized stochastic Petri nets

This paper investigates the different policies and concepts followed in the traffic management of automated guided vehicle (AGV) systems, and develops the controls for automatically eliminating potential vehicle conflicts in an AGV system. The planning of the AGV system is performed in such a way that there are no conflicts or deadlocks for the vehicles using stochastic Petri nets (SPNs). The major effort is devoted to determining the benefits of the tandem AGV control in comparison with the conventional AGV control method. SPNs have been used to model the different designs of flexible manufacturing systems (FMSs) and with different policies for the movement of material, vehicle path control, inventory planning and tool control. The SPN model is solved and the performance of the system can be evaluated. In this study, the effort is directed to model an FMS with two different types of AGV traffic management methods, namely the conventional and tandem AGV control. A SPN program is used which takes the FMS Petri net model as the input and evaluates the different properties of the Petri net. Finally the performance measures are obtained, which helps in evaluating and comparing the two different AGV traffic management methods.