Comparison of two simulation/animation tools for synchronous manufacturing

This paper describes the use of two animation tools, namely CINEMA and PROOF, for simulation for the purpose of teaching synchronous manufacturing concepts.

This paper does not address the question of execution speed or comparison of results. The authors were really only concerned with the comparison of concurrent and post-processed animators.     

Using simulation to improve synchronous flow in pinion manufacturing

The quality of Management decision-making is greatly improved when a good animation of the manufacturing operation clearly shows how everything is going to work.

This paper describes the use of one of the best current animation tools, namely Witness 7 from AT&T ISTEL, applied to the decision to modify a current operation.

The paper describes how the simulation analysis played an important role in assuring that the management decision was correct.     

Animation - a new dimension in computer simulation of automotive assembly processes

American automotive companies are moving toward increased use of JIT (i.e., Just-In-Time), SPD (i.e., Sequenced Parts Delivery), and ILVS (i.e., In-line Vehicle Sequencing) in order to produce quality vehicles at reduced cost.

Maintaining vehicles in the proper sequence leads to calculations which are functions of plant conditions (e.g., job rate, out-of--sequence conditions, etc.).

The recent advances of color animation tools to supplement the analytical simulation languages have made the understanding of these operations easier to grasp. This paper addresses the use of animation for presentation of ILVS alternatives.

The paper is separated into four sections. The first section presents ILVS concepts. This is followed by a discussion of how vehicles get out of sequence and of re-sequencing procedures. Then methods for sizing re-sequencers are described. The final section focuses on the use of animation for presenting ILVS.     

Use of simulation in the analysis of shop floor operations

The use of computers in actual system applications is increasing with the availability of intelligent terminals on the shop floor. These terminals can be used by management as tools in the decision making process of planning shop floor operation. This paper discusses a pilot simulation study in the use of conventional Fortran-based simulation programs by shop floor management to:

1. 1. Participate in the evaluation of proposed FMS systems,

2. 2. Assess the impact of FMS acquisition on existing facilities,

3. 3. Assist in the identification of operational alternatives in “bottle neck” situations.

The pilot study employs a batch-oriented MRP system to provide daily updates of outstanding production center loadings on a monthly planning horizon. Two intelligent terminals are used to access a mini computer facility that executes the simulation models. The terminals have AT-compatible capabilities and are also used as data acquisition devices that support the numerically controlled operations within each work center.

The simulation models represent the 13 work centers of the firm and provide information about the average utilization of each work center, the number of parts in each queue and the average delay of parts in the queues. Future extensions of the models are planned to utilize the terminals' graphic animation capabilities to display the flow of production orders through the manufacturing facility.     

Integrating simulation with activity-based management to evaluate manufacturing cell part sequencing

This paper presents an integrated simulation and activity-based management approach for determining the best sequencing scheme for processing a part family through a manufacturing cell. The integration is illustrated on a loop or U-shaped manufacturing cell and a part family consisting of four part types (A, B, C, and D). Production requirements for the cell demand that part batches be processed one type at a time. For example, all part A’s are processed until weekly demand is met, then part B’s, etc. The objective of this example is to determine the best part sequence (e.g., ABCD, DCBA or CABD). In addition to traditional measures, the simulation model produces detailed activity-based costing estimates. Analysis of cost and performance parameters that indicates part sequence CDBA provides the best overall choice. This sequence achieves a low per unit manufacturing cost, minimizes average time in the system and in-cell inventory cost, and maximizes unused production capacity. Although the scope of this effort was restricted to a small scale manufacturing cell, the costing concepts have general applicability to manufacturing operations at all levels.     

Research problems in clothing simulation

Clothing simulation and animation are of great importance in computer animation. If cloth simulations could be improved to the point that they could generate realistic cloth motion in real-time, they would find uses in many aspects of daily life such as in fashion design and manufacturing. The area of cloth simulation and animation is full of technical challenges: creating more realistic results, achieving faster run-times, and developing methods capable of constructing and simulating more complex garments. This paper provides an overview of the key procedures involved in the creation of clothed characters, describes the current state-of-the-art techniques, and proposes the research problems that most require further study. Three technical aspects of cloth simulation are considered in this paper: garment construction, physically based simulation, and collision resolution.     

Animation toolkit based on a database approach for reusing motions and models

As animations become more readily available, simultaneously the complexity of creating animations has also increased. In this paper, we address the issue by describing an animation toolkit based on a database approach for reusing geometric animation models and their motion sequences. The aim of our approach is to create a framework aimed for novice animators. Here, we use an alternative notion of a VRML scene graph to describe a geometric model, specifically intended for reuse. We represent this scene graph model as a relational database. A set of spatial, temporal, and motion operations are then used to manipulate the models and motions in an animation database. Spatial operations help in inserting/deleting geometric models in a new animation scene. Temporal and motion operations help in generating animation sequences in a variety of ways. For instance, motion information of one geometric model can be applied to another model or a motion sequence can be retargeted to meet additional constraints (e.g., wiping action on a table can be retargeted with constraints that reduce the size of the table). We present the design and implementation of this toolkit along with several interesting examples of animation sequences that can be generated using this toolkit.     

Laying out objects with geometric and physical constraints

Modeling scenes involves two tasks:object modeling andobject layout. This paper focuses on object layout and proposes a constraint-based approach which yields a powerful object layout environment. The approach uses collision detection and physical simulation to ensure geometric and physical consistency of the resulting scenes, such as no interpenetration, and physical stability of the objects. A prototype system is developed, providing six basic operations; PUT, PUSH/PULL, TURN/TILT, PICK-UP, TRANSLATE, and ROTATE. The system: ensures geometric and physical consistency; provides easy-to-use operations analogous to object placement in real life; allows twodimensional control easily specified by mouse. Interactive speed is achieved on graphics workstations by using rasterized collision detection and simple quasi-static motion simulation. The system is interfaced to modeling/rendering/animation systems, and realizes an integrated environment for object modeling, object layout, rendering, and animation. We describe several scenes that have been modeled using the system and argue that these experiments confirm that the scene modeling task is greatly simplified by our constraint-based approach.     

SimEnvir++: An object-based simulation environment

In this paper an object-oriented discrete event simulation environment, SimEnvir++ is presented. The aim of the environment is to provide a research environment for design, analysis and management of electronic manufacturing systems. SimEnvir++ combines interactive simulation model design, object manipulation, simulation, output analysis and animation, to provide an intuitive modeling capability.     

Design of a suitable production management system for a manufacturing company

This paper reports on the design of a suitable production management system (PMS) for a manufacturing company, located in Western Australia. The company was experiencing problems in scheduling and plant layout leading to further problems in materials flow, labour control, inventory and purchasing, material handling system, and production space.

Group technology (GT) was used to design a new plant layout. A G.T. algorithm was developed to minimise machine duplications. A Kanban system was designed to assist execution of scheduling based on a pull system. The design was tested by simulation using actual data collected on existing operations.     

编译支持的多线程程序多变体执行方法

多变体执行（multi-variant execution,MVX）是目前最流行的主动防御技术之一。理想情况下,当未受到攻击时,多变体执行架构提供正常的程序功能。但不幸的是,当多线程程序在多变体执行架构下运行时,由于各个程序变体中共享资源操作的线程执行顺序不一致,不同变体将会产生状态不一致,从而产生攻击误报,该问题导致了多线程程序难以以多变体执行方式运行。基于多变体执行环境,提出了一种编译支持的多线程程序对共享资源操作的同步编译模型,该模型以共享资源操作为同步点,分析确定多线程程序中对共享资源的操作时机和操作方式,保证各程序变体在运行时多线程对共享资源操作的一致性,从而消除了由此而引起的攻击误报。以LLVM 12.0编译框架为基础,设计实现了基于该同步编译模型的原型系统,并对该原型系统进行了仿真实验测试。实验结果显示,经过原型系统处理的多线程程序在多变体执行架构中的误报率显著降低,表明该同步编译模型作为一种通用性的方法,可有效消除多线程程序在多变体执行架构下运行时的攻击误报,提高了多变体执行的可用性。     

Using online simulation in Holonic manufacturing systems

This paper deals with the use of online simulation on Holonic manufacturing systems. Concepts needed for the use of online simulation in a classical hierarchical system were already defined, the observer being the central one. The behavior's differences between both classes of systems are studied to determine the best way to adapt these concepts to this new environment. In the product resource order staff approach (PROSA) reference architecture, staff holons were chosen to welcome the simulation models and the observer. An application on an industrial sized Holonic manufacturing system is described to demonstrate the validity of the approach.     

排队网络在制造系统中的应用及其三维仿真实现

首先讨论了排队网络建模仿真工具的功能需求，提出了基于有向图的排队网络仿真建模机制，以及将面向对象与离散事件结合起来的仿真方法，根据排队网络的理论，结合图形建模方法和动画仿真技术的发展，研究了排队网络法的3D仿真实现，开发了一个面向制造系统和基于3D仿真的排队网络分析工具。     

3DS MAX中体视动画生成模块的实现

介绍了体视动画的生成方法，讨论了如何基于流行的三维动画软件3DS MAX开发体视动画的生成模块。最后给出了建筑动态模拟体视动画中的一帧图像。     

联合作战模拟系统体系结构设计需求分析

联合作战模拟已成为现代化军队进行作战指挥、训练的主要形式。该文介绍了联合作战模拟的相关基本概念；从联合作战模拟系统体系结构顶层分析角度，论述了联合作战模拟系统体系结构设计的研究背景，归纳了系统应支持的联合作战基本形式，提出了系统的应用形式，分析了实现系统必须解决的关键问题。     

A decision support system for production planning and bid preparation for a small job shop manufacturer

With the advent of the inexpensive micro-computer, small manufacturers have been able to automate many applications in their day-to-day operations. Under the auspices of the State of Missouri “Productivity Improvement Program” - a program to aid small manufacturing businesses in improving their productivity, a Decision Support System (DSS) was developed to assist a small metals manufacturing company in production planning and bid preparation.

The DSS was developed at UMR by a graduate student as part of his master's thesis; the work was funded by both the Productivity Improvement Program and the small manufacturer. After development of the DSS, the graduate student was hired full time for one year to assist the manufacturer in implementing the DSS and to train on site personnel in its operation.

This paper discusses the development of the DSS, its implementation, and its utilization.     

Design of a synchronous manufacturing system with just-in-time production (SMS/JITP)

One of the goals of a manufacturing system is to minimize the cost of production. A significant source of manufacturing cost is attributable to material handling. The sources of material handling cost include equipment, labor, work-in-process, and floor space. One approach to reduce material handling cost is through the implementation of synchronous manufacturing with just-in-time production. Although, the concept of a synchronous manufacturing is known, techniques to design and plan such systems are yet to be formalized. In this paper, a quantitative modeling framework for the design and analysis of a synchronous manufacturing system with just-in-time production is presented. The approach is composed of principles and techniques drawn from scheduling, layout planning, material handling, and computer simulation.     

Database considerations in manufacturing systems integration

This paper deals with ideas that could form a basis for manufacturing integration. In recent times more attention is being paid to the idea of applying artificial intelligence (AI) techniques to manufacturing. However, very little attention is being paid to the proper use of these techniques. This research work explores three basic ideas:

1. 1. Applications of the entity-relationship approach to knowledge representation.

2. 2. The basic philosophy of expert database systems and

3. 3. Integration of manufacturing systems from the above two concepts.

The approaches for 1 and 2 are explained with actual implementation experiences, while a framework for integration is proposed from a more philosophical perspective.     

图形技术在系统仿真中的应用

本文首先从应用对系统仿真提出的要求出发，讨论了图形技术在系统仿真中的地位及应用范围，然后着重介绍了系统仿真中的动画仿真和图形建模技术，提出了实现动画仿真和图形建模必须解决的关键技术问题，并结合ＩＭＳＳ给出了实现动画仿真和图形建模的一种方法。